Prospective matched-pair comparison of outcome after treatment for lobular and ductal breast carcinoma

Background: Whether the prognosis of invasive lobular carcinoma is different from that of other invasive breast cancers is controversial. The aim of this study was to compare the outcome in age- and stage-matched patients with lobular carcinoma and those with invasive breast cancer, and in particular to compare predictors of outcome. Methods: Data were obtained from a prospectively maintained database that included patients who had breast surgery for invasivc cancer. Patients were matched for International Union Against Cancer stage and age at diagnosis within 5 years. Two patients with invasive ductal carcinoma were matched to each patient with invasive lobular carcinoma. Results: There was no significant difference between invasive ductal and lobular carcinomas in terms of overall survival. Oestrogen receptor (ER)-positive invasive ductal carcinoma had a better prognosis than ER-positive invasive lobular carcinoma (P = 0.011). Similarly, ER-negative invasive ductal carcinoma was associated with worse survival than ER-negative invasive lobular carcinoma (P = 0.054). Conclusion: These results suggested that the differences in outcome between invasive ductal and lobular carcinomas may be determined by ER status.