Table 4.
Multivariable prostate cancer incidence by disease severity among 31 925 men in the Health Professionals Follow-up Study according to reported ejaculation frequency at different timesa
| Ejaculation frequency | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 0–3 EPM | 4–7 EPM | 8–12 EPM | ≥13 EPM |
p value for trend |
|||||
| Cases (n) |
MV HR (95% CI) |
Cases (n) |
MV HR (95% CI) |
Cases (n) |
MV HR (95% CI) |
Cases (n) |
MV HR (95% CI) |
||
| Age 20–29 yr | |||||||||
| Low grade (GS ≤ 3 + 4) | 76 | 0.88 (0.68–1.13) | 283 | 1.00 (Ref) | 785 | 1.00 (0.87–1.15) | 1364 | 0.86 (0.76–0.98) | 0.006 |
| High grade (GS ≥ 4 + 3) | 39 | 1.32 (0.91–1.92) | 93 | 1.00 (Ref) | 244 | 1.00 (0.78–1.27) | 451 | 0.93 (0.74–1.16) | 0.08 |
| Organ-confined | 98 | 1.04 (0.82–1.30) | 309 | 1.00 (Ref) | 877 | 1.04 (0.91–1.18) | 1508 | 0.89 (0.78–1.00) | 0.0008 |
| Advanced | 21 | 0.79 (0.48–1.29) | 72 | 1.00 (Ref) | 156 | 0.87 (0.65–1.15) | 268 | 0.80 (0.62–1.05) | 0.23 |
| Lethal | 14 | 0.63 (0.35–1.14) | 57 | 1.00 (Ref) | 113 | 0.83 (0.60–1.14) | 200 | 0.82 (0.60–1.10) | 0.71 |
| Age 40–49 yr | |||||||||
| Low grade (GS ≤ 3 + 4) | 106 | 0.76 (0.62–0.93) | 689 | 1.00 (Ref) | 1010 | 0.90 (0.82–0.99) | 703 | 0.76 (0.68–0.85) | <0.0001 |
| High grade (GS ≥ 4 + 3) | 57 | 1.38 (1.03–1.86) | 197 | 1.00 (Re) | 318 | 1.01 (0.85–1.21) | 255 | 0.99 (0.82–1.19) | 0.23 |
| Organ-confined | 132 | 0.86 (0.71–1.03) | 749 | 1.00 (Ref) | 1126 | 0.93 (0.84–1.02) | 785 | 0.78 (0.71–0.86) | <0.0001 |
| Advanced | 33 | 0.98 (0.67–1.44) | 146 | 1.00 (Ref) | 185 | 0.83 (0.66–1.03) | 153 | 0.85 (0.67–1.07) | 0.16 |
| Lethal | 24 | 0.95 (0.61–1.49) | 107 | 1.00 (Ref) | 133 | 0.83 (0.64–1.08) | 120 | 0.95 (0.73–1.24) | 0.78 |
| Year before | |||||||||
| questionnaire (1991) | |||||||||
| Low grade (GS ≤ 3 + 4) | 778 | 1.04 (0.94–1.15) | 869 | 1.00 (Ref) | 587 | 0.97 (0.87–1.08) | 274 | 0.82 (0.72–0.95) | 0.003 |
| High grade (GS ≥ 4 + 3) | 284 | 1.08 (0.91–1.29) | 264 | 1.00 (Ref) | 180 | 1.07 (0.88–1.30) | 99 | 1.13 (0.89–1.43) | 0.68 |
| Organ-confined | 901 | 1.08 (0.98–1.18) | 952 | 1.00 (Ref) | 648 | 1.00 (0.90–1.11) | 291 | 0.82 (0.72–0.94) | 0.0008 |
| Advanced | 211 | 0.99 (0.79–1.22) | 157 | 1.00 (Ref) | 88 | 0.98 (0.75–1.28) | 61 | 1.37 (1.00–1.86) | 0.11 |
| Lethal | 169 | 0.95(0.74–1.22) | 114 | 1.00 (Ref) | 60 | 1.01 (0.74–1.39) | 41 | 1.48(1.02–2.15) | 0.05 |
EPM = ejaculations per month; MV = multivariable; HR = hazard ratio; CI = confidence interval; GS = Gleason score.
a
Organ-confined disease: stage T1/2N0M0 at diagnosis that did not progress to metastasis or death during the follow-up period. Advanced disease: stage T3b/4 or N1 or M1 at diagnosis or prostate cancer death or distant metastasis during follow-up. Lethal disease: prostate cancer death or metastases to bone or other organs before the end of the follow-up period.