Table 3. Cancer incidence in the cohort for selected sites, by type of treatment.
|
All women (n=7317)a |
Women prescribed ovarian-stimulating drugs (n=3180)a |
Women not prescribed ovarian-stimulating drugs (n=3949)a |
||||||
|---|---|---|---|---|---|---|---|---|
| Cancer | ICD-10 | O/Eb | SIR (95% CI) | O/Eb | SIR (95% CI) | O/Eb | SIR (95% CI) | RR (95% CI)c |
| All | C00-C85, C88-C94.3, C94.7-C97.9, D32, D33, D42, D43 | 367/358.8 | 1.02 (0.92–1.13) | 197/179.1 | 1.10 (0.95–1.26) | 161/170.8 | 0.94 (0.80–1.10) | 1.17 (0.94–1.45) |
| Digestive system | C15-C26, C48 | 29/41.2 | 0.70 (0.47–1.01) | 15/19.8 | 0.76 (0.42–1.25) | 14/20.6 | 0.68 (0.37–1.14) | 1.11 (0.50–2.49) |
| Colorectum | C18-C21 | 17/25.1 | 0.68 (0.39–1.08) | 11/12.2 | 0.90 (0.45–1.62) | 6/12.4 | 0.48 (0.18–1.05) | 1.87 (0.64–6.17) |
| Liver and biliary tract | C22-C24 | 3/2.4 | 1.25 (0.26–3.65) | 3/1.2 | 2.59 (0.53–7.58) | 0/1.2 | 0.00 (0.00–3.09) | 5.05 (0.29–6254) |
| Respiratory system | C30-C39, C45 | 16/25.5 | 0.63 (0.36–1.02) | 7/12.3 | 0.57 (0.23–1.17) | 9/12.7 | 0.71 (0.32–1.35) | 0.80 (0.25–2.42) |
| Bone and articular cartilage | C40, C41 | 4/2.8 | 1.42 (0.39–3.63) | 1/1.4 | 0.74 (0.02–4.10) | 3/1.4 | 2.17 (0.45–6.36) | 0.34 (0.01–4.21) |
| Malignant melanoma of skin | C43 | 14/16.7 | 0.84 (0.46–1.41) | 6/8.1 | 0.74 (0.27–1.60) | 8/8.1 | 0.99 (0.43–1.95) | 0.74 (0.21–2.44) |
| Breast | C50 | 177/157.3 | 1.13 (0.97–1.30) | 102/80.7 | 1.26 (1.03–1.53) | 72/72.6 | 0.99 (0.78–1.25) | 1.27 (0.93–1.75) |
| Cervix uteri | C53 | 5/23.5 | 0.21 (0.07–0.50) | 1/11.6 | 0.09 (0.00–0.48) | 4/11.1 | 0.36 (0.10–0.92) | 0.24 (0.00–2.43) |
| Corpus uteri | C54, C55 | 31/15.3 | 2.02 (1.37–2.87) | 18/7.8 | 2.31 (1.37–3.64) | 12/7.2 | 1.66 (0.86–2.90) | 1.39 (0.63–3.16) |
| Ovary | C56, C57.0-C57.4 | 21/21.7 | 0.97 (0.60–1.48) | 12/10.9 | 1.10 (0.57–1.93) | 8/10.3 | 0.78 (0.34–1.53) | 1.42 (0.53–3.99) |
| Urinary tract | C64-C68 | 5/9.3 | 0.54 (0.17–1.25) | 1/4.5 | 0.22 (0.01–1.24) | 3/4.6 | 0.65 (0.13–1.90) | 0.34 (0.01–4.27) |
| Nervous system (incl. benign and unspecified), eye and ear | C69-C72, D32, D33, D42, D43 | 14/7.3 | 1.91 (1.05–3.21) | 7/3.6 | 1.96 (0.79–4.03) | 5/3.5 | 1.42 (0.46–3.30) | 1.38 (0.38–5.52) |
| Thyroid and other glands | C73-C75 | 6/5.1 | 1.18 (0.43–2.57) | 4/2.4 | 1.66 (0.45–4.25) | 2/2.5 | 0.79 (0.10–2.86) | 2.10 (0.30–23.2) |
| Lymphatic and haematopoietic system | C81-C85, C88, C90.0-C90.2, C91.0-C91.4, C91.5-C94.3, C94.6-C94.9, C96.0-C96.3, C96.7, C96.9 | 32/22.9 | 1.40 (0.95–1.97) | 14/11.1 | 1.26 (0.69–2.12) | 17/11.2 | 1.51 (0.88–2.42) | 0.83 (0.38–1.80) |
CI=confidence interval; SIR=standardised incidence ratio.
Numbers differ slightly from those shown in Table 2 because of deaths, cancer incidence and migrations prior to 1 January 1971 when national follow-up for cancer incidence began. Information on treatment was missing for 182 women eligible for analyses on incidence, and information on the start date of treatment was missing for an additional six women: these women were excluded from the analyses on treatment.
Numbers of observed (O) and expected (E) incident cancers estimated assuming the cohort experienced the same age and calendar year-specific cancer incidence rates as the England and Wales female general population.
Relative risk (95% confidence interval) associated with ovarian stimulation as estimated by the ratio between the two corresponding SIRs.