C-Reactive Protein and Radiotherapy Skin Toxicity in Patients With Breast Cancer
In a study reported in the Journal of Clinical Oncology, Hu et al found that higher postradiotherapy levels of the inflammatory marker high-sensitivity C-reactive protein (hsCRP) were associated with an increased risk of early grade 4+ skin toxicity in patients with breast cancer.
Study Details
The study involved 1,000 patients who underwent radiotherapy between 2011 and 2013 and were evaluated prospectively for skin toxicities through the National Cancer Institute–funded Wake Forest University Community Clinical Oncology Program Research Base. Preradiotherapy and postradiotherapy plasma hsCRP levels were measured, and Oncology Nursing Society skin toxicity criteria (0 to 6 scale) were used to assess radiotherapy-induced skin toxicities. A multivariate analysis of associations of hsCRP with toxicity included age, body mass index (BMI), race, ethnicity, diabetes, mastectomy, tumor stage, lymph node radiotherapy, prior chemotherapy, radiotherapy dose, and radiotherapy fractionation. Among the 1,000 patients, 623 were white, 280 were African American, 64 were Asian/Pacific Islander, and 33 were of another race; 24% of the patients were Hispanic, and 47% were obese.
Risk for Skin Toxicity
Overall, approximately 42% and 15% of patients developed grade 3+ and 4+ skin toxicities. Plasma hsCRP levels differed significantly by race and BMI, but not ethnicity. In a multivariate analysis, grade 4+ skin toxicity was significantly associated with obesity (BMI ≥ 30 kg/m2; odds ratio [OR] = 2.17, 95% confidence interval [CI] = 1.41–3.34), postradiotherapy hsCRP ≥ the median of 4.11 mg/L (OR = 1.61, 95% CI = 1.07–2.44), and both factors combined (OR = 3.65, 95% CI = 2.18–6.14). In nonobese patients, postradiotherapy hsCRP above the median level (OR = 1.93, 95% CI = 1.03–3.63) and an increase in hsCRP of ≥ 0.10 mg/L (OR = 2.80, 95% CI = 1.42–5.54) were significantly associated with grade 4+ skin toxicity.
The investigators concluded, “This large prospective study is the first to our knowledge of hsCRP as an inflammatory biomarker in [radiotherapy]-induced skin toxicities in breast cancer. We demonstrate that nonobese patients with elevated [radiotherapy]-related change in hsCRP levels have a significantly increased risk of grade 4+ skin toxicity. The outcomes may help to predict [radiotherapy] responses and guide decision-making.”
The study was supported by National Cancer Institute grants.
Jennifer J. Hu, PhD, of the Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
