Phototherapy and childhood cancer: Shared risk factors

Risk of childhood neoplasms related to neonatal phototherapy- a systematic review and meta-analysis

CONTEXT

Observational studies have shown conflicting results as to whether exposure to neonatal phototherapy is associated with increased rates of childhood cancer.

OBJECTIVE

To describe the rates of childhood neoplasms and cancer after neonatal phototherapy.

DATA SOURCES

The CENTRAL, PubMed, Scopus, and Web of Science databases.

STUDY SELECTION

Observational studies regardless of design were included.

DATA EXTRACTION

The data were extracted by one author and validated by another. The risk-of-bias assessment was performed using the ROBINS-E and Joanna Briggs Institute critical appraisal tools.

RESULTS

Six cohort and 10 case-control studies were included. The overall risk of bias was high in seven and low in nine studies. In cohort studies, the odds ratio (OR) was increased for hematopoietic cancer (1.44; confidence interval [CI]: 1.16-1.80) and solid tumors (OR: 1.18; CI: 1.00-1.40). In case-control studies, the OR was 1.63 (CI: 0.99-2.67) for hematopoietic cancers and 1.18 (CI: 1.04-1.34) for solid tumors.

CONCLUSIONS

Children with a history of neonatal phototherapy had increased risk of hematopoietic cancer and solid tumors. The evidence quality was limited due to the high risk of bias and potential residual confounding.

IMPACT STATEMENT

Exposure to neonatal phototherapy increased later risk of hematopoietic cancer and solid tumors. This is the most comprehensive study on the association between phototherapy and cancer, but the evidence quality was limited due risk of bias and residual confounding. Future large scale well conducted studies are still needed to better estimate the association and.

Update on Phototherapy and Childhood Cancer in a Northern California Cohort

OBJECTIVES

We 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.

METHODS

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.

RESULTS

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 (hazard ratio [HR]: 1.13, 95% confidence interval [CI]: 0.83-1.54), hematopoietic cancer (HR: 1.17, 95% CI: 0.74-1.83), or solid tumors (HR: 1.01, 95% CI: 0.65-1.58). We also found no association with cancer diagnoses at age ≥4 years.

CONCLUSIONS

We did not confirm previous, concerning associations between phototherapy and adjusted risk of any cancer, nonlymphocytic leukemia, or brain and/or central nervous systems tumors in later childhood.