Long-term patterns of relapse and survival following definitive intensity-modulated radiotherapy for non-endemic nasopharyngeal carcinoma

Oral Oncol. 2016 Feb:53:67-73. doi: 10.1016/j.oraloncology.2015.11.015. Epub 2015 Dec 7.

Abstract

Background: We report treatment outcomes for a large non-endemic cohort of patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT) and chemotherapy.

Methods: We identified 177 consecutive patients with newly diagnosed, non-metastatic nasopharyngeal cancer treated with definitive IMRT between 1998 and 2011. Endpoints included local, regional, distant control, and overall survival.

Results: Median follow-up was 52months. The 3-/5-year actuarial rates of local control, regional control, distant control, and overall survival were 92%/83%, 93%/91%, 86%/83%, and 87%/74%, respectively. The median time to local recurrence was 30months; the annual hazard of local recurrence did not diminish until the 6th year of follow-up.

Conclusions: Overall, we observed excellent rates of disease control and survival consistent with initially reported results from our institution. Attaining locoregional control in patients with extensive primary tumors remains a significant clinical challenge. With mature follow-up we observed that more than half of observed local relapses occurred after 2years, a pattern distinct from that of carcinomas arising from other head and neck sites. These findings raise the possibility that patients with NPC may benefit from close follow-up during post-treatment years 3-5.

Keywords: Clinical outcomes; IMRT; Nasopharyngeal carcinoma; Radiotherapy.

MeSH terms

  • Adult
  • Aged
  • Carcinoma
  • Combined Modality Therapy / methods
  • Disease-Free Survival
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Nasopharyngeal Carcinoma
  • Nasopharyngeal Neoplasms / drug therapy
  • Nasopharyngeal Neoplasms / radiotherapy*
  • Neoplasm Recurrence, Local / epidemiology*
  • Radiotherapy, Intensity-Modulated / methods*
  • Retrospective Studies
  • Treatment Outcome