Table 4
Predictive values
| A: Predictive values (% and 95% CI) of the variables first-degree family history, MSI analysis, IHC analysis for the MLH1, MSH2 and MSH6 proteins and referral to clinical geneticist to detect germline mutations (n = 174) |
|---|
| Sensitivity | Specificity | PPV | NPV |
|---|
| Family history | 76% (53% to 90%) | 64% (56% to 71%) | 19% (11% to 29%) | 96% (91% to 98%) |
| MSI analysis | 82% (59% to 94%) | 70% (62% to 77%) | 23% (14% to 35%) | 97% (92% to 99%) |
| IHC analysis | 88% (66% to 97%) | 84% (78% to 89%) | 38% (24% to 53%) | 99% (95% to 100%) |
| Referral | 29% (13% to 53%) | 90% (84% to 94%) | 24% (11% to 45%) | 92% (87% to 95%) |
| B: Predictive values (% and 95% CI) to detect germline mutations after preselection for a positive first-degree family history (n = 70) |
|---|
| Sensitivity | Specificity | PPV | NPV |
|---|
| MSI analysis | 59% (36% to 78%) | 90% (85% to 94%) | 40% (23% to 59%) | 95% (91% to 98%) |
| IHC analysis | 76% (53% to 90%) | 95% (90% to 97%) | 62% (41% to 79%) | 97% (93% to 99%) |
| C: Predictive values (% and 95% CI) of IHC analysis to detect pathogenic mutations after preselection for MSI-high tumours (n = 61) |
|---|
| Sensitivity | Specificity | PPV | NPV |
|---|
| IHC analysis | 71% (47% to 87%) | 89% (83% to 93%) | 41% (26% to 59%) | 97% (92% to 99%) |
| D: Predictive values (% and 95% CI) of immunohistochemical stainings of MLH1, MSH2 and MSH6 (n = 174) |
|---|
| Sensitivity | Specificity | PPV | NPV |
|---|
| MLH1 | 80% (38% to 96%) | 89% (84% to 93%) | 18% (7.3% to 38%) | 99% (96% to 100%) |
| MSH2 | 100% (57% to 100%) | 96% (92% to 98%) | 45% (21% to 72%) | 100% (98% to 100%) |
| MSH6 | 86% (49% to 97%) | 93% (88% to 96%) | 33% (16% to 56%) | 99% (96% to 100%) |
| E: Odds ratios for the presence of a germline mismatch repair gene mutation, calculated by multivariate analysis with backward selection for the variables first-degree family history, referral, MSI and IHC (n = 174) |
|---|
| p Value | OR | 95% CI | |
|---|
| Family history | 0.013 | 5.4 | 1.4 to 20.0 | |
| IHC | 0 | 38.3 | 9.0 to 184 | |
| MSI | 0.207 | 2.5 | 0.6 to 10.2 | |
| Referral | 0.263 | 0.4 | 0.1 to 2.1 | |