Proportional distribution of tumour origin according to age in PJS patients compared to the general population
| Tumour | Age (years) | PJS cohort % (absolute numbers) | General population | p Value |
| GI cancer (♂+♀) | All ages | 48.8% (21/43) | 22.7% | <0.001 |
| 5–34 | 55.5% (5/9)* | 5%* | <0.001* | |
| 35–54 | 45.8% (11/24) | 15.3% | <0.001 | |
| 55+ | 50% (5/10) | 25.3% | 0.073 | |
| GI cancer (♂) | All ages | 72.2% (13/18) | 23.5% | <0.001 |
| 5–34 | 75% (3/4) | 5.9% | 0.001 | |
| 35–54 | 70% (7/10) | 23.6% | 0.002 | |
| 55+ | 75% (3/4) | 24.2% | 0.046 | |
| GI cancer (♀) | All ages | 32% (8/25) | 21.7% | 0.214 |
| 5–34 | 40% (2/5) | 4.2% | 0.017 | |
| 35–54 | 28.6% (4/14) | 10.3% | 0.048 | |
| 55+ | 33.3% (2/6) | 26.9% | 0.663 | |
| Gynaecological cancer (♀) | All ages | 24% (6/25) | 11.5% | 0.051 |
| 5–34 | 40% (2/5) | 13.8% | 0.144 | |
| 35–54 | 21.4% (3/14) | 12.6% | 0.406 | |
| 55+ | 16.7% (1/6) | 11.1% | 0.505 | |
| Breast cancer (♀) | All ages | 20% (5/25) | 32.7% | 0.174 |
| 5–34 | 0% (0/5) | 22.1% | 0.593 | |
| 35–54 | 14.3% (2/14) | 48.1% | 0.014 | |
| 55+ | 50% (3/6) | 28% | 0.359 |
↵* That is 55.5% of cancers in the PJS cohort (♂+♀) aged 5–34 years concerned gastrointestinal (GI) cancers (five GI cancers among nine cancers diagnosed in this subgroup=55.5%), whereas this was 5% in the general population (♂+♀) aged 5–34 years (p<0.001).
Note: Cancers diagnosed in the PJS cohort before 1960 were not included in these analyses.