Abstract 873: Association of rib anomalies and childhood cancers
Authors: Zierhut Heather A. , Murati Michael A. , Holm Tara , Hoggard Eric , Spector Logan G. 
Published: June 2012

Major and minor congenital anomalies are found more often in children with cancer than in those without. Rib abnormalities (RAs) are common anomalies which have been associated with childhood cancer in three studies; however the studies differed in the specific type of RAs (abnormal rib number or cervical ribs) implicated. This study sought to clarify the literature using the clinical population of the University of Minnesota.

Methods: RAs were assessed in a hospital based case-control study. Cases consisted of cancer patients aged 0-19 years old treated at the University of Minnesota during 2003-2009. Controls were randomly selected pediatric patients who received a chest X-ray at a community hospital during 2003-2008. Data collected from medical records were sex, ethnicity, date of birth, date of radiograph, indication for chest radiograph, and ZIP code of residence. Cancer type and date of diagnosis was also collected for cases. Two radiologists oversaw one radiology resident's evaluation of rib number, cervical, bifid, and post-surgical rib anomalies, predominantly by X-ray. Pearson's Chi-square test was used to assess categorical data differences between cases and controls. Dichotomous variables were created for normal (24) or abnormal (&gt;24, &lt;24) rib number and cervical ribs. Logistic regression was used to calculate the odds ratios and 95% CI adjusting for age and sex. All statistical analyses were performed using SAS® 9.2.

Results: Images were available for 76.5% (478/625) of cases and 93.2% (1398/1499 = 93.2%) of controls. Of the available images, 96.0% (459/478) and 81.2% (1135/1398) were evaluable. There were significant differences between childhood cancer cases and controls for age at imaging (cases =5.57 years, controls = 9.45 years, p&lt;0.0001), residence within the state of Minnesota (controls = 97.9% and cases = 67.4% were residents, p&lt;0.0001). Gender was not significantly different (cases = 56.4% male, controls =59.7%, p=0.23). Data on ethnicity was missing in over 20% of controls and 50% of cases and was not included in the analysis. There was a significant difference in the number of abnormal ribs in cases versus controls after controlling for age and sex (OR = 1.66 (95%CI 1.00, 2.74), p=0.05). The presence of cervical ribs was not significantly associated with overall childhood cancer (p-value = 0.38). Collectively renal tumors had a significantly increased number of abnormal ribs (OR = 4.15 (95%CI 1.17, 14.80) p-value = 0.03).

Conclusions: The results of this study support previous reports that there is an association of RAs with childhood cancer. Children with renal malignancies had a significantly higher prevalence of RAs. There was no association between childhood cancer and cervical ribs. Further research is warranted to investigate the significance of the association of RAs and childhood cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 873. doi:10.1158/1538-7445.AM2011-873