Table 1.
Postmenopausal Hormone (PMH) Therapy and Incident Colorectal Cancer (CRC), by KRAS Mutation Status
| KRAS MUTATION | |||||
|---|---|---|---|---|---|
| KRAS mutation-negative | KRAS mutation-positive | ||||
| PMH Therapy | Person-Years | Events, N | RR (95% CI)a | Events, N | RR (95% CI)a |
| Never user | 341,377 | 224 | 1.00 (ref.) | 111 | 1.00 (ref.) |
| Ever user | 212,696 | 119 | 0.83 (0.66–1.06) | 53 | 0.82 (0.58–1.16) |
| p valueb | 0.14 | 0.27 | |||
| Former user | 151535 | 89 | 0.81 (0.63–1.06) | 37 | 0.80 (0.54–1.17) |
| Current user | 61,161 | 30 | 0.90 (0.61–1.34) | 16 | 0.90 (0.51–1.58) |
| p valuec | 0.24 | 0.38 | |||
| Duration ≤ 5 years | 148,704 | 90 | 0.88 (0.67–1.14) | 36 | 0.84 (0.57–1.24) |
| Duration > 5 years | 60,064 | 29 | 0.78 (0.52–1.16) | 14 | 0.70 (0.38–1.28) |
| p valued | 0.15 | 0.18 | |||
Adjusted for age, body mass index, waist to hip ratio, smoking status, age at menopause, age at menarche, oral contraceptive use, physical activity level, alcohol consumption, self-reported diabetes mellitus, and daily intake of total energy, total fat, sucrose, red meat, calcium, folate, methionine and vitamin E, as described in the Methods section. Event rates for KRAS mutation-positive cases differ slightly across exposure categories due to missing data.
p-value comparing KRAS-specific CRC risk in PMH ever users to PMH never users
test for trend p-value assessing dose-response association of the ordered variable PMH never vs. former vs. current use with risk of KRAS-specific CRC risk
test for trend p-value assessing dose-response association of the ordered variable PMH never vs. ≤ 5 years total use vs. > 5 years total use with risk of KRAS-specific CRC risk.