Invasive lobular carcinoma of the breast: should this be regarded as a chronic disease?

Abstract

Background: The surgical treatment of patients with invasive lobular carcinoma is still controversial due to its different clinical and pathological features. Most studies report local recurrence after relatively short follow-up periods, which is usually 5 years. However there is some evidence to suggest that local recurrence may occur late in the course of follow-up.

Aim of the study: To study the implications and outcome of extending the follow-up period of patients treated for invasive lobular carcinoma.

Patients and methods: Patients (268) treated between 1989 and 1996 were reviewed. Thirty-three patients were excluded as they had primary hormonal therapy. The outcomes for 235 patients were analyzed.

Results: Seventy-nine patients (33.6%) had breast conservation surgery (group I), which was followed by re-excision due to positive margins in 23 patients (29%), and 156 patients (66.3%) had mastectomy (group II). Compared to group II, tumours in group I were smaller (mean size 17 vs. 37 mm, P=0.001), multifocal [20 (25%) vs. 14 (9%), P=0.003] and with more positive margins [23 (29%) vs. 24 (15%), P=0.0009]. Only 33 patients (21%) in group II, and all patients in group I had post-operative radiotherapy (P=0.0001). Forty-eight patients (17.9%) developed local recurrence [27 (34%) in group I and 21 (13.4%) in group II, P=0.0005] after a median follow-up period of 167.8 months. The mean time to local recurrence was 127 (range 24-196) months. Univariate analysis showed that the type of surgery, margin status, adjuvant radiotherapy and chemotherapy significantly affected local recurrence (P=0.0005, 0.02, 0.04 and 0.05 respectively). Cox regression analysis showed that the only factor affected local recurrence was the type of surgery (relative risk 2.43, 95% confidence interval 1.22-4.83, P=0.01) The overall survival was 99.3 months (78.2%). Univariate and Cox regression analyses showed that only the patients age at diagnosis significantly affected survival (P=0.003).

Conclusion: Local recurrence may be a late event in patients treated for invasive lobular carcinoma of the breast and extended follow-up may be considered. In this study mastectomy offers better local control.