Triple-negative breast cancer in the older population.

Breast cancer in advanced age has been associated with a slightly increased probability of favourable tumour biology (e.g. hormone receptor-positive and human epidermal growth factor-2 [HER2]-negative by immunohistochemistry). Nevertheless, a substantial proportion of older women (≈ 15-18%) still develop 'triple-negative' breast cancer (TNBC), which is generally associated with a poor prognosis. To date, there have been very few investigations comparing the prognosis of younger and older women with TNBC; however, some emerging studies suggest that older patients with TNBC may have a better outcome when compared with their younger counterparts. The reasons for these differences in prognosis have yet to be fully elucidated, but may be due to age-related biological variations, as suggested by observed differences in the distribution of histological subtypes of TNBC, or perhaps other unknown (biological) factors. Despite the evidence of benefit of chemotherapy in TNBC in older women, there is still a tendency for geriatric patients to receive less adjuvant chemotherapy than their younger counterparts.