Table 2.
Adjusted hazard ratios of hormonal related risk factors by outcome.
| Esophageal adenocarcinoma | Esophageal SCC | |||||||
|---|---|---|---|---|---|---|---|---|
| Risk factor | Total number of women (N=161,080) n (%) |
Number of cases (N=23) n (%) |
HR* | [95% CI] | Total number of women (N=161,080) n (%) |
Number of cases (N=34) n (%) |
HR** | [95% CI] |
| Hormone therapy use | ||||||||
| Never users | 60,031 (38.1) | 9 (39.1) | 1.00 | ref. | 59,091 (38.2) | 21 (65.6) | 1.00 | ref. |
| Past users only | 22,998 (14.6) | 3 (13.0) | 0.74 | [0.20, 2.82] | 22,622 (14.6) | 2 (6.3) | 0.25 | [0.06, 1.10] |
| Current users | 74,704 (47.4) | 11 (47.8) | 0.87 | [0.35, 2.17] | 73,132 (47.2) | 9 (28.1) | 0.41 | [0.18, 0.94] |
| Type of hormone therapy (in current users) | ||||||||
| Never users | 60,031 (44.6) | 9 (45.0) | 1.00 | ref. | 59,109 (38.2) | 21 (70.0) | 1.00 | ref. |
| E-alone | 39,630 (29.4) | 5 (25.0) | 0.57 | [0.15, 2.13] | 38,846 (29.4) | 6 (20.0) | 0.96 | [0.28, 3.29] |
| E+P | 35,068 (26.0) | 6 (30.0) | 1.12 | [0.35, 3.59] | 34,280 (25.9) | 3 (10.0) | 0.25 | [0.07, 0.86] |
| Duration of hormone therapy use (years) | ||||||||
| Never users | 60,031 (40.3) | 9 (45.0) | 1.00 | ref. | 59,091 (40.4) | 21 (67.7) | 1.00 | ref. |
| < 10 | 54,215 (36.4) | 7 (35.0) | 0.94 | [0.34, 2.62] | 53,133 (36.4) | 3 (9.7) | 0.19 | [0.06, 0.64] |
| ≥ 10 | 34,623 (23.3) | 4 (20.0) | 0.72 | [0.20, 2.57] | 33,950 (23.3) | 7 (22.6) | 0.62 | [0.24, 1.56] |
| Ptrend=0.632 | Ptrend=0.093 | |||||||
| Use of oral contraceptives | ||||||||
| No | 92,222 (58.4) | 15 (65.2) | 1.00 | ref. | 90,630 (58.5) | 25 (78.1) | 1.00 | ref. |
| Yes | 65,641 (41.6) | 8 (34.8) | 0.92 | [0.37, 2.28] | 64,345 (41.5) | 7 (21.9) | 0.47 | [0.19, 1.15] |
| Number of term pregnancies | ||||||||
| None | 18,638 (11.9) | 2 (8.7) | 0.91 | [0.17, 5.02] | 18,351 (11.9) | 5 (15.6) | 0.65 | [0.22, 1.97] |
| 1–2 | 53,250 (33.9) | 9 (39.1) | 1.39 | [0.42, 4.59] | 52,160 (33.8) | 7 (21.9) | 0.34 | [0.12, 0.92] |
| 3–4 | 61,984 (39.5) | 8 (34.8) | 0.87 | [0.26, 2.90] | 60,889 (39.5) | 11 (34.4) | 0.46 | [0.19, 1.10] |
| ≥ 5 | 23,094 (14.7) | 4 (17.4) | 1.00 | ref. | 22,754 (14.8) | 9 (28.1) | 1.00 | ref. |
| Ptrend=0.681 | Ptrend=0.239 | |||||||
| Ever breastfed§ | ||||||||
| No | 57,194 (41.8) | 13 (61.9) | 1.00 | ref. | 56,018 (41.7) | 10 (37.0) | 1.00 | ref. |
| Yes | 79,709 (58.2) | 8 (38.1) | 0.44 | [0.18, 1.07] | 78,444 (58.3) | 17 (63.0) | 1.32 | [0.60, 2.89] |
| Number of months breastfed§ | ||||||||
| Never breastfed | 57,194 (41.9) | 13 (61.9) | 1.00 | ref. | 56,018 (41.8) | 10 (37.0) | 1.00 | ref. |
| 1–6 | 40,174 (29.4) | 3 (14.3) | 0.32 | [0.09, 1.13] | 39,483 (29.5) | 12 (44.4) | 1.73 | [0.75, 4.02] |
| ≥ 7 | 39,102 (28.7) | 5 (23.8) | 0.57 | [0.21, 1.60] | 38,539 (28.8) | 5 (18.5) | 0.84 | [0.29, 2.48] |
| Ptrend=0.183 | Ptrend=0.960 | |||||||
| Age at menopause (years) | ||||||||
| < 45 | 43,060 (29.0) | 4 (20.0) | 1.00 | ref. | 42,343 (29.0) | 8 (28.6) | 1.00 | ref. |
| 45–49 | 36,185 (24.4) | 7 (35.0) | 2.55 | [0.70, 9.30] | 35,552 (24.4) | 4 (14.3) | 0.51 | [0.14, 1.79] |
| 50–54 | 51,502 (34.7) | 5 (25.0) | 1.33 | [0.31, 5.78] | 50,652 (34.7) | 10 (35.7) | 0.86 | [0.29, 2.53] |
| ≥ 55 | 17,670 (11.9) | 4 (20.0) | 2.63 | [0.54, 12.77] | 17,328 (11.9) | 6 (21.4) | 1.36 | [0.40, 4.62] |
| Ptrend=0.450 | Ptrend=0.527 | |||||||
| Age at menarche (years) | ||||||||
| < 12 | 18,428 (14.0) | 4 (19.1) | 1.00 | ref. | 18,187 (14.0) | 6 (20.7) | 1.00 | ref. |
| 12 | 27,470 (20.8) | 6 (28.6) | 1.07 | [0.30, 3.79] | 27,003 (20.8) | 9 (31.0) | 0.99 | [0.35, 2.80] |
| 13 | 34,365 (26.0) | 4 (19.1) | 0.59 | [0.15, 2.36] | 33,824 (26.0) | 4 (13.8) | 0.35 | [0.10, 1.24] |
| 14 | 22,826 (17.3) | 3 (14.3) | 0.70 | [0.15, 3.15] | 22,474 (17.3) | 5 (17.2) | 0.65 | [0.20, 2.14] |
| ≥ 15 | 29,041 (22.0) | 4 (19.1) | 0.72 | [0.18, 2.91] | 28,532 (21.9) | 5 (17.2) | 0.51 | [0.16, 1.69] |
| Ptrend=0.482 | Ptrend=0.169 | |||||||
| Age at first term pregnancy (years) | ||||||||
| < 20 | 20,112 (16.1) | 4 (21.1) | 1.43 | [0.42, 4.85] | 19,779 (16.1) | 2 (8.0) | 0.44 | [0.10, 1.96] |
| 20–24 | 59,431 (47.7) | 8 (42.1) | 1.00 | ref. | 58,455 (47.7) | 13 (52.0) | 1.00 | ref. |
| 25–29 | 33,407 (26.8) | 5 (36.3) | 1.26 | [0.41, 3.87] | 32,833 (26.8) | 5 (20.0) | 0.67 | [0.24, 1.90] |
| ≥ 30 | 11,751 (9.4) | 2 (10.5) | 1.52 | [0.32, 7.22] | 11,501 (9.4) | 5 (20.0) | 1.91 | [0.67, 5.45] |
| Ptrend=0.883 | Ptrend=0.195 | |||||||
Numbers only for women with no-missing values for the exposure of interest and corresponding adjusting variables.
Adjusted for BMI (continuous), heartburn (did not occur/mild/moderate/severe), White race (white/non-white) and stratified by age (50–59/60–69/70–79), hysterectomy status and study type (HT trial/OS or non-HT trials).
Adjusted for pack-years of smoking (never/<5/5–19.9/20–39.9/≥40), drinking (non-drinker/past drinker/<1 drink per week/1–7 drinks per week/>7 drinks per week), and stratified by age (50–59/60–69/70–79), hysterectomy status and study type (HT trial/OS or non-HT trials).
Adjusted for past use of HT (defined as non-current users relative to baseline in the OS and non-HT trials but reported use of HT before baseline; and users of HT before randomization in the HT trial but assigned to the placebo arm).
Adjsuted for past use of E (similar definition to past use of HT).
Adjusted for past use of P+E (similar definition to past use of HT).
Only women with at least one live birth.