Annual changes in colorectal carcinoma incidence in Japan. Analysis of survey data on incidence in Aomori Prefecture

Tumour-Associated Macrophages (TAMs) in Colon Cancer and How to Reeducate Them

Tumour-associated macrophage (TAM) serves as the site in which most inflammatory cells coreside. It plays an important role in determining the progression and metastasis of a tumour. The characteristic of TAM is largely dependent on the stimuli present in its tumour microenvironment (TME). Under this environment, however, M2 macrophages are found to be in abundance compared to M1 macrophages which later promote tumour progression. Numerous studies have elucidated the relationship between TAM and the progression of tumour; hence, TAM has now been the subject of interest among researchers for anticancer therapy. This review discusses the role of TAM in colorectal cancer (CRC) and some of the potential candidates that could reeducate TAM to fight against CRC. It is with hope that this review will serve as the foundation in understanding TAM in CRC and helping other researchers to select the most suitable candidate to reeducate TAM that could assist in enhancing the tumouricidal activity of M1 macrophage and eventually repress the development of CRC.

Colorectal cancer burden and trends in a South Asian cohort: experience from a regional tertiary care center in Sri Lanka

Objective

Colorectal cancer (CRC) burden is increasing in the south Asian region due to the changing socio-economic landscape and population demographics. There is a lack of robust high quality data from this region in order to evaluate the disease pattern and comparison. Using generalized linear models assuming Poisson distribution and model fitting, authors describe the variation in the landscape of CRC burden along time since 1997 at a regional tertiary care center in Sri Lanka.

Results

Analyzing 679 patients, it is observed that both colon and rectal cancers have significantly increased over time (pre 2000—61, 2000 to 2004—178, 2005 to 2009—190, 2010 to 2014–250; P < 0.05). Majority of the cancers were left sided (82%) while 77% were rectosigmoid. Over 25% of all CRC were diagnosed in patients less than 50 years and the median age at diagnosis is < 62 years. Increasing trend is seen in the stage at presentation while 33% of the rectal cancers received neoadjuvant chemoradiation. Left sided preponderance, younger age at presentation and advanced stage at presentation was observed. CRC disease pattern in the South Asian population may vary from that observed in the western population which has implications on disease surveillance and treatment.

Study of Clinicopathological Profile of Sporadic Cases of Colorectal Cancer

Objectives

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the world. This study was carried out to see the epidemiological and clinicopathological profile of sporadic cases of CRC in Bangladesh.

Materials and methods

The patients diagnosed to have colorectal carcinoma in two private medical centers of Bangladesh from January 2012 to December 2014 were enrolled in this study. Demographic data, clinical presentations, site of lesions, and histological types were analyzed.

Results

Total 158 patients were included in this study. The mean age was 50.77 years and male to female ratio was 1.55:1. Rectal bleeding was the commonest symptom irrespective of age and sex followed by abdominal pain (33, 20.9%), weight loss (29, 18.3%), abdominal mass (26, 16.4%), and altered bowel habit (22, 13.9%). Common histological type was adenocarcinoma (156, 98.7%).

Conclusion

Colorectal cancer commonly affects males >40 years of age. Most common site of involvement is rectum, which is followed by left colon.

How to cite this article

Saha M, Shil BC, Saha SK, Banik RK, Perveen I, Chowdhury MKS, Nazmul Islam ASM, Saifullah ANM. Study of Clinicopathological Profile of Sporadic Cases of Colorectal Cancer. Euroasian J Hepato-Gastroenterol 2016;6(2):134-136.

Incidence and mortality rates of colorectal cancer in Malaysia

OBJECTIVES

This is the first study that estimates the incidence and mortality rate for colorectal cancer (CRC) patients in Malaysia by sex and ethnicity.

METHODS

The 4,501 patients were selected from National Cancer Patient Registry-Colorectal Cancer data. Patient survival status was cross-checked with the National Registration Department. The age-standardised rate (ASR) was calculated as the proportion of CRC cases (incidence) and deaths (mortality) from 2008 to 2013, weighted by the age structure of the population, as determined by the Department of Statistics Malaysia and the World Health Organization world standard population distribution.

RESULTS

The overall incidence rate for CRC was 21.32 cases per 100,000. Those of Chinese ethnicity had the highest CRC incidence (27.35), followed by the Malay (18.95), and Indian (17.55) ethnicities. The ASR incidence rate of CRC was 1.33 times higher among males than females (24.16 and 18.14 per 100,000, respectively). The 2011 (44.7%) CRC deaths were recorded. The overall ASR of mortality was 9.79 cases, with 11.85 among the Chinese, followed by 9.56 among the Malays and 7.08 among the Indians. The ASR of mortality was 1.42 times higher among males (11.46) than females (8.05).

CONCLUSIONS

CRC incidence and mortality is higher in males than females. Individuals of Chinese ethnicity have the highest incidence of CRC, followed by the Malay and Indian ethnicities. The same trends were observed for the age-standardised mortality rate.

Modulatory efficacy of rosmarinic acid on premalignant lesions and antioxidant status in 1,2-dimethylhydrazine induced rat colon carcinogenesis

Colorectal cancer is one of the leading causes of cancer related deaths in Western countries and is becoming increasingly common in Asia. Rosmarinic acid (RA), one of the major components of polyphenol possesses attractive remedial features. The purpose of this study is to investigate the possible chemopreventive mechanism of action of RA against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the circulatory antioxidant status and colonic bacterial enzymes activities. Additionally, we analyzed the aberrant crypt foci (ACF) formation and multiplicity in the colon of experimental groups. Wistar male rats were divided into six groups. Group 1 was control rats, group 2 rats received RA (10 mg/kg b.w., p.o. everyday), rats in groups 3-6 received DMH (20 mg/kg b.w., s.c.) for the first 4 weeks. In addition to DMH, groups 4-6 received 2.5, 5, and 10 mg/kg b.w. RA respectively. The results revealed that supplementation with RA significantly reduced the formation of ACF and ACF multiplicity in DMH treated rats. Moreover RA supplementation prevented the alterations in circulatory antioxidant enzymes and colonic bacterial enzymes activities. Overall, our results showed that all three doses of RA inhibited carcinogenesis, though the effect of the intermediary dose of 5 mg/kg b.w. was more pronounced.

An overview of colorectal cancer survival rates and prognosis in Asia

Colorectal cancer is a rapidly rising trend in Asia. The incidence in many Asian countries is on par with the West. Several studies have provided data regarding the survival of patients with colorectal cancer. In Asia, the overall cure rate of colorectal cancer has not improved dramatically in the last decade, 5-year survival remaining at approximately 60%. Colorectal cancer survival time has increased in recent years, but mortality rate remains high. Although studies have determined a number of factors that can predict survival of patients after diagnosis, life expectancy has not been increased dramatically. It seems that among the prognostic factors explored so far, the most important are those that relate to early diagnosis of cancer. Primary detection is feasible since efficient screening modalities are available. Colonoscopic surveillance is needed, especially in subjects at higher risk.

Trends in colorectal cancer incidence: a period and birth-cohort analysis in a well-defined French population

BACKGROUND

France stands among high-risk areas for colorectal cancer. Different trends in CRC incidence are reported around the world. The aim of this study was to provide temporal trends in CRC incidence over a 30-year period in a French well-defined population.

METHODS

Between 1976 and 2005, 17,028 new cases were registered by the Burgundy digestive cancer registry. The mean variations in age-standardized incidence rates were estimated using a Poisson regression adjusted for age for each gender and location. The cumulative risk by birth cohort of developing a cancer over the age range 0-74 years was estimated using an age-cohort model.

RESULTS

Incidence rates for right and left colon cancers increased more rapidly in males (respectively +11.7% and +10.3% on average by 5-year period) than in females (respectively +5.9% and +6.1%). It remained stable for sigmoid cancers in males (-0.1%) and decreased in females (-5.2%). It also decreased for rectal cancers both in males (-2.7%) and in females (-2.0%). The cumulative risk increased from 3.9% for males born around 1900 to 4.9% for those born around 1930 and then slightly decreased (4.5% among those born around 1950). It remained at the same level for females born around 1900 (2.7%) as for those born around 1930 (2.7%) and then slightly increased (2.9%) for those born around 1950. For right colon cancers, the cumulative risk increased strikingly in successive birth cohorts from 0.53% to 1.2% in males and 0.55% to 0.77% in females. The corresponding cumulative risks for the left colon were 0.24% and 0.42% in males and 0.14% and 0.29% in females. For sigmoid cancer, they decreased from 1.59% to 1.08% in males, and 0.88% to 0.80% in females.

CONCLUSION

Temporal variations in incidence rates of colorectal cancers differed according to subsite, suggesting different aetiological factors and implications for diagnosis and screening strategies. Total colonoscopy must be the preferred strategy in high-risk groups or after a positive faecal occult blood test.

The comparison of the clinical manifestations and risk factors of colorectal cancer and adenomas: results from a colonoscopy-based study in southern Chinese

BACKGROUND AND AIMS

Colorectal cancer (CRC) is one of the most common gastrointestinal tumors in the world. This study aimed to compare the clinical manifestations and risk factors of CRC and adenomas in native patients of Guangzhou.

METHODS

Patients who underwent colonoscopy for the first time at Nanfang Hospital between July 2008 and July 2009 were recruited. Data on demographic information, main clinical manifestations, results of endoscopies and pathology, and possible risk factors of colorectal tumor were collected. Chi-square test and logistic regression were used to compare the clinical characteristics and risk factors for CRC and adenomas.

RESULTS

Hematochezia and body weight loss were more frequent in proximal and distal CRC groups, respectively (P ≤  0.05). Older age [odds ratio (OR), 1.079; 95% confidence interval (CI), 1.065-1.093], smoking status (OR, 1.712; 95% CI, 1.158-2.531), BMI =18.5-24.9 and  ≥ 25.0 (OR, 2.384; 95% CI, 1.250-4.549; OR, 2.162; 95% CI, 1.044-4.478, respectively) were significant risk factors for advanced adenoma, while female (OR, 0.638; 95% CI, 0.429-0.949) and using aspirin (OR, 0.188; 95% CI, 0.042-0.845) were significant protective factors. Hyperlipemia (OR, 0.109; 95% CI, 0.013-0.886) was identified as a protective factor for proximal CRC. Smoking (OR, 1.717; 95% CI, 1.093-2.696), drinking (OR, 1.817; 95% CI, 1.145-2.883), DM history (OR, 2.204; 95% CI, 1.044-4.652) were identified as independent risk factors for distal CRC, and using aspirin (OR, 0.190; 95% CI, 0.043-0.840) was a protective factor. Drinking (OR, 3.288; 95% CI, 1.546-6.994; OR, 1.862; 95% CI, 1.037-3.343, respectively) was an independent risk factor for both poorly to moderately differentiated CRC and well-differentiated CRC. Besides, DM (OR, 3.761; 95% CI, 1.615-8.762) and hypertension (OR, 0.384; 95% CI, 0.178-0.828) were identified as independent risk factor and protective factor for well-differentiated CRC, respectively.

CONCLUSIONS

Hematochezia and body weight loss were representative manifestations for distal and proximal CRC, respectively. For southern Chinese the most important influential factors for colorectal tumor are age, smoking, drinking, nutritional state, DM, hypertension, and the use of aspirin.

Trends in colorectal cancer incidence in Norway 1962-2006: an interpretation of the temporal patterns by anatomic subsite

There have been rapid increases in the incidence of colorectal cancer in Norway since the 1960s, and rates rank among the highest worldwide. The primary objectives are to describe trends in left- and right-sided colon cancer and rectal cancer by calendar period and birth cohort and to generate hypotheses as to the etiological factors in operation. Although the age-adjusted incidence rates of both colon and rectal cancer increased in Norway in both sexes up to the 1980s, subsite- and age-specific analyses reveal a deceleration in the rate of increase thereafter, apparent in the rates of both left-sided colon and rectal cancer. Overall trends in incidence of right-sided colon cancer continue to increase in both sexes. Rates in both left- and right-sided colon cancers have tended to stabilize or decrease among successive generations born after 1950, however, while incidence rates of rectal cancer appear to be increasing in recent generations. The all-ages rates are thus in keeping with the commonly reported "left to right shift" of colon cancer, although standardization masks important observations. The cohort patterns provide further evidence that factors earlier in life are important, and while the complex etiology makes interpretation difficult, modifications in diet, obesity and physical activity in Norway are likely among the drivers of the trends in one or more of the colorectal subsites examined. In summary, the recent downturn in the disease at younger ages provides some reason for optimism, although possible increases in rectal cancer among recent birth cohorts are of concern.

Colorectal cancer distribution in 220 Indian patients undergoing colonoscopy

AIM

Colorectal cancer is one of the major cancers in the developed world. The incidence of colorectal cancer is low in India. The aim of the present study was to describe the anatomical distribution and age at diagnosis of colorectal cancer in India.

METHODS

Retrospective descriptive analysis of anatomical distribution, age at diagnosis and demography of 220 cases (149 [67.7%] men) of adenocarcinoma of the colon or rectum diagnosed at colonoscopy over a period of five years.

RESULTS

The mean age at diagnosis was 58.4 years (SD 13.3; range 23-85 years). Twenty-eight (12.7%) cases were below the age of 40 years. The majority (31.8%) cases were aged between 61-70 years. Most of the tumors (n=163, 74%) were located distal to the splenic flexure. Multivariate logistic regression analysis showed that bleeding per rectum (OR 2.8; 95% CI 1.2-6.2) was associated with distal cancer, and palpable mass (OR 3.9; 95% CI 1.7-8.6) was associated with proximal cancer.

CONCLUSIONS

Almost one-third of the colorectal cancers in this series occurred in the seventh decade and were located distal to the splenic flexure.

Changes on the disease pattern of primary colorectal cancers in Southern China: a retrospective study of 20 years

PURPOSE

Some changes on the disease pattern of colorectal cancer (CRC) have occurred in some Asian countries recently. However, nothing is known about it in China lately. The present study is to determine whether there are any changes on the disease pattern of CRC in Southern China.

PATIENTS AND METHODS

Data were collected from all consecutive patients accepting colonoscopy in our endoscopy center during the last 20 years. The sociodemographic data, clinical presentations, endoscopic descriptions, and histological subtypes of patients confirmed as CRC by pathology were analyzed retrospectively.

RESULTS

A total of 37,578 patients accepted colonoscopy from 1987 to 2006, in which 2,876 patients were diagnosed as CRC. The median age of patients in the 2nd decade (1997-2006; 62 years) was getting older than the 1st decade (1987-1996; 58 years; P = 0.043). Hematochezia was the most frequent symptom (55.8%), while rectum was the most common site distribution of CRC (51.0%). The incidence of right-sided colonic cancers in the 2nd decade (21.0%) was higher than the 1st decade (17.3%; P = 0.0314). Histologically, adenocarcinoma was the most common (92.4%), of which moderately differentiated tumors were more frequent (67.7%). CRCs with high-grade malignancy were more likely to occur in the 1st decade (P < 0.0001).

CONCLUSIONS

Rectum remains the most common site of CRC in southern China. But a rightward shift in the site distribution has occurred and patients are getting older. Tumors with high-grade malignancy have the tendency to decrease.

Animal origin foods and colorectal cancer risk: a report from the Shanghai Women's Health Study

The association of animal-origin food consumption and cooking patterns with colorectal cancer (CRC) risk was evaluated in a cohort of 73,224 participants of the Shanghai Women's Health Study. After a mean follow-up time of 7.4 yr, 394 incident cases of CRC (colon = 236; rectal = 158) were diagnosed. Overall, no association was found between the risk of CRC and intake of total meat and total fish. Eel (P(trend) = 0.01), shrimp (P(trend) = 0.06), and shellfish (P(trend) = 0.04) consumption were positively associated with CRC risk. High egg intake and high intake of total cholesterol were also related to risk of CRC (RR for the highest vs. lowest quintiles of intake were 1.4 (95% CI = 1.1-2.0) for eggs and 1.6 (95% CI = 1.1-2.3) for cholesterol). Milk intake was inversely associated with the risk of colon cancer (P(trend) = 0.05). Common Chinese cooking practices except the smoking method of cooking were not related to CRC risk. The latter was positively associated with colon cancer (RR = 1.4 for ever vs. never, 95% CI = 1.1-1.9). A possible role of cholesterol and environmental pollution in the etiology of CRC was suggested.

Prevalence of colorectal neoplasms in Asian Americans

PURPOSE

To determine the yield of colonoscopy in a predominantly Asian American gastroenterology practice in California from 8/2003 to 2/2005.

RESULTS

A total 2,723 subjects were included: 87% were Asian and 13% were non-Asian. Advanced neoplasia prevalence was 12% in Asian men and 9% in non-Asian men (P = 0.21), and 8% and 7% in women (P = 0.62). Similar results were found in asymptomatic patients (13% and 13%, P = 0.99, for men; 8% and 6%, P = 0.46, for women). Factors associated with presence of advanced neoplasia were total number of polyps and presence of right-sided lesions. Asian men were more likely to have neoplasia overall compared with non-Asian men with odds ratio (OR) of 2.14 (1.23-3.72); however, there were no significant differences in the prevalences of advanced neoplasia in the two groups.

CONCLUSIONS

Colorectal neoplasia is as prevalent in Asian Americans and preventive guidelines for colorectal cancer should also be advocated for this ethnic group.

Screening CT colonography in an asymptomatic average-risk Asian population: a 2-year experience in a single institution

OBJECTIVE

The purpose of our study was to report the results of screening CT colonography (CTC) in an asymptomatic average-risk Asian population.

MATERIALS AND METHODS

In 2005 and 2006, 1,015 Korean adults (609 men and 406 women; mean age, 51 years) underwent screening CTC using a 16-MDCT scanner and an automated CO2 delivery system. During the study period, the protocols were changed to use less vigorous purgation and lower radiation doses; fecal tagging (n = 890) and primary 3D interpretation (n = 966) were generally used. CTC results were categorized as C0, inadequate; C1, no significant polyp; C2, one or two 6- to 9-mm polyps; C3, polyps > or = 10 mm or > or = three 6- to 9-mm polyps; and C4, mass. Patients with positive CTC results were referred to gastroenterologists for follow-up or management planning.

RESULTS

Categories C0-C4 were assigned to 21 (2.1%), 916 (90.2%), 54 (5.3%), 23 (2.3%), and one (0.1%) patients, respectively. Fifty-four patients with C4 (n = 1), C3 (n = 20), or C2 (n = 33) underwent subsequent optical colonoscopy: complete (n = 53) and incomplete (n = 1). Per-patient positive predictive values (PPVs) for categories C3-C4 and C2-C4 were 90% (18/20) and 74% (39/53), respectively. Per-polyp PPVs at 10- and 6-mm thresholds were 92% (22/24) and 69% (45/65), respectively. The diagnostic yield for advanced neoplasm was 1.5% (15/1,015).

CONCLUSION

Our results seem comparable to Western experiences, showing that a successful screening CTC program can be reproduced in an Asian population.

Clinical predictors of colorectal polyps and carcinoma in a low prevalence region: Results of a colonoscopy based study

AIM: To estimate the prevalence of colorectal cancer (CRC) in patients with long lasting colonic symptoms undergoing total colonoscopy; and to establish clinical features predicting its occurrence.

METHODS: This prospective study was carried out in Imam Hospital, Tabriz University of medical sciences, Iran. Continuous patients with long lasting lower gastrointestinal tract symptoms who had the criteria of a colonoscopy were included. The endoscopist visualized the caecum documented by a photo and/or a specimen from terminal ileum.

RESULTS: Four hundred and eighty consecutive symptomatic patients [mean age (SD): 42.73 (16.21)] were included. The prevalence of colorectal neoplasia was 15.3% (34 subjects) and 37.7% (181 subjects) had a completely normal colon. Adenomatous polyps were detected in 56 (11.7%) patients, in 12.3% of men and 10.9% of women. The mean age of the patients with a polyp was significantly higher than the others (49.53 ± 14.16 vs 41.85 ± 16.26, P = 0.001). Most of the adenomatous polyps were left sided and tubular; only 22.5% of polyps were more than 10 mm. Cancer was detected in 16 (3.6%) of our study population, which was mostly right sided (57.2%). The mean age of patients with cancer was significantly higher than the others (60.25 ± 8.26 vs 42.13 ± 16.08, P < 0.005) and higher than patients with polyps [60.25 (8.26) vs 49.53 (1.91) (P < 0.0005)]. None of the symptoms (diarrhea, abdominal pain, rectal bleeding, constipation, altering diarrhea and constipation, history of cancer, known irritable bowel disease, history of polyp and fissure or family history of cancer) were predictors for cancer or polyps, but the age of the patient and unexplained anemia independently predicted cancer.

CONCLUSION: Less advanced patterns and smaller sizes of adenomas in Iran is compatible with other data from Asia and the Middle East, but in contrast to western countries. Prevalence of colonic neoplasia in our community seems to be lower than that in western population. Colonic symptoms are not predictors for polyps or cancer but unexplained anemia and elder age can predict CRC.

Pathophysiology, clinical presentation, and management of colon cancer

Colon cancer is believed to arise from two types of precursor polyps via two distinct pathways: conventional adenomas by the conventional adenoma-to-carcinoma sequence and serrated adenomas according to the serrated adenoma-to-carcinoma theory. Conventional adenomas arise from mutation of the APC gene; progression to colon cancer is a multistep process. The fundamental genetic defect in serrated adenomas is unknown. Environmental factors can increase the risk for colon cancer. Advanced colon cancer often presents with symptoms, but early colon cancer and premalignant adenomatous polyps commonly are asymptomatic, rendering them difficult to detect and providing the rationale for mass screening of adults over age 50.

Relationship between meat and cereal consumption and colorectal cancer in Korea and Japan

BACKGROUND AND AIM

The incidence of colorectal cancer in Asian countries is increasing. The change to a more westernized diet is known to be related to these increases, and there are reports on the relationship between meat consumption and colorectal cancer in Japan. The aim of this study was to investigate the relationship between dietary change and colorectal cancer in Korea and Japan.

METHODS

The data of meat and cereal consumption in Japan (1950-2002) and Korea (1970-2003), and the data of colorectal cancer incidence in Japan (1975-1998) and Korea (1992-2002) were investigated with a 20-year difference between the two countries.

RESULT

We found that the changes in meat and cereal consumption, as well as the increases in the incidence of colon and rectal cancer, were similar between those two countries with a 20-year difference.

CONCLUSION

These similarities between Korea and Japan could be helpful for predicting future colorectal cancer incidences for Korea and other Asian countries.

Colorectal neoplasm in asymptomatic Asians: a prospective multinational multicenter colonoscopy survey

BACKGROUND

Colorectal neoplasm is rapidly increasing in Asia, but a guideline for screening is not available.

OBJECTIVE

To evaluate the characteristics of colorectal neoplasm in asymptomatic Asian subjects.

DESIGN

Prospective cohort study.

SETTING

Multinational multicenters, including both primary and referral centers in Asia.

PATIENTS

A total of 860 consecutive asymptomatic adults undergoing screening colonoscopy in 11 Asian cities from July 2004 to December 2004. Patients under 16 years old; those patients with a colorectal resection history, colonoscopies, or barium enema within 5 years; symptoms suggestive of colorectal diseases; and those who had undergone surveillance colonoscopy were excluded.

MAIN OUTCOME MEASUREMENTS

The incidence and distribution of colorectal neoplasm and advanced neoplasm.

RESULTS

The mean age (+/-SD) was 54.4+/-11.6 years; 471 were men (54.8%). The prevalence of colorectal neoplasm and advanced neoplasm was 18.5% and 4.5%, respectively. Male sex, advancing age, and a family history of colorectal cancer were risk factors for advanced neoplasm. Of the 168 patients with colorectal neoplasm, 76 had distal neoplasm only (45.2%), 66 had proximal neoplasm only (39.3%), and 26 had both proximal and distal neoplasms (15.5%). Although the presence of distal advanced neoplasm was a significant risk factor for proximal advanced neoplasm, 14 of the 758 subjects without distal neoplasm had proximal advanced neoplasm (1.8%).

LIMITATIONS

The small number of enrolled subjects, especially from certain ethnic groups.

CONCLUSIONS

The overall prevalence of advanced colorectal neoplasm in asymptomatic Asians is comparable with the West. Male sex, advancing age, and a family history of colorectal cancer were associated with a higher risk of advanced neoplasm.

Evaluation of relationships among national colorectal cancer mortality rates, genetic lactase non-persistence status, and per capita yearly milk and milk product consumption

Colorectal cancer (CRC) is one of the leading causes of mortality in Western countries. Its putative pathogenesis revolves around genetic and environmental factors, particularly diet. One of the most studied dietary factors, dairy product intake, is still debated as a protective agent. The role of lactose as a candidate prebiotic (stimulating lactic acid bacteria) and its relation to genetic lactase non-persistence (LNP) status has not been evaluated. We undertook a review and analysis of national per capita dairy product consumption, national LNP prevalence, and national CRC mortality rates (CRCM) to determine whether relationships existed among these variables. Data on these three items were obtained from the available literature. A negative binomial regression model was used to compare national LNP status with national CRCM rates for three time periods. Pearson correlation was used to compare national per capita dairy food intake with national CRCM rates for the approximate midpoint time period of reviewed articles. We found that there was a significant positive correlation between per capita dairy food intake and CRCM rates. However, there was also a significant negative correlation between national LNP prevalence and CRCM rates. Population-based studies supported the suggestion that in both homogeneous high and homogeneous low prevalence LNP countries characterized by low and high dairy food intake respectively, dairy food consumption exerted a protective effect against CRC and CRCM rate. Because some population studies contradict the hypotheses that dairy food intake promotes CRC or that LNP status protects against CRC, we hypothesize that dairy food consumption may operate by two distinct mechanisms--one that operates at low doses in LNP subjects and another in high doses in non-LNP subjects.

Increasing incidence of colorectal cancer in Asia: implications for screening

Many Asian countries, including China, Japan, South Korea, and Singapore, have experienced an increase of two to four times in the incidence of colorectal cancer during the past few decades. The rising trend in incidence and mortality from colorectal cancer is more striking in affluent than in poorer societies and differs substantially among ethnic groups. Although changes in dietary habits and lifestyle are believed to be the reasons underlying the increase, the interaction between these factors and genetic characteristics of the Asian populations might also have a pivotal role. Non-polypoidal (flat or depressed) lesions and colorectal neoplasms arising without preceding adenoma (de novo cancers) seem to be more common in Asian than in other populations. The absence of polypoid growth preceding malignancy has posed difficulties in screening for early colorectal cancer by radiological imaging or even endoscopic techniques. Although epidemiological data are scanty, most Asian populations are not aware of the growing problem of colorectal cancer. More work is needed to elucidate the magnitude of the problem in Asia.

Colorectal cancer in Asians: a demographic and anatomic survey in Malaysian patients undergoing colonoscopy

BACKGROUND

Colorectal cancer is one of the most common forms of gastrointestinal cancer in the world today. In the Asia-Pacific area, it is the fastest emerging gastrointestinal cancer.

AIM

To determine the basic demographic features of patients with colorectal cancer and the anatomic distribution and characteristics of the tumour in a local Asian population.

METHODS

We conducted a review of consecutive patients who had undergone colonoscopy from 1999 to 2003 at the University of Malaya Medical Center, Kuala Lumpur, Malaysia.

RESULTS

Analysis was carried out on 3404 patients who underwent colonoscopy. A total of 228 patients (7%) were diagnosed with carcinoma. The mean age of diagnosis (+/-s.d.) was 64.4 +/- 13.1 years. The male to female ratio was 1.15. Polyps were noted in 470 patients (14%). Polyps detected concomitantly with a colorectal cancer were noted in 55 patients (2%). Four patients (0.1%) were diagnosed to have familial adenomatous polyposis coli. Of the 228 patients 209 (92%) had tumours at only one site whereas 19 (8%) had synchronous lesions. Tumours were mainly left sided [198 of 248 patients (80%)] with the majority located in the recto-sigmoid region. Detailed records of treatment were available only in 176 patients. A total of 147 of 176 patients (84%) underwent surgery and 50 (28%) also received adjuvant or palliative chemotherapy (28%). Seven of 154 patients (5%) were diagnosed to have stage A cancers, 64 (42%), stage B, 23 (15%), stage C and 60 (39%), stage D. Multivariate analysis using multiple logistic regression analysis showed that age > or =65 years (OR = 1.78; 95% CI: 1.35- 2.36) and Malay (OR = 2.09; 95% CI: 1.30-3.35) and Chinese (OR = 1.77; 95% CI: 1.77-2.69) race were significant independent predictive factors for colorectal cancer.

CONCLUSIONS

The demography of colorectal cancer is different from western patients. Tumours were mainly left sided in our patients. However, no differences in anatomic location were found between races, men and women and younger and older age groups. Colorectal cancer presented in an advanced stage in the majority of patients.

From Colonic Polyps to Colon Cancer: Pathophysiology, Clinical Presentation, and Diagnosis

Epidemiologists, basic researchers, clinicians, and public health administrators unite! Develop and implement a simple, safe, and effective preventive and screening test for colon cancer. The public will willingly and enthusiastically accept such a test. Many thousands of lives are at stake every year.

The pathophysiology, clinical presentation, and diagnosis of colon cancer and adenomatous polyps

A review of the pathophysiology, clinical presentation, and diagnosis of colon cancer and colonic polyps is important and timely. This field is rapidly changing because of breakthroughs in the molecular basis of carcinogenesis and in the technology for colon cancer detection and treatment. This article reviews colon cancer and colonic polyps, with a focus on recent dramatic advances, to help the pri-mary care physician and internist appropriately refer patients for screening colonoscopy and intelligently evaluate colonoscopic findings to reduce the mortality from this cancer.

Methylenetetrahydrofolate reductase polymorphism, alcohol intake, and risks of colon and rectal cancers in Korea

Several, but not all, studies have reported that a variant genotype of the polymorphism (C677T) of 5,10-methylenetetrahydrofolate reductase (MTHFR), an enzyme in folate metabolism, is associated with a decreased risk of colorectal cancer. A case-control study was conducted to investigate the association of MTHFR polymorphism and heavy alcohol intake to colon and rectal cancer in Korean. Cases were a consecutive series of patients with histologically confirmed, incident colorectal cancer who were admitted to two university hospitals in Seoul, Korea between 1998 and 2000, and controls were selected at the same hospitals. A total of 243 cases (colon 111, rectum 132) and 225 controls were enrolled. While the genotype of MTHFR was not associated with the overall risk of colorectal cancer, increased colon cancer risk was found to be associated with the CT and TT genotypes combined (multivariate odds ratio [OR] 2.01, 95% confidence interval [CI] 1.14-3.53) compared with the wild type. The risk of rectal cancer was found to be, though statistically non-significant, lower in those with the CT and TT genotypes combined (multivariate OR 0.67, 95% CI: 0.43-1.07). Those consuming two or more drinks per day (30 g+/day) had nearly twice the colorectal cancer risk (multivariate OR 1.94, 95% CI 1.03-3.68) of light or non-drinkers (<5 g/day). The present study did not find a reduced risk of colorectal or rectal cancer among those with a variant genotype of the MTHFR polymorphism, but observed rather an increased risk of colon cancer, suggesting that the effects of the MTHFR genotype may differ in populations with different levels of folate intake.

Trend of incidence, subsite distribution and staging of colorectal neoplasms in the 15-year experience of a specialised cancer registry

BACKGROUND

Two-thirds of colorectal malignancies are localised in the left colon and rectum. Recent studies suggest a trend towards an increase of right-sided tumours which might have important implications for screening and surveillance. A colorectal cancer registry was set up in Modena, northern Italy, with the purpose of examining incidence, subsite distribution and staging of colorectal malignancies over a 15-year period.

PATIENTS AND METHODS

From 1984 to 1998, 2517 tumours in 2462 patients were detected and staged with the tumour node metastasis (TNM) system. The 'right colon' was considered from caecum to splenic flexure; the 'left colon' included descending and sigmoid colon; and the 'rectum' included rectosigmoid junction, ampulla and anus.

RESULTS

Cancer incidence showed an overall increase. Considering the various subsites, an increase of 33.7% in all colonic segments was shown whereas rectal tumours tended to decline. TNM staging showed a gradual increase of localised lesions (41.2% in 1984 versus 53.3% in 1998), with a proportional reduction of advanced tumours.

CONCLUSIONS

Our study indicates an increase of tumour incidence in all colonic segments more than a shift to the right colon. TNM staging tended to improve with an appreciable increase of localised lesions. These findings could be consequent to a more extensive use of colonoscopy.

Factors associated with colorectal cancer screening among the US urban Japanese population

OBJECTIVES

The author examined the prevalence and predictors of colorectal cancer screening among the urban Japanese population of the United States.

METHODS

A sample of Japanese residents of major US metropolitan areas completed a self-administered mailed survey.

RESULTS

Physician recommendation, acculturation, and perceived psychological costs were consistent predictors of screening for colorectal cancer. Gender and marital status were related to screening via fecal occult blood testing; age, susceptibility, and health insurance were related to sigmoidoscopy/colonoscopy screening.

CONCLUSIONS

Colorectal cancer screening among the urban Japanese population could be increased with interventions seeking to promote physician recommendations for screening, alleviate perceived psychological costs among patients, and improve physician-patient communication.

Molecular epidemiology of colon cancer

Colorectal cancer appears to have rapidly increased over the past two decades in Korea. Environmental factors, characterized by a western life style, seem to be closely related to the increased risk of colorectal cancer. Higher intakes of meat, a lower vegetable intake, a lack of physical activity, obesity, and alcohol drinking have been suggested to be risk factors for colorectal cancer in the numerous epidemiologic studies. Several specific associations have also been observed between genetic polymorphisms and colorectal cancer. Moreover, it has been postulated that environmental factors and a genetic predisposition work in concert in colorectal cancer development. A stronger association between red meat intake and colorectal cancer among those with rapid acetylators at either the NAT1 or NAT2 locus was reported, particularly for colorectal cancer associated with K-ras mutations. The protective effect of the homozygous variant TT form of the MTHFR genotype on the risk of colon cancer seems to be modified by the level of methyl diets, i.e., by folate, which has a protective effect, or conversely by alcohol. The insulin-related pathway, which possibly explains at a mechanistic level the effect of physical activity and obesity on colon cancer, appears to be a common denominator in colon cancer and in other metabolic disorders, such as diabetes mellitus and dyslipidemia. Hyperinsulinemia has been proposed as an explanation for the association between a Western lifestyle and colon cancer risk. Further studies, that incorporate both genetic and environmental factors, are needed to fully explain and identify the underlying pathway of colorectal carcinogenesis.

Increasing colorectal cancer incidence rates in Japan

We examined trends of colorectal cancer incidence rates among Japanese (Miyagi Prefecture) and United States (US) whites (State of Connecticut) between 1959 and 1992. Age-standardized rates in Japan have increased dramatically and are now similar to US white rates. For both colon and rectum, age-specific rates in Japanese men born after 1930 exceed those in US whites, and the Japanese excess increases with year of birth. Similar patterns are evident for women. The current trends suggest that colorectal cancer will become a major source of morbidity and mortality in Japan, as these young Japanese age and their risks increase.

A Population-Based Study on Defecatory Conditions in Japanese Subjects: Methods for Self-Evaluation

We examined the defecatory conditions in a population of Japanese subjects and analyzed the measured parameters as a means for self-evaluation of defecation. Subjects (n=1195) were residents of northern Japan and were all aged over 40 years. The state of defecation and fecal characteristics were assessed with regard to nine parameters including "self-reported bowel habit" and "bowel movement frequency." Logistic regression analysis was carried out to analyze the association between the complaint of constipation and other eight parameters. A higher tendency for constipation was noted in women than in men. The highest value of the odds ratio was "bowel movement frequency"; especially the value "once per three days or more" was noted in both genders (odds ratio: 13.38 and 42.46 in men and women, respectively). In addition, "stool appearance", "length of time for bowel movement", "straining after bowel movement", "alternating diarrhea/constipation/disorder" and "travel-related changes in bowel movements" were significantly related with the complaint of constipation ("self-reported bowel habits") in both genders. In conclusion, the study elucidated that personal and subjective evaluation of bowel habits in normal subjects consisted of various factors under the heading of "bowel movement frequency".

Effect of age, period of diagnosis and birth cohort on large bowel cancer incidence in a well-defined French population, 1976-1995

The objective of this study was to present trends in colorectal cancer incidence by sex and subsite in a well-defined French population. All of the 4486 large bowel cancer cases registered between 1976 and 1995 in the Burgundy registry of digestive tract cancers was included in this study. Time trends in colorectal cancer incidence were analysed over the 1976-95 period. The effects of age, period and cohort were evaluated using a log-linear Poisson model. The incidence rates for right colon cancer increased over time: + 21.6% (95% CI: + 13.5; + 29.7) per 5-year period in males and +10.4% (95% CI: + 3.4; + 17.3) in females. Left colon cancer rates increased in males (+ 10.6% 95% CI: + 4.6; + 16.6). Left colon cancer in females and rectal cancer incidence rates did not significantly change. Between the 1901 cohort to the 1941 cohort, estimated cumulative risks for right colon cancer increased sharply. The increase was less marked for left colon and the cumulative risk for rectal cancer remained almost stable. Temporal trends were different by subsites and sexes. In conclusion, our results confirm the existence of different trends in colorectal cancer incidence between subsites and sexes. These differences probably reflect aetiological distinctions.

Epidemiology and screening of colorectal cancer

Knowledge of the descriptive epidemiology of colorectal cancer is essential to a better understanding of the aetiology of the disease and the development of screening strategies. Considerable research efforts have been launched over the last 15 years to evaluate the ability of screening tests to decrease the incidence and mortality of colorectal cancer. This chapter provides a worldwide update of the incidence of colorectal cancer and reviews the evidence for screening for colorectal cancer based on published studies.

Pathology of colorectal cancer

The earliest phases of colorectal tumourigenesis initiate in the normal mucosa, with a generalised disorder of cell replication, and with the appearance of clusters of enlarged crypts (aberrant crypts) showing proliferative, biochemical and biomolecular abnormalities. The large majority of colorectal malignancies develop from adenomatous polyps. These can be defined as well demarcated masses of epithelial dysplasia, with uncontrolled crypt cell division. An adenoma can be considered malignant when neoplastic cells pass through the muscularis mucosae and infiltrate the submucosa. Definitions like "carcinoma in situ" or "intramucosal carcinoma" should be abandoned, since they lead to confusion. Although several lines of evidence indicate that carcinomas usually originate from pre-existing adenomas, this does not imply that all polyps undergo malignant changes, and does not exclude "de novo" carcinogenesis. Besides adenomas, other types of polypoid lesions include hyperplastic polyps (showing elongated crypts often with cystic dilatation), serrated adenomas (with a serrated glandular pattern], flat adenomas (flat lesions which are difficult to detect in routine lower endoscopy, but may possess malignant potential), hamartomatous polyps (which show a complex branching pattern of smooth muscle supporting normal lamina propria and glands), and inflammatory polyps. Colorectal carcinomas are one of the most frequent neoplasms in Western society; the macroscopic appearance of these lesions may be that of a polypoid vegetating mass or of a flat infiltrating lesion. Most of these tumours are adenocarcinomas (96%), that, in some cases, show a mucinous component. More rare malignancies of the large bowel include signet-ring cell carcinoma, squamous carcinoma, undifferentiated neoplasms and medullary type adenocarcinoma (solid carcinoma with minimal glandular differentiation or slight cellular pleomorphism). Colorectal carcinoma can be graded into well, moderately and poorly differentiated lesions; there is little evidence, however, that grading may be of help in evaluating prognosis of affected patients. In conclusion, colorectal tumours cover a wide range of premalignant and malignant lesions, many of which can easily be removed at endoscopy. It follows that colorectal neoplasms might be prevented by interfering with the various steps of carcinogenesis, which begins with uncontrolled epithelial cell replication, continues with the formation of adenomas of various dimensions, and eventually evolves into malignancy.

Differences between features of adenoma in the rectum versus sigmoid colon

OBJECTIVE

Although the prevalence of cancer in the rectosigmoid is high compared with that in the more proximal colon, the features of cancer developing from an adenoma have yet to be elucidated. The aim of this study is to examine the clinicopathological relationship between cancer and adenoma in the rectosigmoid.

METHODS

A total of 340 adenomas located in the rectosigmoid in 255 patients were retrospectively examined regarding such clinicopathological factors as location and the grade of dysplasia.

RESULTS

The prevalence of adenoma was 102 in the rectum and 238 in the sigmoid colon, respectively, whereas the prevalence of adenoma with high-grade dysplasia was 39 in the rectum and 48 in the sigmoid colon, respectively. This prevalence of adenoma with high-grade dysplasia was thus significantly higher in the rectum than in the sigmoid colon (p < 0.02).

CONCLUSIONS

These findings suggest the possibility of different types of cancer development between adenoma of the rectum and sigmoid colon.

Trace element levels in drinking water and the incidence of colorectal cancer

We determined the levels of 15 elements in drinking water from 34 water treatment plants in Aomori Prefecture and studied how element levels relate to colorectal cancer incidence by district. Colorectal cancer incidence was calculated from the data of Aomori Colorectal Cancer Registry. Multiple regression analysis was performed by using age-adjusted incidences of rectal cancer and colon cancer by gender as object variables and each element level as an explanatory variable. The standardized partial regression coefficient was significant in gold (p < 0.01), magnesium (p < 0.01), selenium (p < 0.01) and tin (p < 0.05) for age-adjusted rectal cancer incidence in men as objective variable; in gold (p < 0.05), calcium (p < 0.01) and phosphorus (p < 0.01) with age-adjusted colon cancer incidence in men as the objective variable; and in sodium (p < 0.05), phosphorus (p < 0.05), tin (p < 0.05) and strontium (p < 0.01) with age-adjusted colon cancer incidence in women as the objective variable. These results confirm the need to further study trace elements in drinking water and food, and relationship to colorectal carcinogenesis.