Table 3. Childhood BMI and the risk of endometrioid adenocarcinoma, following women from 1995 when HRT information was availablea.

Censoring for unopposed oestrogen use	Age (years)	N	Cases	BMI z-score (approximate percentile)b													P-valuec
				−1.5 (7th)		−1.0 (16th)		−0.5 (31st)		0 (50th)	0.5 (69th)		1.0 (84th)		1.5 (93rd)
				HR	95% CI	HR	95% CI	HR	95% CI	HR	HR	95% CI	HR	95% CI	HR	95% CI
No censoring	7	131 120	572	0.96	0.78–1.18	0.92	0.82–1.04	0.93	0.84–1.02	1.00 (ref.)	1.08	0.98–1.20	1.26	1.11–1.41	1.52	1.27–1.81	0.05
	8	132 493	583	0.97	0.77–1.22	0.93	0.82–1.06	0.93	0.84–1.03	1.00 (ref.)	1.07	0.97–1.19	1.27	1.13–1.43	1.60	1.34–1.90	0.02
	9	127 482	583	0.93	0.73–1.19	0.93	0.81–1.05	0.94	0.85–1.04	1.00 (ref.)	1.06	0.96–1.18	1.27	1.13–1.43	1.64	1.37–1.95	0.02
	10	123 940	578	0.97	0.77–1.24	0.90	0.79–1.02	0.89	0.80–0.98	1.00 (ref.)	1.13	1.02–1.25	1.35	1.20–1.52	1.67	1.39–2.01	0.02
	11	123 007	580	0.95	0.75–1.22	0.90	0.79–1.03	0.91	0.82–1.00	1.00 (ref.)	1.10	1.00–1.22	1.33	1.18–1.50	1.70	1.41–2.04	0.02
	12	121 950	578	0.88	0.68–1.13	0.86	0.75–0.98	0.88	0.80–0.98	1.00 (ref.)	1.13	1.02–1.25	1.34	1.18–1.51	1.62	1.34–1.96	0.14
	13	120 133	566	0.85	0.66–1.10	0.83	0.73–0.95	0.86	0.78–0.96	1.00 (ref.)	1.16	1.04–1.28	1.34	1.18–1.51	1.55	1.29–1.88	0.27
Censored	7	131 120	501	0.96	0.76–1.20	0.91	0.80–1.04	0.91	0.82–1.01	1.00 (ref.)	1.10	0.99–1.23	1.31	1.16–1.49	1.64	1.37–1.97	0.02
	8	132 493	512	0.91	0.71–1.18	0.90	0.79–1.03	0.92	0.83–1.02	1.00 (ref.)	1.09	0.98–1.21	1.31	1.15–1.48	1.66	1.39–1.99	0.04
	9	127 482	512	0.88	0.67–1.15	0.90	0.78–1.04	0.94	0.84–1.05	1.00 (ref.)	1.07	0.96–1.19	1.30	1.14–1.47	1.70	1.42–2.05	0.03
	10	123 940	508	0.97	0.75–1.25	0.89	0.77–1.02	0.88	0.79–0.98	1.00 (ref.)	1.14	1.02–1.27	1.39	1.22–1.58	1.77	1.46–2.14	0.01
	11	123 007	510	0.90	0.69–1.19	0.88	0.76–1.01	0.89	0.80–1.00	1.00 (ref.)	1.12	1.00–1.25	1.37	1.21–1.56	1.78	1.47–2.15	0.04
	12	121 950	510	0.84	0.63–1.11	0.84	0.73–0.97	0.88	0.79–0.98	1.00 (ref.)	1.14	1.02–1.27	1.38	1.21–1.56	1.72	1.41–2.09	0.16
	13	120 133	498	0.82	0.62–1.09	0.81	0.70–0.93	0.85	0.76–0.95	1.00 (ref.)	1.18	1.05–1.31	1.38	1.21–1.58	1.63	1.34–1.98	0.31

Abbreviations: BMI, body mass index; CI, confidence interval; HR, hazard ratio; HRT, hormone replacement therapy.

^aCox model stratified by 5-year birth cohorts. BMI was modelled using linear splines with two knots at z-scores of ±0.68.

^bThe exact percentile equivalents to the z-scores change with age, so approximate percentiles are shown.

^cTest for linearity using a likelihood ratio test.