NEW YORK (Reuters Health) – Pediatric inflammatory bowel disease (IBD) patients are not at increased mortality risk compared with their IBD-free peers, but they do face a three-fold increased risk of cancer, according to a new study of the world’s largest cohort of these patients.
Importantly, the cancers that did occur are easily detectable, and can be identified and treated effectively with appropriate surveillance, the study’s lead author, Dr. Corrine Gower-Rousseau of Lille Hospital and University Nord de France, told Reuters Health.
“Preventive measures such as endoscopic surveillance of the colon, protection against ultraviolet radiation and lifelong dermatologic and gynecologic screening are mandatory,” she said in an email.
Pediatric IBD is on the rise, and these patients frequently are prescribed immunosuppressants and biologics, Dr. Gower-Rousseau and her team note in The American Journal of Gastroenterology online August 13. “In this context, data on mortality and cancer risk are important because they would allow patients and their families to be aware of prognosis and make informed decisions about treatment,” they write.
To investigate, Dr. Gower-Rousseau and her colleagues looked at 698 patients, including 538 with Crohn’s disease and 160 with ulcerative colitis. The patients were diagnosed at a median age of 14, and median follow-up time was 11.5 years. Some patients were followed for up to 22 years.
Six patients died during follow-up, for a mortality rate of 0.84%, which was not different from that of the general population. Nine patients (1.3%) developed cancer, including two with colon cancer, one with biliary tract cancer, one with cervical cancer, one with penile cancer, two with basal cell carcinoma, one with acute leukemia and one with small bowel carcinoid. The standardized cancer incidence ratio for the IBD patients was 3.0 (p <0.02).
Four of the patients who developed cancer had been taking immunosuppressants or anti-tumor necrosis factor alpha therapy, and three of these patients had been on combination therapy.
“With such a low number of cancers, our study was statistically unable to prove a supposed role of the disease and/or the immunosuppressant treatment in the occurrence of the malignancy,” Dr. Gower-Rousseau said. “However, the heterogeneity of the cancer location (colonic, uterine cervix, non-melanoma skin cancers) lets us think that both should be involved.”
Dr. Edward V. Loftus Jr., of the Mayo Clinic in Rochester, Minnesota, told Reuters Health that some of the cancers that occurred in the patients were likely associated with immunosuppressant or biologic use.
“I think it’s always a risk-benefit tradeoff, but in most cases the benefit of taking those drugs probably still outweighs the risk of cancer,” said Dr. Loftus, who directs the Inflammatory Bowel Disease Interest Group at Mayo and did not take part in Dr. Gower-Rousseau’s study. “We know from other studies that these drugs can alter the natural history of the condition by reducing need for hospitalization and reducing need for surgery.”
While cancer risk was indeed higher for the IBD patients, he added, “the absolute risk I would argue is still fairly low.”
“Patients with Crohn’s disease may be at higher risk of certain cancer subtypes than people without Crohn’s disease, but the absolute number of patients developing cancer is limited,” Dr. Tine Jess, who heads the department of epidemiology research at Statens Serum Institut in Copenhagen, told Reuters Health. Dr. Jess did not participate in the new study. “It is essential to encourage patients to stop smoking as this is a definite risk factor for development of cancer in these patients.”