SAN ANTONIO — Breast conservation therapy resulted in significantly better 5-year overall survival, compared with mastectomy, investigators found in a study of 202 patients with triple receptor–negative breast cancer.
Triple receptor–negative breast tumors lack estrogen-, progesterone-, and Her-2/neu-receptor expression. These aggressive cancers account for 15%–20% of the more than 1 million breast cancers diagnosed each year worldwide.
“Despite the aggressive nature [of these tumors], our hypothesis was that breast conservation therapy [might be a] viable option for some patients,” Dr. Catherine C. Parker said at the annual Academic Surgical Congress.
She and her colleagues at Louisiana State University, Shreveport, studied outcomes of 63 patients (31%) who had breast conservation therapy and 139 who received mastectomy. Cancer recurrence rates and survival were the primary outcomes. Mean tumor size at baseline was significantly greater in the mastectomy group, 3.1 cm, versus 2.5 cm in the breast conservation group. A total of 26% of the mastectomy patients had T3 or T4 tumors, compared with 5% of the breast conservation group, a statistically significant difference.
All patients were offered standard of care treatment and surveillance. The mean follow-up was 53 months. Disease-free survival at 5 years was 56% for the mastectomy group and 69% for the breast conservation therapy group. The difference was not statistically significant, Dr. Parker said.
“Five-year overall survival was significantly better for breast conservation therapy [89% vs. 69%],” said Dr. Parker of the department of surgery at LSU.
Reasons for disparity in overall survival include the larger mean tumor size and more advanced stage of disease in the mastectomy group, Dr. Parker said.
Recurrence rates were 30% for the breast conservation group and 43% for the mastectomy group.
A multivariate analysis indicated that the surgical approach had no effect on disease-free or overall survival.
Dr. Parker had no relevant disclosures.