Number of trials with results not published in a peer-reviewed journal (PRJ) by cancer subtype. For those subgroups with at least 16 trials, we run a significant test in order to see if these percentages were different from the global non-publication tendency. For each cancer subtype, OR were calculated taking as reference the global set minus this cancer subtype subset
| No of trials | Results not published on PRJ | OR (95% CI) | p Value | |
| Brain | 34 | 14 (41.2%) | 0.85 (0.42 to 1.72) | 0.65 |
| Breast | 66 | 25 (37.9%) | 0.71 (0.42 to 1.22) | 0.21 |
| Cervical | 18 | 11 (61.1%) | 1.98 (0.75 to 5.20) | 0.16 |
| Colorectal | 29 | 11 (37.9%) | 0.74 (0.34 to 1.59) | 0.43 |
| Endometrial | 9 | 3 (33.3%) | 0.61 (0.15 to 2.46) | 0.48 |
| Oesophagus | 4 | 3 (75%) | 3.72 (0.38 to 36) | 0.22 |
| Eye | 8 | 5 (62.5%) | 2.07 (0.49 to 8.76) | 0.31 |
| Gastric | 8 | 3 (37.5%) | 0.73 (0.17 to 3.10) | 0.67 |
| Head and neck | 84 | 47 (55.6%) | 1.72 (1.07 to 2.77) | 0.03 |
| Kidney | 2 | 2 (100.0%) | NaN | 0.12 |
| Leukaemia | 25 | 9 (36.0%) | 0.68 (0.29 to 1.56) | 0.36 |
| Liver | 8 | 4 (50.0%) | 1.23 (0.30 to 4.98) | 0.77 |
| Lung | 52 | 25 (48.1%) | 1.15 (0.65 to 2.06) | 0.63 |
| Melanoma | 1 | 1 (100.0%) | NaN | 0.27 |
| Metastasis | 5 | 4 (80.0%) | 4.98 (0.55 to 44.9) | 0.11 |
| Myeloma | 3 | 2 (66.7%) | 2.47 (0.22 to 27.39) | 0.44 |
| Pancreatic | 11 | 4 (36.4%) | 0.69 (0.20 to 2.41) | 0.56 |
| Prostate | 42 | 19 (45.2%) | 1.01 (0.54 to 1.92) | 0.97 |
| Bladder | 9 | 5 (55.5%) | 1.55 (0.41 to 5.83) | 0.52 |
| Lymphoma | 21 | 7 (33.3%) | 0.60 (0.24 to 1.51) | 0.27 |
| Sarcoma | 12 | 4 (33.3%) | 0.61 (0.18 to 2.04) | 0.41 |
| Other | 13 | 8 (61.5%) | 2 (0.64 to 6.21) | 0.22 |