A prospective study of obesity and cancer risk (Sweden).
OBJECTIVE
[corrected] We evaluated the relation between obesity and the risks for various forms of cancer.


METHODS
In a population-based cohort of 28,129 hospital patients (8165 men, 19,964 women) with any discharge diagnosis of obesity (9557 only diagnosis, 5266 primary, 13,306 secondary) during 1965-1993, cancer incidence was ascertained through 1993 by record linkage to the nationwide Swedish Cancer Registry. Cancer risk was estimated using the standardized incidence ratio (SIR, with 95% confidence interval), which is the ratio of the observed number of cancers to that expected.


RESULTS
Overall, a 33% excess incidence of cancer was seen in obese persons, 25% in men and 37% in women. Significant risk elevations were observed for cancers of the small intestine (SIR = 2.8; 95% CI 1.6-4.5), colon (1.3; 1.1-1.5), gallbladder (1.6; 1.1-2.3), pancreas (1.5; 1.1-1.9), larynx (2.1; 1.1-3.5), renal parenchyma (2.3; 1.8-2.8), bladder (1.2; 1.0-1.6), cervix uteri (1.4; 1.1-1.9), endometrium (2.9; 2.5-3.4), ovary (1.2; 1.1-1.5), brain (1.5; 1.2-1.9), and connective tissue (1.9; 1.1-3.0), and for lymphomas (1.4; 1.0-1.7), with higher risk observed for Hodgkin's disease only in men (3.3; 1.4-6.5) and for non-Hodgkin's lymphoma only in women (1.6; 1.2-2.1). The association of obesity with risk of breast, prostate and pancreas cancers was modified by age.


CONCLUSIONS
Obesity is associated with more forms of cancer than previously reported.
Karolinska Institute, Department of Medical Epidemiology, Stockholm, Sweden. Alicja.Wolk@mep.ki.se
A
A
Wolk
G
G
Gridley
M
M
Svensson
O
O
Nyrén
J K
JK
McLaughlin
J F
JF
Fraumeni
H O
HO
Adam
D000293:Adolescent; D000328:Adult; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D009765:Obesity / Q000150:complications*; D010351:Patient Discharge / Q000706:statistics & numerical data; D011159:Population Surveillance; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D013548:Sweden / Q000453:epidemiology