Table 3.

Multivariate regression analysis of characteristics for survival in elderly patients (≥65 years) before PSM

Variables	Multivariate analysis for OS			Multivariate analysis for CSS
	HR	95% CI	p	HR	95% CI	p
Age
65–75 years	1 (Referent)			1 (Referent)
>75 years	1.373	0.954–1.977	0.088	1.231	0.775–1.955	0.378
Gender
Male	1 (Referent)			1 (Referent)
Female	1.028	0.678–1.557	0.898	0.939	0.571–1.544	0.803
Race
White	1 (Referent)			1 (Referent)
Black	1.367	0.726–2.572	0.333	1.333	0.621–2.859	0.460
Other	1.598	0.782–3.269	0.199	1.767	0.777–4.018	0.175
Marital status
Married	1 (Referent)			1 (Referent)
Unmarried	1.228	0.852–1.770	0.271	1.417	0.906–2.217	0.127
Year of diagnosis
1973–2009	1 (Referent)			1 (Referent)
2010–2015	0.931	0.634–1.365	0.714	1.027	0.638–1.651	0.913
Tumor site
Head	1 (Referent)			1 (Referent)
Body/tail	1.104	0.734–1.661	0.635	0.872	0.538–1.415	0.580
Overlap	1.226	0.692–2.171	0.485	0.859	0.422–1.749	0.676
Other	1.709	0.784–3.729	0.178	1.758	0.773–3.997	0.178
Histological grade
Well/moderately	1 (Referent)			1 (Referent)
Poorly/undifferentiated	3.062	2.118–4.425	0.000	3.641	2.351–5.640	0.000
Tumor size
≤4 cm	1 (Referent)			1 (Referent)
>4 cm	0.862	0.568–1.308	0.485	0.790	0.476–1.310	0.361
Unknown	0.798	0.463–1.375	0.416	0.812	0.423–1.558	0.531
Primary site surgery
No	1 (Referent)			1 (Referent)
Yes	0.392	0.252–0.612	0.000	0.362	0.206–0.637	0.000

Note: Variables with univariate analysis p<0.1 underwent further multivariate analysis.

Abbreviations: OS, overall survival; CSS, cancer-specific survival; PSM, propensity score matching.