A Cohort Study of p53 Mutations and Protein Accumulation in Benign Breast Tissue and Subsequent Breast Cancer Risk

Table 1

Number of cases and controls by center and exclusions.

	London	Portland	Total
Number of unique individuals	452	613	1065
(i) Number of controls used an additional 1×	0	7
(ii) Number of controls used an additional 2×	0	3
(iii) Number of controls that reappear as cases	8	6
Total number of records	460	632	1092
(i) Number of case records	230	316	546
(ii) Number of control records	230	316	546
Exclusions (breast cancer before baseline, no breast tissue, missing pathology data)	128	2	130
(i) Cases records excluded	53	2	55
(ii) Control records excluded	75	0	75
Total number of records after exclusions (used in unmatched analysis)	332	630	962
(i) Cases after exclusions	177	314	491
(ii) Controls after exclusions	155	316	471
Total number of women after exclusions	326	611	937
Total number of case-control sets (used in matched analysis)	148^1	316^1	464

1Matched pairs only.