Risk of gastrointestinal cancers among 1-year patients with breast cancer, by subgroups
| Observed/expected | Incidence rate per 100 000 person years (95% CI) | Standardised incidence ratio (95% CI) | |
| Upper gastrointestinal cancers | |||
| Age group | |||
| 18–49 years | 40/23 | 23 (16 to 30) | 1.72 (1.23 to 2.35) |
| 50–69 years | 164/136 | 43 (36 to 50) | 1.21 (1.03 to 1.41) |
| ≥70 years | 75/63 | 68 (53 to 84) | 1.18 (0.93 to 1.48) |
| Breast cancer stage | |||
| Localised | 151/138 | 38 (32 to 44) | 1.09 (0.93 to 1.28) |
| Regional | 128/84 | 48 (40 to 56) | 1.52 (1.27 to 1.81) |
| Oestrogen receptor status* | |||
| Positive | 124/105 | 40 (33 to 47) | 1.18 (0.98 to 1.40) |
| Negative | 26/19 | 41 (25 to 56) | 1.40 (0.91 to 2.05) |
| Unknown | 50/39 | 42 (30 to 54) | 1.28 (0.95 to 1.69) |
| HER2 status* | |||
| Positive | 5/2 | 57 (7 to 106) | 2.16 (0.70 to 5.04) |
| Negative | 12/11 | 33 (15 to 52) | 1.08 (0.56 to 1.89) |
| Unknown | 183/150 | 41 (35 to 47) | 1.22 (1.05 to 1.41) |
| Lower gastrointestinal cancers | |||
| Age group | |||
| 18–49 years | 149/119 | 85 (72 to 99) | 1.25 (1.06 to 1.47) |
| 50–69 years | 861/777 | 225 (210 to 240) | 1.11 (1.04 to 1.18) |
| ≥70 years | 419/404 | 381 (344 to 417) | 1.04 (0.94 to 1.14) |
| Breast cancer stage | |||
| Localised | 864/811 | 217 (202 to 231) | 1.07 (1.00 to 1.14) |
| Regional | 565/490 | 211 (194 to 229) | 1.15 (1.06 to 1.25) |
| Oestrogen receptor status* | |||
| Positive | 715/623 | 230 (213 to 247) | 1.15 (1.06 to 1.23) |
| Negative | 123/108 | 193 (159 to 227) | 1.14 (0.95 to 1.36) |
| Unknown | 243/229 | 204 (179 to 230) | 1.06 (0.93 to 1.20) |
| HER2 status* | |||
| Positive | 22/13 | 249 (145 to 353) | 1.68 (1.05 to 2.54) |
| Negative | 76/64 | 212 (164 to 259) | 1.19 (0.94 to 1.49) |
| Unknown | 983/883 | 219 (205 to 233) | 1.11 (1.04 to 1.18) |
| Other gastrointestinal cancers | |||
| Age group | |||
| 18–49 years | 46/35 | 26 (19 to 34) | 1.32 (0.96 to 1.75) |
| 50–69 years | 252/249 | 66 (58 to 74) | 1.01 (0.89 to 1.15) |
| ≥70 years | 118/125 | 107 (88 to 127) | 0.94 (0.78 to 1.13) |
| Breast cancer stage | |||
| Localised | 264/255 | 66 (58 to 74) | 1.04 (0.92 to 1.17) |
| Regional | 152/154 | 57 (48 to 66) | 0.99 (0.84 to 1.16) |
| Oestrogen receptor status* | |||
| Positive | 196/194 | 63 (54 to 72) | 1.01 (0.87 to 1.16) |
| Negative | 39/34 | 61 (42 to 80) | 1.16 (0.83 to 1.59) |
| Unknown | 66/72 | 56 (42 to 69) | 0.92 (0.71 to 1.17) |
| HER2 status* | |||
| Positive | † | 23 (0 to 54) | 0.50 (0.06 to 1.81) |
| Negative | 16/19 | 45 (23 to 66) | 0.84 (0.48 to 1.36) |
| Unknown | † | 63 (56 to 70) | 1.03 (0.91 to 1.15) |
*Restricted to 1996 onwards due to limitations in data availability.
†Observed and expected numbers are not reported due to too few events.
HER2, human epidermal growth factor receptor 2.