NEW YORK (Reuters Health) — There may be an association between childhood cancer and birthmarks, according to a new study.Minor malformations, such as birthmarks, may reflect “altered prenatal development,” which could also increase the risk developing cancer, Dr. Julie A. Ross, of the University of Minnesota, Minneapolis, and colleagues point out in the medical journal Pediatrics. In addition, children with certain leukemias and soft tissue tumours have been shown to have “a significant increased frequency of birthmarks.”

To further investigate this relationship, the researchers used data from a cohort for 49,503 children born between 1959 and 1966. Birthmarks were documented as definite or suspected during the first year of life and included strawberry birthmarks, port-wine stains, pigmented moles, and cafDe-au-lait spots.

Overall, 2505 children had a documented definite or suspected birthmark. Out of the whole group, 47 children were diagnosed with cancer before age eight years and seven of these had a definite or suspected birthmark.

When all cancers were included, having a birthmark was associated with a threefold increased likelihood of developing cancer. The team notes that birthmarks did not appear to be associated with any specific type of childhood cancer.

Because of the small number of cancer cases, it’s possible that the findings could have arisen by chance, Dr. Ross’s group notes.

Nonetheless, they hope the results may lead to insights into the cause of childhood malignancies.