The incidence of colorectal carcinoma is rising at an alarming pace in
Asian urban societies such as Hong Kong. Detailed examination of the
epidemiological pattern and genetic mutation of colorectal cancer in t
he Hong Kong Chinese population is overdue. We compared the reported a
ge incidence of colorectal carcinoma in Hong Kong with that of Scotlan
d and other countries. Hong Kong showed a much higher incidence of col
orectal carcinoma among the young age groups. By comparison with other
countries, this raised incidence among the young appeared to be relat
ed to southern Chinese societies. The recent dramatic rise in colorect
al cancer in Hong Kong was largely attributable to an increase in the
over 50 years age group, while the young incidence remained unchanged.
We also defined the mutation spectrum of p53 and Ki-ras in 67 unselec
ted cases by direct DNA sequencing. Interestingly, insertion/deletion
mutations in p53 from colorectal carcinoma in Hong Kong showed a signi
ficantly higher frequency (17.2%) than the Scottish data (0%) and the
world database (6.6%), although the overall frequency of p53 mutation
(43%) in Hong Kong was similar to others. The high incidence of colore
ctal carcinoma in young people and the raised proportion of frameshift
mutations in p53 encourage further search for a genetic basis for sus
ceptibility to this disease in the Hong Kong Chinese population.