Tuesday, October 6, 2015
Intraperitoneal (IP) chemotherapy delivers drugs directly into the abdominal cavity, bathing cancer cells in them. Though the treatment, which was pioneered for ovarian cancer at Memorial Sloan Kettering in the 1980s, is highly effective, it remains underused at other cancer hospitals. MSK gynecologic surgeon Dennis Chi discusses how it works, which patients benefit most, and why some doctors may still be reluctant to use it.
- Intraperitoneal (IP) chemotherapy delivers drugs into the abdomen.
- It was pioneered at MSK in the 1980s for ovarian cancer.
- It has proven to be effective in multiple studies.
- The treatment is still surprisingly underused by many doctors.
Intraperitoneal (IP) chemotherapy, which delivers drugs directly into the abdominal cavity, has long been known to significantly extend the lives of women with advanced ovarian cancer. But despite the treatment’s success, a widely reported recent study showed that nearly half of American hospitals don’t offer IP chemotherapy to eligible patients.
This underuse persists despite decades-old research showing the treatment could add 16 months or more to women’s lives compared with intravenous (IV) chemotherapy alone when used after optimal debulking surgery, which usually involves removing not only the ovaries but also the uterus, cervix, fallopian tubes, and most or all visible tumor cells.
MSK pioneered IP chemotherapy in the 1980s and has long considered the treatment to be the standard of care for ovarian cancer. Dennis Chi, Deputy Chief and Head of the Section of Ovarian Cancer Surgery, discussed with us how IP chemotherapy works, who is most likely to benefit from it, and how MSK has led the development of the treatment.
How is IP chemotherapy given at MSK?
We perform IP chemotherapy on an outpatient basis after optimal debulking surgery. A catheter is surgically inserted into the patient’s abdomen and connected to an access port that is implanted under the skin. This allows chemotherapy to be dripped into the peritoneal cavity — the area between the muscles and the organs in the belly. We ask the patient to move around periodically during the infusion to make sure the chemotherapy fluid distributes throughout the peritoneal space. The process takes a few hours, and then the patient can go home. The infusion is repeated five times over a period of months.
Why does this form of chemotherapy appear to work better than standard IV therapy in many patients?
It’s not completely known why it works as well as it does. Since the chemotherapy fluid remains in the abdomen and dissipates over time, the obvious first theory is that we’re bathing cancer cells in it. Another theory is that it’s a double hit, since the chemotherapy then gets absorbed into the bloodstream and goes to the cancer a second time.Back to top
Which patients are most likely to benefit from IP chemotherapy?
There are no hard-and-fast rules, but the patients who benefit the most tend to have stage III ovarian cancer, in which the disease has spread beyond the ovaries but is confined to the abdomen. About 65 percent of our patients have been diagnosed with stage III cancer and have received optimal debulking surgery. About two-thirds of these stage III patients undergo both IV and IP chemotherapy following this surgery. We may also consider IP chemotherapy for patients with stage IV ovarian cancer if extensive surgery has first removed all visible tumor traces, even if the disease has spread to the liver or spleen.Back to top
What are possible side effects of this treatment?
Since the chemotherapy fluid stays in the abdomen while it’s absorbed, patients can temporarily feel bloated and uncomfortable after the procedure. A 2006 study also showed that the treatment can trigger more digestive problems, fatigue, low blood counts, and tingling and pain in the limbs than IV chemotherapy. Our later research at MSK showed that modifying the dosage of the therapy decreased all these side effects. Once patients are off the treatment for six months or longer, their side effects greatly decrease as well.Back to top
Why do you think IP chemotherapy hasn’t been more widely used across the United States, despite its clear benefits?
Like many other aspects of medicine, it first comes down to whether you believe the research. There are skeptics who think there may have been flaws in the studies and others who believe in it but feel IP chemotherapy is too cumbersome for them to administer or for patients to receive. It’s certainly one of the more technically challenging chemotherapies to give, and you do need experience giving it.
Also, some institutions aren’t as proactive as we are with optimal debulking surgery and choose to do surgery after first giving IV chemotherapy. This approach leaves fewer advanced ovarian cancer patients eligible to receive IP chemotherapy. Upcoming results from ongoing national trials should shed even more light on which approach may benefit patients more.Back to top
What factors make MSK a leader in the use of IP chemotherapy?
What makes us a leader is our vast experience of giving it and learning to anticipate and deal with the potential complications. To my knowledge, MSK performs more ovarian cancer debulking surgical procedures than any other single institution in the United States. We also have one of the largest volumes of patients in the world that have undergone IP chemotherapy.
Many patients have come to us for IP chemotherapy who have had problems getting it elsewhere, such as ports malfunctioning or fluid being infused into the wrong part of the abdomen. We have such a long track record here that there’s very little in terms of things going wrong that somebody on our staff hasn’t seen before. They know that mild glitches happen and not to give up.Back to top