Pentosan polysulfate is a medication that is similar to low-molecular-weight heparin, which has been used in the treatment of interstitial cystitis. In this condition, it reduces bladder pain, apparently by reducing irritation of the bladder wall. Pentosan polysulfate has been evaluated in patients with cancer for treatment of radiation-induced diarrhea.
Research Evidence Summaries
Pilepich, M.V., Paulus, R., St. Clair, W., Barasacchio, R.A., Rostock, R., & Miller, R.C. (2006). Phase III study of pentosanpolysulfate (PPS) in treatment of gastrointestinal tract sequelae of radiotherapy. American Journal of Clinical Oncology, 29(2), 132–137.doi: 10.1097/01.coc.0000203758.77490.fd
Intervention Characteristics/Basic Study Process:
Patients were randomized to one of three groups. In group one, patients received 100 mg of pentosanpolysulfate (PPS) three times per day. PPS is a glycosaminoglycan marketed as Elmiron® and SP54. It has been used to treat radiation-induced sequelae of the bladder. In group two, patients received 200 mg PPS three times per day. In group three, patients received placebo three times per day. If no improvement occurred in two months, treatment was discontinued. If symptoms improved or resolved, treatment was continued for an additional four months.
- The study initially involved 180 patients from 34 institutions. The final study reported on 168 evaluable patients.
- Group one consisted of 48 patients, group two consisted of 50 patients, and group three consisted of 53 patients.
- Subjects had received radiation therapy to the abdomen or pelvis and experienced grade 1–3 treatment-related proctitis, diarrhea, and melena at least four weeks after completion of therapy. No concurrent chemotherapy was included.
- National Cancer Institute (NCI) Common Terminology for Adverse Events (CTCAE) was used to measure proctitis, diarrhea, and melena.
- A complete response was defined as the absence of symptoms and cessation of symptom medications.
- A partial response was defined as a reduction in severity grade.
Quality of life endpoints were evaluated via the following tools.
- Functional Alterations Due to Changes in Elimination (FACE) questionnaire
- Functional Assessment of Cancer Therapy (FACT) questionnaire
- Medical Outcomes Survey (SF-12®)
- Spitzer Quality of Life Index (SQLI)
No significant differences were found among the three arms of the study.
- A previous pilot study had more promising results not found in this study. Further dosing trials or possible rectal administration are recommended.
- A proportion of patients (20%–25%) reported deterioration in the first three months of the study.