title: Sex differences in colorectal cancer survival: population-based analysis of 164,996 colorectal cancer patients in Germany.
abstract: Risk of colorectal cancer (CRC) is considerably higher in men compared to women; however, there is inconclusive evidence of sex differences in CRC prognosis. We aimed to assess and explain sex differences in 5-year relative survival using standard and model-based period analysis among 164,996 patients diagnosed with CRC from 1997 to 2006 and reported to 11 German cancer registries covering a population of 33 million inhabitants. Age-adjusted 5-year relative survival was higher in women (64.5% vs. 61.9%, P<0.0001). A substantial survival advantage of women was confirmed in multivariate analysis after adjusting for CRC stage and subsite in subjects under 65 years of age (relative excess risk, RER 0.86, 95% CI 0.82-0.90), but not in older subjects (RER 1.01, 95% CI 0.98-1.04); this pattern was similar in the 1st and in the 2nd to 5th year after diagnosis. The survival advantage of women varied by CRC stage and age and was most pronounced for localized disease (RERs 0.59-0.88 in various age subgroups) and in patients under 45 years of age (RERs 0.59, 0.72 and 0.76 in patients with localized, regional or advanced disease, respectively). On the contrary, sex differences in survival did not vary by location of CRC. In conclusion, our large population-based study confirmed a survival advantage of female compared to male CRC patients, most notably in young and middle aged patients and patients with localized disease. The effect of sex hormones, either endogenous or through hormonal replacement therapy, might be the most plausible explanation for the observed patterns.
authors.affiliation: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Majek
authors.forename: Adam
authors.initials: A
authors.lastname: Gondos
authors.forename: Lina
authors.initials: L
authors.lastname: Jansen
authors.forename: Katharina
authors.initials: K
authors.lastname: Emrich
authors.forename: Bernd
authors.initials: B
authors.lastname: Holleczek
authors.forename: Alexander
authors.initials: A
authors.lastname: Katalinic
authors.forename: Alice
authors.initials: A
authors.lastname: Nennecke
authors.forename: Andrea
authors.initials: A
authors.lastname: Eberle
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009367:Neoplasm Staging; D011159:Population Surveillance; D012042:Registries; D012189:Retrospective Studies; D012737:Sex Factors; D055815:Young Adult