Table 4.
Meta-analysed percentage of patients with cancer
| Organ of incidentaloma | No of systematic reviews | No of primary studies | No of incidentalomas | Meta-analysed proportion of malignancies (%; 95% CI) | τ2 | I2 (%) | Proportion (%) of heterogeneity explained by study size (R2 via meta-regression) |
|---|---|---|---|---|---|---|---|
| Adrenal | 1 | 9 | 1040 | 0.0007 (0 to 0.5) | 0 | 0 | NA |
| Ovary | 1 | 5 | 363 | 28 (11 to 48) | 0.05 | 94 | 76 |
| Brain | 1 | 15 | 1864 | 0 (0 to 0.0001) | 0 | 0 | NA |
| Breast | 2 | 17 | 661 | 42 (31 to 54) | 0.04 | 85 | 0 |
| Extra-colonic | 1 | 11 | 998 | 14 (4 to 28) | 0.07 | 95 | 11 |
| Renal | 1 | 16 | 1530 | 25 (16 to 34) | 0.04 | 94 | 0.7 |
| Thyroid* | 1 | 2 | 111 | 28 (20 to 37) | 0 | 0 | NA |
| Thyroid† | 1 | 31 | 3659 | 19 (15 to 24) | 0.02 | 89 | 42 |
| Colon‡ | 2 | 36 | 661 | 17 (12 to 21) | 0.02 | 86 | 7 |
| Parotid§ | 1 | 11 | 210 | 5 (2 to 10) | 0 | 0 | NA |
| Prostate§ | 1 | 6 | 771 | 11 (1 to 28) | 0.005 | 69 | 0 |
NA=not applicable.
Analysis only includes asymptomatic patients without a history of cancer.
Sensitivity analysis including patients with known or suspected cancer; 5.9% of these cancers metastasised to the thyroid (28 of 477), and systematic review authors did not provide the number of metastases per primary study, thus it was not possible to exclude them from meta-analysis.
Main analysis was not possible because only one primary study included patients who did not have cancer. This analysis included patients with known or suspected cancer. Systematic review authors did not state whether their data included or excluded metastasis, but metastasis to colon is rare.
Main analysis was not possible because primary studies only included patients with cancer. This analysis includes patients with known or suspected cancer, but metastases have been excluded.