Colorectal cancer: incidence and trend in Brunei Darussalam

The incidence of colorectal cancer (CRC) is reported to be increasing. This study assessed the incidence and trend of CRCs in Brunei Darussalam, a developing nation.

All histologically-confirmed CRCs over a 22-year period (1986-2007) were identified from the National Cancer and the Department of Pathology registries and retrospectively reviewed.

There was a total of 576 (male 59.0 percent, mean age 59.6 +/- 14.8 years, adenocarcinoma 97.6 percent, rectum 31.4 percent) CRCs diagnosed during this period. There was an increasing trend in the mean age at diagnosis, 55.2 +/- 17.5 years in 1986 to 62.0 +/- 13.0 years in 2007, but this was not significant (p-value equals 0.150, ANOVA). 18.8 percent were diagnosed in patients aged 45 years or below. There was no difference in the age at diagnosis between the genders (p-value equals to 0.432) and tumour sites, colon vs. rectum (p-value equals to 0.279). Overall, there was an increase in the age standardised rate (ASR) from 10.36 (1986-90) to 13.75 (1991-95), 15.90 (1996-2000), 16.87 (2001-05) and 24.31 per 100,000 (2006-07). Among the ethnic groups, the Chinese had higher ASRs (41.44) compared to the Malays (including the indigenous groups) with 15.46 per 100,000. The mean age of the Chinese (62.6 +/- 14.0 years) was significantly higher than that of the Malays (58.2 +/- 14.9 years, p-value equals to 0.001) at diagnosis. The age-specific incidence rates for the genders were comparable, except for the age groups of older than 55-59 years, where the rate for males was higher.

The incidence of CRC is increasing in our local setting with differences observed among the ethnic groups. The Chinese had a higher incidence but developed CRC at a later age. These have important implications if screening for CRC is to be considered in our local setting.