Table 2.

Relative and absolute excess risks of cancers of breast, ovary, and corpus uteri among 225 786 women who underwent assisted reproduction in Great Britain, 1991-2010, including and excluding the first year after the start of treatment

Type of cancer	Follow-up (No of person years)	No of observed cancers	No of expected cancers	Standardised incidence ratio (95% CI)	Absolute excess risk (95% CI) per 100 000 person years at risk
Including first year of follow-up
Breast*	2 257 789	2578	2641.2	0.98 (0.94 to 1.01)	−2.8 (−7.1 to 1.8)
Corpus uteri†	2 257 789	164	146.9	1.12 (0.95 to 1.30)	0.8 (−0.3 to 2.0)
Ovary‡	2 257 789	405	291.82	1.39 (1.26 to 1.53)	5.0 (3.3 to 6.9)
Excluding first year of follow-up
Breast*	2 004 121	2384	2501.6	0.95 (0.92 to 0.99)	−5.9 (−10.6 to −1.0)
Corpus uteri†	2 004 121	157	141.79	1.11 (0.94 to 1.30)	0.8 (−0.4 to 2.1)
Ovary‡	2 004 121	356	271.9	1.31 (1.18 to 1.45)	4.2 (2.44 to 6.10)

^*Breast cancer=ICD-9 codes 1740-1749, 2330, and 2383; ICD-10 codes C500-C509, D050-D059, and D486.

^†Corpus uteri cancer=ICD-9 codes 1820-1828 and ICD-10 code C54.

^‡Ovarian cancer=ICD-9 codes 1830-1839 and 2362; ICD-10 codes C56, C570-C574, C481, C482, and D391.