Effect of surgical subspecialization on breast cancer outcome

There is increasing pressure for specialization of medical services. The effect of surgical specialization on the outcome of breast cancer in Bedford has been assessed.

The Bedford Breast Cancer Registry, which contains prospective diagnostic, treatment and follow-up data on all breast cancers treated in North Bedfordshire, was analysed to compare breast cancer outcome between 1990-1992 and 1993-1996, that is before and after the advent of surgical subspecialization. All 784 patients were analysed, including patients with metastases (4 per cent) and those treated by tamoxifen alone (8 per cent). Outcome was compared in terms of disease-free survival (DFS), locoregional and all (locoregional and metastases) recurrence rates assessed by Cox proportional hazard and Kaplan-Meier analyses.

Overall DFS was 75 per cent and the locoregional recurrence rate was 8 per cent at 3 years. The tumour stage and grade at presentation and the proportion of screen-detected cancers were similar for both intervals. The outcome for patients before specialization (1990-1992; n = 329) was worse: hazard ratio (HR) for DFS 1.5 (95 per cent confidence interval 1.2-2.0) and HR for locoregional recurrence 2.0 (1.2-3.5). After subspecialization (1993-1996, n = 455) DFS improved from 70 to 79 per cent (P = 0.009) and the all recurrence rate fell from 22 to 12 per cent (P = 0.0004) at 3 years. The improvement in outcome was mainly in younger patients (aged less than 70 years), in whom DFS improved from 72 to 81 per cent (P = 0.02) and the all recurrence rate fell from 24 to 12 per cent (P = 0.001) at 3 years. The improvement was associated with increased axillary surgery (47 to 74 per cent; P < 0.0001), and more frequent use of tamoxifen (74 to 84 per cent; P = 0.004) and chemotherapy (10 to 27 per cent; P < 0.0001) in this age group.

There was a significant improvement in outcome for patients with breast cancer after surgical subspecialization in Bedford. This may relate to the more frequent use of appropriate systemic therapy.