10-YEAR RESULTS OF A RANDOMIZED TRIAL COMPARING 2 CONSERVATIVE TREATMENT STRATEGIES FOR SMALL-SIZE BREAST-CANCER

We report the 10-year results of a randomised clinical trial in which two different breast conservation treatment strategies were compared i n women with small, non-metastatic primary breast cancer: quadrantecto my, axillary dissection and radiotherapy (QUART) versus tumorectomy an d axillary dissection followed by external radiotherapy and a boost wi th Ir-192 implantation (TART). No second surgery was given to women wi th affected surgical margins. Axillary node positive women received ad juvant medical therapy. From 1985-1987, this trial accrued 705 patient s, 360 in the QUART and 345 in the TART arm. Crude cumulative incidenc e curves for intrabreast tumour recurrence (IBTR) and metastases as fi rst events and mortality curves in each of the two treatment arms were computed. A crude cumulative incidence curve of IBTR as a second even t (in women who had already had a local recurrence) was also computed. The two groups were compared in terms of hazard for IBTR, metastases or death occurrence by using Cox regression models, both with and with out adjustment for patient age, tumour size, number of metastatic axil lary nodes and histology. Possible interactions between the aforementi oned prognostic factors and the type of surgery were also investigated . The two groups were well matched for baseline patient and tumour cha racteristics, the only exception being resection margins, which were m ore often positive in the TART group. At the Cox model, a significant difference between groups was detected for IBTR (P<0.0001), but not fo r distant metastases and overall survival. In particular, 5- and 10-ye ar estimates of crude cumulative incidence of IBTR were 4.7 and 7.4% i n the QUART group and 11.6 and 18.6% in the TART group. The difference was not substantially affected by patient or disease characteristics. Likewise, the status of resection margins in women who underwent TART treatment did not significantly influence the risk of occurrence of I BTRs. Finally, the rate of second IBTR occurrence was relatively high, when compared with the rate of IBTR occurrence as first event. In sum mary, the results of this trial show that a better local control of th e disease can be obtained with the more extensive surgical resection, i.e. QUART. (C) 1998 Elsevier Science Ltd. All rights reserved.