Table 2 Relative risk of breast cancer in relation to experience of stress and adverse life events during the 5Â years preceding entry to the study, Breakthrough Generations Study
| Â | Oestrogen-receptor status of breast cancer | |||||
|---|---|---|---|---|---|---|
| Â | All cases | Positive | Negative | |||
Factor | No. of cases | Adjusted RR (95Â % CI)b | No. of cases | Adjusted RR (95Â % CI)b | No. of cases | Adjusted RR (95Â % CI)b |
Frequency of experience of stress a | ||||||
Never/occasionally | 1112 | 1.00 | 871 | 1.00 | 161 | 1.00 |
Frequently | 460 | 0.92 (0.83–1.03) | 355 | 0.91 (0.81–1.04) | 74 | 1.01 (0.77–1.34) |
Continuously | 86 | 0.92 (0.73–1.15) | 70 | 0.96 (0.75–1.23) | 9 | 0.70 (0.36–1.38) |
|  |  | P trend = 0.15 |  | P trend = 0.26 |  | P trend = 0.55 |
Adverse life events b : | ||||||
Death of husband/partner | Â | Â | Â | Â | Â | Â |
 No | 1606 | 1.00 | 1255 | 1.00 | 236 | 1.00 |
 Yes | 64 | 1.13 (0.88–1.46) | 48 | 1.07 (0.80–1.44) | 11 | 1.52 (0.82–2.82) |
Death of child/parent or other close relative | Â | Â | Â | Â | Â | Â |
 No | 1200 | 1.00 | 933 | 1.00 | 185 | 1.00 |
 Yes | 470 | 0.87 (0.78–0.97) | 370 | 0.88 (0.78–0.99) | 62 | 0.76 (0.57–1.02) |
Death of close friend | Â | Â | Â | Â | Â | Â |
 No | 1390 | 1.00 | 1088 | 1.00 | 201 | 1.00 |
 Yes | 280 | 0.94 (0.83–1.08) | 215 | 0.91 (0.79–1.05) | 46 | 1.16 (0.84–1.61) |
Personal illness/injury | ||||||
 No | 1520 | 1.00 | 1189 | 1.00 | 221 | 1.00 |
 Yes | 150 | 1.03 (0.87–1.22) | 114 | 0.99 (0.82–1.21) | 26 | 1.28 (0.85–1.93) |
Loss of job | Â | Â | Â | Â | Â | Â |
 No | 1534 | 1.00 | 1196 | 1.00 | 230 | 1.00 |
 Yes | 136 | 1.09 (0.91–1.30) | 107 | 1.09 (0.89–1.33) | 17 | 0.94 (0.57–1.54) |
Divorce/separation | ||||||
 No | 1541 | 1.00 | 1207 | 1.00 | 222 | 1.00 |
 Yes | 129 | 1.15 (0.96–1.38) | 96 | 1.09 (0.89–1.33) | 25 | 1.54 (1.01–2.34) |
Other stressful life event | ||||||
 No | 929 | 1.00 | 745 | 1.00 | 124 | 1.00 |
 Yes | 741 | 0.95 (0.86–1.05) | 558 | 0.90 (0.80–1.00) | 123 | 1.17 (0.91–1.51) |
Any of the above | ||||||
 No | 425 | 1.00 | 339 | 1.00 | 57 | 1.00 |
 Yes | 1245 | 0.95 (0.85–1.06) | 964 | 0.92 (0.81–1.04) | 190 | 1.12 (0.83–1.52) |
Number of events | ||||||
 0 | 425 | 1.00 | 339 | 1.00 | 57 | 1.00 |
 1 | 714 | 0.97 (0.86–1.09) | 560 | 0.95 (0.83–1.09) | 107 | 1.10 (0.80–1.53) |
 2 | 373 | 0.93 (0.81–1.07) | 285 | 0.88 (0.75–1.03) | 54 | 1.07 (0.73–1.55) |
 ≥3 | 158 | 0.93 (0.77–1.12) | 119 | 0.87 (0.70–1.07) | 29 | 1.37 (0.87–2.16) |
|  |  | P trend = 0.25 |  | P trend = 0.050 |  | P trend = 0.25 |