Pathological features of primary breast cancer in the elderly based on needle core biopsies--a large series from a single centre.

Most breast cancer patients are diagnosed at>65 years but research efforts are mainly focussed on younger patients. Knowledge related to elderly breast cancer is urgently needed. Patients>70 years presenting with early operable primary breast cancer were studied. Pathological features of diagnostic needle core biopsies taken from 2078 tumours from 2061 consecutive patients managed under a dedicated elderly breast cancer service, in 1987-2006, were reviewed. There were 1996 invasive carcinoma of mammary type (96%) with (N=200) or without associated ductal carcinoma in situ (DCIS); 81 were DCIS only (3.9%). One malignant adenomyoepithelioma was seen. Among the invasive carcinomas, ductal carcinoma of no special type was seen in 87.1% while lobular and mucinous features were noted in 6.9% and 3.1%, respectively. Histological grades and oestrogen receptor (ER) status were assessed respectively in 826 and 1557 invasive carcinomas. Majority were grade 2 (62.7%), followed by grade 1. Around 82% were ER-positive. Their pattern was compared with that in 2674 tumours from younger (< or =70 years) counterparts. In all age groups there was a marked biphasal distribution of ER-positivity, but in patients>70 years this distribution was more marked, with a great preponderance of highly ER-positive tumours, and a substantial minority being ER-negative, with very few in intermediate groups. We believe that this is the largest dataset of pathological features of elderly primary breast cancer from one institution. We have clearly confirmed the high frequency of ER-positive tumours in elderly patients. Further work is underway to assess long-term outcome and clinical relevance.