Incidence of human papillomavirus (HPV)-associated oropharyngeal
cancer continues to increase globally. The younger age,
significant better survival, and longer expected duration of life
in this population have led to the popularization of the concept
of treatment de-escalation. Multimodality treatment achieves a
high percentage of cure in HPV+ OPC, but also brings on high rate
of treatment-related morbidity. As a result, de-escalation of
treatment for limiting toxicity without compromising high cure
rates has emerged as a major issue in in HPV+ OPC clinical
research. Primary surgery with minimally invasive excision of the
primary tumor may allow for the elimination of chemotherapy and
decrease radiation dose intensity. Primary dose-reduced
radiotherapy, with or without systemic therapy, is also under
study, as is replacing concurrent cisplatin with newer systemic
agents.
The recent published outcomes of the first 2 randomized de-
escalation trials, however, have shown a significant worsening in
survival when cisplatin is omitted or substituted. Two large
phase III trials, RTOG 1016 and De-ESCALaTE, which attempted to
reduce toxicity by replacing radiotherapy in combination with
cisplatin with the use of cetuximab in combination with
radiotherapy, recently suggested that radiotherapy + cetuximab
leads to decreased survival compared with standard therapy
(observed HRs of 1.45 and 5 in RTOG 1016 and De-ESCALaTE), as
well as increased rates of locoregional failure. In view of these
results, implementation into clinical practice before high-level
evidence available should not be undertaken. Finally, harm-
minimization techniques should also be evaluated as an
alternative to de-escalation of treatment in these patient
groups. |