Thursday, May 19, 2016
Colorectal cancer is the second leading cause of cancer death in the United States. However, there are more than one million survivors of colon and rectal cancer nationwide, as improvements in screening, radiation, chemotherapy, and surgical techniques have contributed to a significant drop in the mortality rate.1 These improvements have also made it possible for many more patients to undergo sphincter-preserving surgery (SPS) and avoid a permanent stoma, or “bag.” More than half of rectal cancer patients in the United States have had SPS, and at National Comprehensive Cancer Network specialty centers, 77 percent of patients are able to have SPS.2
However, these treatments are accompanied by considerable morbidity. Bowel dysfunction is the biggest problem negatively affecting the quality of life (QoL) in rectal cancer patients following treatment. As many as 60 percent of patients undergoing SPS still have bowel dysfunction one to two years after surgery, with function never returning to baseline.3 Medical management may include diet, biofeedback, fiber supplements, or opioid agonists. Nevertheless, many patients still struggle with deleterious symptoms.
Approaches for Treating Bowel Dysfunction
Efforts to treat bowel dysfunction with new approaches have become an important focus of research within our Colorectal Service. Recent studies of patients with benign conditions that cause incontinence show great improvement with the use of the InterStim™ neuromodulation device (Medtronic), which stimulates the sacral nerves in the rectal and anal sphincters. Some studies indicate that the device improves anal squeeze pressure and sensitivity, and may exert a regulating effect on bowel motility. InterStim was approved by the FDA for the treatment of fecal incontinence in 2011, and has been used by more than 2,600 patients to date. Studies have shown that more than 70 percent of patients report improvements that last up to five years, but symptoms return when the device is turned off.
In light of these reports and anecdotal evidence, we think it is possible that sacral neuromodulation may also work for rectal cancer patients, with different and more complex bowel dysfunction, but there is limited data on its use in this population. Unlike patients with benign disease, rectal cancer patients may experience low anterior resection syndrome, a set of symptoms that includes incomplete evacuation, clustering, urgency, lack of sensory control, and sometimes incontinence.Back to top
Clinical Trial: A Neuromodulation Device for Rectal Cancer Surgery Patients
To address these issues, we launched an important clinical trial at Memorial Sloan Kettering Cancer Center to see if sacral neuromodulation using the InterStim device improves bowel function in rectal cancer patients who have received SPS treatment: “Randomized crossover study of the efficacy of sacral neuromodulation (SNM) with InterStim™ for bowel dysfunction following surgery for rectal cancers with sphincter preservation.”
In the study, InterStim is implemented in two phases. In the first phase, a stimulating electrode is placed near the S3 nerve root for 7 to 14 days to make sure it works. During this time, patients must avoid all rigorous activity. If it does not work, the wire is removed, but if it does, the patient moves on to the second phase and a pacemaker-like device is implanted in the buttock. Following implantation of either the wire or the pacemaker-like device, the patient is precluded from having an MRI. These procedures are usually covered by health insurance.
In order to assess patient satisfaction and QoL following device implantation, we have combined three measures in a survey packet that takes patients less than 20 minutes to complete. The Memorial Sloan Kettering Bowel Function Instrument (BFI), developed in 2004, is the only measure in the country validated for use in this population and consists of 19 questions. The Low Anterior Resection Score is a validated five-question instrument developed in Europe specifically for rectal cancer patients. Finally, the Fecal Incontinence Quality of Life (FIQOL) measure is a 29-item survey that asks patients to rate QoL across lifestyle, coping/behavior, depression/self-perception, and embarrassment categories. The FIQOL has been widely used in other InterStim trials for patients with benign fecal incontinence.
This exciting new study began accruing patients last year; so far, we have enrolled ten. To be eligible to enroll, patients must be English-speaking and 18 years or older, have had SPS for rectal cancer, and be experiencing problems with bowel function such as urgency, leakage, incomplete emptying, or frequent bowel movements. The BFI will measure several additional requirements for eligible patients. Patients treated for rectal cancer at other institutions may also be accepted, following review of their medical records by the principal investigator. In the future, the trial may be broadened to include other participating cancer centers.
Patients interested in this trial can contact, or ask their physician to contact, Dr. Larissa Temple at 212-639-6081.Back to top