Neoadjuvant versus adjuvant chemotherapy for triple negative breast cancer

The study aim was to investigate factors that predict the use of neoadjuvant versus adjuvant chemotherapy in patients with triple negative breast cancer (TNBC) and the overall survival in each group.

We identified 493 patients with Stage I-III TNBC between 1998 and 2008. Patients were divided according to receipt of neoadjuvant, adjuvant, or none/unknown chemotherapy. Data were compared using chi(2) and Fisher's exact test. For more than two group comparisons and analyzing multiple dependent variables, MANOVA was used. Kaplan-Meier curves were generated.

Of 493 patients with TNBC, 154 (31%) received neoadjuvant chemotherapy, 251 (51%) received adjuvant chemotherapy, and 88 (18%) had no or unknown chemotherapy. Patients undergoing neoadjuvant chemotherapy were younger (mean 50, range 20-83) compared with those undergoing adjuvant chemotherapy (mean 53, range 25-83) or none/unknown chemotherapy (mean 62, range 29-86) (P < 0.0001). The three groups did not differ significantly by patient race, tumor histology, or tumor grade. Increased tumor size, nodal positivity, and advanced stage were more likely to be associated with use of neoadjuvant chemotherapy (all comparisons P < 0.0001). After controlling for covariates associated with survival in unadjusted tests, patients undergoing adjuvant therapy were less likely to die compared with patients undergoing neoadjuvant therapy or none/unknown therapy (overall aHR 0.476, 95% CI 0.295-0.770).

Women with TNBC who underwent adjuvant chemotherapy were 52% less likely to die overall compared with those who received neoadjuvant chemotherapy or none/unknown chemotherapy in this institutional series. Prospective studies are necessary to determine if this finding is durable.