Triple-negative Breast Cancer

Triple-negative breast cancer refers to any breast cancer that does not express the genes for estrogen receptor (ER), progesterone receptor (PR) and Her2/neu. Triple negative is sometimes used as a surrogate term for basal-like; however, more detailed classification may provide better guidance for treatment and better estimates for prognosis.

Triple negative breast cancers comprise a very heterogeneous group of cancers. There is conflicting information over prognosis for the various subtypes but it appears that the Nottingham prognostic index is valid and hence general prognosis is rather similar with other breast cancer of same stage, except that more aggressive treatment is required. Some types of triple negative breast cancer are known to be more aggressive with poor prognosis, while other types have prognosis very similar or better than hormone receptor positive breast cancers. Pooled data of all triple negative subtypes suggest that with optimal treatment 20 year survival rates are very close to those of hormone positive cancer.

Triple negative breast cancers have a relapse pattern that is very different from hormone-positive breast cancers: the risk of relapse is much higher for the first 3–5 years but drops sharply and substantially below that of hormone-positive breast cancers after that. This relapse pattern has been recognized for all types of triple negative cancers for which sufficient data exists although the absolute relapse and survival rates differ across subtypes.

While it is frequently presumed to affect predominantly young women, the distribution is similar in all age groups.