Inguinal hernia in patients with Ewing sarcoma: a clue to etiology

Various congenital anomalies have been associated with childhood cancer, but as yet no anomaly has been consistently found with Ewing sarcoma (ES). Recently a large case-control study of ES patients reported a greater number of hernias in both cases and their sibling controls than in population controls. Most of these hernias were inguinal. Because these anomalies were also reported previously in two case series, we looked for inguinal hernias in a different population of ES patients.

We abstracted medical records for 306 pathologically confirmed ES/primitive neuroectodermal tumor (PNET) patients seen at NIH between 1960 and 1992. Epidemiological data on demographics and medical conditions were analyzed. The frequency of anomalies was compared to expected rates to calculate relative risk and confidence intervals.

Anomalies were present in 67 (22%) cases. A particular anomaly, inguinal hernia, was reported for 13 (5%) NIH cases. Compared to population estimates for white children, the relative risk of inguinal hernia among white NIH cases was 13.3 (95% CI 3.60-34.1) for females and 6.67 (95% CI 2.67-13.7) for males.

The findings of inguinal hernias in some patients with ES suggest that a disruption in normal embryological development occurred. This may provide an important clue to the etiology of ES. We hypothesize that these hernias may relate to an in utero exposure or indicate an underlying genetic disorder. Future studies should carefully evaluate ES families for genetic disease and explore environmental factors. Med. Pediatr. Oncol. 34:195-199, 2000. Published 2000 Wiley-Liss, Inc.