Premenopausal breast cancer patients treated with conservative surgery, radiotherapy and adjuvant chemotherapy have a low risk of local failure

Abstract

The use of adjuvant chemotherapy in premenopausal breast cancer patients with positive nodes is now routine, but the optimal local treatment of these patients is uncertain. To determine the effect of adjuvant chemotherapy on the likelihood of local recurrence as the first site of failure in premenopausal patients treated with conservative surgery (CS) and radiotherapy (RT), we examined the outcome of 74 patients treated with CS, RT, and adjuvant chemotherapy and compared it to the outcome in 192 patients treated with CS and RT alone. Adjuvant chemotherapy consisted of four or more cycles of either a doxorubicin-containing regimen or cyclophosphamide, methotrexate, and 5-fluorouracil. All patients were less than 50 years old, had UICC-AJCC Stage I or II breast cancer treated between 1968 and 1981, had gross excision of the primary tumor, and had a total radiation dose to the primary tumor bed of ≥6000 cGy. Factors predicting for local recurrence, such as extensive intraductal carcinoma and age less than 35, were equivalent in the two groups. Women treated with adjuvant chemotherapy had significantly worse T- and N-stages than women treated with conservative surgery and radiotherapy alone: 61% versus 36% had T2 tumors ( p = 0.0003), 34% versus 6% had clinically positive nodes ( p < 0.0001), and 97% versus 4% had pathologically positive nodes ( p < 0.0001). Despite the poorer prognosis of patients treated with adjuvant chemotherapy, within 5 years of diagnosis, 4% of patients who received adjuvant chemotherapy had their initial relapse in the breast and 24% had initial failure elsewhere, compared with 15% local failure first and 14% failure elsewhere first for those treated without chemotherapy ( p = 0.01). We conclude that premenopausal patients with positive nodes treated with combined modality therapy (conservative surgery, radiation therapy, and adjuvant chemotherapy) have a low risk of local recurrence as a first site of failure. These results suggest a possible interaction between radiation therapy and chemotherapy in their effects on local tumor control.