Phototherapy could be associated with neonatal cancer

Although phototherapy is an established and valuable treatment for infants with neonatal hyperbilirubinemia, some investigations have raised concerns that the treatment is associated with cancer. Now a large study shows that whereas phototherapy may slightly increase the risk of cancer in the first year after birth, the increase in absolute risk is small.

According to an analysis of comprehensive data for about 5 million infants born in California from 1998 to 2007, 1100 of these infants received a cancer diagnosis, a population incidence of 21.4/100,000. The most common cancers were leukemia (23%), brain or nervous system cancer (16%), and eye or orbit cancer (9%). In unadjusted analyses, infants who received phototherapy were 1.6 times more likely to develop some type of cancer than those who did not receive phototherapy.

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Risk ratios for specific cancers (all risk ratios persisted in adjusted analyses) were 2.7 for myeloid leukemia and for kidney cancer, and 1.7 for other cancers (which included an excess of bone cancer). Investigators also found that for infants with Down syndrome, the absolute risk increase of cancer associated with phototherapy was almost 10 times higher than in other infants because these children have a higher baseline risk for the disease (Wickremasinghe AC, et al. Pediatrics. 2016;137[6]:e20151353).

Commentary: The phototherapy-associated increased risk of cancer in the first year of life, as reported here, is small. The researchers estimate that 10,638 babies would need to be treated with phototherapy before 1 additional child develops cancer. They do not suggest that phototherapy should be abandoned. Rather, they remind us that no therapy is without risk and that we always need to weigh risk and benefit, using therapies only when indicated. -Michael G Burke, MD 

Ms Freedman is a freelance medical editor and writer in New Jersey. Dr Burke, section editor for Journal Club, is chairman of the Department of Pediatrics at Saint Agnes Hospital, Baltimore, Maryland. The editors have nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.