Trend of colorectal cancer in Hong Kong: 1983-2006.

BACKGROUND AND AIM: The incidence of colorectal cancer (CC) is increasing in many Asian countries, but decreasing in western countries. The present study examined the local incidence of CC in the past few decades. METHODS: A population based study, using data from Hong Kong (HK) Cancer Registry, was carried out to examine the trends of CC in different age groups in HK. Comparison with other countries was made. RESULTS: The crude rate of CC in HK increased from 29.6/100,000 in 1983 to 57.1/100,000 in 2006. Age standardized rate (ASR) increased by less than 20%. It was markedly smaller than the 190% increase in crude rate. ASR progressively increased in males. In females, ASR peaked in 1994 and declined in the last decade. In most countries, the risk of CC was higher and increasing in males, but stable or decreasing in females. With respect to age, increasing risk was noted in males above 60 years old and females above 70 years old. However, a declining rate was noted in those below 50 years old. The decrease was over 40% in the 30-34 years group over the past two decades. CONCLUSIONS: Increasing incidence of CC in HK was mostly in the older and male population, but not in the younger age group.

Epidemiology of colorectal cancer in Asia.

The prevalence of colorectal cancer is increasing in Asia. However, the age-standardized rate has reached a plateau in some countries. Some studies have shown a male predominance difference and increasing risk in the elderly, but not in the younger population. 'Right shifting' of colorectal cancer, not accountable by difference in age or the indications for endoscopic examination, has also been noted. Westernized diet is associated with colorectal cancer, but controversy remains on how it causes colorectal cancer. Alcohol consumption, obesity, diabetes mellitus, consumption of red and processed meat and cigarette smoking are linked to bowel cancer epidemiologically. Only high dietary calcium has a consistent negative (or 'protective') effect. The efficacy of fish oil, vitamin D, soy, phytoestrogens, folate, methionine, riboflavin and vitamin B6 has not been established. Aspirin and non-steroidal anti-inflammatory drugs use decrease risk of colorectal cancer after 5-10 years of use. There is no evidence for a detrimental effect of proton pump inhibitors or benefit of statins in colorectal cancer. In conclusion, there is a rising trend and prevalence of colorectal cancer in Asia. Dietary modification or supplementation may not be effective in preventing colorectal cancer. Surveillance of colorectal cancer in high-risk groups, according to current recommendation, is probably most effective.

Prevalence and time trend of intestinal metaplasia in Hong Kong.

BACKGROUND AND METHODS: Upper endoscopy records from 1998 to 2003 were reviewed. The demographic data, endoscopic diagnosis, results of rapid urease test and the absence or presence of intestinal metaplasia (IM) in histology were reviewed, to evaluate the prevalence of IM and Helicobacter pylori (Hp) infection over time in Hong Kong. RESULTS: Among 1805 endoscopies performed, 1751 had both rapid urease test and histology available. A significant drop in the prevalence of duodenal ulcers from 17.9% in 1998 to 9.8% in 2003 was found (P = 0.015). Prevalence of IM was 13.9%, 5.9% and 9.4% in Hp positive, Hp negative and overall respectively (P < 0.05). The prevalence of IM increased with age, and the patterns were similar amongst subjects in 1998-2000 and those in 2001-2003. There was progressive decrease in Hp prevalence from 58% in 1998 to 40% in 2001 (P = 0.014), but no further decrease was seen in 2002-3. There was no corresponding decrease in IM prevalence. Instead IM prevalence in 2002-2003 was significantly higher than the prevalence in previous few years (P = 0.04). CONCLUSION: The prevalence of IM did not change in the period from 1998 to 2003 despite a drop in the prevalence of Hp infection since 1994.

Factors affecting physicians' practices related to Helicobacter pylori infection: effect of experience and mode of practice.

BACKGROUND: Studies found that guidelines on the management of Helicobacter pylori were not always followed in clinical practice. This study investigated factors that were responsible for the deviation. METHODS: A cross-sectional survey using a structured self-administered questionnaire was used to ask physicians whether they would offer testing and treatment for H. pylori infection in different clinical scenarios. RESULTS: 170 medical practitioners completed the questionnaires. Respondents in the private sector were significantly more likely to test and treat than those in the public sector for patients with a history of peptic ulcer, gastric cancer or no symptom (p = 0.018, <0.001 and 0.041, respectively). Significant differences in practice were noted amongst practitioners of different specialty and seniority, but not qualification. Medical practitioners in the private sector complied with the guidelines significantly better than those in the public sector (p = 0.002) and so did senior practitioners compared with junior practitioners (p < 0.001). The specialty and qualification of the respondents, however, did not have a significant effect. CONCLUSION: There were significant differences in the management of H. pylori amongst medical practitioners from the private and public sectors and amongst senior and junior practitioners. Published guidelines were not completely followed. Further educational campaigns are needed.

Decreasing trend of esophageal adenocarcinoma in Hong Kong.

BACKGROUND: The incidence of esophageal adenocarcinoma was increasing in the Western Europe and United States, but not in East Asian countries. Population based study on the trend of esophageal adenocarcinoma in Hong Kong was not available. MATERIALS AND METHODS: Population-based data of Hong Kong Cancer Registry from 1984 to 2003 were used. Cases were grouped into four 5-year periods. Average age standardized rate (WSR) of each period was calculated by averaging the WSR of the 5 years in each period, basing on the world standard population, with adjustment made for cases with missing histology. RESULTS: 10,751 new cases of esophageal neoplasm were studied (8,637 males and 2,114 females). Esophageal adenocarcinoma declined among both males and females, with the total number decreased from 224 in 1984 to 1988 to 131 in 1998 to 2003. WSR decreased from 1.10 of 100,000 in 1984 to 1988 to 0.34 of 100,000 in 1998 to 2003. The decline was faster than that for esophageal squamous cell carcinoma so that the relative ratio of esophageal adenocarcinoma decreased from 11.7% in 1984 to 1988 to 6.4% in 1998 to 2003. CONCLUSIONS: The incidence of esophageal adenocarcinoma and ratio of esophageal adenocarcinoma versus esophageal squamous cell carcinoma decreased in Hong Kong.

Chinese tea consumption and lower risk of Helicobacter infection.

BACKGROUND: Our first study had shown that Chinese tea has anti-Helicobacter activity. The present study investigated the relationship between patients'Helicobacter status and the history of Chinese tea consumption. METHODS: Chinese patients who had their first upper endoscopy were recruited. Before the procedure, patients completed questionnaires about their current Chinese tea consumption habits and those when they were around 10-25 years old. This information was used to calculate the tea consumption indices (TCI). Gastric biopsies (two from the antrum and two from the corpus) were taken for histological examination for Helicobacter. RESULTS: Eighty patients were recruited. Eight patients were rejected because of either an incomplete questionnaire, absence of gastric biopsy or a suspected history of treatment for Helicobacter infection. Of the 72 patients, 42 (58.3%) were Helicobacter positive. The age, sex ratio and indications for endoscopy were similar in both Helicobacter-positive and -negative groups. Classifying patients using either current, past or total TCI, patients with high tea consumption had significantly lower Helicobacter infection rate than those with low tea consumption (45% compared to 74%, 42% compared to 67% and 40% compared to 83%, respectively). Helicobacter-negative patients had higher overall TCI than Helicobacter-positive patients (28.2:17.3). When current and previous histories were analyzed separately, Helicobacter-negative patients also had a trend towards higher TCI currently (16.6:11.0) and in their 20s (11.6:6.1). CONCLUSIONS: There is a significant inverse relationship between Chinese tea consumption and Helicobacter infection. Chinese tea consumption may decrease the chance of Helicobacter infection.