J Korean Neurosurg Soc.  2020 Jan;63(1):119-135. 10.3340/jkns.2018.0209.

Newly-Diagnosed, Histologically-Confirmed Central Nervous System Tumours in a Regional Hospital in Hong Kong : An Epidemiological Study of a 21-Year Period

• He Z
• Wong ST
• Yam KY

• KMID: 2501699
• DOI: http://doi.org/10.3340/jkns.2018.0209

Abstract

Objective
: To investigate the epidemiology of newly-diagnosed, histologically-confirmed (NDHC) central nervous system (CNS) tumours and its changes over a 21-year period in a regional hospital in Hong Kong.
Methods
: This is a single-institute retrospective descriptive study of patients undergoing surgery for CNS tumours in a regional hospital of Hong Kong in the period from January 1996 to December 2016. The histological definition of CNS tumours was according to the World Health Organization classification, while the site definition for case ascertainment of CNS tumours was as set out by the Central Brain Tumour Registry of the United States. Patients of any age, who had NDHC CNS tumours, either primary or secondary, were included. The following parameters of the patients were retrieved : age at diagnosis, gender, tumour location, and histological diagnosis. Population data were obtained from sources provided by the Government of Hong Kong. The incident rate, estimated by the annual number of cases per 100000 population, for each histology grouping was calculated. Statistical analyses, both including and excluding brain metastases, were performed. Statistical analysis was performed with Microsoft Excel, 2016 (Microsoft, Redmond, WA, USA).
Results
: Among the 2134 cases of NDHC CNS tumours, there were 1936 cases of intracranial tumours and 198 cases of spinal tumours. The annual number of cases per 100000 population of combined primary intracranial and spinal CNS tumours was 3.6 in 1996, and 11.1 in 2016. Comparing the 5-year average annual number of cases per 100000 population of primary CNS tumours from the period 1996–2000 to 2011–2015, there was an 88% increase, which represent an increase in the absolute number of cases by 4.52 cases/100000 population. This increase was mainly contributed by benign histologies. In the aforementioned periods, meningiomas increased by 1.45 cases/100000 population; schwannomas by 1.05 cases/100000 population, and pituitary adenomas by 0.91 cases/100000 population. While gliomas had a fluctuating 5-year average annual number of cases per 100000 population, it only had an absolute increase of 0.51 cases/100000 population between the 2 periods, which was mainly accounted for by the change in glioblastomas.
Conclusion
: This retrospective study of CNS tumour epidemiology revealed increasing trends in the incidences of several common CNS tumour histologies in Hong Kong, which agrees with the findings in large-scale studies in Korea and the United States. It is important for different geographic locations to establish their own CNS tumour registry with well-defined and structured data collection and analysis system to meet the international standards.

Keyword

Epidemiology; Brain; Central nervous system; Neoplasm; Hong Kong

Figure

• 

  Fig. 1. Annual number of cases of primary intracranial and spinal tumours.

• 

  Fig. 2. Population in the catchment area of NTWC and total population of Hong Kong. The change from 2001 to 2002 represents a relocation of neurosurgical service of a hospital to another cluster. *The population in the NTWC catchment area (unit : million). †The mid-year total population of Hong Kong (unit : million). ‡The percentage of the population in the NTWC catchment area over the mid-year total population of Hong Kong. NTWC : New Territory West Cluster.

• 

  Fig. 3. Annual number of cases of intracranial glioma. The pathological grade of intracranial glioma is based on the World Health Organization Classification of Tumors of the Central Nervous System applicable to the year of histological diagnosis.

• 

  Fig. 4. The distribution of primary intracranial tumours by age at diagnosis. The distribution is right-skewed with most intracranial tumours diagnosed at 50–55 age group.

• 

  Fig. 5. Distribution of primary and metastasis intracranial tumours by age at diagnosis and histology.

• 

  Fig. 6. Distribution of intracranial tumours by sex. Different histological types of intracranial tumours are represented by the bar, with its length corresponding to the actual number of cases. *For statistically significant differences between male and female patients.

• 

  Fig. 7. The 5-year average annual number of cases for intracranial tumours (unit : per 100000 population).

• 

  Fig. 8. The 5-year average annual number of cases for intracranial glioma by different WHO grading (unit : per 100000 population). The pathological grade of intracranial glioma is based on the WHO Classification of Tumors of the Central Nervous System applicable to the year of histological diagnosis. WHO : World Health Organization.

• 

  Fig. 9. The number of primary spinal tumours for different age groups.

• 

  Fig. 10. The 5-year average annual numbers of cases for different primary spinal tumours (unit : per 100000 population).

• 

  Fig. 11. The 5-year average of annual numbers of cases for primary central nervous system tumours (unit : per 100000 population).

Reference

References

1. Census and Statistics Department of Hong Kong. Hong Kong 2011 Population Census - Summary Results. Hong Kong: Census And Statistics Department of Hong Kong;2012.

2. Census and Statistics Department of Hong Kong. Hong Kong 2001 population census main report, Vols. I & II. Hong Kong: Census And Statistics Department of Hong Kong;2012.

3. Census and Statistics Department of Hong Kong. Hong Kong 2006 population by-census main report: volume I. Hong Kong: Census And Statistics Department of Hong Kong;2007.

4. Census and Statistics Department of Hong Kong. Hong Kong 2016 Population By-Census - Main Results. Hong Kong: Census And Statistics Department of Hong Kong;2017.

5. Census and Statistics Department of Hong Kong. Population and household statistics analysed by district council district - 2001. Hong Kong: Census And Statistics Department of Hong Kong;2002.

6. Census and Statistics Department of Hong Kong. Population and household statistics analysed by district council district - 2003. Hong Kong: Census And Statistics Department of Hong Kong;2003.

7. Census and Statistics Department of Hong Kong. Population and household statistics analysed by district council district - 2010. Hong Kong: Census And Statistics Department of Hong Kong;2011.

8. Census and Statistics Department of Hong Kong. Population and household statistics analysed by district council district - 2016. Hong Kong: Census And Statistics Department of Hong Kong;2017.

9. Census and Statistics Department, Hong Kong Special Administrative Region. Hong Kong monthly digest of statistic. Hong Kong: Census and Statistics Department, Hong Kong Special Administrative Region;2016.

10. Census and Statistics Department, Hong Kong Special Administrative Region. Hong Kong monthly digest of statistic. Hong Kong: Census and Statistics Department, Hong Kong Special Administrative Region;2017.

11. Dho YS, Jung KW, Ha J, Seo Y, Park CK, Won YJ, et al. An updated nationwide epidemiology of primary brain tumors in Republic of Korea, 2013. Brain Tumor Res Treat. 5:16–23. 2017.

12. Ho-Cheong H. Intracranial tumours among Chinese in Hong Kong. Surg Neurol. 12:317–318. 1979.

13. Hospital Authority. Hospital Authority Statistical Report (2016-2017). Hong Kong: Hospital Authority;2018.

14. Hong Kong Cancer Registry. Hong Kong Cancer Statistics. Hong Kong: Hong Kong Cancer Registry;2015.

15. Hong Kong Cancer Registry. Overview of Hong Kong Cancer Statistics of 2016. Hong Kong: Hong Kong Cancer Registry;2018.

16. Jung KW, Ha J, Lee SH, Won YJ, Yoo H. An updated nationwide epidemiology of primary brain tumors in republic of Korea. Brain Tumor Res Treat. 1:16–23. 2013.

17. Lee CH, Jung KW, Yoo H, Park S, Lee SH. Epidemiology of primary brain and central nervous system tumors in Korea. J Korean Neurosurg Soc. 48:145–152. 2010.

18. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, Jouvet A, et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 114:97–109. 2007.

19. Louis DN, Perry A, Reifenberger G, von Deimling A, Figarella-Branger D, Cavenee WK, et al. The 2016 World Health Organization classification of tumors of the central nervous system: a summary. Acta Neuropathol. 131:803–820. 2016.

20. Ng HK, Poon WS, South JR, Lee JC. Tumours of the central nervous system in Chinese in Hong Kong: a histological review. Aust N Z J Surg. 58:573–578. 1988.

21. Ostrom QT, Gittleman H, Farah P, Ondracek A, Chen Y, Wolinsky Y, et al. CBTRUS statistical report: primary brain and central nervous system tumors diagnosed in the United States in 2006-2010. Neuro Oncol. 15 Suppl 2:ii1–ii56. 2013.

22. Ostrom QT, Gittleman H, Fulop J, Liu M, Blanda R, Kromer C, et al. CBTRUS statistical report: primary brain and central nervous system tumors diagnosed in the United States in 2008-2012. Neuro Oncol. 17 Suppl 4:iv1–iv62. 2015.

23. Ostrom QT, Gittleman H, Liao P, Rouse C, Chen Y, Dowling J, et al. CBTRUS statistical report: primary brain and central nervous system tumors diagnosed in the United States in 2007-2011. Neuro Oncol. 16 Suppl 4:iv1–iv63. 2014.

24. Ostrom QT, Gittleman H, Liao P, Vecchione-Koval T, Wolinsky Y, Kruchko C, et al. CBTRUS statistical report: primary brain and other central nervous system tumors diagnosed in the United States in 2010-2014. Neuro Oncol. 19(suppl_5):v1–v88. 2017.

25. Ostrom QT, Gittleman H, Xu J, Kromer C, Wolinsky Y, Kruchko C, et al. CBTRUS statistical report: primary brain and other central nervous system tumors diagnosed in the United States in 2009-2013. Neuro Oncol. 18(suppl_5):v1–v75. 2016.

26. Pu JK, Ng GK, Leung GK, Wong CK. One-year review of the incidence of brain tumours in Hong Kong Chinese patients as part of the Hong Kong brain and spinal tumours registry. Surgical Practice. 16:133–136. 2012.

27. Wen HL, Cheung SY. Incidence of tumors in the nervous system in Hong Kong. J International surgery. 58:555–556. 1973.

28. Zülch KJ. Histological typing of tumours of the central nervous system. Geneva: World Health Organization;1979.