Patients with long-standing ulcerative colitis (UC) and Crohn's disease (CD) have an increased risk of developing colorectal cancer. Furthermore, immunosuppressive medical therapies for inflammatory bowel disease (IBD) have been reported to be associated with an increased risk of specific types of cancer. There is a paucity of data on cancer risk among patients with IBD who require more aggressive therapy with corticosteroids (CS), immunomodulators (IM) or biologics for disease control. Our aim was to study the cancer incidence rates (IR) among elderly IBD patients after they were started on therapy and compare them with younger IBD patients as well as the general population.Methods:
This was a retrospective cohort study using MarketScan (January 01, 2010–December 31, 2014), a US commercial claims database. All adult patients with at least 2 ICD-9 diagnostic claims for UC (556.xx) or CD (555.xx) ≥30 days apart were included. Patients entered the study on the date of first initiation of CS, IM or anti-TNF and natalizumab biologic therapy after IBD diagnosis within the study period. The outcome of incident cancer was identified using first evidence of ICD-9 diagnosis codes for all cancers. The presence of at least 2 diagnosis codes for cancer within 2 months during the follow-up was used to confirm a cancer diagnosis. IR and frequencies for all cancers were calculated among elderly and younger age groups and compared with the general population using reported age-matched Surveillance, Epidemiology and End Results (SEER) data statistics.Results:
Among 59,916 IBD patients, 7338 (12.25%) were elderly. With a median follow-up of 2.2 years (representing 15,824 person years [PY] for ≥65 yr olds and 109,472 PY for 18–64 yr olds), 1581 patients developed cancer. Of those with cancer, 564 (7.7%) were elderly and 1017 (1.9%) were 18 to 64 years old. Compared to the SEER database with age-specific all cancer IR of 2.03/100 PY for ≥65 year olds and 0.22/100 PY for those <65 years, this study cohort had higher all cancer IR of 3.56/100 PY (95% CI, 3.28, 3.87) and 0.93/100 PY (95% CI, 0.87, 0.99) for the ≥65 and 18 to 64 year olds, respectively. Among the elderly, the most common malignancies were prostate cancer (17.7%), lung cancer (12.8%), female breast cancer (13.7%), urinary tract cancer (10.3%) and colorectal cancer (7.6%). A higher incidence of colorectal cancer (IR: 0.27/100 PY versus 0.20/100 PY), Non-Hodgkin's lymphoma (IR: 0.14/100 PY versus 0.09/100 PY) and urinary tract malignancy (IR: 0.37/100 PY versus 0.12/100 PY) were observed among those ≥65 years when compared to cancer IR in the SEER database for the same age group. Prostate, lung and female breast cancers also had higher IR in the elderly subgroup compared with the age-matched SEER database.Conclusions:
Based on this retrospective database study, elderly IBD patients had higher cancer IR compared with younger IBD patients (3.56/100 PY versus 0.93/100 PY, respectively) and with the general population in the same age group (2.03/100 PY). These findings indicate a need for more focused screening for cancer risk and careful consideration of treatment decisions when managing elderly IBD patients.