The majority of men who undergo radiation treatment for prostate cancer will develop proctitis, which is a painful condition resulting in the inflammation of the anus and rectum’s lining. Proctitis can produce alarming symptoms and discomfort that can develop immediately following the start of radiation therapy or after therapy has been completed.
Acute proctitis occurs within the first 3 months after irradiation, while chronic proctitis can persist for longer periods and symptoms may not transpire until months (8 to 12 months on average) after cessation of therapy. Treatment and supportive measures can control symptoms in more than 80% of acute proctitis cases, however, treatment of chronic proctitis is extremely challenging.
Causes & Risk Factors
Proctitis associated with prostate cancer is caused by radiation therapy to the pelvic region. During therapy, a high dose of radiation is targeted to the pelvic region and concentrated close to the rectum, which damages healthy tissue while also treating the cancer. Studies around external beam radiation have noted the incidence of proctitis to range from 2% - 39%.
Clinical manifestation of the injury to the rectum due to radiation may include diarrhea and tenesmus, a constant urge to urinate or have a bowel movement despite an empty colon. In addition to diarrhea and rectal pain, patients can also experience lasting complications such as bleeding. Severe bleeding signifies chronic changes of the rectal lining; the blood vessels are fragile and, with the onset of minor trauma, can bleed easily.
Acute radiation proctitis is very common. In a small number of patients (about 20%), the severity of symptoms requires interruption of therapy. Symptoms include:
- Frequent urgency to have a bowel movement (tenesmus);
- Minor rectal bleeding;
- Mucous discharge from the rectum;
The majority of these symptoms will subside within weeks after cessation of radiation therapy.
Approximately 2% - 20% of patients who receive pelvic radiotherapy develop chronic radiation proctitis. Chronic proctitis can have a significantly larger impact on a patient’s quality of life due to amplified symptoms and discomfort. In addition to the symptoms listed above, symptoms can include:
- Severe bleeding;
- Bowel obstruction;
The treatment of radiation-induced proctitis depends on the severity of symptoms. In most cases, proctitis can be successfully treated using anti-inflammatory pills or suppositories to reduce inflammation and minimize bleeding. A stool softener is also commonly recommended if the patient is having difficulty with hard stool or constipation, as both increase the risk of painful defecation and further irritation to the anus and rectum.
- Radiation Induced Injury to the Colon and Rectum. (September 12, 2014). International Foundation for Functional Gastrointestinal Disorders. Retrieved September 12, 2014, from http://www.iffgd.org/site/gi-disorders/other/radiation-injury
- Proctitis. (October 2011). National Digestive Diseases Information Clearinghouse (NDDIC). Retrieved October 9, 2014 from http://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/proctitis/Pages/facts.aspx
- WebMD (August 2012). Proctitis Basics. Retrieved November 17, 2014, from http://www.webmd.com/digestive-disorders/proctitis
- Side effects of prostate cancer radiotherapy. (February 2014). Cancer Research UK. Retrieved October 5, 2014, from http://www.cancerresearchuk.org/about-cancer/type/prostate-cancer/treatment/radiotherapy/side-effects-of-prostate-cancer-radiotherapy
- Nhue L. Do, et al. Radiation Proctitis: Current Strategies in Management. (January 2011). Gastroenterology Research and Practice. Volume 2011 (2011), Article ID 917941. Retrieved September 12, 2014, from http://www.hindawi.com/journals/grp/2011/917941/