Steven J. Isakoff, MD, PhD, Director of Breast Cancer Clinical Research at Massachusetts General Hospital, Boston, found the TAMARISK study “interesting.”

“Looking at genomic profiles of uterine cancer in both tamoxifen-associated uterine cancer, the researchers found a lower frequency of PIK3 driver mutations than in de novo uterine cancer, but PIK3 signaling is present in tamoxifen-associated uterine cancer. This raises the idea that tamoxifen is inducing PI3K in uterine tissue,” Dr. Isakoff said.

Steven J. Isakoff, MD, PhD

However, uterine cancer from tamoxifen is rare. “This is interesting as a mechanistic finding that opens up a new way of thinking about tamoxifen activating PI3K signaling. It suggests the possibility of therapeutic options for tamoxifen-associated uterine cancer to inhibit PI3K, even in the absence of PI3K mutations,” he added. 

DISCLOSURE: Dr. Isakoff has served as a consultant or advisor to AbbVie, Genentech/Roche, Hengrui Therapeutics, Immunomedics, Myriad Genetics, and Puma Biotechnology; and has received institutional research funding from AbbVie, AstraZeneca/MedImmune, Genentech, Merck, OncoPep, and PharmaMar.