Table 4.
Epithelial ovarian cancer-specific mortality stratified by tumor histologic subtype in the NHS and NHSII
| Epithelial ovarian cancer-specific mortality |
|||||
|---|---|---|---|---|---|
| High-grade serous or poorly differentiated histology |
Nonserous or low-grade serous histology |
p-heterogeneity | |||
| n, deaths/cases | HR (95%CI) | n, deaths/cases | HR (95% CI) | ||
| Prediagnosis smoking | |||||
| Never smoker | 250/384 | 1.00 (ref) | 80/211 | 1.00 (ref) | 0.13 |
| Former smoker | 252/339 | 1.27 (1.07,1.52) | 58/147 | 0.89 (0.63,1.27) | |
| Current smoker | 82/109 | 1.20 (0.92,1.55) | 16/54 | 1.15 (0.65,2.03) | |
| Prediagnosis smoking rate | |||||
| Never smoker | 250/384 | 1.00 (ref) | 80/211 | 1.00 (ref) | 0.046 |
| Former smoker, <15 cigs/day | 121/171 | 1.14 (0.91,1.42) | 33/82 | 0.95 (0.62,1.45) | |
| Former smoker, ≥15 cigs/day | 126/162 | 1.42 (1.14,1.77) | 24/62 | 0.82 (0.50,1.32) | |
| Current smoker, <15 cigs/day | 30/46 | 0.99 (0.67,1.45) | 5/16 | 1.01 (0.40,2.57) | |
| Current smoker, ≥15 cigs/day | 47/58 | 1.30 (0.94,1.79) | 11/36 | 1.30 (0.67,2.54) | |
| Prediagnosis smoking duration | |||||
| Never smoker | 250/384 | 1.00 (ref) | 80/211 | 1.00 (ref) | 0.06 |
| <20 years | 118/159 | 1.26 (1.01,1.58) | 31/92 | 0.73 (0.47,1.13) | |
| ≥20 years | 211/282 | 1.25 (1.04,1.51) | 42/107 | 1.15 (0.78,1.70) | |
| Prediagnosis smoking pack-years | |||||
| Never smoker | 250/384 | 1.00 (ref) | 80/211 | 1.00 (ref) | 0.19 |
| <20 pack-years | 162/222 | 1.18 (0.97,1.44) | 39/115 | 0.93 (0.63,1.38) | |
| ≥20 pack-years | 163/215 | 1.32 (1.08,1.62) | 34/83 | 0.95 (0.63,1.45) | |
| Prediagnosis time since quitting smoking | |||||
| Never smoker | 250/384 | 1.00 (ref) | 80/211 | 1.00 (ref) | 0.06 |
| <15 years | 74/96 | 1.22 (0.93,1.60) | 23/53 | 0.96 (0.60,1.56) | |
| 15 to <22 years | 49/66 | 1.36 (1.00,1.86) | 12/37 | 0.66 (0.35,1.25) | |
| ≥22 years | 125/171 | 1.25 (1.00,1.56) | 22/56 | 0.89 (0.53,1.48) | |
| Postdiagnosis smoking | |||||
| Never smoker | 202/336 | 1.00 (ref) | 66/197 | 1.00 (ref) | 0.02 |
| Former smoker | 227/324 | 1.41 (1.16,1.71) | 49/152 | 0.83 (0.56,1.23) | |
| Current smoker | 53/69 | 1.71 (1.25,2.34) | 8/34 | 0.84 (0.39,1.79) | |
| Postdiagnosis smoking rate | |||||
| Never smoker | 202/336 | 1.00 (ref) | 66/197 | 1.00 (ref) | 0.02 |
| Former smoker, <15 cigarettes/day | 111/167 | 1.32 (1.04,1.68) | 29/84 | 1.01 (0.63,1.61) | |
| Former smoker, ≥15 cigarettes/day | 109/149 | 1.44 (1.14,1.83) | 20/65 | 0.71 (0.42,1.20) | |
| Current smoker, <15 cigarettes/day | 20/33 | 1.17 (0.73,1.86) | 2/11 | 0.90 (0.21,3.81) | |
| Current smoker, ≥15 cigarettes/day | 31/33 | 2.73 (1.82,4.09) | 6/21 | 1.48 (0.60,3.65) | |
| Change in smoking from prediagnosis to postdiagnosis1,2 | |||||
| Never smoker | 196/326 | 1.00 (ref) | 65/189 | 1.00 (ref) | 0.01 |
| Former smoker | 205/285 | 1.43 (1.17,1.75) | 44/129 | 0.70 (0.46,1.06) | |
| Quit smoking after diagnosis | 18/29 | 0.85 (0.52,1.41) | 4/13 | 0.73 (0.24,2.22) | |
| Remained current smoker | 50/64 | 1.60 (1.15,2.21) | 8/30 | 1.31 (0.59,2.92) | |
Nonserous histologic subtype refers to mucinous, endometrioid, clear cell, transitional/Brenner, carcinosarcoma or mixed subtypes of ovarian cancer. Never smoker is defined as being a never smoker at both prediagnosis and postdiagnosis assessments; Former smoker is defined as being a former smoker at both assessments; Quit smoking after diagnosis is defined as being a current smoker before diagnosis and former smoker after diagnosis; Remained current smoker is defined as being a current smoker at both assessments. Models adjusted for age and calendar year at diagnosis, stage, body mass index (BMI, categorical), and cohort. Postdiagnosis models additionally adjusted for nonsteroidal anti-inflammatory drug (NSAID) usage.
Models adjusted for age and calendar year at diagnosis, stage, prediagnosis BMI (categorical), change of BMI (categorical) and NSAID usage from prediagnosis to postdiagnosis, and cohort.
Due to the small sample size, participants who reported past smoking before diagnosis and current smoking after diagnosis were excluded (n = 2).
Abbreviations: CI, confidence interval; HR, hazard ratio; NHS, Nurses’ Health Study; NHSII, Nurses’ Health Study II.
Bold values indicate p < 0.05.