title: Gender differences in long-term survival of patients with colorectal cancer.
abstract: BACKGROUND
  Significant differences exist in the immunological response to surgery. This raises the possibility that gender differences exist concerning the outcome after curative colorectal cancer resection.
  
  
  METHODS
  To study this hypothesis, a database of patients with colorectal cancer was analysed prospectively.
  
  
  RESULTS
  Some 894 patients were included, 500 (55.9 per cent) were men and 394 (44.1 per cent) were women. Median follow-up was 54.5 months for the entire group and 63.3 months for survivors. The mean(s.e.m.) patient age was 65.3(0.4) years (women 66.1(0.6), men 64.7(0.5) years; P < 0.05). Women lived significantly longer after cancer resection than men (57.8(1.5) versus 52.0(1.3) months; P < 0.05, log rank 0.009). Disease-free survival was significantly longer in women than in men (51.6(1.7) versus 46.0(1.4) months; P < 0.05). Subgroup analysis revealed significant gender differences in Union Internacional Contra la Cancrum (UICC) stages I (n = 195, log rank 0.01) and UICC IV (n = 38, log rank 0.021). Survival analysis after rectal cancer resection revealed significant advantages for women (log rank 0.02), while no gender differences were detected when comparing patients after resection for colonic cancer. Moreover, patients older than 50 years (n = 635) showed significant gender-related survival differences (log rank 0.015).
  
  
  CONCLUSIONS
  Significant gender differences following curative rectal cancer resection were observed. In women disease-free and overall survival were significantly longer. Whether or not these gender differences are related to gender-specific immune functions or to other gender-related local or systemic factors remains to be determined.
authors.affiliation: Department of Surgery, Ludwig-Maximilians University, Klinikum Grosshadern, Marchioninistrasse 15, D-81377 Munich, Germany.
authors.forename: M W
authors.initials: MW
authors.lastname: Wichmann
authors.forename: C
authors.initials: C
authors.lastname: Müller
authors.forename: H M
authors.initials: HM
authors.lastname: Hornung
authors.forename: U
authors.initials: U
authors.lastname: Lau-Werner
authors.forename: F W
authors.initials: FW
authors.lastname: Schildberg
mesh_terms: D000367:Age Factors; D000368:Aged; D003082:Colectomy / Q000379:methods; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D012737:Sex Factors; D017741:Survivors