Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma that occurs in the intraepithelial mucosa of the nasopharynx and is characterized by distant metastasis. The prognosis of nasopharyngeal carcinoma after metastasis is very poor, and the mortality within one year after initial metastasis is 91%. According to the data of the international agency for research on cancer, nasopharyngeal carcinoma has obvious regional bias. In 2018, there were 129000 newly confirmed cases of nasopharyngeal carcinoma in the world, of which more than 70% occurred in Southeast Asia and East Asia.
Nasopharyngeal carcinoma is rare in the world, but it is common in China. In 2018, the age standardized incidence rate (Asir) of nasopharyngeal carcinoma in China was 3.0 cases per 100000 people, about 7 times higher than most white people. In addition, although previous studies have shown that the global incidence rate and mortality of nasopharyngeal carcinoma are declining, this proportion is rising in some regions of China. NPC is a huge health burden in China.
Previous studies have evaluated the incidence rate and mortality of nasopharyngeal carcinoma in China in specific years, and analyzed the long-term trend of disease burden. These studies provide important information for understanding the health burden of nasopharyngeal carcinoma in China. However, few studies have explored the changes of nasopharyngeal carcinoma incidence rate and mortality in different age groups in China. In addition, the potential impact of national time trends remains unknown. In this study, researchers used the age cycle cohort (APC) framework to evaluate the long-term trends in the incidence rate and mortality of nasopharyngeal carcinoma in China, and to investigate the potential impact of these trends (age effect, cycle effect and cohort effect).
Trend of incidence rate and mortality of nasopharyngeal carcinoma in China from 1990 to 2019
Figure 1A shows the trend of incidence rate of nasopharyngeal carcinoma in both sexes in China from 1990 to 2019. In 1990, the Asir of NPC was 3.3 per 100000 people, and in 2019, it increased to 5.7 per 100000 people (an increase of 72.7%). The crude incidence rate (CIR) was 2.7 in 1990 and increased to 7.8 per 100000 people (an increase of 188.9%).
Figure 1b shows the trend of NPC Asir and cir by sex in China from 1990 to 2019. For men, Asir increased from 4.3 to 8.6 per 100000 (an increase of 100.0%), and cir increased from 3.4 to 11.4 per 100000 (an increase of 235.3%). For women, Asir increased from 2.3 per 100000 in 1990 to 2.8 per 100000 in 2019 (an increase of 21.7%), and the CIR of NPC increased from 1.9 per 100000 in 1990 to 3.9 per 100000 in 2019 (an increase of 105.3%).
Figure 2A shows the mortality trend of NPC of both sexes in China from 1990 to 2019. In 1990, the age standardized mortality rate (ASMR) of nasopharyngeal carcinoma was 2.9 per 100000 people, and fell to 1.4 per 100000 people in 2019 (a decrease of 51.7%). The crude mortality rate (CMR) was 2.2 in 1990 and fell to 2.0 per 100000 in 19 (a decrease of 9.1%).
Figure 2B shows the trend of ASMR and CMR of the National People's Congress by sex in China from 1990 to 2019. For men, ASMR decreased from 3.9 per 100000 to 2.2 per 100000 (a decrease of 43.6%), and CMR increased from 2.9 per 100000 to 3.0 per 100000 (an increase of 3.4%). For women, ASMR decreased from 2.0 per 100000 in 1990 to 0.7 per 100000 in 2019 (a decrease of 65.0%), and the CMR of NPC decreased from 1.6 per 100000 in 1990 to 1.0 per 100000 in 2019 (a decrease of 37.5%).
Net drift and local drift of incidence rate and mortality of nasopharyngeal carcinoma in China
Figure 3A shows the net drift and local drift of the incidence rate of nasopharyngeal carcinoma in China. The net drift value of the incidence rate of nasopharyngeal carcinoma was 2.8% (95% CI = 2.5% to 3.0%) in men and 0.6% (95% CI = 0.3% to 0.8%) in women. The local drift value of the incidence rate of nasopharyngeal carcinoma was greater than 0 in men aged 20-79 and women aged 30-59 (P <0.05). Among people aged 30-34, the maximum local drift value was 5.6% (95% CI = 5.1% to 6.2%) for men and 2.3% (95% CI = 1.9% to 2.8%) for women aged 35-39. The local drift of the incidence rate of nasopharyngeal carcinoma in women aged 65-84 years was less than 0 (P <0.05).
Figure 3B shows the net drift and local drift values of NPC mortality in China. The net drift in nasopharyngeal carcinoma mortality was – 2.2% (95% CI = -2.4% to -2.0%) and -4.2% (95% CI = -4.5% to -4.0%), respectively. The local drift value of nasopharyngeal carcinoma mortality in all age groups of both sexes was less than 0 (P <0.05), indicating that the mortality of nasopharyngeal carcinoma in all age groups in China has decreased in the past 30 years.
Longitudinal age curve of incidence rate and mortality of nasopharyngeal carcinoma in China
Figure 4A shows the incidence rate curve of nasopharyngeal carcinoma at a specific age in China. For people under the age of 30-34, the incidence rate of nasopharyngeal carcinoma in the same birth cohort was similar between men and women, while the incidence rate of nasopharyngeal carcinoma in people over the age of 39 was significantly higher in men than in women (P < 0.05), and the curve increased significantly with age.
Figure 4B shows the age-specific mortality curve of nasopharyngeal carcinoma in China. The trend was similar to the incidence rate, and the mortality of men was significantly higher than that of women after the age of 39 (P <0.05).
Cycle and cohort RR of incidence rate and mortality of nasopharyngeal carcinoma in China
Figure 5A shows the incidence cycle of nasopharyngeal carcinoma in China. Compared with the reference period (2000-2004), the periodic RRs of the incidence rate of nasopharyngeal carcinoma in men increased monotonously, and the nrrs of women increased after 2000. Figure 5B shows the periodic RRs of nasopharyngeal carcinoma mortality in China, indicating a monotonic decline pattern in men and women.
Compared with the reference period (2000-2004), the RR of each period was adjusted for age and nonlinear cohort effect, and the corresponding 95% CI.
Figure 6A shows that the cohort RR of the incidence rate of nasopharyngeal carcinoma in men continued to increase with each birth year, but stopped increasing in the most recent birth cohort (1983-1997). For women, the incidence rate of nasopharyngeal carcinoma increased after the 1938-1942 birth cohort, but this increase stopped after the 1978-1982 birth cohort. Figure 6B shows that with the advance of the year of birth, the RR of the NPC mortality cohort in men and women decreases monotonously.
Overall, this study shows that from 1990 to 2019, ASMR and CMR of NPC decreased, but Asir and cir of China increased. Using the APC framework, it was confirmed that the incidence rate of nasopharyngeal carcinoma increased in men aged 20-79 and women aged 30-59, but decreased in elderly women aged 65-84. Mortality rates have declined in every age group. Although the potential death risk of nasopharyngeal carcinoma decreased in different periods and birth cohorts, it was found that the risk of incidence rate of nasopharyngeal carcinoma increased with the extension of the cycle. In view of the continuous aging process, NPC may have a huge impact on China's health in the future. This situation makes it necessary to identify the prevention risk factors related to nasopharyngeal carcinoma, further develop prevention and treatment strategies, focus on screening high-risk groups, and implement measures to improve the diagnosis and treatment of nasopharyngeal carcinoma. Maximize the accuracy of nasopharyngeal carcinoma staging, responsibly allocate public health resources, and reduce the burden of nasopharyngeal carcinoma.
Source of original text:
Bai R, Sun J, Xu Y, Sun Z, Zhao X. Incidence and mortality trends of nasopharynx cancer from 1990 to 2019 in China: an age-period-cohort analysis. BMC Public Health. 2022 Jul 15; 22(1):1351. doi: 10.1186/s12889-022-13688-7. PMID: 35840964; PMCID: PMC9284805.
Article source：
https://www.medsci.cn/article/show_article.do?id=9a82e330318c
