Prognostic significance of pathological response of primary tumor and metastatic axillary lymph nodes after neoadjuvant chemotherapy for locally advanced breast carcinoma.

PURPOSE

The prognostic significance of pathological response of primary tumor and metastatic axillary lymph nodes after neoadjuvant chemotherapy was assessed in patients with noninflammatory locally advanced breast carcinoma.

PATIENTS AND METHODS

Between January 1989 and April 1995, 148 consecutive patients with locally advanced breast carcinoma participated in the study. Of these, 140 fully evaluable patients (67, stage IIIA; 73, stage IIIB) were treated with three courses of 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC), followed by modified radical mastectomy when technically feasible or definitive radiation therapy. The median age was 53 years (range, 26 to 75 years); 55% of patients were postmenopausal.

RESULTS

Objective response was recorded in 99 of 140 patients (71%; 95% confidence interval, 63% to 79%). Complete response occurred in 11 patients (8%), and partial response occurred in 88 patients (63%). No change was recorded in 37 patients (26%), and progressive disease occurred in 4 patients (3%). One hundred and thirty-six patients underwent the planned surgery. Maximal pathological response of the primary tumor (in situ carcinoma or minimal microscopic residual tumor) was observed in 24 (18%); 112 patients (82%) presented minimal pathological response of the primary tumor (gross residual tumor). The number of metastatic axillary nodes after neoadjuvant chemotherapy was as follows: N0, 39 patients (29%); N1-N3, 35 patients (26%); > N3, 62 patients (45%). Considering the initial TNM status, 75% of the patients had decreases in tumor compartment after neoadjuvant chemotherapy. Also, 31% and 23% of patients with clinical N1 and N2, respectively, showed uninvolved axillary lymph nodes. A significant correlation was noted between pathological response of primary tumor and the number of metastatic axillary lymph nodes. Median disease-free survival was 34 months, whereas median overall survival was 66 months. Pathological responses of both primary tumor and metastatic axillary lymph nodes were strongly correlated with disease-free survival and overall survival in univariate analyses. Additionally, in a proportional hazard regression model and in an accelerated failure time model, metastatic axillary lymph nodes significantly influenced both disease-free survival and overall survival, whereas pathological response of primary tumor did so on disease-free survival only.

CONCLUSION

After neoadjuvant chemotherapy, pathological responses of both primary tumor and metastatic axillary lymph nodes had a marked prognostic significance and influenced outcome for patients with locally advanced breast carcinoma. Our results suggest that maximal tumor shrinkage and sterilization of potentially involved axillary nodes may represent a major goal of neoadjuvant chemotherapy. Further studies are warranted to clarify whether these results reflect the therapeutic effect or intrinsic biologic factors of the tumor.