Radiosensitive Variation Key in HPV-Positive Head and Neck Cancer

Kate JohnsonMay 01, 2013Source: medscape.com  GENEVA, Switzerland — Increased radiosensitivity likely contributes to improved outcomes in patients human papillomavirus (HPV)-positive head and neck squamous cell carcinomas (HNSCC), according to a new study. The findings point to a potential new approach that could enhance radiosensitivity further in these tumors, said Thorsten Rieckmann, PhD, from University Medical Center Hamburg Eppendorf in Germany. The study results, which he presented here at the 2nd European Society for Radiotherapy & Oncology (ESTRO) Forum, were also published online April 19 in Radiation and Oncology. The work was named 1 of 2 top-scoring abstracts at the ESTRO meeting. Dr. Rieckmann and colleagues compared a panel of 5 HPV-positive and 5 HPV-negative HNSCC cell lines, and demonstrated a statistically significant difference in average radiosensitivity between the 2 panels. However, in the HPV-positive cells, "we saw a very high variation in radiosensitivity, so clearly not every HPV-positive cell line is equally highly radiosensitive," Dr. Rieckmann told meeting delegates. "Therefore, caution should be urged when considering the deintensification of therapy via dose reduction," the researchers write. "Additional stratification within the subentity of HPV/p16-positive HNSCC may be necessary to more precisely predict individual tumor sensitivity." "Until we have molecular markers to predict radiosensitivity in HPV-positive HNSCC, pack-years of smoking, as suggested by Ang et al [N Engl J Med. 2010;363:24-35], are probably the best option," he told Medscape Medical News. The study demonstrated that a compromised DNA repair process is likely the reason behind the more favorable prognosis for patients with HPV-positive HNSCC treated [...]