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

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 52 months. 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 30 months; the annual hazard of local recurrence did not diminish until the 6th year of follow-up. Conclusion s. 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 2 years, 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.

Effects of induction docetaxel, platinum, and fluorouracil chemotherapy in patients with stage III or IVA/B nasopharyngeal cancer treated with concurrent chemoradiation therapy: Final results of 2 parallel phase 2 clinical trials

“…The prevailing use of IMRT with concurrent chemotherapy has significantly improved the outcomes of patients with locally advanced NPC, especially with respect to local control. However, the reported 5‐year OS rates in retrospective studies for patients with stage III and IVA/B NPC have remained suboptimal with ranges of approximately 70%to 75% and 60% to 65%, respectively, after such a combination without induction chemotherapy . Because most patients treated in our trials received IMRT, our original sample size calculation, based on the OS rates from conventional radiation therapy (65% and 45% for stage III and IVA/B NPC, respectively), might have underestimated the true OS rates in the IMRT era.…”

Reirradiation with intensity‐modulated radiotherapy for locally recurrent T3 to T4 nasopharyngeal carcinoma

“…However, it inevitably happens in some patients, especially those with advanced disease, and remains a very challenging problem to tackle. In modern series using IMRT, the reported local failure rate is 5% to 15% overall, and is much higher at 15% to 45% for T4 disease . Aggressive salvage treatment with a curative intent is advocated for locally recurrent NPC because many patients could still achieve long‐term survival .…”

“…In modern series using IMRT, the reported local failure rate is 5% to 15% overall, and is much higher at 15% to 45% for T4 disease. [1][2][3][4][5][6][7] Aggressive salvage treatment with a curative intent is advocated for locally recurrent NPC because many patients could still achieve long-term survival. 8 Both nasopharyngectomy and reirradiation are the mainstay of therapy, but surgical salvage is only applicable for early-stage recurrence and rT3 to rT4 diseases are not suitable candidates.…”

Clinical characteristics and prognostic value of pre‐retreatment plasma epstein‐barr virus DNA in locoregional recurrent nasopharyngeal carcinoma

“…However, local recurrence and distant metastasis remain as the main causes of treatment failure. Local recurrence still occurs in 5%‐10% of the NPC patients, even when treated with advanced techniques such as intensity modulated radiation therapy (IMRT) . Our previous study of long‐term outcomes and prognostic factors of re‐irradiation for locally recurrent NPC indicated that salvage re‐irradiation by IMRT improve local tumor control and prolong patient survival …”