Definitive radiochemotherapy or initial surgery for oropharyngeal cancer : To what extent can p16 expression be used in the decision process?

BACKGROUND: The decision between definitive radio(chemo)therapy (RCT) or a surgical strategy, i. e. surgery ± adjuvant radio(chemo)therapy for optimal treatment of oropharyngeal cancer is highly debated. Human papillomavirus(HPV)-related tumours are a distinct entity associated with p16 overexpression. While this represents a major prognostic factor, its predictive significance remains unknown. RESULTS: Among 183 consecutive unselected patients treated between 2009 and 2013 with a state-of-the-art surgical procedure ± adjuvant radio(chemo)therapy or definitive RCT including intensity-modulated radiotherapy, 3­year disease-free survival (DFS) was 74 vs. 57%, respectively (p = 0.007). When focusing on p16+ patients (49%), there was no significant difference in tumour control rate between surgery ± radio(chemo)therapy and the definitive RCT group (3-year DFS 83 vs. 82%, respectively; p = 0.48). However, delayed severe dysphagia was significantly lower in favour of definitive RCT: 35 vs. 4%, respectively; p = 0.0002. CONCLUSION: Our results highlight distinct outcomes after definitive RCT or initial surgical treatment according to p16 status, which should thus be considered during the decision process.

Biobanking of Fresh-Frozen Human Adenocarcinomatous and Normal Colon Tissues: Which Parameters Influence RNA Quality?

Medical research projects become increasingly dependent on biobanked tissue of high quality because the reliability of gene expression is affected by the quality of extracted RNA. Hence, the present study aimed to determine if clinical, surgical, histological, and molecular parameters influence RNA quality of normal and tumoral frozen colonic tissues. RNA Quality Index (RQI) was evaluated on 241 adenocarcinomas and 115 matched normal frozen colon tissues collected between October 2006 and December 2012. RQI results were compared to patients' age and sex, tumor site, kind of surgery, anastomosis failure, adenocarcinoma type and grade, tumor cell percentage, necrosis extent, HIF-1α and cleaved caspase-3 immunohistochemistry, and BRAF, KRAS and microsatellites status. The RQI was significantly higher in colon cancer tissue than in matched normal tissue. RQI from left-sided colonic cancers was significantly higher than RQI from right-sided cancers. The RNA quality was not affected by ischemia and storage duration. According to histological control, 7.9% of the samples were unsatisfactory because of inadequate sampling. Biobanked tumoral tissues with RQI ≥5 had lower malignant cells to stromal cells ratio than samples with RQI <5 (p <0.05). Cellularity, necrosis extent and mucinous component did not influence RQI results. Cleaved caspase-3 and HIF-1α immunolabelling were not correlated to RQI. BRAF, KRAS and microsatellites molecular status did not influence RNA quality. Multivariate analysis revealed that the tumor location, the surgical approach (laparoscopy versus open colectomy) and the occurrence of anastomotic leakage were the only parameters influencing significantly RQI results of tumor samples. We failed to identify parameter influencing RQI of normal colon samples. These data suggest that RNA quality of colonic adenocarcinoma biospecimens is determined by clinical and surgical parameters. More attention should be paid during the biobanking procedure of right-sided colon cancer or laparoscopic colectomy specimen. Histological quality control remains essential to control sampling accuracy.