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• Clinical Management Principles:
  • Dictionary and Definitions:
    • Several terms are utilized throughout the guidelines in different sections and recommendations
• Important definitions used by the committee are included below:
  • General definitions:
    • Active surveillance:
      • The ongoing observation or active monitoring of a known or suspected primary, intrathyroidal, low-risk DTC with serial imaging as an alternative to upfront surgical intervention
      • This is a type of expectant management and is only appropriate for a subset of low-risk DTCs (see Recommendation 11)
      • This does not pertain to persistent or recurrent thyroid cancer, in which case the term “monitoring” is employed (see below)
      • Some proportion of patients who undergo active surveillance may be recommended to pursue thyroid surgery if there is concern for disease progression or based on patient preference
    • Disease monitoring:
      • Monitoring for biochemical (elevated level of serum Tg) and / or structural persistence or recurrence of disease (as confirmed by imaging and / or biopsy) following the diagnosis and initial treatment (surgery – RAI) of thyroid cancer
      • It is deployed to evaluate patients for disease progression and inform the type and timing of interventions deemed appropriate
    • Response to therapy:
    • Response assessment is performed after intervention:
      • Either for initial or clinically persistent / recurrent disease (see Recommendation 29 and Table 9 of the ATA 2025 Guidelines)
    • Excellent response:
      • No biochemical or structural evidence of persistent thyroid cancer (i.e., remission)
    • Indeterminate response:
      • The presence of nonspecific findings on imaging; mildly elevated serum Tg levels; or positive, but stable or declining, anti-Tg antibody (TgAb) levels in persons who have undergone total thyroidectomy with or without RAI
      • Most patients in this category prove to have a “good” clinical response to therapy, especially if they have a low risk of clinical recurrence, and findings are nonspecific
      • However, those at intermediate or high risk of clinical recurrence based on histopathologic and staging characteristics in this category:
        • May have higher rates of recurrence
    • Biochemically incomplete response:
      • Elevated serum Tg concentrations or rising TgAb levels without radiological evidence of structural recurrence in persons who have undergone total thyroidectomy with or without RAI
    • Structurally incomplete response:
      • Structural evidence of disease recurrence (by imaging or biopsy), usually in conjunction with elevated Tg and / or TgAb levels
    • Persistent or recurrent disease:
      • See Recommendation 29 and Table 9 of the ATA 2025 Guidelines
    • Clinically persistent disease:
      • Biochemical or structural evidence of disease within 90 days of initial therapy (or intervention for persistent disease)
    • Clinically recurrent disease:
      • Biochemical or structural disease subsequently identified in patients previously deemed to have an excellent response following therapy
      • Clinically recurrent disease likely represents progression of residual disease that is below the lower limits of detection
    • Risk of recurrence:
      • They use the term “recurrence” to mean clinical recurrence, recognizing that most recurrences reflect growth of residual disease to clinically detectable levels (Figure )
      • An overall assessment of risk of biochemical or structural recurrence determined by incorporating a combination of factors:
        • Histopathologic characteristics of the resected tumor, American Joint Committee on Cancer (AJCC) staging, imaging, molecular analysis of tumor, and response to therapy at subsequent evaluation
      • For the purpose of these guidelines, categories are designated as:
        • Low (< 10%) risk of recurrence
        • Low Intermediate (10% to 15%) risk of recurrence
        • Intermediate-high (≥ 16% to 30%) risk of recurrence
        • High (> 30%) risk of recurrence

• Treatment Definitions:
  • Extent of surgery definitions (ATA website definitions):
    • Total thyroidectomy: 
      • Surgical removal of the entire thyroid gland
    • Near-total thyroidectomy:
      • Intended extent of resection for thyroid cancer is total thyroidectomy:
        • But a small remnant may be left for a specific reason (usually confidence in nerve preservation)
    • Lobectomy or hemithyroidectomy with or without isthmusectomy: 
      • Surgical removal of one lobe (half) of the thyroid with or without the isthmus
    • Subtotal thyroidectomy: 
      • Surgical removal of almost all of the thyroid gland, leaving 3 to 5 g of thyroid tissue with the intent of maintaining adequate thyroid hormone production:
        • This operation is not recommended if the diagnosis of thyroid cancer is known preoperatively
      • Completion thyroidectomy: 
        • Surgical removal of the remnant thyroid tissue following procedures of less than total or near-total thyroidectomy
  • Extent of lymphadenectomy definitions:
    • Central neck dissection:
      • Central neck lymph nodes include Levels VI and VII (Figure)
      • Central neck dissection is a comprehensive removal of pretracheal and prelaryngeal lymph nodes, along with at least one paratracheal nodal basin
      • It can be unilateral or bilateral; the laterality and extent of dissection should be documented at the time of operation in addition to surgical intent (therapeutic vs. prophylactic)
    • Therapeutic neck dissection:
      • It implies that metastatic nodal disease is apparent clinically preoperatively or intraoperatively by examination and / or imaging, cN1a
    • Prophylactic neck dissection:
      • It implies that no metastatic nodes are detected by examination or imaging preoperatively or intraoperatively, cN0
    • Lateral neck dissection:
      • Full compartment dissection of the lateral cervical neck lymph nodes in Levels IIA, III, IV, and VB ipsilateral to the tumor and performed for clinical evidence of metastatic involvement
      • Dissection of Levels I, IIB, and VA are not regularly performed but can be considered based on findings suggestive of metastatic disease in these compartments (Figure)
    • Completeness of surgical resection:
      • The goal of surgery is to remove safely as much thyroid cancer as possible
      • To define the completeness of resection, the AJCC created definitions that are used in these guidelines to facilitate communications
      • An R0 resection:
        • Means that the surgical margin is microscopically negative for residual tumor
      • An R1 resection:
        • Means that there is no residual macroscopic tumor but that microscopically positive margins still demonstrate the presence of tumor
      • An R2 resection:
        • Means that gross (macroscopic) disease remains post-surgery

• ¹³¹I, RAI administration definitions:
  • Remnant ablation:
    • RAI administration to destroy benign remnant thyroid tissue following total or near-total thyroidectomy
  • Adjuvant therapy:
    • RAI administration to destroy suspected (but not identified) remaining thyroid cancer following total or near-total thyroidectomy
  • Therapeutic treatment:
    • RAI administration to treat known residual or recurrent thyroid cancer, either initially or with subsequent progression of thyroid cancer after total or near-total thyroidectomy
  • Thyrotropin suppression therapy:
    • Use of thyroid hormone to suppress serum thyrotropin (TSH) concentrations below the normal range based on the risk of recurrence and / or response to therapy

• Recommendation #7 from ATA 2025 Guidelines:
  • Preoperative neck ultrasound to evaluate cervical lymph nodes in the central and lateral neck compartments as well as for gross extrathyroidal extension is recommended for all patients undergoing surgery for malignant cytologic or molecular findings:
    • Strong recommendation, Moderate certainty evidence
  • Ultrasound-guided FNA of sonographically suspicious lymph nodes greater than 8 to 10 mm in the smallest diameter should be performed to confirm malignancy if this would change management:
    • Strong recommendation, Moderate certainty evidence
  • The addition of FNA-Tg washout in the evaluation of suspicious cervical lymph nodes may be performed in select preoperative patients, but interpretation may be dif cult in patients with an intact thyroid gland:
    • Conditional recommendation, Low
      certainty evidence
• Differentiated thyroid cancer (DTC), and particularly PTC:
  • Involves cervical lymph nodes in 20% to 50% of patients in most series using standard
    pathological techniques:
    • These metastases may be present even when the primary tumor is small and intrathyroidal
  • The frequency of micrometastases (less than 2 mm) may approach 90%, depending on the sensitivity of the detection method:
    • However, the clinical implications
      of micrometastases are likely less significant compared with macrometastases:
      • They do not appear to affect survival when they are in the central neck
      • They also do not appear to increase recurrence
• Preoperative ultrasound identifies suspicious cervical adenopathy in:
  • 20% to 31% of cases:
    • Potentially altering the surgical approach:
      • In as many as 20% of patients
  • It has significantly less clinical utility in identifying central neck lymph nodes:
    • Due to the presence of the overlying thyroid gland
• Sonographic features suggestive of abnormal metastatic lymph nodes include:
  • Enlargement
  • Loss of the fatty hilum (odds ratio [OR] 1.9)
  • A rounded rather than oval shape:
    • Long axis / short axis ≤ 2; OR 1.6
  • Hyperechogenicity (OR 5.4)
  • Cystic change (OR 71.8)
  • Calcifications (OR 6.2)
  • Peripheral vascularity or abnormal blood flow (OR 3.8)
• No single sonographic feature has adequate sensitivity for detecting lymph nodes with metastatic thyroid cancer; however:
  • Cystic change:
    • Has the highest odds of malignancy
  • Absence of a fatty hilum, cystic changes, microcalcifications, abnormal vascularity, and cortical hyperechogenicity are all independent features of metastatic lymph nodes:
    • With a high specificity of 87% to 99.6%
  • Absence of a fatty hilum has the highest sensi-
    tivity but low specificity at 66.4%
• The location of the lymph nodes also may be useful for decision-making:
  • Metastatic lymph nodes are much more likely to occur in Levels III, IV, and VI than in Level II:
    • Although this may not be true for PTC tumors arising in the upper pole of the thyroid:
      • Which have a higher propensity to produce skip metastases to Levels II and III
• Confirmation of malignancy in lymph nodes
  with a suspicious sonographic appearance:
  • Is achieved by ultrasound-guided FNA aspiration for cytology and / or measurement of Tg in the needle washout (FNA-Tg):
    • Tg washout is a helpful adjunct to FNA:
      • Particularly in cases where the lymph nodes are cystic, cytological evaluation of the lymph node is inadequate, or the cytological and sonographic evaluations disagree:
        • Example – normal cytological biopsy of a large lymph node with microcalcifications
    • False positive Tg washout may occur:
      • Particularly in lymph nodes in the central compartment when the thyroid gland is still present
        • But it remains valid in the presence of positive serum TgAb
      • Recommendation 31 reviews the role of
        FNA-Tg washout in lymph nodes in the postoperative setting
    • Data are limited to support a definitive FNA-Tg threshold for diagnosis of a metastatic lymph node
    • A systematic review and meta-analysis showed that FNA cytology with FNA-Tg washout has a negative predictive value (NPV) of 99.4% and accuracy of 86.8% in the evaluation of pathological-appearing lymph nodes:
      • If the FNA-Tg level is 1.0 ng/mL or lower, then the NPV approximates 100%
      • However, non-metastatic lymph nodes can have concentrations as high as 32 ng/mL
      • Accuracy, specificity, positive predictive value (PPV), and NPV are significantly higher if the FNA-Tg threshold is 28.5 ng/mL
    • Another systematic review analyzed 22 studies with 2,670 suspicious lymph nodes during thyroid nodule workup or PTC follow-up:
      • Found that the highest sensitivity was observed with a FNA-Tg cut-off of 1 ng/mL and the highest specificity was observed with a cutoff of 40 ng/mL:
        • In this study, other factors that influenced the accuracy of FNA-Tg included TSH suppression, presence of serum Tg, and methodologic differences in Tg measurement
    • Another study found the presence of serum TgAb interferes with circulating serum Tg
      measurement:
      • But does not appear to interfere with FNA-Tg measurements
    • Further studies are needed to determine an optimal FNA-Tg threshold to diagnose metastatic lymph nodes
• In addition to assessing for pathological lymph nodes:
  • Ultrasound evaluation of the thyroid gland to gauge gross extrathyroidal extension is important for surgical planning:
    • As this typically demonstrates indication for RAI and therefore total thyroidectomy
• If there is evidence of more advanced locoregional disease:
  • Additional imaging with computed tomography (CT) may be useful
  • While ultrasound is more specific for nodal disease:
    • CT is more sensitive:
      • The combination of both may increase diagnostic accuracy
    • In view of the higher cost of CT compared with ultrasound, the associated radiation exposure, and potent risks of intravenous contrast administration in specific populations:
      • It is important to determine the imaging needs on an individual patient basis
    • Accurate staging is important for determining the prognosis and tailoring treatment for patients with DTC:
      • However, unlike many tumor types, the presence of metastatic disease does not obviate the need for thyroidectomy:
        • Because distant metastatic disease may respond to RAI therapy, removal
          of the thyroid as well as the primary tumor and accessible loco-regional disease is an important component of initial treatment for most patients with distant metastatic disease

¿Quién debe realizar cirugía de tiroides?

•  Su entrenamiento es el siguiente:

  • Tumores de Cabeza y Cuello / Cirugía Endocrina: Fox Chase Cancer Center

• Tumores de Cabeza y Cuello / Cirugía Endocrina:IFHNOS / Memorial Sloan Kettering Cancer Center

 

Cirugía Oncológica Compleja: Fox Chase Cancer Center

 

• Cirugia General y Gastrointestinal:
  • Michigan State University

• Maestría en Ciencias de Investigación:Drexel University

• Differentiated thyroid cancer (DTC) includes papillary, follicular, and oncocytic carcinomas:
  • Comprising the vast majority (> 90%) of all thyroid cancers
• In the United States:
  • It is estimated that there were 44,020 new cases of thyroid cancer in 2024:
    • Compared with 37,200 in 2015 when the last American Thyroid Association (ATA) guidelines were published
• The yearly incidence tripled from 4.9 per 100,000 in 1975 to:
  • 14.3 per 100,000 in 2015
• Approximately 25% of the new thyroid cancers diagnosed in 1988 to 1989 were < 1 cm:
  • Compared with 39% of the new thyroid cancer diagnoses in 2008 to 2009:
    • This shift to earlier detection / diagnosis correlates with the increasing use of neck ultrasonography and other imaging along with the advent of ultrasound-guided fine needle aspiration (FNA)
• The incidence of thyroid cancer, and particularly small thyroid cancers:
  • Has reduced in the United States since 2014:
    • This change in incidence trajectory is likely a reflection of the adoption of guidelines’ recommendations from the ATA and other organizations discouraging FNA of small nodules < 1 cm in the absence of abnormal lymph nodes or local invasion:
      • Due to the overall outstanding prognosis associated with these tumors and weighed against the potential risks of unnecessary treatment
• In addition to changes in the management of early-stage thyroid cancer:
  • Prior guidelines introduced criteria to enhance initial decision-making and a response framework following interventions to facilitate further management decisions:
    • These have been validated since the prior guidelines, enabling adoption in clinical practice
• There have been major advances in understanding the molecular causes of thyroid cancer development and progression that have created newly approved treatment options for subsets of patients:
  • Published data in these and other areas require serial updates of existing guidelines to facilitate clinical care
• In the current guidelines, an approach to clinical decision-making is introduced based upon the individual patient and clinician journey with thyroid cancer:
  • Which they term DATA:
    • Diagnosis
    • Risk / benefit Assessment
    • Treatment decisions
    • Response Assessment
• This approach begins at the initial diagnosis of thyroid cancer, the diagnosis of residual disease or a clinical recurrence:
  • It includes assessment to determine whether a particular intervention is appropriate based on risks and benefits as well as individual patient factors:
    • When multiple possible management strategies are available, the framework supports identification of the best treatment option
• Then, after intervention, an assessment of response using the 2025 ATA risk assessment tool is deployed to determine whether more treatment or monitoring is appropriate
• The clinician and the patient can use this DATA framework to help make clinical decisions from diagnosis through the patient’s entire disease course.

• In 1996, the ATA published treatment guidelines for patients with thyroid nodules and DTC:
  • Over the last 25 to 30 years, there have been remarkable advances in knowledge affecting the diagnosis and treatment of DTC, but clinical controversy continues to exist in many areas
  • In the end, the goal is to provide individualized therapy for each patient based on the best application of clinical data to their unique case:
    • For example, a less aggressive approach would be recommended for individuals with early stage DTC who have an excellent prognosis or for individuals at higher risk of side effects, while a more aggressive approach would be recommended for those patients with higher risk disease or those with inadequate response to initial therapy

• American Thyroid Association Thyroid Cancer Management 2025 Guidelines
• Recommendation 6:
  • Due to lower complication rates and improved outcomes on average associated with high volume thyroid surgeons (> 25 to 50 thyroidectomies / year):
    • Patients with thyroid cancer should be offered referral to a high-volume surgeon;
      • Particularly for tumors requiring more extensive surgery:
        • Strong recommendation, Moderate certainty evidence
  • Physician experience and expertise have long been revered in patient care:
    • But quantifying the benefits can be challenging, particularly at an individual provider level
  • There are many aspects of care where physician expertise is important in the diagnosis, staging, and management of patients with
    thyroid cancer, including sonography, pathology, surgery, endocrinology, nuclear medicine, oncology, and radiation
    therapy
  • Ultrasound of the neck is a prime example, due to its well-documented dependence on the skill and experience of the sonographer coupled with its importance for preoperative diagnosis, staging, and surveillance
  • The experience of the cytopathologist also has been demonstrated to improve the accuracy of ultrasound-guided FNA biopsy diagnosis
  • The evidence supporting improved outcomes at the hands of experienced surgeons is most compelling
  • The relationship between thyroid surgery case volume and patient outcomes has been studied extensively during the past 20 years:
    • In one of the recent studies examining the relationship between surgeon volume and thyroidectomy outcomes:
      • Sosa et al. found a strong association between higher surgeon volume and favorable patient outcomes:
        • Especially with respect to recurrent laryngeal nerve injury and wound complications
        • This was most pronounced for patients undergoing total thyroidectomy for thyroid cancer
    • Others have made similar observations on a larger scale:
      • In a study of the Health Care Utilization Project Nationwide Inpatient Sample (HCUP-NIS);
        • Over 80% of thyroidectomies were performed by low- and intermediate-volume surgeons (< 29 thyroidectomies /year)
        • On average, high-volume surgeons (> 30 thyroidectomies / year) had the lowest
          complication rates for patients who underwent total thyroidectomy for cancer (high 7.5% vs. intermediate 13.4% vs. low 18.9%; p < 0.001)
    • A recent meta-analysis including 22 studies found unanimity in the association of lower complication rates with higher thyroid surgery volume
  • When hospital volume and surgeon volume are both considered:
    • On average, high-volume surgeons are associated with lower complication rates, lower hospital mortality, and lower cost:
      • Whereas high-volume centers are associated primarily with lower cost and shorter lengths of stay
  • Estimates of the annual thyroid surgical volume necessary to achieve lower complication rates range from 25 to 50:
    • With one series suggesting > 50 cases for more advanced thyroid
      cancer
• A study specically designed to address this number concluded that annual total thyroidectomy case volume > 25 / year was associated with improved outcomes
• Patients have an 87% increase in the odds of having a complication if the surgeon performed just 1 case / year:
  • 68% for 2 to 5 cases / year
  • 42% for 6 to 10 cases / year
  • 22% for 11 to 15 cases / year
  • 10% for 16 to 20 cases / year
  • 3% for 21 to 25 cases / year
• Patients undergoing total thyroidectomy for cancer at the hands of high-volume surgeons also are reported to have signicantly less thyroid remnant tissue after resection:
  • Resulting in a reduced radioiodine dose requirement for remnant ablation (if indicated)
• Finally, patients having thyroid cancer surgery at low-volume centers were signicantly more
  likely to have an involved tumor margin compared to those treated at high-volume centers.
• An overwhelming body of evidence demonstrates improved outcomes for patients undergoing thyroid cancer surgery with higher-volume surgeons
• Referral of patients to high-volume thyroid surgeons is associated with, on average, superior outcomes:
  • However, referral is not always possible, in view of the relative scarcity of high-volume surgeons and their geographic concentration in larger urban areas
• Conclusions at an overall population level cannot
  always be applied to individual surgeons and patient circumstances:
  • It seems reasonable to encourage referral of patients with grossly invasive and/or extensive disease to a high-volume surgeon experienced in the management of advanced thyroid cancer, and perhaps even to refer those patients undergoing
    total thyroidectomy for low- to intermediate-risk cancers

• Mechanism of Action:
  • Target:
    • Cetuximab is a chimeric monoclonal IgG1 antibody directed against the epidermal growth factor receptor (EGFR / ErbB1)
  • Binding: 
    • It binds with higher affinity than natural ligands (EGF, TGF-α):
      • Blocking ligand-induced EGFR activation
  • Downstream effects:
    • Inhibition of EGFR autophosphorylation → suppression of downstream pathways (RAS / RAF / MEK / ERK and PI3K / AKT) → reduced proliferation and survival
    • Induces cell cycle arrest and apoptosis.
    • Inhibits angiogenesis:
      • Via VEGF downregulation
    • Enhances radiosensitivity and chemosensitivity
    • Triggers antibody-dependent cellular cytotoxicity (ADCC):
      • Due to IgG1 Fc interaction with NK cells
• Indications in Head & Neck Oncology:
  • Locally Advanced Head & Neck Squamous Cell Carcinoma (HNSCC):
    • In combination with definitive radiotherapy in patients not suitable for high-dose cisplatin
    • Based on the Bonner trial (NEJM 2006):
      • Cetuximab + RT improved locoregional control and OS compared with RT alone
  • Recurrent or Metastatic HNSCC:
    • First-line (EXTREME regimen): 
      • Cetuximab + platinum (cisplatin / carboplatin) + 5-FU:
        • Demonstrated OS benefit (Vermorken et al., NEJM 2008)
    • As monotherapy or maintenance:
      • In platinum-refractory or palliative setting
  • Special Situations:
    • Considered for cisplatin-ineligible patients
    • Investigated in combination with immunotherapy (e.g., PD-1 inhibitors), though data are evolving
• Adverse Effects:
  • Dermatologic (most common):
    • Acneiform rash (papulopustular eruption) in ~ 80%:
      • Correlates with better response
    • Xerosis, pruritus, paronychia
  • Infusion-related reactions:
    • Fever, chills, bronchospasm, hypotension
    • Severe (anaphylaxis-like) reactions more common in the Southeastern US:
      • Linked to preexisting IgE antibodies against galactose-α-1,3-galactose from tick bites
  • Electrolyte disturbances:
    • Hypomagnesemia:
      • Due to renal Mg wasting
    • Hypokalemia
    • Hypocalcemia
  • Other:
    • Diarrhea, mucositis, fatigue
  • Rare:
    • Interstitial lung disease, cardiotoxicity
• Management of Adverse Effects:
  • Skin toxicities:
    • Prophylaxis:
      • Sunscreen, moisturizers, topical steroids, oral tetracyclines (doxycycline / minocycline)
    • Management:
      • Topical antibiotics (clindamycin), systemic tetracyclines; dose modification for grade ≥ 3 rash
  • Infusion reactions:
    • Premedication:
      • H1 antihistamines ± corticosteroids
    • Severe reactions:
      • Immediate discontinuation, epinephrine, airway support
  • Electrolyte disturbances:
    • Routine monitoring of Mg, K, Ca during therapy and up to 8 weeks post-treatment
    • Oral / IV replacement as needed
• References:
  • Bonner JA et al. Radiotherapy plus cetuximab for squamous-cell carcinoma of the head and neck. NEJM. 2006;354:567–78.
  • Vermorken JB et al. Platinum-based chemotherapy plus cetuximab in head and neck cancer. NEJM. 2008;359:1116–27.
  • NCCN Guidelines: Head and Neck Cancers. Version 2025.
    Cohen EEW et al. Cetuximab in HNSCC: updated evidence. JCO.

• Ductal carcinoma in situ (DCIS):
  • Is a noninvasive carcinoma of the breast
  • It is defined as the proliferation of malignant epithelial cells:
    • Confined to the mammary ducts and without evidence of invasion through the basement membrane
  • Because it is noninvasive:
    • DCIS does not pose a risk of metastasis
• Lobular carcinoma in situ (LCIS):
  • Was previously considered a form of noninvasive carcinoma:
    • But is now understood to be a benign entity that is a pathologic marker of increased breast cancer risk:
      • In either breast
  • Atypical lobular hyperplasia (ALH) and LCIS:
    • Are both forms of lobular neoplasia and, together with atypical ductal hyperplasia (ADH):
      • Represent proliferative nonmalignant breast lesions

• Mechanisms of Action:
  • 5-Fluorouracil (5-FU):
    • Converted intracellularly to:
      • Fluorodeoxyuridine monophosphate (FdUMP), which forms a ternary complex with thymidylate synthase (TS) and reduced folate:
        • Blocks deoxythymidine monophosphate (dTMP) synthesis, leading to “thymineless death”
    • Other metabolites (fluorouridine triphosphate, FUTP; fluorodeoxyuridine triphosphate, FdUTP):
      • Misincorporate into RNA and DNA, contributing to cytotoxicity
    • Leucovorin:
      • Enhances TS inhibition
  • Methotrexate (MTX):
    • Antifolate:
      • That inhibits dihydrofolate reductase (DHFR)
    • Intracellular polyglutamation increases potency and extends inhibition to other folate-dependent enzymes:
      • Impairing purine and pyrimidine synthesis:
        • Leading to cell death
• Indications in Head and Neck Squamous Cell Carcinoma (HNSCC):
  • 5-Fluorouracil (5-FU):
    • Induction therapy:
      • Used in docetaxel + cisplatin + 5-FU (TPF) regimen:
        • Which improved progression-free survival (PFS) and overall survival (OS) vs. cisplatin + 5-FU (PF) in TAX 323 / 324
    • Concurrent chemoradiation (CRT):
      • Carboplatin + 5-FU with radiation therapy (RT):
        • Is an option for cisplatin-ineligible patients
    • Recurrent / Metastatic (R/M):
      • Backbone of the EXTREME regimen (platinum + 5-FU + cetuximab):
      • Which improved OS compared to platinum + 5-FU alone
  • Methotrexate (MTX):
    • Single-agent palliative therapy:
      • Historically a standard for recurrent / metastatic HNSCC:
      • Often given weekly intravenous (IV) 40 mg/m², with activity and tolerability in frail or heavily pretreated patients
    • Combination therapy:
      • Sometimes paired with cetuximab in cisplatin-unfit patients
• Adverse Effects and Management:
  • 5-Fluorouracil (5-FU):
    • Mucositis, diarrhea, myelosuppression, hand-foot syndrome (HFS):
      • Supportive care; oral cryotherapy may reduce mucositis (bolus 5-FU)
    • Cardiotoxicity (vasospasm, ischemia):
      • Discontinue 5-FU
      • Treat as vasospastic angina with nitrates and / or calcium channel blockers
    • Neurotoxicity (cerebellar syndrome, hyperammonemic encephalopathy):
      • Stop 5-FU
      • Hydrate, correct metabolic derangements
    • Dihydropyrimidine dehydrogenase (DPD) deficiency:
      • Screen with DPYD testing where available:
        • Poor metabolizers should avoid fluoropyrimidines
      • Antidote:
        • Uridine triacetate (Vistogard) within 96 hours of overdose or early severe toxicity
  • Methotrexate (MTX):
    • Mucositis, myelosuppression, hepatotoxicity:
      • Monitor complete blood count (CBC) and liver function tests (LFTs); hold dose for grade ≥3 toxicity.
      • Folinic acid (leucovorin) rescue may be used for high-dose or severe toxicity
    • Renal elimination:
      • Requires dose adjustment in renal impairment
      • Avoid interactions with trimethoprim-sulfamethoxazole (TMP-SMX), nonsteroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), and some penicillins, which increase MTX toxicity
• Key References:
  • Vermorken JB et al., NEJM 2007; Posner MR et al., NEJM 2007; Lorch JH et al., Lancet Oncol 2011 – TPF vs PF in induction therapy.
  • Vermorken JB et al., NEJM 2008 – EXTREME regimen in R/M HNSCC.
  • NCCN Guidelines: Head and Neck Cancers, 2025 Insights.
  • Amstutz U, Froehlich TK, Largiadèr CR. Clin Pharmacol Ther 2011 – DPD deficiency and 5-FU toxicity.
  • US FDA Label: Uridine triacetate (Vistogard).
    Specenier P, Vermorken JB. Oral Oncol 2009 – Methotrexate in head and neck cancer.

• Mechanism of Action:
  • Paclitaxel and docetaxel:
    • Are microtubule-stabilizing agents:
      • They bind to the β-subunit of tubulin:
        • Promoting microtubule assembly while inhibiting depolymerization
      • This leads to stabilization of the mitotic spindle:
        • Blocking cell cycle progression in the G2 /M phase, ultimately triggering apoptosis
    • Additional effects:
      • Anti-angiogenic activity at low doses
      • Modulation of apoptotic pathways:
        • Bcl-2 phosphorylation
      • Potential immune-modulatory effects
• Indications in Head and Neck Squamous Cell Carcinoma (HNSCC):
  • Locally Advanced / Induction Therapy
    TPF regimen (Docetaxel + Cisplatin + 5-FU) has demonstrated improved survival and locoregional control compared with PF (cisplatin + 5-FU)
    • TAX 323 and TAX 324 trials showed significant OS and PFS benefit with TPF in unresectable or locally advanced disease
• Concurrent Chemoradiation:
  • Weekly paclitaxel or docetaxel (often combined with carboplatin) is used as an alternative for patients ineligible for cisplatin
  • Demonstrated radiosensitizing effects.
• Recurrent / Metastatic HNSCC:
  • Single-agent docetaxel or paclitaxel provides palliative benefit with response rates ~ 20% to 30%
  • Often used as part of combination chemotherapy (e.g., taxane + platinum + cetuximab)
• Adverse Effects:
  • Hematologic:
    • Neutropenia (dose-limiting, especially with docetaxel)
    • Febrile neutropenia
  • Neurologic:
    • Peripheral neuropathy (sensory > motor), cumulative and dose-dependent
    • Hypersensitivity Reactions:
      • Due to the lipid solvent:
        • Cremophor EL in paclitaxel
        • Polysorbate 80 in docetaxel
      • Flushing, rash, bronchospasm, anaphylaxis
    • Other:
      • Mucositis
      • Stomatitis
      • Alopecia
      • Fluid retention:
        • More with docetaxel
      • Onycholysis
      • Skin / nail changes
      • Fatigue
      • Myalgia / arthralgia
• Management of Adverse Events:
  • Premedication:
    • Paclitaxel:
      • Corticosteroids + H1/H2 antagonists (e.g., dexamethasone, diphenhydramine, ranitidine)
    • Docetaxel:
      • Dexamethasone to reduce hypersensitivity and fluid retention
  • Neutropenia:
    • Dose reduction, prophylactic G-CSF for high-risk regimens (especially TPF)
  • Neuropathy:
    • Dose modification or discontinuation
    • Supportive care:
      • Duloxetine may help with painful neuropathy
  • Mucositis:
    • Oral hygiene, saline rinses, cryotherapy, topical analgesics
  • Fluid Retention (docetaxel):
    • Steroid premedication, diuretics if symptomatic
• Key References:
  • Vermorken JB, Remenar E, van Herpen C, et al. Cisplatin, fluorouracil, and docetaxel in unresectable head and neck cancer. N Engl J Med. 2007;357(17):1695–704. 【TAX 323】
  • Posner MR, Hershock DM, Blajman CR, et al. Cisplatin and fluorouracil alone or with docetaxel in head and neck cancer. N Engl J Med. 2007;357(17):1705–15. 【TAX 324】
  • NCCN Clinical Practice Guidelines in Oncology: Head and Neck Cancers. Version 2.2025.
  • Hitt R, et al. Phase III study comparing TPF with PF in locally advanced head and neck cancer. J Clin Oncol. 2005;23(34):8636–45.
  • Colevas AD, et al. Chemotherapy options for patients with cisplatin-ineligible head and neck cancer. J Clin Oncol. 2018;36(19):1942–50.

• What each test is built to do:
  • Afirma GSC (± Xpression Atlas): 
    • RNA whole-transcriptome classifier optimized as a rule-out test:
      • XA adds variants / fusions if GSC is Suspicious PMCVeracyte
  • ThyroSeq v3 GC: 
    • DNA / RNA next-gen panel across many genes (mutations, fusions, copy-number alterations, helpful in oncocytic cell lesions / Hürthle cell lesions) designed for rule-out + rule-in and therapy-relevant profiling JAMA NetworkThyroSeq
  • ThyGeNEXT + ThyraMIR v2 (Interpace): 
    • Two-step oncogene panel → reflex miRNA classifier; aims for balanced rule-out with stronger rule-in when driver / miRNA high-risk pattern is present PMCThygenext Thyramir
• Performance (typical ranges in Bethesda III–IV):
  • Afirma GSC: 
    • High sensitivity / NPV in VS and real-world cohorts:
      • PPV modest to moderate
    • Many studies report:
      • NPV ~ 94% to 97%
      • PPV ~ 45% to 65%
    • Real-world series show improved yield vs validation PMCScienceDirect
  • ThyroSeq v3: 
    • Validation and multi-center series show high sensitivity / NPV with higher PPV than Afirma in several cohorts:
      • PPV ~ 60% to 65%
    • Institutional data show sensitivity ~ 92% to 95% (Bethesda III to IV) JAMA NetworkACS Publications
  • ThyGeNEXT/ThyraMIR v2: 
    • Reported NPV ~ 93% to 96%
    • Useful PPV when drivers / miRNA risk present
    • 2025 systematic review suggests high surgical avoidance rates among platforms PMCResearchGate
• Prognostic/management information (actionability):
  • Afirma GSC + XA: 
    • If Suspicious, XA reports fusions / variants (e.g., RET, NTRK, ALK):
      • Which can guide targeted therapy decisions down the line
    • GSC itself primarily aids avoiding surgery Veracyte
  • ThyroSeq v3: 
    • Reports BRAF, RAS, TERT-p, RET / NTRK/ ALK, gene expression and copy-number profiles:
      • Useful for risk stratification (e.g., TERT / BRAF V600E for aggressiveness) and for operative planning (extent, LN assessment) and potential targeted options
      • Particularly helpful in Hürthle-predominant nodules JAMA NetworkThyroSeq
  • ThyGeNEXT/ThyraMIR v2: 
    • Calls out high-risk drivers (BRAF V600E, TERT, ALK, etc.) and refines intermediate results with miRNA pairs:
      • Useful for deciding between surveillance vs diagnostic lobectomy when imaging / clinical risk is equivocal PMCInterpace Biosciences®, Inc.
• Independent comparisons and guidelines:
  • Contemporary reviews / meta-analyses: 
    • Afirma GSC and ThyroSeq v3 both excel as rule-out tests (high sensitivity / NPV), with ThyroSeq often showing higher PPV (rule-in)
    • Interpace’s combined platform performs comparably on NPV with strong rule-in behavior in some studies ScienceDirect+1PMC
• Societal guidance (ETA 2023):
  • Molecular tests can reduce diagnostic surgery and should be selected to match pretest risk and clinical goals rather than “one best test for all.” PMC
• Bottom line (how to choose today):
  • If your primary goal is to avoid surgery (rule-out) in Bethesda III to IV with low–intermediate pretest risk:
    • Afirma GSC or ThyroSeq v3 are both appropriate:
      • Real-world data support high NPV for both PMCJAMA Network
  • If you want both strong rule-out and richer “what kind of cancer is this if positive?” detail to guide extent of surgery and future therapy:
    • ThyroSeq v3 generally provides more granular prognostic / actionable data (TERT/driver profile, CNA burden, Hürthle copy-number signature) and often a higher PPV than Afirma
    • This makes it my usual pick when operative planning may hinge on genotype JAMA NetworkThyroSeq
  • If you favor a stepwise, cost-conscious approach with meaningful rule-in capability when drivers /miRNA are high-risk:
    • ThyGeNEXT + ThyraMIR v2 is reasonable:
      • Pooled data show competitive NPV and good surgical-avoidance rates PMCResearchGate
• Practical take for your clinic:
  • For Bethesda III to IV nodules with indeterminate US where you want to minimize unnecessary operations and inform extent if positive: 
    • ThyroSeq v3 is the most versatile single test today
  • For surgeon’s “rule-out first” workflows with straightforward nodules and low pretest risk: 
    • Afirma GSC is perfectly acceptable:
      • Add XA if suspicious and you want therapy targets.
  • For equivocal cases where a rule-in signal would materially change from surveillance to surgery, or when prior testing is ambiguous: 
    • ThyGeNEXT + ThyraMIR v2 is a solid option

Interpretation & Take-Home

• Best Rule-Out (Highest NPV and Sensitivity):
  • Afirma GSC (real-world meta-analysis: SN ~97%, NPV ~99%) and ThyroSeq v3 (UCLA trial: SN 97%, NPV 99%) are essentially neck-and-neck in ruling out malignancy. Both demonstrate excellent reliability in avoiding unnecessary surgeries.
• Better Rule-In (Higher PPV):
  • ThyroSeq v3 edges ahead slightly with PPV ~64% versus Afirma’s ~57% in comparable settings, meaning a positive result is more likely to indicate true malignancy.
• Manufacturer-Reported MPTX (ThyGeNEXT + ThyraMIR):
  • Claims very strong performance (SN ~ 95%, SP ~ 90%, NPV ~ 97%, PPV ~ 75%):
    • But these results may reflect idealized cohorts with prevalence adjustments
    • Real-world studies show more conservative metrics:
      • SN ~ 76%, SP ~ 75%, NPV ~ 83%, PPV ~ 67%).
• In Summary:
  • For maximum confidence in rule-out:
    • Afirma GSC and ThyroSeq v3 are clearly superior
  • If positive actionable findings (e.g., higher PPV, molecular prognostic detail) are crucial:
    • ThyroSeq v3 offers an advantage
  • MPTX is promising, especially if you value a modular approach, but real-world validation remains less robust than for the other two