News from the Front

In each newsletter, Dr. James Ford will provide insights into relevant research and recent headlines involving gastric cancer. Dr. Ford is a Gastric Cancer Fund board member and medical oncologist and geneticist at Stanford University Medical Center.

It’s not often that new treatments for gastric cancer make the headlines of the New York Times and the Wall Street Journal.  This year, a very exciting advance was reported at the June American Society for Clinical Oncology (ASCO) meeting in Florida, regarding targeted treatment for HER2-expressing gastric cancer with the monoclonal antibody trastuzumab.  HER2 is an “oncogene,” known to be overexpressed in a number of cancers, but particularly in about 20% of breast cancers, leading to uncontrolled cell growth.  It is quite famous, as it was identified as a potential target for therapy in breast cancer, and in fact one of the first approved monoclonal antibodies for cancer treatment, trastuzumab (or “Herceptin”), has shown significant activity in HER2+ (or inappropriately overexpressing) breast cancer.

An international research group lead by Eric Van Cutsem of Belgium tested over 3800 patients with advanced or metastatic gastric and GE junction cancer for expression of the HER2 oncogene, and similar to breast cancer, about 20% were positive, with up to 35% of GE junction cancers expressing HER2.  580 of these patients entered a randomized trial of chemotherapy with 5-FU and cisplatin with or without trastuzumab, and the latter arm showed impressive activity with improved overall survival.  Therefore, this is the first trial showing a substantial benefit using a “targeted” therapy for a subgroup of gastric cancer.

However, the majority of patients on this trial were from Asia and South America, and so it is unclear how relevant these findings are for our typical patients in the US.  In fact, another study reported at the 8th International Gastric Cancer Congress held in Krakow, Poland in June, found that in over 1000 gastric cancer patients from the UK and Germany, only 6% overexpressed HER2, and that 90% of these were of the intestinal variant (not the type we typically see in the US).

Therefore, it remains unclear how relevant this new advance in gastric cancer therapeutics is to our typical US population.  As one of the very first projects using the Gastric Cancer Fund registry, we plan on looking at the incidence of HER2 overexpression in tumor samples from all of our Stanford patients.  Should this be in the 10 – 20% range, then we plan to design a “personalized” gastric cancer treatment trial using HER2 testing to select patients for antibody therapies.