National Surgical Adjuvant Bowel and Breast Project B-18

• The National Surgical Adjuvant Bowel and Breast Project B-18 was designed to:
  • Determine whether preoperative chemotherapy:
    • Would result in improved survival compared to postoperative chemotherapy
  • Secondary aims included:
    • Evaluation of pCR rates
    • Comparison of breast conservation rates and ipsilateral recurrence rates between the two groups
  • Between 1988 and 1993:
    • 1523 patients with clinical T1 to T3 N0 to N1 operable breast cancer were enrolled in the trial:
      • 763 were randomized to preoperative therapy while 760 were randomized to postoperative therapy
  • At 16 years of follow-up:
    • There was no difference in:
      • Disease-free survival (HR = 0.93, 95% CI, 0.81 to 1.06, p = 0.27) or
      • Overall survival (HR = 0.99, 95% CI, 0.85 to 1.16, p = 0.90):
        • Between the postoperative and preoperative chemotherapy groups
  • In the preoperative group:
    • A pCR was documented in 13% of patients
  • Preoperative chemotherapy patients:
    • Had a significantly increased incidence of having pathologically negative nodes compared to postoperative chemotherapy patients:
      • 58% vs. 42%, respectively:
        • p<0.0001
  • The rate of breast conservation:
    • Was higher among women who received neoadjuvant chemotherapy compared to women who received postoperative chemotherapy:
      • 68% versus 60%, respectively:
        • p = 0.001
    • The significant downstaging:
      • Of tumors > 5cm in the preoperative chemotherapy arm:
        • Primarily drove this breast conservation trend
  • There was a trend toward a higher rate:
    • Of ipsilateral breast tumor recurrence with preoperative vs postoperative chemotherapy:
      • 13% of 506 patients vs
      • 10% of 450 patients, respectively:
        • Although this difference was not statistically significant (p = 0.21)
  • Retrospective series later found:
    • No difference in surgical complications between women who received preoperative or postoperative chemotherapy

REFERENCES

1. Fisher B, Bryant J, Wolmark N, et al. Effect of preoperative chemotherapy on the outcome of women with operable breast cancer. J Clin Oncol. 1998;16(8):2672-2685.
2. Boughey JC, Peitinger F, Meric-Bernstam F, et al. Impact of preoperative versus postoperative chemotherapy on the extent and number of surgical procedures in patients treated in randomized clinical trials for breast cancer. Ann Surg. 2006;244(3):464–470.
3. Rastogi P, Anderson SJ, Bear HD, et al. Preoperative chemotherapy: updates of National Surgical Adjuvant Breast and Bowel Project Protocols B-18 and B-27. J Clin Oncol. 2008;26(5):778-785.

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