HER2 Genes Not Just For Her

Solid cancer tumors also have HER2 mutations

(RxWiki News) The HER2 gene is best known for its role in breast cancer. Having this faulty gene increases a woman’s risk of developing breast cancer. But the influence of HER2 may be far more wide-reaching.

New research discovered HER2 mutations in 14 different types of cancers, including esophageal, uterine and lung cancers, as well as a really tough-to-treat form of breast cancer called “triple-negative.”

Existing medications, such as Herceptin (trastuzumab), may be able to treat these advanced cancers.

"Discuss genetic testing with your oncologist."

The HER2 gene is supposed to help with DNA repair. So mutations - or changes - in the gene can fuel cancer development, growth and spread.

Massimo Cristofanilli, MD, FACP, professor of Medical Oncology and Director of the Jefferson Breast Center at the Kimmel Cancer Center and Thomas Jefferson University Hospital, presented the study findings at the 2013 American Society of Clinical Oncology Annual Meeting.  

“No one ever thought that there would be such a variety of genomic alterations in HER2 in this many solid tumors,” Dr. Cristofanilli said in a press release.

From a clinical standpoint, the fact that targeted therapies are available to treat these errant genes may widen treatment options for people with all different types of cancer, according to Dr. Cristofanilli.

He added that "...from a research perspective, it builds on the idea that it is the genomic profile of a tumor that is relevant in providing biological information for planning of personalized treatments — not where the cancer is located or where it develops."

Dr. Cristofanilli donated samples from 50 breast cancer tumors. Then Foundation Medicine, which led and funded the research, screened for more than 182 genes and 14 genetic rearrangements.

A total of 2,223 tumor samples from 20 different advanced solid tumor types were analyzed.

A variety of HER2 mutations were found in samples of esophageal, uterine, breast, stomach and lung cancers.

Dr. Cristofanilli had a triple-negative breast cancer patient whose tumor was shown to have HER2 irregularities. Currently, triple-negative breast cancers don’t have any treatable targets, so these tumors tend to be aggressive and hard to treat.

The woman with triple-negative breast cancer was given Herceptin along with chemotherapy, and Dr. Cristofanilli said the patient “...derived clinical benefit.”

Herceptin is currently approved by the US Food and Drug Administration to treat breast and stomach (gastric) cancers.

dailyRx News spoke with Adam Brufsky, MD, PhD, professor of medicine at the University of Pittsburgh School of Medicine, about these findings. 

“This may expand the use of traztuzumab outside of breast cancer and gastric cancer. It is hoped that the same success seen with this drug in breast cancer could be replicated in other solid tumors,” Dr. Brufsky said.

According to the study authors, "Widespread use of this approach could provide more treatment options and enable more rapid accrual to ongoing and planned trials of agents targeting pathways under study."

Two other anti-HER2 therapies are currently available — Perjeta (pertuzumab) and Kadcyla (ado-trastuzumab emtansine).

All research is considered preliminary before it’s published in a peer-reviewed journal.

No conflicts of interest were disclosed by Dr. Cristofanilli.

Review Date: 
June 5, 2013