The Prolactin Receptor and Triple-Negative Breast Cancer

According to a study published in Nature in October 2016, in triple-negative breast cancer, the hormone prolactin and its cell-surface sensor, the prolactin receptor, may be important markers for extending survival and avoiding intensive treatment.

Triple-negative breast canceris aggressive, has fewer targeted options than other breast cancers and contains subtypes.

Advanced genetic analyses examined tissue from 580 patients, including prolactin-production genes (PRL, JAK2, STAT5a).

The most striking result was longer survival with tumors rich in prolactin receptors.

Animal experiments also found prolactin inhibited cancer-cell proliferation.

What Does This Study Mean Clinically?

• Triple-negative breast cancer, one of 4 subtypes, is itself diverse. Doctors therefore need biomarkers to select treatment. Measuring prolactin receptor density may help choose the most appropriate option.
• Future treatment of receptor-positive tumors may combine prolactin and chemotherapy.
• Prolactin supports breast milk production. Breastfeeding naturally maintains high levels in breast tissue. The findings also support breastfeeding’s protective breast cancer effect.