Table 2.

Multivariate Cox proportional hazards regression for the effect of gender on disease-specific survival using two different initial age cutoffs while adjusting for stage within each age group, with P value for gender differences shown

Population	Patients, n	Deaths, n	15-yr survival (%)	95% CI for 15-yr survival	HR	95% CI for HR	P value
All ages
Males	953	30	91	0.86–0.94	1.00
Females	2619	34	96	0.93–0.98	0.73	0.44–1.20	0.215
Initial age cutoff of <45 yr
Age group <45 yr
Males	437	2	99	0.96–1.00	1.00
Females	1507	2	100	0.98–1.00	0.39	0.05–2.88	0.356
Age group 45–59 yr
Males	320	13	87	0.75–0.93	1.00
Females	731	11	91	0.81–0.96	0.55	0.24–1.26	0.159
Age group 60–74 yr
Males	156	10	81	0.64–0.90	1.00
Females	293	12	93	0.88–0.96	0.73	0.31–1.70	0.466
Age group ≥75 yra
Males	40	5	65	0.27–0.86	1.00
Females	88	9	85	0.72–0.92	1.19	0.38–3.66	0.767
Initial age cutoff of <55 yr
Age group <55 yr
Males	663	13	94	0.89–0.97	1.00
Females	2055	8	98	0.94–0.99	0.33	0.13–0.81	0.016
Age group 55–69 yr
Males	214	9	87	0.75–0.94	1.00
Females	416	13	91	0.78–0.96	1.01	0.42–2.37	0.983
Age group >70 yra
Males	76	8	67	0.38–0.85	1.00
Females	148	13	85	0.75–0.91	1.17	0.48–2.85	0.737

Initial age cutoff of less than 45 yr shows the usual staging age cutoff of less than 45 yr; the initial age cutoff of less than 55 yr shows a cutoff of less than 55 yr based on menopause. Patients younger than either 45 or 55 yr were combined as a group because there were very few deaths in these age groups. HR = 1.0 for stage I and II.

^aSurvival probability and 95% CI were based on 10 yr, rather than 15 yr.