In oropharyngeal cancer, HPV status impacts distant mets risk

(HealthDay)—In patients with oropharyngeal cancer (OPC), human papillomavirus (HPV) status and T and N staging categories affect the rate of distant control (DC) and may help identify candidates for treatment deintensification strategies, according to research published online Jan. 7 in the Journal of Clinical Oncology.

Brian O'Sullivan, M.D., of the Princess Margaret Hospital/University of Toronto, and colleagues conducted a study involving 899 patients with OPC to identify patients with HPV-associated OPC who would be suitable for treatment deintensification strategies, that omit chemotherapy, based on their having a low risk of distant metastasis (DM).

Of the cohort, HPV status was ascertained for 505 patients, of which 382 were HPV-positive and 123 HPV-negative. During a median follow-up of 3.9 years, the researchers found that HPV-positive patients had significantly higher local and regional control but similar DC, compared with HPV-negative patients. HPV negativity, N2b-N3, T4, and radiation therapy alone were predictive of lower recurrence-free survival. HPV-positive patients were classified according to whether their risk of DM was low (T1-3N0-2c; DC, 93 percent) or high (N3 or T4; DC, 76 percent). HPV-negative patients were also classified into low (T1-2N0-2c; DC, 93 percent) and high DM risk (T3-4N3; DC, 72 percent) groups. In the HPV-positive, low-risk N2c subset, the DC rate was lower with treatment by radiotherapy alone (73 versus 92 percent for chemoradiotherapy).

"The prognostic value of T and N categories on DM risk seems to be different for HPV-positive versus HPV-negative patients," the authors write. "A deintensification philosophy might be most optimally deployed in such subgroups with the least likelihood of DM."