Replies to LegCo questions

LCQ17: Cancer cases

     Following is a question by the Hon Lau Kong-wah and a written reply by the Secretary for Health, Welfare and Food, Dr Yeoh Eng-kiong, in the Legislative Council today (May 5):

 

Question:

 

     Regarding cancer cases, will the Government inform this Council of:

 

(a)  the number of cancer cases newly diagnosed each year since 2000, together with a breakdown by the types of cancer and the patients' age profile (in age groups each covering five years);

 

(b)  the types of cancer showing an upward trend in incidence rates in recent years; and

 

(c)  the trends on cure rates and mortality rates for various types of cancer in recent years?

 

Reply:

 

(a)  At present, statistical information about cancer cases is compiled by the Hong Kong Cancer Registry (the Registry) of the Hospital Authority (HA).  It regularly collects cancer-related information from public and private hospitals as well as the Department of Health.  Due to the need to cross-check over 140,000 cases reported from different sources to avoid double-counting and to verify the accuracy of the data, the compilation of data is very time-consuming.  The Registry can only produce verified reports of various types of cancer cases up to 2001.  The numbers of new cases of cancer diagnosed in 2000 and 2001 are 21,349 and 21,404 respectively.  A detailed breakdown is at Annex.

 

(b)  To adjust for the effects of population growth and ageing, it is the international practice to use the age-standardised incidence rate (rather than the absolute number of new cases) as the measure of cancer incidence trend.  With regard to the ten most common cancers in 2001, the ones with rising age-standardised incidence rates are prostate cancer, female breast cancer and colorectal cancer.

 

(c)  The overall age-standardised mortality rate for all cancer types has been decreasing.  Common cancers showing decreasing age-standardised mortality rates include cancers of the lung, liver, nasopharynx etc.  The age-standardised mortality rate for breast cancer remained relatively stable.  Colorectal cancer and prostate cancer showed an increase in age-standardised mortality rate.

 

     There is no universally-accepted definition of "cure rate" for cancer in the field of medicine because it is not possible to ascertain the true absence of cancer in people, who may or may not have cancer treatment before.

 

     It is however an international practice to compare treatment results of cancer using the "five-year relative survival rate" (survival rate), which is defined as the ratio of the proportion of observed survivors in a cohort of cancer patients to the proportion of expected survivors in a comparable set of individuals who do not have any cancer history.  HA is in the process of compiling the five-year survival rates of selected cancers by matching cases of individual cancer patients with the information of the Death Registry for the period between 1996 and 2001.  The statistics will be available at a later stage.

 

Ends/Wednesday, May 5, 2004

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-- Annex (PDF file)