Remission rates following preoperative chemotherapy and radiation therapy in patients with breast cancer

Purpose: To evaluate remission and breast-conservation rates after preopera tive chemotherapy or chemo-radiotherapy (CT-RT). Patients and Methods: Seventy-three patients with 74 biopsy-proven invasive breast cancers prospectively entered the protocol. Eighteen patients were treated by neoadjuvant chemotherapy followed by surgery and adjuvant irradi ation (chemotherapy group). Fifty-five patients with 56 tumors were treated with combined neoadjuvant chemo-radiotherapy, followed by surgery (chemo-r adiotherapy group). Most patients of both treatment groups received 4 cycle s of EC chemotherapy. In some patients with large tumors 4 cycles of CMF we re added. Chemotherapy was followed by hormonal treatment with tamoxifen or LHRH agonists in case of positive hormone-receptor status. Preoperative ra diotherapy Was administered using 2 Gy fractions up to a total dose of 50 G y, followed by a tumor boost of 6 to 11 Gy. The median overall treatment ti me was 41 days (range: 35 to 55 days). The median time interval between end of neoadjuvant therapy and surgery was 11 weeks (range: 10 to 22 weeks) an d 27 weeks (range: 11 to 41 weeks) for the chemotherapy- and chemo-radiothe rapy group. The median time interval between End of chemotherapy and the be ginning of irradiation ranged between 2 and 8 weeks (median 4 weeks) in the chemo-radiotherapy group. Results: Side-effects due to chemo- or radiotherapy were moderate and rever sible. In the chemotherapy group 17/18 patients (94%) achieved a partial (p PR) and 1/18 patients (6%) a complete histopathological response (pCR). In the chemo-radiotherapy group 32/56 (57%) showed a pPR and 24/56 (43%) a pCR , The difference in complete remission is significant (Fisher's Exact Test: p = 0.004). In 45/74 cases (61%) the breast was preserved, immediate breas t reconstructions with rectus myocutaneous flaps (TRAM) after mastectomy we re performed in 8/74 cases (11%) and modified radical mastectomies without reconstruction were required in 21/74 cases (28%). The breast conservation rates were similar in both treatment groups. Conclusions: Even though the small number of patients in the present protoc ol does not permit definite conclusions, the results of combined modality t reatment seem promising with regard to tumor remission within the treated b reast and as a tool for breast conservation in advanced stage disease. On t he basis of these encouraging data a prospective Phase-III study has been i nitiated.