The Hong Kong Cancer Registry first started computerization of data in 1983. Together with the latest release of the 2007 results, the Registry has now collected 25 years of population based cancer statistical information.

Over these 25 years, the number of new cancer cases continued to rise at a rate of around 2% per annum. Crude incidence rates, expressed as the number of all new cancer cases per 100,000 population per year, rose from 320 to 396.4 and 246.1 to 310.9 in men and women, respectively between 1983 and 2007. The average annual increment was 1% for men and 0.8% for women. As over 60% of all new cancers were in people older than 60, the increase in number could largely be explained by the growing and ageing population in the territory.

Crude incidence rates reflect the cancer burden in a population regardless of age structure, and are particularly useful in health care service planning. On the other hand, age-standardized rates, whereby the crude rates are standardized to the predefined age structure of the world population, give a better indication of the relative risk of cancer over time, after correcting for ageing and population factors. According to the Registry data, the age-standardized incidence rates have been decreasing steadily over the 25-year period for both genders, the average annual percent change for all cancers being -1.4% for men and -0.8% for women during 1983-2007. A downward trend was most obvious in cancers of the nasopharynx, oesophagus, stomach, lung as well as cervix, while an upward trend was observed for cancers of the female breast, corpus, ovary, prostate and male colorectum. Socio-economic and life style changes could partly be responsible for the changing trends and overall Hong Kong is becoming healthier than ever. Other contributing factors include technical changes in coding practices, introduction of screening activities as well as improvement in diagnostic practices. For these latter reasons, trend analysis must be based on data covering long enough time period in order to arrive at meaningful conclusions.