Age at menarche and breast cancer risk stratified by hormone receptor expression
| First author (reference) . | Country (study) . | Cases (n) . | Age at menarche (y) . | . | Risk estimate (95% CI)* . | . | ||
|---|---|---|---|---|---|---|---|---|
| . | . | . | Reference group . | Age category . | . | . | ||
| ER+ | ER− | |||||||
| Kreiger (35) | Canada (ON) | 528 | <12 | 12-14 | 0.8 (0.5-1.1) | 0.9 (0.5-1.6) | ||
| 15+ | 0.8 (0.5-1.3) | 0.7 (0.3-1.5) | ||||||
| Zhu† (27) | United States (TN) | 281 | <13 | 13+ | 1.0 (0.6-1.6) | 1.2 (0.7-2.1) | ||
| Cooper (36) | Australia | 380 | <13 | 13 | 0.9 (0.6-1.5) | 0.9 (0.6-1.7) | ||
| 14+ | 1.0 (0.6-2.1) | 0.8 (0.4-1.4) | ||||||
| Hislop (37) | Canada (BC) | 512 | <13 | 13 | 0.9 (0.7-1.1) | 0.9 (0.7-1.2) | ||
| 14+ | 1.0 (0.8-1.2) | 1.1 (0.8-1.4) | ||||||
| McTiernan (39) | United States (CASH-WA) | 240 | <13 | 13+ | 1.3 (0.8-1.9) | 1.8 (1.1-3.0) | ||
| Yoo (41) | Japan | 455 | Per 2 y older | Continuous | 1.0 (0.9-1.2) | 1.1 (0.9-1.3) | ||
| PR+ | PR− | |||||||
| Kreiger (35) | Canada (ON) | 528 | <12 | 12-14 | 0.7 (0.5-1.1) | 0.9 (0.6-1.5) | ||
| 15+ | 0.8 (0.5-1.3) | 0.7 (0.4-1.4) | ||||||
| Yoo (41) | Japan | 455 | Per 2 y older | Continuous | 0.8 (0.7-1.0) | 1.2 (1.0-1.4) | ||
| ER+/PR+ | ER−/PR− | |||||||
| Cotterchio (24) | Canada (ON) | 3,276 | <12 | Premenopause | ||||
| 12 | 0.6 (0.4-0.9) | 1.1 (0.6-1.9) | ||||||
| 13 | 0.5 (0.3-0.8) | 1.1 (0.6-1.8) | ||||||
| 14+ | 0.5 (0.3-0.8) | 1.1 (0.6-2.0) | ||||||
| Postmenopause | ||||||||
| 12 | 1.3 (1.0-1.7) | 1.0 (0.7-1.5) | ||||||
| 13 | 1.2 (0.9-1.5) | 1.0 (0.7-1.4) | ||||||
| 14+ | 0.8 (0.6-1.1) | 0.9 (0.6-1.4) | ||||||
| Huang (32) | United States (CBCS) | 783 | <12 | 12+ | 0.7 (0.5-0.9) | 0.9 (0.7-1.4) | ||
| McCredie (23) | Melbourne (Australia) | 618 | <13 | 13+ | 0.8 (0.6-1.1) | 0.9 (0.5-1.8) | ||
| Britton (29) | United States (WISH) | 1,212 | <13 | 13+ | 0.8 (0.6-0.9) | 0.8 (0.6-1.0) | ||
| Potter (17) | United States (IWHS) | 610 | <13 | 13+ | 0.7 (0.6-0.9) | 1.1 (0.7-1.7) | ||
| Yoo (41) | Japan | 455 | Per 2 y older | Continuous | 0.8 (0.7-1.0) | 1.1 (0.9-1.4) | ||
| First author (reference) . | Country (study) . | Cases (n) . | Age at menarche (y) . | . | Risk estimate (95% CI)* . | . | ||
|---|---|---|---|---|---|---|---|---|
| . | . | . | Reference group . | Age category . | . | . | ||
| ER+ | ER− | |||||||
| Kreiger (35) | Canada (ON) | 528 | <12 | 12-14 | 0.8 (0.5-1.1) | 0.9 (0.5-1.6) | ||
| 15+ | 0.8 (0.5-1.3) | 0.7 (0.3-1.5) | ||||||
| Zhu† (27) | United States (TN) | 281 | <13 | 13+ | 1.0 (0.6-1.6) | 1.2 (0.7-2.1) | ||
| Cooper (36) | Australia | 380 | <13 | 13 | 0.9 (0.6-1.5) | 0.9 (0.6-1.7) | ||
| 14+ | 1.0 (0.6-2.1) | 0.8 (0.4-1.4) | ||||||
| Hislop (37) | Canada (BC) | 512 | <13 | 13 | 0.9 (0.7-1.1) | 0.9 (0.7-1.2) | ||
| 14+ | 1.0 (0.8-1.2) | 1.1 (0.8-1.4) | ||||||
| McTiernan (39) | United States (CASH-WA) | 240 | <13 | 13+ | 1.3 (0.8-1.9) | 1.8 (1.1-3.0) | ||
| Yoo (41) | Japan | 455 | Per 2 y older | Continuous | 1.0 (0.9-1.2) | 1.1 (0.9-1.3) | ||
| PR+ | PR− | |||||||
| Kreiger (35) | Canada (ON) | 528 | <12 | 12-14 | 0.7 (0.5-1.1) | 0.9 (0.6-1.5) | ||
| 15+ | 0.8 (0.5-1.3) | 0.7 (0.4-1.4) | ||||||
| Yoo (41) | Japan | 455 | Per 2 y older | Continuous | 0.8 (0.7-1.0) | 1.2 (1.0-1.4) | ||
| ER+/PR+ | ER−/PR− | |||||||
| Cotterchio (24) | Canada (ON) | 3,276 | <12 | Premenopause | ||||
| 12 | 0.6 (0.4-0.9) | 1.1 (0.6-1.9) | ||||||
| 13 | 0.5 (0.3-0.8) | 1.1 (0.6-1.8) | ||||||
| 14+ | 0.5 (0.3-0.8) | 1.1 (0.6-2.0) | ||||||
| Postmenopause | ||||||||
| 12 | 1.3 (1.0-1.7) | 1.0 (0.7-1.5) | ||||||
| 13 | 1.2 (0.9-1.5) | 1.0 (0.7-1.4) | ||||||
| 14+ | 0.8 (0.6-1.1) | 0.9 (0.6-1.4) | ||||||
| Huang (32) | United States (CBCS) | 783 | <12 | 12+ | 0.7 (0.5-0.9) | 0.9 (0.7-1.4) | ||
| McCredie (23) | Melbourne (Australia) | 618 | <13 | 13+ | 0.8 (0.6-1.1) | 0.9 (0.5-1.8) | ||
| Britton (29) | United States (WISH) | 1,212 | <13 | 13+ | 0.8 (0.6-0.9) | 0.8 (0.6-1.0) | ||
| Potter (17) | United States (IWHS) | 610 | <13 | 13+ | 0.7 (0.6-0.9) | 1.1 (0.7-1.7) | ||
| Yoo (41) | Japan | 455 | Per 2 y older | Continuous | 0.8 (0.7-1.0) | 1.1 (0.9-1.4) | ||
NOTE: Table excludes Morabia et al. (33), who found that an older age at menarche similarly reduced the risk of both ER+ and ER− breast cancers; however, ORs were not presented in the article.
ORs were the reported risk estimates for case-control studies and RRs for cohort designs.
Among African American women.