2016 Gastrointestinal Cancers Symposium Highlights, with Smitha S. Krishnamurthi, MD

January 19, 2016
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In this podcast, Dr. Smitha Krishnamurthi discusses three studies highlighted at the 2016 Gastrointestinal Cancers Symposium, which examined two new treatment options for people with advanced neuroendocrine tumors and a new pre-surgical treatment option for people with locally advanced rectal cancer. 



ASCO: You're listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the world's leading professional organization for doctors that care for people with cancer.

In today's podcast, we'll discuss three studies highlighted at the 2016 Gastrointestinal Cancers Symposium which examined two new treatment options for people with advanced neuroendocrine tumors and a new pre-surgical treatment option for people with locally advanced rectal cancer. The 2016 Gastrointestinal Cancers Symposium, held January 21st through the 23rd, is co-sponsored by ASCO and offers presentations on the latest multidisciplinary research for gastrointestinal cancers. This podcast will be led by Dr. Smitha Krishnamurthi, who is a medical oncologist at the University Hospital's Case Medical Center and Associate Professor of Medicine at the Case Western Reserve University. Dr. Krishnamurthi is also a member of ASCO's Cancer Communications Committee. ASCO would like to thank Dr. Krishnamurthi for summarizing this research.

Dr. Krishnamurthi: Hello, I'm Smitha Krishnamurthi, a medical oncologist at the Siedman Cancer Center in Cleveland, Ohio. I'm going to discuss three studies highlighted at the Gastrointestinal Cancers Symposium in terms of their importance for patients. The first study I'll be talking about is for patients with locally advanced rectal cancer. In this study, that meant that the standard treatment for these patients would be radiation combined with chemotherapy to shrink the tumor before it's surgically removed. This study compared the effect of a short, five-day course of radiation followed by FOLFOX chemotherapy and then surgery versus standard long-course radiation, which is five and a half weeks, which is given with chemotherapy and then surgery. It should be noted that the chemotherapy combined with the standard radiation in this study was 5-FU leucovorin and oxaliplatin. We know from other studies that oxaliplatin added to 5-FU leucovorin adds more side effects without improving outcomes. So it's not considered a standard to have oxaliplatin added with the radiation anymore. So just keep that in mind.

The study found that patients who have the short-course radiation followed by chemotherapy had less early side effects than the patients who had the long-course chemoradiation. But keeping in mind that this long-course radiation included oxaliplatin chemotherapy, which is known to increase side effects, we can't know from this study if short-course radiation is really less toxic than long-course. However, more importantly, the study found that after three years, patients who received the short-course radiation had the same rate of being alive without cancer as patients who received the long-course radiation. The study also suggested that there was an improvement in overall survival for the patients who received the short-course radiation, and this finding was a borderline statistical significance. So, conclusions from the study are that a more convenient five-day radiation treatment compares to the five and a half week's radiation treatment before surgery for locally advanced rectal cancer was just as active as the standard radiation in preventing rectal cancer recurrence. We still need to hear about the long term side effects from this study. Two previous comparisons of short course versus long course radiation for rectal cancer found no significant difference in the later toxicities. The short course radiation has been more popular in Europe than in the United States but these results combined with results from other studies may lead to increased usage of this method of radiation here.

The next two studies I'll be discussing are for patients with slow-growing neuroendocrine cancers of the gastrointestinal tract also known as carcinoid tumors. So, the first of these studies enroll patients with these neuroendocrine cancers of the gastrointestinal tract and also those with neuroendocrine cancers of unknown origin. Most of those cancers of unknown origin would likely have started in the gastrointestinal tract. Now patients with these slow-growing neuroendocrine cancers of the gastrointestinal tract are frequently treated with injections of somatostatin analog which can help to slow down the growth of the cancer. This study enrolled patients with these cancers after their disease had progressed on somatostatin analog injections or surgery or chemotherapy. And the patients were randomly assigned to treatment with everolimus versus placebo. Everolimus is a pill that can inhibit pathways involved in cell growth and cancer. It is already been found to be active for pancreatic neuroendocrine cancer. This study, which compared everolimus versus placebo, found that the everolimus reduced the risk of the cancer progressing by 40% compared to placebo. The median progression for survival was 13.1 months with everolimus, compared to 5.4 months with placebo. As expected, patients treated with everolimus had more side effects, such as inflammation of the mouth, infections, diarrhea, swelling, and fatigue, but the treatment was tolerable for most patients. So, conclusions from this study are that there have been few treatment options for patients with neuroendocrine cancers of the gastrointestinal tract or carcinoid tumors, and now we know that everolimus can slow down the growth of these tumors. So this may become a treatment option in future.

The last study I'll be discussing was also conducted in patients with neuroendocrine cancers of the gastrointestinal tract or carcinoid tumors, and as we discussed, these patients have limited treatment options. This study presented results of a new type of treatment for this disease. Patients enrolled onto the study had advanced neuroendocrine cancers that had started in the lower part of the small intestine or the early colon, which is known as the mid gut. And they were enrolled after their disease was no longer responding to somatostatin analog injections. The experimental treatment in this study was Lutetium-DOTATATE which is a somatistatin analog attached to a radioactive molecule so the Lutetium-DOTATATE can deliver radiation therapy to the neuroendocrine cancers, which have somatistatin receptors on their cell surfaces. So patients are randomly assigned to four injections of the Lutetium-DOTATATE versus high-dose monthly somatistatin analog injections. Treatment with the Lutetium-DOTATATE showed an impressive improvement in progression-free survival, which means living without the cancer growing. The median progression-free survival was eight months in the patients treated with high-dose somatistatin analog injections compared to an estimated 40 - 4-0 - months in the patients treated with Lutetium-DOTATATE. The rate of significant tumor shrinkage was 18% with the Lutetium-DOTATATE and with only 3% with the high-dose somatistatin analog injections. The main side effects of the Lutetium-DOTATATE were nausea and vomiting, so conclusion from this study is that this new modality of a radioactive label somatistatin analog known as Lutetium-DOTATATE showed impressive ability to slow down the growth of neuroendocrine tumors of the gastrointestinal tract.

ASCO: Thank you, Dr. Krishnamurthi. More information on gastrointestinal cancers can be found at www.cancer.net. And for more expert interviews and stories from people living with cancer, visit the Cancer.Net Blog at www.cancer.net/blog.

Cancer.Net is supported by the Conquer Cancer Foundation, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high-quality cancer care. Thank you for listening to this Cancer.Net podcast.