Pleomorphic Lobular Carcinoma of the Breast: A Review of 35 Cases at a Single Institution

Objectives: Pleomorphic lobular carcinoma (PL) is an aggressive subtype of invasive lobular carcinoma. There are few case series reporting on this aggressive form of breast cancer. This report features a descriptive and survivorship comparison of a large case series of PL reviewed by a single breast pathologist. Methods: From 1993-2010 we retrospectively reviewed 198 cases of invasive lobular carcinomas, 35 cases (34 patients with one patient presenting with 2 independent cancers) of PL and 163 cases of non-pleomorphic invasive lobular carcinoma (NPL). The pathology was reviewed by a single breast pathologist and classified as either PL or NPL according to WHO classification. Kaplan-Meier survivals were computed and compared with a log rank test using SPSS 18. Overall survival (OS) was computed from date of diagnosis. Progression free survival (PFS) until either local or metastatic failure was computed. Results: Median follow-up was 59.5 months and 73 months, for NPL and PL respectively. Median age of diagnosis was 55 and 58.67 for PL and NPL groups. Of the NPL group, 75.5% were post-menopausal opposed to 67.6% in PL group. PL cases were ER positive 87.1% vs. 90.1% of the NPL cases. Her-2/neu status was known in nearly 50% of cases with 17 positive NPL and 5 positive PL. Clinical stage at presentation was stage IIB or less in 67.6% of the PL and 80.1% of the NPL. Six presented (17.6%) with metastatic disease in the PL group and 12 (7.7%) in the NPL group. None of the descriptive comparisons were significantly different by χ2 analyses. PFS at 5 years was 30% and 21% in PL and NPL, respectively (p=0.73). OS at 5 years was 68.5% for PL and 83.9% for NPL (p=0.031). Conclusions: PL patients showed a statistically significant decreased OS, but no significant difference in PFS, at 5 years from diagnosis.