Table 2.

Summary of Meta-Analysis Results

Analysis	Outcome	Measure	Point Estimate	95% CI	p value	No. of Studies	CPM (n=)	No CPM (n=)
All studies17–19,21,24,26	OS	RR	1.09	1.06, 1.11	<0.001	6	10,666	145,490
		RD	7.4%	5.6%, 9.3%	<0.001
FGR – Elevated18,21,24		RR	1.09	0.97, 1.24	0.157	3	618	1318
		RD	6.6%	−1.2%, 14.3%	0.096
FGR – Varying17,19,26		RR	1.10	1.09, 1.11	<0.001	3	10,048	144,172
		RD	8.4%	7.8%, 8.9%	<0.001
All studies17–19,24	BCM	RR	0.69	0.56, 0.85	0.001	4	10,120	142,105
		RD	−3.5%	−4.0%, −3.0%	<0.001
FGR – Elevated18,24		RR	0.66	0.27, 1.64	0.283	2	464	454
		RD	−4.2%	−9.5%, 1.1%	0.123
FGR – Varying17,19		RR	0.63	0.56, 0.70	<0.001	2	9656	141,651
		RD	−3.5%	−4.0%, −3.0%	<0.001
All studies13,16,19,21,24,26,43,44,47	SCBC	Rate	4.8%	3.4%, 6.2%	-	9	3438	-
FGR – Elevated21,24			5.7%	1.8%, 9.6%	-	2	233	-
FGR – Varying13,16,19,43–45,47			4.8%	3.2%, 6.3%	-	7	3205	-
All studies16,18,19,21,23,24,26,42	MCBC	RR	0.04	0.02, 0.08	<0.001	8	2325	4840
		RD	−18.0%	−42.0%, 5.9%	0.118
FGR – Elevated18,21,23,24		RR	0.04	0.02, 0.09	<0.001	4	764	1654
		RD	−24.0%	−35.6%, −12.4%	0.013
FGR – Varying16,19,26,42		RR	0.08	0.01, 0.46	0.005	4	1561	3186
		RD	−11.1%	−5.9%, 37%	0.240
All studies16,18,24,26,42	DMR	RR	0.64	0.51, 0.81	<0.001	5	953	3323
		RD	−4.9%	−7.2%, −2.6%	<0.001
FGR – Elevated18,24		RR	0.71	0.53, 0.94	0.018	2	464	454
		RD	−5.9%	−10.7%, −1.0%	0.017
FGR – Varying16,26,42		RR	0.58	0.40, 0.83	0.003	3	489	2869
		RD	−4.4%	−6.7%, −2.0%	<0.001

BCM, breast-cancer-specific mortality; CI, confidence interval; CPM, contralateral prophylactic mastectomy; DMR, distant/metastatic recurrence; FGR, familial/genetic risk; OS, overall survival; MCBC, metachronous contralateral breast cancer; SCBC, synchronous contralateral breast cancer; RD, risk difference; RR, relative risk