PATHOLOGICAL RESPONSE TO INDUCTION CHEMOTHERAPY IN LOCALLY ADVANCED-CARCINOMA OF THE BREAST - A DETERMINANT OF OUTCOME

BACKGROUND: The prognosis for patients with locally advanced carcinoma of the breast remains poor, This study examines the pathologic eviden ce of response of the mammary tumor and axillary nodes after preoperat ive chemotherapy. We sought to determine if there was a relationship b etween the histologic response and clinical outcome, STUDY DESIGN Betw een 1987 and 1992, 36 patients with locally advanced carcinoma of the breast received three cycles of chemotherapy after incisional biopsy, Modified radical mastectomy was then performed, The breast and axillar y nodes were examined pathologically for therapeutic effect and a grad ing scale was assigned, Postoperatively, patients received completion chemotherapy with the same agents used preoperatively followed by radi ation therapy to the chest wall, RESULTS: Fourteen tumors (39 percent) showed near total therapeutic effect, five (14 percent) showed greate r than 50 percent but less than tol:al effect, 12 (33 percent) showed less than 50 percent effect, and five (14 percent) showed no effect, N odal positivity was seen in 61 percent of the patients, Overall clinic al response to induction chemotherapy was seen. in 86 percent of the p atients, There was poor correlation between clinical and pathologic re sponse, Only 50 percent of the patients with complete clinical respons e were pathologically free of disease, Patients with excellent patholo gic therapeutic response had a 79 percent overall five-year survival r ate compared with 34 percent for tumors with a lesser response. This w as irrespective of nodal status. While pathologic response was critica l in determining outcome, clinical response was not, CONCLUSIONS: Thes e results indicate that patients whose tumors have the best pathologic response to induction chemotherapy experience the best outcome.