Table 4.
Potential risk factors for thymoma
| Cancer risk factor | Evidence regarding relevance in thymoma* |
Comment |
|---|---|---|
| Tobacco/alcohol | - | Absence of increased risk of tobacco and alcohol related cancers. |
| Ionizing radiation | -- | No increased risk following radiation for benign enlarged thymus or other cancers. |
| Occupation | 0 | No data |
| Environmental contaminants | 0 | No data |
| Diet and nutrition | 0 | No data |
| Genetic variants | + | No family clustering. However, increased risk among Asians/Pacific Islanders, and association with sarcomas, are suggestive. |
| Immunosuppression | --- | No increased risk in HIV-infected people or transplant recipients. |
| Infections | - | Unconfirmed reports of associations with viral infections. However, EBV is likely involved in lymphoepithelial carcinoma variant. |
Abbrevitations: EBV Epstein Barr virus, HIV human immunodeficiency virus
*
Symbols range from 3 minus signs (strong evidence against relevance), to a zero (no evidence), to 3 plus signs (strong evidence for relevance).