James C H Chow1, Anthony H P Tam2, Ka-Man Cheung3, Victor H F Lee4, Chi-Leung Chiang4, Macy Tong5, Edwin C Y Wong6, Alice K W Cheung7, Sunny P C Chan7, Jessica W Y Lai8, Roger K C Ngan4, Wai-Tong Ng9, Anne W M Lee10, Kwok-Hung Au3. 1. Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong. Electronic address: cch932@ha.org.hk. 2. The Hong Kong Cancer Registry, Hong Kong Hospital Authority, Hong Kong. 3. Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong. 4. Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. 5. Department of Clinical Oncology, Prince of Wales Hospital, Hong Kong. 6. Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong. 7. Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong. 8. Department of Clinical Oncology, Princess Margaret Hospital, Hong Kong. 9. Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong; Comprehensive Oncology Centre, Hong Kong Sanatorium & Hospital, Hong Kong. 10. Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong; Department of Clinical Oncology, The University of Hong Kong-Shenzhen Hospital, China.
Abstract
OBJECTIVES: Long-term risk of second primary cancer (SPC) after definitive intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) remains unclear. This study aims to evaluate the risk, predictive factors and survival impact of SPC in a large territory-wide cohort of NPC survivors in an endemic region. MATERIALS AND METHODS: In this multicenter study, consecutive NPC patients (n = 3166) who underwent definitive IMRT in all six public oncology centers in Hong Kong between 2001 and 2010 were included. SPC risks were quantified by standardized incidence ratios (SIRs) and absolute excess risks (AERs) estimated from corresponding age-, sex-, and calendar year-specific population cancer incidence data from the Hong Kong Cancer Registry. Predictive factors and SPC-specific mortality were analyzed. RESULTS: Over a median follow-up period of 10.8 years, 290 cases of SPC were observed with a crude incidence of 9.2%. Cancer risk in NPC survivors was 90% higher than that in general population [SIR, 1.9; 95% confidence interval (CI), 1.7-2.2], with an AER of 52.1 (95% CI, 36.8-67.3) per 10,000 person-years at risk. Significant excess cancer risks were observed for oral cavity, sarcoma, oropharynx, paranasal sinus, salivary gland, thyroid, skin and lung. Advanced age, smoking, hepatitis B status, and re-irradiation were independent predictive factors. SPC accounted for 9.4% of all deaths among NPC survivors during the study period, and 10-year SPC-specific mortality was 3.4%. CONCLUSIONS: Second cancer risk after IMRT was substantial among NPC patients. SPC impairs long-term survival, and close surveillance is warranted as part of survivorship care.
OBJECTIVES: Long-term risk of second primary cancer (SPC) after definitive intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) remains unclear. This study aims to evaluate the risk, predictive factors and survival impact of SPC in a large territory-wide cohort of NPC survivors in an endemic region. MATERIALS AND METHODS: In this multicenter study, consecutive NPC patients (n = 3166) who underwent definitive IMRT in all six public oncology centers in Hong Kong between 2001 and 2010 were included. SPC risks were quantified by standardized incidence ratios (SIRs) and absolute excess risks (AERs) estimated from corresponding age-, sex-, and calendar year-specific population cancer incidence data from the Hong Kong Cancer Registry. Predictive factors and SPC-specific mortality were analyzed. RESULTS: Over a median follow-up period of 10.8 years, 290 cases of SPC were observed with a crude incidence of 9.2%. Cancer risk in NPC survivors was 90% higher than that in general population [SIR, 1.9; 95% confidence interval (CI), 1.7-2.2], with an AER of 52.1 (95% CI, 36.8-67.3) per 10,000 person-years at risk. Significant excess cancer risks were observed for oral cavity, sarcoma, oropharynx, paranasal sinus, salivary gland, thyroid, skin and lung. Advanced age, smoking, hepatitis B status, and re-irradiation were independent predictive factors. SPC accounted for 9.4% of all deaths among NPC survivors during the study period, and 10-year SPC-specific mortality was 3.4%. CONCLUSIONS: Second cancer risk after IMRT was substantial among NPC patients. SPC impairs long-term survival, and close surveillance is warranted as part of survivorship care.
Authors: Wing Lok Chan; James Chung Hang Chow; Zhi-Yuan Xu; Jishi Li; Wing Tung Gobby Kwong; Wai Tong Ng; Anne W M Lee Journal: Front Oncol Date: 2022-02-01 Impact factor: 6.244