Last week’s 2015 Gastrointestinal Cancers Symposium in San Francisco provided an excellent snapshot of the current standard of care for GI cancers, as well as insight into future treatment strategies. This broad category of cancers includes esophageal, stomach, pancreatic, liver, appendix, colon, anal, GIST, and gall bladder malignancies. Several themes emerge from the conference’s esophageal and stomach cancer abstracts, including the benefits of any type of surgical resection, the testing of novel treatments in clinical settings, and the continuing reliance on, and disagreement over, optimal treatment regimens.
Several large studies offered updates at this conference. In the ARTIST stomach cancer trial in South Korea, a subset of patients with node-positive disease benefitted from the addition of radiotherapy to adjuvant chemotherapy. The ARTIST-2 phase III trial is underway to follow up on this notion. Data from previous large trials continues to be interpreted, including an observation from the JCOG9907 and JCOG9906 trials indicating that chemo with adjuvant surgery was likely preferable in GI cancers compared to chemoradiotherapy. A large, multi-national study of advanced esophageal cancer patients found that chemoradiotherapy led to more long-term survivors compared to radiation treatment alone.
Researchers from Massachusetts General Hospital in Boston presented data showing > 50% response to a monotherapy of Amgen’s oral MET inhibitor AMG 337 in a small subset of patients with MET-amplified GI tumors. However, another Phase II study of the chemo regimen FOLFOX with the MET inhibitor onartuzumab, a monoclonal antibody, did not show any benefits in esophageal cancer. Patients who undergo surgery to remove esophageal tumors after chemoradiotherapy had clear survival benefits. Stomach cancer patients saw “promising efficacy” in a small study using nanoparticle albumin-bound paclitaxel, as well as phase II results using dose-dense chemo plus panitumumab.
Several intriguing non-invasive treatments and diagnostics discussed include a “breathalyzer” for diagnosing esophageal cancer, a study of the benefits of pre-operative exercise in newly-diagnosed stage I stomach cancer patients, and the prognostic value of H. pylori infection in GI cancers. In addition to the “breathalyzer,” several effective, non-invasive GI screening strategies were outlined, including a biomarker based on methylated Reprimo (RPRM) cell-free DNA, and a simple blood test using Surface-Enhanced Raman Scattering (SERS).
Many new studies are underway, including the Asian-based RILOMET-2 trial of MET inhibitor rilotumumab. The UK’s National Health Service is conducting a single-center study of the usefulness of molecular profiling in GI tumors, as part of their FOrMAT study. Japanese researchers also presented data about the efficacy of Phase I investigational treatments in general, finding in their own small trial that outcomes for patients using investigational treatments was not significantly different from patients not using clinical trials, although it does not appear they compared data for long-term survivors.