Phototherapy for neonatal hyperbilirubinemia not associated with childhood cancer: Study

The incidence of childhood cancer was higher for infants with phototherapy (25.1 per 100,000 person-years) and untreated jaundice (23.0 per 100,000) compared to unexposed infants (21.6 per 100,000).

A group of researchers aimed to reassess the relationship between phototherapy and cancer in an extended version of a previous cohort and to replicate a report from Quebec of increased cancer risk after phototherapy beginning at age 4 years.

This cohort study included 139 100 children born at ≥35 weeks' gestation from 1995 to 2017, followed through March 16, 2019, in Kaiser Permanente Northern California hospitals who had a qualifying bilirubin level from −3 mg/dL to +4.9 mg/dL from the American Academy of Pediatrics phototherapy threshold; an additional 40 780 children and 5 years of follow-up from our previous report. The exposure was inpatient phototherapy (yes or no), and the outcomes were various types of childhood cancer. We used Cox proportional hazard models, controlling for propensity-score quintiles, and allowed for time-dependent exposure effects to assess for the risk of cancer after a latent period.

The results of the study are as follows:

• Over a mean (SD) follow-up of 8.2 (5.7) years, the crude incidence of cancer per 100 000 person-years was 25.1 among those exposed to phototherapy and 19.2 among those not exposed (233 cases of cancer).
• After propensity adjustment, phototherapy was not associated with any cancer, hematopoietic cancer, or solid tumours
• The researchers also found no association with cancer diagnoses at age ≥4 years.

Thus, the researchers concluded that they did not confirm previous, concerning associations between phototherapy and adjusted risk of any cancer, nonlymphocytic leukaemia, or brain and/or central nervous systems tumours in later childhood.

Reference:

A study titled, "Update on Phototherapy and Childhood Cancer in a Northern California Cohort" By Jean C. Digitale, et al. was published in the Pediatrics.

DOI: https://doi.org/10.1542/peds.2021-051033