ADJUVANT CONCURRENT CHEMORADIOTHERAPY FOR STAGE-I AND STAGE-II BREAST-CANCER - A FEASIBILITY STUDY OF A NEW THERAPEUTIC APPROACH

Adjuvant radiotherapy is the rule after conservative surgery for breas t cancer. Furthermore, an anthracycline-based chemotherapy is recommen ded in node-positive patients and in poor prognosis tumors. The optima l schedule of treatment has yet to be determined but ideally, none of these the theraputic modalities should be delayed. We have therefore c onducted a feasibility trial using post-operative concurrent chemoradi ation therapy with an anthracenedione. Between May 1990 and October 19 94, 154 patients with stage I or II breast cancer who had benefited of either limited or radical surgery were treated with adjuvant concurra nt chemoradiotherapy. Radiotherapy consisted of 50 Gy in 25 fractions overs 5 weeks to the chest wall or to the breast and to the supraclavi cular and internal mammary lymph nodes. When indicated a boost of 15 G y teas then delivered to the primary tumor bed (n = 75). Starting on t he first week of radiotherapy combined chemotherapy with 5-fluorouraci l, mitoxantrone, and cyclophosphamide was administered at 21-day inter vals, for 4 to 6 cycles. Compliance to therapy was excellent Median ra diotherapy dose was 49.5 Gy to the chest wall or breast and to the lym ph nodes, and 14.2 Gy to the tumor bed Chemotherapy was given at full nose in over 80% of the cases and the 21-day interval between cycles w as respected in 31%. In val longer than 28 days was necessary in the r emainder of the patients. Main toxicities were nausea and vomiting (20 .8%) and grade 3-4 neutropenia (12.3%). Grade 1 cutaneous toxicity occ urred in 62.3% of the cares, and severe grade 3 radiation dermatitis r equiring temporary interruption of therapy in 4.5%. With the exception of one case of grade 3 acute cardiac toxicity, there was no other sev ere side-effects. In conclusion, this pilot study demonstrates the fea sibility of concurrent chemoradiation therapy with an anthracenedione for stage I and II breast cancer in the adjuvant setting. Whether this approach compares favorably with standard sequential therapy in terms of long-term results remains to be determined and should be assessed in a phase III trial.