- Common sites of distant metastasis in melanoma patients are, in order of decreasing frequency:
- Skin and subcutaneous tissues (40%)
- Lungs (12% to 36%)
- Liver (15% to 20%)
- Brain (12% to 20%)
- Other sites include the:
- Gastrointestinal tract
- Bone
- Adrenal gland
- Distant skin
- Soft tissue, and / or lymph nodes
- Less commonly:
- The spleen or pancreas
- Historically, patients with systemic metastases have had a poor prognosis:
- With a median survival ranging from 6 to 12 months
- Fortunately, a wave of effective systemic therapies have ushered in a new era of treatment options for patients with unresectable or distant metastatic disease
- Indeed, the approach to treatment for such patients is now associated with improved and sometimes durable long-term survival and continues to evolve
- Contemporary systemic therapy represents the mainstay of treatment for most patients with distant metastatic disease:
- Although surgery (curative or palliative) and other modalities (e.g., intralesional therapy):
- Continue to play an evolving role in carefully selected patients as part of a multidisciplinary approach to the care of such patients
- Although surgery (curative or palliative) and other modalities (e.g., intralesional therapy):
- In view of continued advances in the clinical arena and the common need to often consider second- or subsequent line treatments, clinical trials represent an important and attractive option for many patients
- Surgery:
- The decision to perform surgery in patients with distant melanoma metastasis:
- Should be considered as part of a multidisciplinary approach to care
- Overall, given the advances in systemic therapy, surgery as a sole component of the care of these patients is relatively uncommon
- The role of metastasectomy in this setting:
- Whether curative or palliative in intent:
- Continues to evolve
- Whether curative or palliative in intent:
- Indeed, most previous trials and retrospective series that have evaluated the role of surgery for patients with distant melanoma metastasis have mostly been conducted prior to this era of more effective systemic therapy:
- As such, if surgery is considered, the rationale, extent, timing, and decision to proceed should involve a multidisciplinary approach and thoughtful consideration of existing systemic treatment options
- Common indications include:
- Palliation of symptoms (e.g., gastrointestinal obstruction or hemorrhage, difficulty in managing cutaneous metastases, intractable pain)
- Isolated metastases not responding to otherwise successful systemic therapy
- Isolated stable oligometastatic disease
- Complete metastasectomy may be considered in patients as part of a multidisciplinary approach to distant metastasis:
- In at least one legacy study, such as the Canvaxin phase III trial, patients underwent complete metastasectomy for stage IV melanoma as part of an adjuvant stage IV clinical trial:
- Despite the overall negative trial results related to the Canvaxin vaccine:
- Patients had a 40% 5-year survival, even though this trial was conducted prior to the era of contemporary systemic therapy
- Despite the overall negative trial results related to the Canvaxin vaccine:
- Other nonrandomized trials of highly selected patients demonstrated similar results after complete resection of distant metastases
- In at least one legacy study, such as the Canvaxin phase III trial, patients underwent complete metastasectomy for stage IV melanoma as part of an adjuvant stage IV clinical trial:
- The decision to perform surgery in patients with distant melanoma metastasis:
- Patient selection is critical for the strategy of complete surgical metastasectomy, whether for curative or palliative intent
- To aid in patient selection, a thorough imaging evaluation is indicated, including:
- MRI of the brain and CT or PET/CT of the chest, abdomen, and pelvis to fully assess disease burden and the potential to offer either a complete or palliative resection
- Patient factors also play a role in patient selection:
- Patients should not have comorbidities that would preclude a possible full recovery from surgery within 4 to 8 weeks:
- To allow for the initiation of adjuvant or systemic therapies
- Moreover, the biology of the melanoma itself should be considered:
- Patients whose distant metastasis developed following a longer disease-free interval or who present with isolated or oligometastatic disease:
- In general, more likely to be considered for surgical resection
- Patients whose distant metastasis developed following a longer disease-free interval or who present with isolated or oligometastatic disease:
- Lastly, the systemic options available and their demonstrated efficacy should be considered:
- This includes, but is not limited to, responsiveness and ability to tolerate immune checkpoint blockade, mutational status, and progression on other lines of therapy:
- Ultimately, these decisions should be made in collaboration with a multidisciplinary team
- Surgery may also offer effective palliation for isolated or oligometastatic accessible distant metastases
- Examples of accessible lesions include isolated visceral metastases, isolated brain metastases, and occasionally isolated lung metastases
- Palliative strategies may improve functional status and render patients more likely to tolerate systemic treatments
- Importantly, surgery may also be considered to support consolidation of a mixed response to systemic therapy
- Overall, the role of surgery in the context of the multidisciplinary management of the patient with distant metastases continues to evolve
- Patients should not have comorbidities that would preclude a possible full recovery from surgery within 4 to 8 weeks:
Rodrigo Arrangoiz MS, MD, FACS, FSSO 