Crohn's disease and cancer: a population-based cohort study.
OBJECTIVE
To study the association between Crohn's disease and cancer, we performed a population-based study of 1251 subjects with Crohn's disease diagnosed in Stockholm from 1955 to 1984 and followed in both the National Cancer Register and the National Cause-of-Death Register until 1989.


METHODS
For comparisons, regional cancer incidence rates in Stockholm County were used together with individually computed person-years at risk in the Crohn's disease cohort.


RESULTS
Overall, 69 malignancies occurred among 67 individuals as compared with 59.80 expected malignancies (standardized morbidity ratio [SMR] = 1.15; 95% confidence interval, 0.90-1.46). An excess number of cancers of the upper gastrointestinal tract (SMR, 3.05; 95% confidence interval, 1.67-5.11) was observed, mainly because of an increased number of cancers of the small intestine (SMR, 15.64; 95% confidence interval, 4.26-40.06). An increased occurrence of urinary bladder cancer was also observed (SMR, 2.68; 95% confidence interval, 1.08-5.53).


CONCLUSIONS
The occurrence of colorectal cancer was not increased.
Division of Epidemiology, Karolinska Institutet, Stockholm, Sweden.
P G
PG
Persson
P
P
Karlén
O
O
Bernell
C E
CE
Leijonmarck
O
O
Broström
A
A
Ahlbom
G
G
Hellers
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003424:Crohn Disease / Q000150:complications* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000150:complications / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000453:epidemiology; D016012:Poisson Distribution; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000150:complications / Q000453:epidemiology