Abstract A45: Inflammatory biomarker c-reactive protein in radiotherapy-induced skin toxicities of breast cancer patients.

Abstract

Abstract Purpose: Post-surgery adjuvant radiotherapy (RT) significantly reduces recurrence and metastasis of breast cancer. However, many patients experience early adverse skin reactions (EASRs) that impact quality of life. This study evaluated an inflammatory biomarker C-reactive protein (CRP) in RT-induced EASRs in breast cancer patients undergoing RT. Methods: We recruited 159 breast cancer patients undergoing RT after breast conserving surgery. The pre- and post-RT plasma CRP levels were measured using a highly-sensitive ELISA CRP assay. RT-induced EASRs were assessed at weeks 3 and 6 using the National Cancer Institute Common Toxicity Criteria (v3.0). Results: RT-induced grade 2+ skin toxicities were observed in 8 (5%) and 79 (50%) patients at weeks 3 and 6, respectively. Significantly higher proportions of African Americans developed grade 3 skin toxicities (13.8% vs. 2.3% in Whites) at week 6. In multivariate analysis, there was a suggestive association between grade 2+ skin toxicities at week 3 and >2 mg/L pre-RT CRP (OR=4.68, 95%CI=0.49, 44.94). However, grade 2+ skin toxicities at week 6 were significantly associated with elevated: CRP > 1 mg/L (OR=3.26; 95%CI=1.35, 7.85, p=0.01), obesity (OR=2.39; 95%CI=1.19, 4.83, p=0.02), or combined both factors (OR=7.80; 95%CI=2.59, 23.49, p<0.001). Conclusion: This is the first study to suggest that CRP has value as an inflammatory biomarker in RT-induced EASRs, particularly combined with obesity. Future larger studies are warranted to validate our findings and facilitate the discovery and development of anti-inflammatory agents to protect normal tissue from RT-induced adverse effects and improve quality of life in breast cancer patients undergoing RT. Citation Format: Jorge L. Rodriguez-Gil, Anne Cooley, Venetta Thomas, Cristiane Takita, Jean Wright, Martine Poitevien, Glenn O. Allen, Isildinha M. Reis, Wei Zhao, Jennifer J. Hu. Inflammatory biomarker c-reactive protein in radiotherapy-induced skin toxicities of breast cancer patients. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A45.