Gender differences in non-small-cell lung cancer survival: an analysis of 4,618 patients diagnosed between 1997 and 2002.
BACKGROUND
Gender has been reported as a predictor for nonsmall cell lung cancer (NSCLC) survival. Most of the reports are limited to selected groups of patients. The magnitude of gender effect on NSCLC survival across disease stage, tumor histology, and therapies needs to be further characterized.


METHODS
A cohort of 4,618 patients diagnosed with NSCLC was prospectively enrolled and actively followed. Vital status of each patient was verified through multiple complementary sources. Cox proportional hazards models were developed to compare postdiagnosis survival between genders adjusting for age at diagnosis, tumor histology and grade, stage, pack-years smoked, and treatment received (resection, radiation, or chemotherapy).


RESULTS
There were 2,724 men (59%) and 1,894 women (41%), with a median age at diagnosis of 68 years in men and 66 in women (p < 0.01). More men smoked and were heavier smokers than women. Adenocarcinoma was the most frequent histology in both genders. No difference was found in stage and treatment between genders. The estimated survival in men was 51% (95% CI: 49%, 53%) and 15% (95% CI: 12%, 17%) at one and five years, respectively, and in women was 60% (95% CI: 58%, 62%) and 19% (95% CI: 16%, 22%). Men were at a significantly increased risk of mortality compared to women following a diagnosis of NSCLC (adjusted relative risk: 1.20, 95% CI: 1.11, 1.30), particularly for patients with stage III/IV disease or adenocarcinoma.


CONCLUSIONS
Male gender is confirmed to be an independent unfavorable prognostic indicator for NSCLC survival.
Visbal
Antonio L
AL
Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA.
Williams
Brent A
BA
Nichols
Francis C
FC
Marks
Randolph S
RS
Jett
James R
JR
Aubry
Marie-Christine
MC
Edell
Eric S
ES
Wampfler
Jason A
JA
Molina
Julian R
JR
Yang
Ping
P
D000230:Adenocarcinoma / Q000401:mortality / Q000628:therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000628:therapy; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015993:Life Tables; D008175:Lung Neoplasms / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology