Study sample stratified by histological subtype, mutation and methylation status. Information on histological subtype was not available for six tumours (‘missing’).
| Histological subtype | Individuals | gBRCA1 (%) | gBRCA2 (%) | gOCgenes (%) | sTP53 (%) | sBRCA1 (%) | sBRCA2 (%) | sOCgenes (%) | sPIK3CA (%) | sPTEN (%) | mBRCA1 (%) | mRAD51C (%) |
| High-grade serous | 373 | 66 (17.7) | 21 (5.6) | 23 (6.2) | 330 (88.5) | 14 (3.8) | 10 (2.7) | 9 (2.4) | 7 (1.9) | 2 (0.5) | 50 (13.4) | 8 (2.1) |
| High-grade endometrioid | 22 | 3 (13.6) | 0 (/) | 2 (9.1) | 9 (40.9) | 2 (9.1) | 1 (4.5) | 2 (9.1) | 5 (22.7) | 6 (27.3) | 2 (9.1) | 0 (/) |
| Serous/papillary grade unknown | 19 | 2 (10.5) | 0 (/) | 1 (5.3) | 18 (94.7) | 1 (5.3) | 0 (/) | 0 (/) | 1 (5.3) | 0 (/) | 2 (10.5) | 1 (5.3) |
| Low-grade serous | 16 | 0 (/) | 1 (6.3) | 1 (6.3) | 2 (12.5) | 0 (/) | 0 (/) | 0 (/) | 2 (12.5) | 1 (6.3) | 0 (/) | 1 (6.3) |
| Low-grade endometrioid | 7 | 1 (14.3) | 0 (/) | 0 (/) | 2 (28.6) | 1 (14.3) | 0 (/) | 1 (14.3) | 2 (28.6) | 4 (57.1) | 0 (/) | 0 (/) |
| Clear cell | 6 | 0 (/) | 0 (/) | 0 (/) | 0 (/) | 0 (/) | 0 (/) | 0 (/) | 4 (66.7) | 1 (16.7) | 0 (/) | 0 (/) |
| Mucinous | 6 | 0 (/) | 0 (/) | 0 (/) | 1 (16.7) | 0 (/) | 0 (/) | 0 (/) | 0 (/) | 1 (16.7) | 0 (/) | 0 (/) |
| Other/unspecified | 18 | 2 (11.1) | 0 (/) | 1 (5.6) | 15 (83.3) | 0 (/) | 0 (/) | 0 (/) | 3 (16.7) | 1 (5.6) | 2 (11.1) | 0 (/) |
| Missing | 6 | 1 (16.7) | 1 (16.7) | 0 (/) | 6 (100) | 0 (/) | 1 (16.7) | 0 (/) | 0 (/) | 0 (/) | 1 (16.7) | 0 (/) |
| Total | 473 | 75 (15.9) | 23 (4.9) | 28 (5.9) | 383 (81.0) | 18 (3.8) | 12 (2.5) | 12 (2.5) | 24 (5.1) | 16 (3.4) | 57 (12.1) | 10 (2.1) |
A total of 18 tumours were summarised as ‘other/unspecified’ of which 11 tumours showed a mixed histopathology (defined by two or more distinct histological subtypes present based on routine histopathological assessment), 4 tumours were undifferentiated, 2 were adenocarcinomas and 1 was a pleomorphic cellular tumour. In the group of individuals with high-grade serous carcinoma, the mean age at first diagnosis was significantly younger in carriers of deleterious germline BRCA1/2 variants (52.4 years, range 30–77; p<0.0001, Student’s t-test) and in individuals with BRCA1 promoter methylation (55.5 years, range 32–78; p=0.0205, Student’s t-test) compared with all individuals with high grade serous carcinoma (59.2 years, range 21–93).
g, germline; mBRCA1, BRCA1 promoter methylation ≥5%; mRAD51C, RAD51C promoter methylation ≥5%; s, somatic.