Chemotherapy with Mitomycin-C and Cyclophosphamide Adjuvant to Surgery for Breast Cancer

The effect of adjuvant chemotherapy on breast cancer was studiedin two trials. In the first, mitomycin-C was administered intravenouslyto 203 patients and cyclophosphamide intravenously or orallyto 72 patients, within four weeks after radical mastectomy.The results were evaluated by compairing the recurrence-freerates of these patients with those of 556 patients who receivedsurgery alone. The effect of postsurgical adjuvant chemotherapy on the recurrence-freerate was statistically significantly better than that of surgeryalone when one or two axillary lymph nodes were involved inmetastasis, possibly because of the suppressive effect of chemotherapyon the establishment of hematogeneous metastases. With no orthree to seven metastases, the recurrence-free rate for patientsreceiving surgical treatment combined with adjuvant chemotherapywas higher than that for those with surgery alone, but the differencewas not statistically significant. In advanced cases havingeight or more axillary lymph node metastases, chemotherapy appearedsignificantly to reduce the recurrence- free rate compared withsurgery alone. This is possibly attributable to deteriorationin host immunity caused by chemotherapy being administered immediatelyafter surgery and affecting the host's defense mechanisms. In the second trial, which is still in progress, oral cyclophosphamidewas administered to 172 patients, 150 mg daily, for 34 daysfrom the seventh day after surgery. When compared with 179 patientshaving surgery alone, this chemotherapy increased the four-yearrecurrence-free rate in patients with no axillary lymph nodemetastases and the two-year recurrence-free rate in patientswith eight or more axillary lymph node metastases.