Adjuvant Chemotherapy or Adjuvant Chemoradiotherapy for Gastric Cancer?—A West Cancer Center Perspective

PracticeUpdate: What question were the authors trying to address in this study?

Dr. Somer: So the question that’s being answered with this study is in gastric cancer we know that giving adjuvant chemoradiation enhanced survival. We know that from 2001 when the intergroup study was published on the Macdonald regimen, 5-FU in combination with radiation became the standard in adjuvant therapy. However, things have changed when the MAGIC trial came out and perioperative chemotherapy became the standard, where we would give neoadjuvant therapy, chemotherapy, and postoperative adjuvant therapy, and that became a new standard where there was enhanced survival with perioperative chemotherapy. The question that this study seeks to address is if you gave everybody neoadjuvant chemotherapy, is there an added benefit for chemoradiation after surgery?

PracticeUpdate: Did the patients who received adjuvant chemoradiation do better than those who received chemotherapy alone?

Dr. Somer: So in this study, there was actually no added benefit to chemoradiation over chemotherapy alone, so essentially establishing that perioperative chemotherapy remains an acceptable standard, but it was about equivalent.

PracticeUpdate: How do these results fit into current practice for gastric cancer?

Dr. Somer: So things have changed in gastric cancer in a sense that we’re adding additional chemotherapy regimens into the perioperative chemotherapy. So now recently, there was data showing that FLOT chemotherapy would have an enhanced survival over prior perioperative chemotherapy regimens with epirubicin, cisplatin, and 5-FU utilized prior in the MAGIC, but in FLOT using 5-FU, oxaliplatin, and Taxotere chemotherapy perioperatively would have enhanced survival benefit. So currently, we’ve shifted, or at least I’ve shifted my practice, to utilizing an alternative chemotherapy regimen and I don’t see any added value in terms of generally speaking applying chemoradiation adjuvantly.

PracticeUpdate: Many patients in the trial were unable to complete their adjuvant therapy. How should this be addressed in the design of future trials?

Dr. Somer: So that was actually one of the interesting things that was found in this study was the fact that patients were randomized on the front end prior to initiating neoadjuvant chemotherapy. So we know that after the surgery, the amount of patients that actually started adjuvant chemotherapy was only about 60% of patients. So of those that were planned to get adjuvant therapy, not that many got actually completed adjuvant chemotherapy and the real question is if you could get the amount of patients that got perioperative chemotherapy or increased the amount of doses or the dose intensity or the amount that is given, the question is would those patients do better?

So clearly, they’re having a hard time tolerating it adjuvantly because they’re recovering from surgery, and there’s surgical complications, or they’re just tired out from prior chemotherapy. So the real question is if you were to give a total neoadjuvant approach where you could give more doses of neoadjuvant chemotherapy rather than adjuvant chemotherapy and give all of the chemotherapy up front, you could actually get all of the chemotherapy regimen in and get 100% of patients getting all perioperative chemotherapy and then going for surgery afterwards, would you enhance the benefit to the patient? And that’s the next wave of trials that, I think, are important, in addition to trials that are looking at variants of molecular profiling and customizing treatment for patients that might have a HER2 mutation or MSI or whatever the molecular change might be for the patient.