Treating Gastrointestinal Neuroendocrine Carcinoma: Beyond Lung-Based Approaches

Announcer:
This is Project Oncology on ReachMD. On this episode, we’ll hear from Dr. Namrata Vijayvergia, who’s an Associate Professor of Hematology and Oncology and the Section Chief of Gastrointestinal Medical Oncology at Fox Chase Cancer Center in Philadelphia, Pennsylvania. She’ll be discussing the use of lung cancer treatment models for gastrointestinal neuroendocrine carcinomas. Here’s Dr. Namrata Vijayvergia now.

Dr. Vijayvergia:
The high-grade gastrointestinal neuroendocrine carcinomas are a relatively rare cancer. Overall, neuroendocrine neoplasms are very rare, and this is a smaller fraction of only about 10 to 15 percent of all neuroendocrine neoplasms typically, because when they were initially diagnosed, their morphology was very similar to what we see in the lung neuroendocrine carcinomas, especially the small cell neuroendocrine carcinoma of the lung, or small cell lung cancer. We started treating it that way because that is what we see most often. It’s very common. It’s a smoking-related cancer. And because these cancers look similar in morphology to the neuroendocrine cancers of the lung, we started treating them that way just because our research was not advanced, and we didn’t know that these are different tumors at the time. And now, as we are learning more about it, we are identifying that these are probably different kinds of cancers. Their molecular makeups are different, and as a result, we may need to be a little more selective in our approaches. 

So a question does come up as to what the challenges are when we try to extrapolate the information from the lung neuroendocrines to extra pulmonary neuroendocrines, and I think the biggest challenge is the fact that many times these neuroendocrine cancers—we believe—arise from a bed of the normal cells that are of that location. So something that’s in the lung and something that starts from the colon or the pancreas may not respond similarly, and as a result, we need data and studies in each of those areas rather than just extrapolating. But because these cancers are so rare, we end up extrapolating anyways because we don’t have better studies to guide us, up until recently. I think that is something we have changed over time. 

As we are learning more about the molecular makeup of GI neuroendocrine carcinomas and how it is different than lung neuroendocrine carcinomas, we see a lot more KRAS in the Rb mutations and less of the TP53 mutations compared to what we see in the lung. We’ve identified that because these tumors arise—even though they look similar, they have different molecular makeup. We have a lot more targeted agents that are coming out, which are more dependent on what specific molecular profile is for a tumor. I think there’s more and more push that we need to develop drugs that are specific for our cancer type. Whether it’s immunotherapy that has already been approved for the small cell lung cancer in addition to chemo, it’s not something that we use yet for extrapulmonary neuroendocrine carcinomas because there is no data, and we want to stay away from that knee-jerk reaction that, oh, it’s working in one cancer, just extrapolate, rather than studying the more rarer cancer.

Announcer:
That was Dr. Namrata Vijayvergia talking about treating gastrointestinal neuroendocrine carcinomas with lung cancer-derived protocols. To access this and other episodes in our series, visit Project Oncology on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!