Gastroenterology Research and Practice

Research Article

Survival after Abdominoperineal and Sphincter-Preserving Resection in Nonmetastatic Rectal Cancer: A Population-Based Time-Trend and Propensity Score-Matched SEER Analysis

Table 2

Prognostic factors for overall and cancer-specific mortality.
  Overall mortality Cancer-specific mortality
Cox regression, full mode Cox regression, variable selectio Unadjuste Cox regression, full mode Cox regression, variable selectio
HR (95% CI)HR (95% CI)HR (95% CI)HR (95% CI)HR (95% CI)HR (95% CI)
Operation            
 CAAReference <0.001Reference 0.001Reference 0.001Reference <0.001Reference 0.004Reference 0.004
 APR1.58 (1.31–1.91)1.37 (1.13–1.67)1.36 (1.12–1.64)1.61 (1.28–2.03)1.39 (1.10–1.76)1.39 (1.11–1.76)
Tumor stage (AJCC 6th ed.)            
 Stage IReference <0.001Reference <0.001Reference <0.001Reference <0.001Reference <0.001Reference <0.001
 Stage IIA1.23 (1.02–1.50)1.47 (1.20–1.80)1.49 (1.22–1.82)1.67 (1.28–2.18)1.90 (1.44–2.50)1.91 (1.45–2.51)
 Stage IIB2.17 (1.58–2.99)2.71 (1.96–3.76)2.67 (1.93–3.70)3.83 (2.63–5.59)4.51 (3.06–6.65)4.45 (3.02–6.55)
 Stage IIIA1.50 (1.11–2.01)1.82 (1.34–2.46)1.82 (1.34–2.46)2.13 (1.45–3.11)2.50 (1.69–3.69)2.47 (1.67–3.64)
 Stage IIIB1.76 (1.46–2.13)2.28 (1.87–2.80)2.29 (1.87–2.81)2.81 (2.18–3.63)3.39 (2.59–4.43)3.38 (2.58–4.42)
 Stage IIIC3.42 (2.81–4.17)4.11 (3.33–5.08)4.09 (3.31–5.06)5.90 (4.56–7.65)6.57 (4.99–8.65)6.54 (4.97–8.61)
Retrieved regional lymph nodes            
 <12Reference0.391Reference<0.001Reference<0.001Reference0.576Reference0.001Reference0.001
 12+0.95 (0.84–1.07)0.79 (0.69–0.90)0.78 (0.69–0.88)0.96 (0.83–1.11)0.77 (0.66–0.90)0.76 (0.65–0.89)
Grading            
 G1Reference<0.001Reference 0.006Reference 0.004Reference <0.001Reference <0.001Reference <0.001
 G21.43 (1.08–1.89)1.26 (0.95–1.68)1.28 (0.96–1.70)2.29 (1.50–3.52)1.92 (1.25–2.95)1.95 (1.27–3.00)
 G3/42.15 (1.59–2.92)1.59 (1.17–2.16)1.61 (1.19–2.19)4.15 (2.66–6.46)2.80 (1.79–4.38)2.84 (1.82–4.45)
 Unknown1.07 (0.74–1.55)1.15 (0.79–1.66)1.16 (0.80–1.68)1.63 (0.97–2.75)1.55 (0.92–2.61)1.59 (0.94–2.68)
Radiation            
 NoneReference <0.001Reference <0.001Reference <0.001Reference <0.001Reference <0.001Reference <0.001
 Before surgery0.58 (0.51–0.67)0.56 (0.48–0.66)0.56 (0.48–0.66)0.74 (0.62–0.87)0.62 (0.51–0.75)0.61 (0.51–0.74)
 After surgery0.82 (0.68–0.99)0.62 (0.51–0.76)0.63 (0.51–0.77)1.00 (0.80–1.25)0.63 (0.49–0.80)0.64 (0.50–0.81)
Year            
 2005Reference 0.068Reference 0.141——Reference 0.029Reference 0.072——
 20060.94 (0.79–1.12)0.99 (0.83–1.18)——0.97 (0.79–1.20)1.02 (0.83–1.25)——
 20070.85 (0.71–1.03)0.85 (0.71–1.03)——0.86 (0.69–1.08)0.86 (0.69–1.09)——
 20080.95 (0.77–1.17)0.99 (0.80–1.22)——1.00 (0.78–1.28)1.02 (0.80–1.31)——
 20090.88 (0.69–1.12)1.06 (0.83–1.35)——0.83 (0.62–1.11)0.96 (0.71–1.30)——
 20100.76 (0.56–1.03)0.84 (0.62–1.15)——0.60 (0.40–0.90)0.65 (0.44–0.98)——
 20110.43 (0.22–0.82)0.51 (0.26–0.97)——0.36 (0.15–0.89)0.40 (0.16–0.99)——
Age            
 <50Reference <0.001Reference <0.001Reference <0.001Reference <0.001Reference <0.001Reference <0.001
 50–641.07 (0.86–1.32)1.10 (0.89–1.37)1.09 (0.88–1.35)0.96 (0.76–1.21)1.01 (0.80–1.27)1.00 (0.79–1.27)
 65–791.80 (1.47–2.21)1.76 (1.43–2.16)1.74 (1.42–2.15)1.37 (1.09–1.72)1.37 (1.09–1.73)1.38 (1.09–1.74)
 80+3.88 (3.10–4.86)3.25 (2.56–4.12)3.14 (2.47–3.98)2.49 (1.92–3.25)2.23 (1.68–2.96)2.21 (1.67–2.93)
Gender            
 MaleReference 0.012Reference 0.282——Reference 0.066Reference 0.641——
 Female1.18 (1.04–1.33)0.93 (0.81–1.06)——1.15 (0.99–1.34)0.96 (0.82–1.13)——
Ethnicity            
 CaucasianReference 0.122Reference 0.152——Reference 0.061Reference 0.145Reference 0.135
 African-American1.24 (1.00–1.54)1.25 (1.00–1.55)——1.34 (1.04–1.72)1.30 (1.00–1.67)1.30 (1.01–1.68)
 Other/unknown0.95 (0.75–1.19)1.02 (0.80–1.28)——0.91 (0.68–1.21)0.97 (0.73–1.30)0.96 (0.72–1.28)
Marital status            
 MarriedReference <0.001Reference <0.001Reference <0.001Reference <0.001Reference 0.001Reference 0.001
 Single/widowed1.81 (1.57–2.07)1.42 (1.22–1.65)1.41 (1.22–1.62)1.66 (1.41–1.97)1.34 (1.12–1.60)1.31 (1.10–1.56)
 Other/unknown1.41 (1.19–1.67)1.41 (1.18–1.68)1.41 (1.19–1.68)1.44 (1.17–1.76)1.37 (1.11–1.69)1.35 (1.10–1.66)
Hazard ratios (HR) with 95% confidence intervals; Cox regression analysis; Cox regression analysis full model; d variable selection from full model multivariable Cox regression analysis full model; ratio tests.