Breast carcinoma in women 35 years and younger: a pathological study

Aims: To document the pathological features of breast carcinoma diagnosed in women aged 35 years or less. Methods: The files of the Department of Pathology, Singapore General Hospital, were searched for cases of breast cancer diagnosed in individuals aged 35 years or less between January 1993 and December 2004. Histological slides and pathology reports were retrieved and reviewed. Pathologic parameters of tumour size, histological grade, accompanying ductal carcinoma in situ (DCIS), lymphovascular invasion, nodal status, hormone receptor and c-erbB-2 profiles, were documented. Results: Of 112 cases of breast cancer, 91 (81.3%) were invasive carcinomas, 17 (15.2%) pure DCIS, three (2.7%) were diagnosed on needle aspirates. No residual tumour was available for microscopic assessment in one (0.9%) patient who underwent bilateral mastectomy in our institution but had her initial surgery elsewhere. Invasive tumour size ranged from 0.3 to 11.5 cm (mean 2.7 cm, median 2.1 cm), with 84 (92.3%) infiltrative ductal, two (2.2%) lobular, two (2.2%) mucinous, two (2.2%) atypical medullary, and one (1.1%) mixed ductal-lobular. The majority were grade 3 (54 cases, 59.3%), with 24 (26.4%) grade 2 and 7 (7.7%) grade 1, while grading was not accomplished in six (6.6%) cases. Nodal status was positive in 39 (42.9%), negative in 25 (27.4%), unknown in the rest (27 cases, 29.7%). Oestrogen and progesterone receptors (ER, PR) were positive in 51 (61.4%) and 43 (51.8%) cases, respectively, out of 83 (91.2%) cases in which they were evaluated. c-erbB-2 immunostaining, carried out in 54 (59.3%) invasive cancers, showed positivity in 16 (29.6%) cases. DCIS cases ranged from 0.25 to 6.2cm (mean 2.2 cm, median 2 cm) in size. Nuclear grade was low in seven (41.2%), intermediate in four (23.5%), and high in six (35.3%). Conclusion: The majority of breast carcinomas in young women are invasive, with T2 disease at presentation, and of poor histological grade. The recent rise in numbers suggests increased detection, plausibly due to improved awareness of breast disease among the younger female population. Pathogenetic causes that differ from breast carcinogenesis in older women have to be further clarified.