Ten year results of a randomised trial comparing two 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 in women with small, non-metastatic primary breast cancer: quadrantectomy, axillary dissection and radiotherapy (QUART) versus tumorectomy and axillary dissection followed by external radiotherapy and a boost with ¹⁹²Ir implantation (TART). No second surgery was given to women with affected surgical margins. Axillary node positive women received adjuvant medical therapy. From 1985-1987, this trial accrued 705 patients, 360 in the QUART and 345 in the TART arm. Crude cumulative incidence curves for intrabreast tumour recurrence (IBTR) and metastases as first events and mortality curves in each of the two treatment arms were computed. A crude cumulative incidence curve of IBTR as a second event (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 without adjustment for patient age, tumour size, number of metastatic axillary nodes and histology. Possible interactions between the aforementioned prognostic factors and the type of surgery were also investigated. The two groups were well matched for baseline patient and tumour characteristics, the only exception being resection margins, which were more often positive in the TART group. At the Cox model, a significant difference between groups was detected for IBTR (P