Table 5. Multivariate Cox Proportional Hazard Analysis of the Survival Factors for Cause-Specific and Overall Survival for All PI-NHL Patients.

Variable	Cause-specific survival HR (95% CI)	P value	Overall survival HR (95% CI)	P value
Year of diagnosis
2000 - 2005	Reference		Reference
2006 - 2010	0.87 (0.80 - 0.96)	0.004	0.88 (0.82 - 0.95)	< 0.001
2011 - 2015	0.72 (0.65 - 0.80)	< 0.001	0.78 (0.72 - 0.84)	< 0.001
Age
< 60 years	Reference		Reference
≥ 60 years	2.13 (1.94 - 2.34)	< 0.001	2.87 (2.65 - 3.10)	< 0.001
Sex
Female	Reference		Reference
Male	1.14 (1.05 - 1.23)	0.006	1.17 (1.10 - 1.24)	< 0.001
Stage
Stage 1	Reference		Reference
Stage 2	1.54 (1.40 - 1.71)	< 0.001	1.26 (1.17 - 1.36)	< 0.001
Stage 3	1.88 (1.59 - 2.22)	< 0.001	1.45 (1.27 - 1.66)	< 0.001
Stage 4	2.56 (2.31 - 2.83)	< 0.001	1.93 (1.79 - 2.09)	< 0.001
Histology
DLBCL	Reference		Reference
Follicular lymphoma	0.19 (0.16 - 0.23)	< 0.001	0.29 (0.26 - 0.32)	< 0.001
MALToma	0.21 (0.17 - 0.25)	< 0.001	0.37 (0.33 - 0.41)	< 0.001
Mantle cell lymphoma	0.60 (0.51 - 0.70)	< 0.001	0.59 (0.52 - 0.67)	< 0.001
Other B-cell lymphoma	0.61 (0.49 - 0.77)	< 0.001	0.68 (0.58 - 0.81)	< 0.001
NHL, NOS	0.76 (0.66 - 0.89)	< 0.001	0.83 (0.74 - 0.93)	0.001
Burkitt lymphoma	1.36 (1.13 - 1.64)	0.001	1.17 (1.00 - 1.38)	0.052
T-Cell non-Hodgkin lymphoma	3.04 (2.67 - 3.46)	< 0.001	2.56 (2.28 - 2.88)	< 0.001
Treatment
None	Reference		Reference
Surgery	0.82 (0.73 - 0.93)	0.008	0.96 (0.88 - 1.05)	0.395
Chemotherapy	0.52 (0.46 - 0.60)	< 0.001	0.59 (0.53 - 0.65)	< 0.001
Chemotherapy and surgery	0.39 (0.34 - 0.44)	< 0.001	0.45 (0.40 - 0.49)	< 0.001

HR: hazard ratio; NHL: non-Hodgkin lymphoma; DLBCL: diffuse large B-cell lymphoma; MALToma: mucosa-associated lymphoid tissue lymphoma; NOS: not otherwise specified; PI-NHL: primary intestinal non-Hodgkin lymphoma; CI: confidence interval.