Gastroenterology’s Evolving Role in the Management of GI Malignancies

Toufic Kachammy, MD

Modern treatment of gastrointestinal (GI) malignancies requires more of a multidisciplinary approach than in previous years, according to Toufic Kachaamy, MD. More often in GI cancer care, gastroenterologists and interventional gastroenterologists are involved with the initial diagnoses and staging.

“Traditionally, cancer care used to be mostly the oncologist, whether surgical oncologist, medical oncologist, radiation oncologist, but there's a lot of other disciplines that not only have to add to the cancer care like gastroenterology, but also make cancer care better,” Kachaamy, Enterprise program leader, Interventional Programs and Medical Director of Gastroenterology at Cancer Treatment Centers of America Phoenix., told Targeted Oncology^TM.

Further, it was noted that many of the adverse events associated with newer cancer therapies are GI-related, and gastroenterologists are working with oncologists to mitigate those toxicities in addition to handling diagnosis and staging.

In an interview with Targeted Oncology™, Kachaamy, discussed in detail the role of the gastroenterology community in staging, diagnosing, and managing GI malignancies.

TARGETED ONCOLOGY: Can you discuss the key recommendation for staging and diagnosis of GI malignancies?

Kachaamy: GI malignancies range from esophageal cancer, gastric cancer, small bowel cancer, and colon cancer. In the United States, we have clear guidelines for screening for colon cancers. The rest of the cancers don't have screening guidelines mostly for cost effective reasons. For the other cancers, the biggest role we play is diagnosis and then symptom management and staging. Staging is the first question we try to answer, and staging is, [for example, if] the patient's stage IV or not. And often this is done with imaging and biopsies. If you determine that the patient has stage IV disease, which has spread far away from the original tumor, then the treatment often will be systemic therapy.

When the patient is not stage IV, it means the tumor is localized and these can potentially be cured endoscopically when identified very early. When they are locally advanced, meaning there is invasion through the wall of the GI tract or into the muscle or even spread locally around the cancer, they cannot be cured endoscopically and they require surgery or chemo and radiation then surgery.

Now, in certain conditions, stage IV disease could be treated also with surgical interventions. This is a general algorithm for non- stage IV: We do local staging, and then based on the local staging, the next step in treatment is determined.

Aside from biopsy, what other procedures may be necessary for physicians to perform for staining and diagnosis?

The most common procedure for local staging is endoscopic ultrasound. Endoscopic ultrasound allows a very high-resolution close-up image of the tumor, which helps in determining the T staging–[if the] tumor is superficial or does invade into the muscle or invade beyond the muscle or invade other structures. This local staging is part of the algorithm when the patient is not stage IV. Sometimes staging is done with imaging, like MRI is for rectal cancer, and sometimes it's done with endoscopic ultrasound, most commonly, for example, in esophageal cancer.

How do you decide on the appropriate treatment for each patient?

There are many reasons to determine the stage. It is important for making treatment decisions. Another reason is prognosis. One more reason is for us to learn over time, how staging impacts treatment, and what we should change. Therefore, determining exactly how the tumor is behaving is important for today in the treatment and for the future and how we change the treatments. So, for example, in pancreatic cancer when there’s pancreatic adenocarcinoma that has spread to the lymph nodes, it is staged as local, but the prognosis long term is worse than pancreatic cancer that has not spread to the lymph node. So, after surgery, the risk of recurrence is higher and long-term survival is lower . This is why staging and prognostics are important, so that we can give the patient a more accurate assessment of how they're going to do long term.

The other area in staging that's important in surgical planning is if there's a visual invasion or direct extension to other organs. For example, in patients who are not staged as IV but have invasion of the aorta. Then surgical resection carries a significant risk for the patient, including risk of one not being able to [resect] the whole tumor and injury to the aorta can be fatal. So, this is partly how staging affects their surgical preparation. In other areas, staging can determine, for example in rectal cancer, whether the patient gets radiation or does not get radiation and the same in esophageal cancer. So, to summarize, staging determines the prognosis which can determine surgical approach or whether to give chemotherapy or radiation.

Can you discuss the expanding role of interventional gastroenterologists in GI cancer care?

I think the role of interventional gastroenterologist, in general, is expanding in GI malignancy and malignancies in general. Technology is improving very fast, sometimes faster than people can keep up with it. So, a lot of things that we need to do surgically 20, 10, or even 5 years ago, [but now] we have endoscopic solutions. For example, if you look at obstruction of the stomach, or gastric outlet obstruction, we traditionally treated this with surgical interventions, then it migrated to being treated with stents and now it's being treated with endoscopic ultrasound, with gastrojejunostomy, placing a stent from the stomach into the jejunum, which combines the benefits of a stent [with] rapid recovery with the long term benefits of surgery.

So, as technology is improving, there's a lot of things that we can do now endoscopically, which is expanding the role of the intervention of gastroenterologist in cancer care. One of the benefits of endoscopic approaches is fast healing. For example, there are certain chemotherapeutic agents or targeted agents like bevacizumab [Avastin], that you need to wait a long time before you give them after surgery to allow the body to heal versus with endoscopy, you don't need to wait that long, the healing is faster. For example, for gastric obstruction, you can give chemotherapy a day or 2 after the procedure, while the surgery might have to wait longer. The internal lining of the body, the mucosal surfaces, heal much faster than the skin. So, when you tackle certain problems endoscopically, healing is faster. And that combined with the improvement in technology, where we can do more endoscopically is leading naturally to an increased role of the interventional gastroenterologist in cancer care. And slowly, we're doing more with endoscopy than we used to do with surgery.

When you look at the symptoms that cancer patients in general have, and specifically patients with GI cancer, out of the 8 most common symptoms 5 are GI related. So, that is also contributing to the increase in the role of gastroenterology–a lot of the symptoms like nausea, bowel obstruction, weight loss, anorexia, need a gastroenterologist to help with their care. So, when you look at the continuum, starting with screening, expanding to staging, palliation and treatment.

In your opinion, what is the importance of multidisciplinary care for GI cancers. What advice can you give community oncologists on working more closely with gastroenterologists?

Traditionally, cancer care used to be mostly the oncologist, whether surgical oncologist, medical oncologist, radiation oncologist, but there's a lot of other disciplines that not only have to add to the cancer care like gastroenterology, but also make cancer care better. There's clearly research showing that endoscopic ultrasound, for example, will impact the outcome of GI cancers. And if you don't have that part of the multidisciplinary team, then you will be missing out on a lot of things. If an oncologist has a patient with a pancreatic mass and they get interventional radiology to biopsy it, the risk is higher. The potential for complication is higher and the yield is lower because of the way the pancreatic mass presents and where it's located. Access to it with endoscopic ultrasound is safer, and has a higher yield. So, when you're missing out on certain specialties, you start missing out on having the best choice for the patients. In addition, because the technology is fast improving, it is impossible for 1 person to know the data on all the potential options. This is where the strength of multidisciplinary care shows the most. An example would be if you have a patient with a colonic obstruction, is the best choice for them surgery? Is it stenting? Or is it chemotherapy? If we place a stent, that affects the oncologist for systemic therapy afterwards. How do you solve these problems without having everyone sitting at the table together? It would be mind-boggling to me because the oncologist neither needs to know, nor do they have the time or the literature in gastroenterology or surgery.

Now, how do you access this multidisciplinary care? If someone is a community oncologist and a single specialty group, the best way in my opinion is to team up with comprehensive cancer centers that have the vision to collaborate with the community.

What are your predictions for the future of GI cancer care based on what's going on now and the latest advances in the space?

It's a very interesting time now in cancer care in general and especially in GI cancer with the introduction of immunotherapy and targeted therapies, we are seeing a significant impact on people who, in the past used to be terminal, and now they have the potential to be disease free. In addition to these therapies, improvement in procedural technology, and improvement in patient access to information about treatment options and clinical trials, things that were difficult to think about 10 years ago are available now. So, when you combine all of these 3 factors together, I think cancer care will continue to improve, patients will continue to be living longer, and I think we will see a bigger focus on living with cancer and quality of life issues.