(ChemotherapyAdvisor) – Accelerated radiotherapy with carbogen breathing and nicotinamide (ARCON) improves metastasis-free survival in laryngeal carcinomas with low carbonic anhydrase IX (CAIX) expression, according to a team of researchers from the Netherlands. The conclusion is based on a paper titled “Predictive Value of CAIX Expression and Staining Pattern in Patients Treated in the Phase III Randomized ARCON Trial (Abstract #OC-0150),” presented at the 31st annual meeting of the European Society for Radiotherapy and Oncology (ESTRO), which occurred from May 9–13 in Barcelona, Spain.
The investigators were interested in exploring the prognostic and predictive value of CAIX, a hypoxia-related endogenous marker with respect to ARCON therapy in patients with advanced stage laryngeal carcinoma. Data were generated from paraffin embedded biopsies from 261 patients and fresh frozen biopsies from 79 patients. Biopsies were sectioned and then immunohistochemically stained for CAIX; stained areas were quantified. Investigators performed a survival analysis to assess the predictive value of CAIX.
“Patients with a low expression of CAIX had a worse outcome compared to patients with a high expression of CAIX,” the investigators wrote. “A significant better regional control was achieved with ARCON in patients with a low CAIX fraction compared to accelerated radiotherapy alone (93% vs. 77%, P=0.03 in paraffin biopsies and 100% vs. 79%, P=0.07 in fresh frozen biopsies), while in patients with a high CAIX fraction no difference was observed. The metastasis-free survival in patients with a low CAIX fraction was improved with ARCON as well (92% vs. 79%, P=0.12 in paraffin biopsies and 100% vs. 67%, P=0.02 in fresh frozen biopsies).”
The investigators concluded: “ARCON improves regional control and metastasis-free survival in patients with tumors with low CAIX expression.”