Does breast-conserving surgery have a higher local recurrence Following neoadjuvant chemotherapy?

One of the major advantages of preoperative chemotherapy (neoadjuvant chemotherapy) is the reduction in size of large tumors, making them amendable to breast-conserving surgery. A large study in the journal Lancet Oncology in 2018 raised concerns about downstaging (reduction in tumor size) in patients undergoing neoadjuvant chemotherapy. Mamtani et al. from Memorial Sloan Kettering Cancer Center recently reported a study on a series of patients from their institution who have been downstaged following neoadjuvant chemotherapy. The study included 282 patients who were not eligible for breast-conserving surgery (lumpectomy) before neoadjuvant chemotherapy but became eligible after treatment. Of these patients, 160 were suitable for a lumpectomy but chose mastectomy. Following surgery, the average follow-up was approximately three years.

Of the 122 patients undergoing lumpectomy, only 13 patients developed a recurrence. Only four of the 160 who chose mastectomy recurred.

For those patients who did recur, the average time to a recurrence was 14 months. The researchers also found that of those patients who had their tumors completely disappear with chemotherapy, only invasion of the lymphatic system within the breast was associated with a recurrence.

Conclusions: In this large consecutive cohort of T1-3 patients receiving NAC, local recurrence rates are low even among those who initially were ineligible to undergo BCS and are downstaged with neoadjuvant chemotherapy. The authors concluded that “for many patients, this approach affords an opportunity for surgical de-escalation to minimize the burden of treatment without compromising oncologic outcomes.”
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