Joel Howlett1, Sarah Hamilton2, Annette Ye3, David Jewett3, Breanna Riou-Green4, Eitan Prisman5, Andrew Thamboo5. 1. Division of Otolaryngology - Head and Neck Surgery, University of British Columbia, 4(th) floor, Gordon and Leslie Diamond Health Care Center, 2775 Laurel Street, Vancouver, British Columbia V5Z1M9, Canada. Electronic address: joel.howlett@alumni.ubc.ca. 2. Division of Radiation Oncology, British Columbia Cancer Agency Vancouver Center (BCCA), 600W 10(th) Ave, Vancouver, British Columbia V5Z4E6, Canada. 3. College of Medicine - University of British Columbia, 317 - 2194 Health Sciences Mall, Vancouver, British Columbia V6T1Z3, Canada. 4. Faculty of Health Sciences, Simon Fraser University, 888 University Dr. Burnaby, British Columbia V5A1S6, Canada. 5. Division of Otolaryngology - Head and Neck Surgery, University of British Columbia, 4(th) floor, Gordon and Leslie Diamond Health Care Center, 2775 Laurel Street, Vancouver, British Columbia V5Z1M9, Canada.
Abstract
OBJECTIVE: Nasopharyngeal carcinoma (NPC) is common in Southeast Asia. Due to the influx of immigrants from this region, the incidence in British Columbia is increasing. Current literature from non-endemic populations encompasses heterogeneous cohorts. This study examines NPC in a North American population, with a high incidence, to understand the population's characteristics, treatment outcomes and recurrence patterns. METHODS AND MATERIALS: A retrospective analysis of patients treated for primary and recurrent NPC over 15-years. Regression analyses were used to identify predictors of disease recurrence and death. A subgroup analysis of the locoregional recurrence cohort was conducted. Five-year survival outcomes were determined. RESULTS: 601 patients were included. Asian ethnicity comprised 77% and the majority had non-keratinizing carcinoma (81%). In total, 19.3% of patients experienced recurrence: 58% local, 22% regional and 20% distant. Five-year overall survival was 70%. Smoking, advancing T-stage, poorer performance status and advanced overall stage were all associated with worse overall survival (p < 0.05). Asian ethnicity improved overall survival but not recurrence free survival. Similar features in addition to non-keratinizing histology were associated with increased locoregional recurrence (p < 0.05). Competing risk analysis indicated radiotherapy alone had a higher recurrence relative to chemoradiotherapy (HR 1.91, CI 1.17-3.09, p = 0.01). CONCLUSIONS: We report the largest study evaluating treatment and outcomes of NPC in a non-endemic population. This unique population falls between described endemic and non-endemic populations. Non-keratinizing pathology and primary radiotherapy did not affect survival; however, both had a propensity for recurrence. Finally, patients experienced more locoregional and less distant recurrence, supporting that this cohort may be amenable to curative salvage therapy.
OBJECTIVE: Nasopharyngeal carcinoma (NPC) is common in Southeast Asia. Due to the influx of immigrants from this region, the incidence in British Columbia is increasing. Current literature from non-endemic populations encompasses heterogeneous cohorts. This study examines NPC in a North American population, with a high incidence, to understand the population's characteristics, treatment outcomes and recurrence patterns. METHODS AND MATERIALS: A retrospective analysis of patients treated for primary and recurrent NPC over 15-years. Regression analyses were used to identify predictors of disease recurrence and death. A subgroup analysis of the locoregional recurrence cohort was conducted. Five-year survival outcomes were determined. RESULTS: 601 patients were included. Asian ethnicity comprised 77% and the majority had non-keratinizing carcinoma (81%). In total, 19.3% of patients experienced recurrence: 58% local, 22% regional and 20% distant. Five-year overall survival was 70%. Smoking, advancing T-stage, poorer performance status and advanced overall stage were all associated with worse overall survival (p < 0.05). Asian ethnicity improved overall survival but not recurrence free survival. Similar features in addition to non-keratinizing histology were associated with increased locoregional recurrence (p < 0.05). Competing risk analysis indicated radiotherapy alone had a higher recurrence relative to chemoradiotherapy (HR 1.91, CI 1.17-3.09, p = 0.01). CONCLUSIONS: We report the largest study evaluating treatment and outcomes of NPC in a non-endemic population. This unique population falls between described endemic and non-endemic populations. Non-keratinizing pathology and primary radiotherapy did not affect survival; however, both had a propensity for recurrence. Finally, patients experienced more locoregional and less distant recurrence, supporting that this cohort may be amenable to curative salvage therapy.
Authors: Muhammad Shahid Iqbal; Aung Tin; Abdul Mian; Akram Ali; James O'Hara; Josef Kovarik; Rahul Patil; Eleanor Aynsley; Charles Kelly Journal: Rep Pract Oncol Radiother Date: 2022-07-29