Table 2.
Risk factors of developing SPMN (bladder cancer or rectum cancer) after prostate cancer diagnosis among patients receiving radiotherapy by Statistical Method.
| Characteristic | Competing risk regression | Poisson regression | ||||||
|---|---|---|---|---|---|---|---|---|
| Univariate analysis HR (95% CI) |
P-value | Multivariable analysis HR (95% CI) |
P-value | Univariate analysis HR (95% CI) |
P-value | Multivariable analysis HR (95% CI) |
P-value | |
| Age at diagnosis | ||||||||
| <50 years | Ref. | Ref. | Ref. | Ref. | ||||
| 50-70 years | 1.89(1.23-2.90) | 0.014※ | 1.78(1.16- 2.73) | 0.027※ | 1.97(1.32-3.12) | 0.009※ | 1.83(1.22-2.9) | 0.02※ |
| >70 years | 2.08(1.35-3.18) | 0.005※ | 2.05(1.33- 3.15) | <0.001※ | 2.32(1.56-3.68) | 0.001※ | 2.18(1.45-3.46) | 0.02※ |
| Race | ||||||||
| White | Ref. | Ref. | Ref. | Ref. | ||||
| black | 0.68(0.61-0.77) | <0.001※ | 0.75(0.66-0.84) | <0.001※ | 0.63(0.56-0.71) | <0.001※ | 0.75(0.66-0.84) | <0.001※ |
| others1 | 0.66(0.55-0.78) | <0.001※ | 0.67(0.57-0.79) | <0.001※ | 0.65(0.55-0.77) | <0.001※ | 0.67(0.56-0.79) | <0.001※ |
| Year of diagnosis | ||||||||
| 1995-1999 | Ref. | Ref. | Ref. | Ref. | ||||
| 2000-2004 | 0.86(0.79-0.93) | <0.001※ | 0.83(0.75-0.9) | <0.001※ | 0.79(0.68-0.9) | <0.001※ | 0.77(0.7-0.85) | <0.001※ |
| 2005-2009 | 0.69(0.63-0.76) | <0.001※ | 0.72(0.64-0.81) | <0.001※ | 0.43(0.39-0.48) | <0.001※ | 0.5(0.45-0.56) | <0.001※ |
| 2010-2014 | 0.67(0.56-0.8) | <0.001※ | 0.96(0.78-0.99) | <0.001※ | 0.16(0.13- 0.18) | <0.001※ | 0.27(0.22-0.33) | <0.001※ |
| Marital status | ||||||||
| Married | Ref. | Ref. | Ref. | Ref. | ||||
| Unmarried | 1.29(1.17-1.42) | <0.001※ | 1.19(1.08-1.31) | 0.004※ | 1.34(1.22-1.48) | <0.001※ | 1.18(1.07-1.3) | 0.005※ |
| Gleason biopsy | ||||||||
| 6 | Ref. | Ref. | ||||||
| 7 | 1.03(0.7-1.5) | 0.89 | 0.99(0.68- 1.47) | 0.98 | ||||
| 8-10 | 1.2(0.76-1.9) | 0.53 | 1.29(0.81-2.03) | 0.35 | ||||
| AJCC Stage Group | ||||||||
| II | Ref. | Ref. | ||||||
| III | 0.95(0.63-1.4) | 0.83 | 0.96(0.62-1.4) | 0.86 | ||||
| IV | 0.47(0.18-1.2) | 0.19 | 0.48(0.15-1.08) | 0.2 | ||||
| Summary stage | ||||||||
| Localized | Ref. | Ref. | ||||||
| Regional | 0.83(0.66-1.04) | 0.18 | 0.84(0.66-1.04) | 0.19 | ||||
| Grade | ||||||||
| Grade I or Grade II | Ref. | Ref. | Ref. | |||||
| Grade III or Grade IV | 0.85(0.79-0.92) | <0.001※ | 0.99(0.91-1.07) | 0.83 | 0.61(0.57-0.66) | <0.001※ | 0.98(0.9-1.07) | 0.768 |
| Radiation strategy | ||||||||
| EBRT | Ref. | Ref. | Ref. | Ref. | ||||
| EBRT+BT | 1.14(1.04-1.25) | 0.023※ | 1.15(1.04-1.26) | 0.02※ | 1.17(1.07-1.29) | 0.004※ | 1.14(1.03-1.25) | 0.02※ |
| BT | 1.17(1.07-1.27) | 0.002※ | 1.16(1.06-1.26) | 0.005※ | 1.15(1.05-1.24) | 0.007※ | 1.14(1.04-1.24) | 0.01※ |
| Latency | ||||||||
| 5-10 years | Ref. | Ref. | Ref. | |||||
| 11-15 years | 1.47(1.34-1.62) | <0.001※ | 1.55(1.39-1.72) | <0.001※ | 2.31(2.1-2.55) | <0.001※ | 1.76(1.59-1.97) | <0.001※ |
| 16-20 years | 1.61(1.46-1.78) | <0.001※ | 1.57(1.39-1.76) | <0.001※ | 3.38(3.06-3.75) | <0.001※ | 2.02(1.8-2.28) | <0.001※ |
| 21-25 years | 1.6(1.38-1.86) | <0.001※ | 1.43(1.2-1.69) | <0.001※ | 3.89(3.32-4.54) | <0.001※ | 2.04(1.7-2.43) | <0.001※ |
EBRT, external beam radiotherapy; EBRT+BT, interstitial brachytherapy or a combination of external beam radiotherapy; BT, brachytherapy; SPMN, second pelvic malignant neoplasm; AJCC, American Joint Committee on Cancer; HR, hazard ratio; CI, confidence interval.
1Other: American/Indian/Alaska/Native and Asian/Pacific Islander.
※ : statistical significance.