Changing site distribution of colorectal cancer in Japan

Third-line treatment patterns and clinical outcomes for metastatic colorectal cancer: a retrospective real-world study

Background

There are multiple recommendations on the third-line therapy of metastatic colorectal cancer (mCRC); however, no consensus has been reached.

Objectives

This study aimed to explore the patient demographics and the real-world third-line treatment landscape of mCRC.

Design

A retrospective real-world cohort study.

Methods

Electronic medical records of mCRC patients from Tianjin Medical University Cancer Institute and Hospital between 2013 and 2020 were collected. Upon descriptive, comparative, and survival analyses, a retrospective study was conducted to describe demographics and clinical outcomes of mCRC patients receiving third-line treatment.

Results

Among 218 mCRC patients receiving third-line therapy, 65.5% received chemotherapy combined with or without targeted drugs, followed by anti-angiogenic monotherapy (18.4%), anti-epidermal growth factor receptor drugs (6.9%) and immunotherapy (6.4%). The overall response rate and disease control rate reached 10.2% and 59.2%, respectively; and median progression-free survival (PFS) and overall survival were 4.0 m and 10.7 m, respectively. After Cox multivariate analysis, we found that therapeutic regime was an independent prognostic factor. Compared to patients receiving anti-angiogenic monotherapy, those receiving chemotherapy combined with or without targeted drugs exhibited better prognosis. For patients whose PFS were longer in the front-line treatment, the PFS of third-line therapy was also relatively longer (p = 0.023). Multiple types of therapies (>3, p = 0.002) or multiple drugs (>5, p = 0.024) in the whole-course management of mCRC are indicators of longer survival.

Conclusion

Chemotherapy combined with or without targeted therapy remained dominated third-line choice and showed favorable efficacy compared with anti-angiogenic monotherapy. With the application of more types and quantities of effective drugs, patients would achieve better survival.

Changing Colorectal Cancer Trends in Asians: Epidemiology and Risk Factors

Once an infrequent disease in parts of Asia, the rate of colorectal cancer in recent decades appears to be steadily increasing. Colorectal cancer represents one of the most important causes of cancer mortality worldwide, including in many regions in Asia. Rapid changes in socioeconomic and lifestyle habits have been attributed to the notable increase in the incidence of colorectal cancers in many Asian countries. Through published data from the International Agency for Cancer Research (IARC), we utilized available continuous data to determine which Asian nations had a rise in colorectal cancer rates. We found that East and South East Asian countries had a significant rise in colorectal cancer rates. Subsequently, we summarized here the known genetics and environmental risk factors for colorectal cancer among populations in this region as well as approaches to screening and early detection that have been considered across various countries in the region.

Genomic landscape of colorectal carcinoma in sub-Saharan Africa

Our understanding of the molecular classification of colorectal carcinoma (CRC) has evolved significantly over the past two decades. Tumours can be broadly categorised as microsatellite stable (MSS), microsatellite instability (MSI) or CpG island-methylator phenotype. Prognostic and predictive information is provided by these categories. The overwhelming majority of the data on which these categories are based have originated from Europe and North America. There is a dearth of information represented from Africa and indigenous African patients. However, some small studies and preliminary data have shown significant differences in all of these groups. The prevalence of MSI in Africa is consistently reported as almost double that of European and North American data. Interestingly, BRAF V600E mutations and MLH1 promotor hypermethylation seem to be uncommon in Africa. The high proportion of MSI tumours is only partly accounted for by germline mutations in mismatch repair genes (Lynch syndrome), suggesting that there are likely to be other mechanisms at play. Within the MSS group, preliminary data suggest that the typical molecular pathways (Wingless/Integrated pathway activation) may not be as dominant in Africa. The purpose of this review is to summarise the current state of the molecular genetic landscape of CRC in Africa and provide insights into areas for further study.

Epidemiology, risk factors, and prevention of colorectal cancer

Background: Colorectal cancer remains the fourth most common malignancy in Korea, and has been ranked as the third leading cause of cancer deaths in 2020. This study aims to describe the epidemiologic status of colorectal cancer in Korea, and provide basic data for effective primary and secondary prevention methods by summarizing risk factors and screening tools.Current Concepts: Although colorectal cancer incidence and mortality have decreased in recent years in Korea, it still poses a significant public health burden. From the early 1990s until the mid-2000s, the 5-year relative survival of patients with colorectal cancer in Korea continuously increased. This can be attributed to the successful introduction of the government-led screening program; development of improved surgical techniques, anticancer drugs, and adjuvant treatment; and advances medical resources and infrastructure along with economic growth. However, since the late 2000s, the improvement in survival has stagnated. The coronavirus disease 2019 outbreak has reduced hospital visits and screenings, which is assumed to cause delays in diagnosis, leading to a worse prognosis in the patients. To overcome these obstacles, it is essential to explore modifiable environmental risk factors and appropriate screening test methods in Korea.Discussion and Conclusion: Primary prevention through risk factor modification and secondary prevention using suitable screening programs can reduce the incidence and mortality rates of colorectal cancer.

Disease characteristics and treatment patterns of Chinese patients with metastatic colorectal cancer: a retrospective study using medical records from China

Background

Colorectal cancer (CRC) is the third most prevalent cancer in China but few large-scale studies were conducted to understand CRC patients. The current study is aimed to gain a real-world perspectives of CRC patients in China.

Methods

Using electronic medical records of sampled patients between 2011 and 2016 from 12 hospitals in China, a retrospective cohort study was conducted to describe demographics and disease prognosis of CRC patients, and examine treatment sequences among metastatic CRC (mCRC) patients. Descriptive, comparative and survival analyses were conducted.

Results

Among mCRC patients (3878/8136, 48%), the fluorouracil, leucovorin, and oxaliplatin (FOLFOX) and other oxaliplatin-based regimens were the most widely-used first-line treatment (42%). Fluorouracil, leucovorin, irinotecan (FOLFIRI) and other irinotecan-based regimens dominated the second-line (40%). There was no a dominated regimen for the third-line. The proportion of patients receiving chemotherapy with targeted biologics increased from less than 20% for the first- and second- lines to 34% for the third-line (p < 0.001). The most common sequence from first- to second-line was from FOLFOX and other oxaliplatin-based regimens to FOLFIRI and other irinotecan-based regimens (286/1200, 24%).

Conclusions

Our findings reflected a lack of consensus on the choice of third-line therapy and limited available options in China. It is evident o continue promoting early CRC diagnosis and to increase the accessibility of treatment options for mCRC patients. As the only nationwide large-scale study among CRC and mCRC patients before more biologics became available in China, our results can also be used as the baseline to assess treatment pattern changes before and after more third-line treatment were approved and covered into the National Health Insurance Plan in China between 2017 and 2018.

Reevaluation of a rightward shift in colorectal cancer: A single-center retrospective study in Tianjin

OBJECTIVES

Some Western reports have shown a proximal shift in colorectal cancer (CRC), but there are few studies in China. This study aimed to provide more information for the management and screening of CRC by investigating trends in the anatomic distribution of CRC among the Chinese population in recent years.

METHODS

A retrospective study was conducted on patients with CRC admitted to the Digestive Endoscopy Center of Tianjin Medical University General Hospital between January 2000 and December 2017. Patients were divided into a left-sided colorectal cancer (LSCRC) group and a right-sided colon cancer (RSCC) group. The detection rates of LSCRC and RSCC based on patients' age and sex, and on the time periods were analyzed.

RESULTS

A total of 2319 cases were diagnosed with CRC among 75 183 consecutive patients. The prevalence of CRC showed a significant reduction from 2000-2008 to 2009-2017 (3.8% vs 2.7%, P < .001). The proportion of RSCC presented a downtrend from 2000-2008 to 2009-2017 (40.6% vs 37.7%, P > .05). There were slightly more RSCCs in female patients than in male patients, with no significant difference (40.9% vs 36.5%, P > .05). The proportion of RSCC in patients aged ≥50 years was similar to that in younger patients. The alarming symptoms between LSCRC and RSCC showed a significant difference (P < .05).

CONCLUSIONS

In the present study, the prevalence of CRC declined significantly with time. However, there did not appear to be a rightward shift in CRC among the patients in Tianjin over the past 18 years.

Risk factors for advanced colorectal neoplasms in the proximal colon in 6218 subjects undergoing complete colonoscopy

BACKGROUND AND AIM

Proximal migration of colonic lesion has been observed; however, risk factors of lesions in the proximal colon remain uncertain. This study aimed to investigate risk factors of lesions in the proximal colon.

METHODS

Consecutive subjects with complete colonoscopy were included. The primary outcome was risk factors associated with advanced neoplasm (AN) and serrated lesion in the proximal colon. Age, gender, first-degree relative (FDR) with colorectal cancer (CRC), smoking, alcohol consumption, body mass index, hypertension, diabetes, ischemic heart disease, and the use of aspirin, non-steroidal anti-inflammatory drug, and anticoagulants were fitted into a regression model, with reference to subjects without colonic finding. Results were measured by odds ratio (OR) with 95% confidence interval (CI).

RESULTS

Among 6218 subjects (mean age 56.65 ± 6.15 years; 46.8% male), 352 (5.7%) had AN; 809 (13.0%) had serrated lesions, and 3648 (58.7%) had no colonic finding. There were 148 (2.4%) and 235 (3.8%) subjects having AN and serrated lesion in the proximal colon. Age ≥ 50 (OR: 13.30; 95% CI: 1.85-95.76), male gender (OR: 1.82; 95% CI: 1.26-2.62), FDR with CRC (OR: 2.12; 95% CI: 1.43-3.15), and hypertension (OR: 1.86; 95% CI: 1.30-2.68) were associated with AN in the proximal colon. Age ≥ 50 (OR: 5.72; 95% CI: 2.10-15.53), male gender (OR: 1.54; 95% CI: 1.15-2.05), and smoking (OR: 1.85; 95% CI: 1.23-2.79) increased risk of serrated lesions in the proximal colon.

CONCLUSION

Age ≥ 50 and male gender were associated with both proximally located AN and serrated lesion; FDR with CRC and hypertension increased the risk of proximal AN, while ever smoking increased the risk of proximal serrated lesion. FDR with CRC was not associated with serrated lesion.

Patterns and presentations of colorectal cancer at Komfo-Anokye teaching hospital Kumasi, Ghana

Introduction

Colorectal cancer is a major cause of morbidity and mortality globally and its incidence is increasing in developing countries. This study determined the incidence, clinical features and the histopathological patterns of colorectal cancer at Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana.

Methods

A retrospective review of all colorectal cancer cases over a six year period from (2009-2015) presented to the Surgical and Oncological Department of KATH. Patients' records were retrieved and information on their demographics, clinical and pathological presentations recorded.

Results

In all, 221 cases of colorectal cancer were identified over the study period. The mean age was 54 ± 16.8 and ranged from 16 to 90 years. Sixteen (7.24%) had family history of cancer and the prevalence of comorbidities was (24.89%). The commonest clinical symptoms presented were weight loss (44.80%), bleeding per rectum (39.82%) and abdominal pain (38.91%) Majority of the patients presented with rectal cancers (48.87%). Microscopically, adenocarcinoma (68.33%) was the most common histopathological type. According to Tumour Node Metastasis (TNM) staging of cancer, majority of the patients 89(40.27%) were identified as being in late stage (TNM Stage III). The overall crude annual incidence was 4.62 per 100000 populations. The age specific standardized incidence rate was 7.93 per 100,000 population

Conclusion

This study has clearly showed a high incidence in colorectal cancer at KATH, with similar trends in clinico-pathological patterns comparable to that of most African countries. These include predominance of rectal cancers, high incidence among younger people and delayed presentation of the disease at advanced stage.

Emerging Gastrointestinal and Liver Diseases in Asia Pacific: Implications to Health Care in the Region (World Gastroenterology Organization: Asian Pacific Association of Gastroenterology Distinguished Global Lecture 2015)

Colorectal cancer (CRC), gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD), and nonalcoholic fatty liver disease are considered important emerging diseases in the Asia Pacific (AP) region. The incidence rate of CRC is the highest among gastrointestinal cancers in the region surpassing that of gastric cancer. However, population CRC screening is limited by availability of adequate health resources and financing. GERD is a highly prevalent disease in AP with the prevalence of GERD symptoms and reflux esophagitis reported to be increasing. The usage of proton pump inhibitors has also been reported to be high. The incidence and prevalence of IBD is not as high as in the west but is now an increasingly recognizable disease in the AP region. Being a complicated disease, IBD will pose a huge financial burden with the increasing use of expensive biological drugs. In tandem with the exponential increase in obesity and diabetes mellitus in AP, nonalcoholic fatty liver disease will become the most important liver disease in the region in the coming years. These emerging diseases reflect the continued fast-paced socioeconomic development in the region with marked lifestyle changes and increasing affluence.

The shifting epidemiology of colorectal cancer in sub-Saharan Africa

The perception that colorectal cancer is rare in sub-Saharan Africa is widely held; however, it is unclear whether this is due to poor epidemiological data or to lower disease rates. The quality of epidemiological data has somewhat improved, and there is an ongoing transition to western dietary and lifestyle practices associated with colorectal cancer. The impact of these changes on the incidence of colorectal cancer is not as evident as it is with other non-communicable diseases such as diabetes. In this Viewpoint, we discuss the epidemiology of colorectal cancer in sub-Saharan Africa. Colorectal cancer in this region frequently occurs at an early age, often with distinctive histological characteristics. We detail the crucial need for hypothesis-driven research on the risk factors for colorectal cancer in this population and identify key research gaps. Should colorectal cancer occur more frequently than assumed, then commensurate allocation of resources will be needed for diagnosis and treatment.

Colorectal cancer incidence in 5 Asian countries by subsite: An analysis of Cancer Incidence in Five Continents (1998-2007)

Colorectal cancer is the fourth most common cancer in Asia. However, the trends in colorectal cancer incidence by subsite have not been analyzed across Asian countries. We used the most recent, high quality data from 6 cancer registries for two 5-year periods, 1998-2002 and 2003-2007, from Cancer Incidence in Five Continents to estimate colorectal cancer incidence by subsite in 5 Asian countries. Cases with overlapping lesions or otherwise unspecified colon cancer were re-distributed as proximal or distal colon cancer. Age-standardized incidence rates (ASRs) per 100,000 population and incidence rate ratios from 1998 to 2002 to 2003-2007 were calculated for each subsite. For 2003-2007, men in Miyagi, Japan, had the highest ASR for cancer in the proximal colon, distal colon and rectum. Men of Jewish ancestry in Israel had a high ASR for proximal and distal colon cancer, but the lowest ASR for rectal cancer. The proportion of rectal cancer was highest among Korean men (51.39%) and lowest among Israeli women (26.6%). From 1998-2002 to 2003-2007, rectal cancer incidence did not significantly change in most registries, except for men in Miyagi, Japan, and both sexes in Korea. However, during the same period cancer incidence in the proximal and distal colon increased in most registries. In conclusion, there was substantial variation in subsite distributions of colorectal cancer in Asian registries and increases in overall incidence of colorectal cancer could be attributed to increases in colon cancer.

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.

Clinical features of colorectal cancer patients in advanced age: a population-based approach

In the immediate future, the number of geriatric patients will continue to rise; consequently we should expect an increase of colorectal cancer, a disease of the elderly population. Through the data of a Cancer Registry, we examined (a) the effect of ageing on the main features of colorectal cancer; (b) changes in management, especially for individuals older than 80 years; and (c) changes in prognosis and survival in subgroups of patients with different age. The Registry provided information on colorectal cancer up to 2010 (27 years). A total of 5293 patients were registered; these were divided into three groups: A (0-64 years), B (65-79) and C (80 or more). Three periods of observation were chosen: 1 (1984-1992), 2 (1993-2001) and 3 (2001-2010). Group A included 1571 patients (29 %), Group B 2539 (48 %) and Group C 1183 (22.3 %). The fraction of old individuals increased during the 27 years of the investigation. In these patients, tumours were predominantly localized to the right colon (42.6 %). The rate of surgery and ratio between curative and palliative approaches were similar among the three groups (p < 0.38). There was disparity (p < 0.002) in the administration of chemotherapy (5.8 % of the elderly vs 34.4 % in remaining patients). Survival increased over time in all three groups. In the elderly, average 5-year survival was 31 % in period 1 and 55 % in period 3. These data show that in Western countries, the standard of care for colorectal cancer diagnosed in geriatric patients has improved over the last 30 years.

Distributions of colorectal cancer in two Chinese cities with contrasting colorectal cancer epidemiology

BACKGROUND AND AIM

The incidence of colorectal cancer (CRC) is rising rapidly in Chinese. We studied the anatomic distributions and characteristics of CRC in Hong Kong (HK) and Chongqing (CQ) with different CRC epidemiology.

METHODS

It was a retrospective study conducted in three large regional hospitals of the two cities. We identified all patients newly diagnosed with CRC between 2003 and 2012. The distribution and characteristics of CRC of the two cities were compared.

RESULTS

Of CRC, 3664 new cases were diagnosed within the study period. CRC was more common in men (>56%) in both cities. The mean age at diagnosis was significantly younger in CQ, the lower prevalence area, than in HK (62.1 vs 70.4 years; P < 0.001). Rectal cancer was the predominant (61.3%) cancer in CQ, but only 18% of cancers in HK were rectal cancer (P = 0.0001). Right-sided colonic cancer, however, was more common in HK than CQ (27.2% vs 17.4%; P < 0.001). Women had more right-sided colonic cancer than men in both cities (P < 0.002), and there was an age-related increase in right-sided colonic cancer in HK but not in CQ. Multivariate analysis showed that older age, female, and living in HK were independent risk factors associated with right-sided colonic cancer.

CONCLUSIONS

There are significant differences in the distribution of CRC between HK and CQ. The discrepancy may be partly accounted by older population and an increase in proximal colonic cancer, particularly in women, in HK.

Rectal and colon cancer: Not just a different anatomic site

Due to differences in anatomy, primary rectal and colon cancer require different staging procedures, different neo-adjuvant treatment and different surgical approaches. For example, neoadjuvant radiotherapy or chemoradiotherapy is administered solely for rectal cancer. Neoadjuvant therapy and total mesorectal excision for rectal cancer might be responsible in part for the differing effect of adjuvant systemic treatment on overall survival, which is more evident in colon cancer than in rectal cancer. Apart from anatomic divergences, rectal and colon cancer also differ in their embryological origin and metastatic patterns. Moreover, they harbor a different composition of drug targets, such as v-raf murine sarcoma viral oncogene homolog B (BRAF), which is preferentially mutated in proximal colon cancers, and the epidermal growth factor receptor (EGFR), which is prevalently amplified or overexpressed in distal colorectal cancers. Despite their differences in metastatic pattern, composition of drug targets and earlier local treatment, metastatic rectal and colon cancer are, however, commonly regarded as one entity and are treated alike. In this review, we focused on rectal cancer and its biological and clinical differences and similarities relative to colon cancer. These aspects are crucial because they influence the current staging and treatment of these cancers, and might influence the design of future trials with targeted drugs.

Microbiota disbiosis is associated with colorectal cancer

The dysbiosis of the human intestinal microbiota is linked to sporadic colorectal carcinoma (CRC). The present study was designed to investigate the gut microbiota distribution features in CRC patients. We performed pyrosequencing based analysis of the 16S rRNA gene V3 region to investigate microbiota of the cancerous tissue and adjacent non-cancerous normal tissue in proximal and distal CRC samples. The results revealed that the microbial structures of the CRC patients and healthy individuals differed significantly. Firmicutes and Fusobacteria were over-represented whereas Proteobacteria was under-represented in CRC patients. In addition, Lactococcus and Fusobacterium exhibited a relatively higher abundance while Pseudomonas and Escherichia-Shigella was reduced in cancerous tissues compared to adjacent non-cancerous tissues. Meanwhile, the overall microbial structures of proximal and distal colon cancerous tissues were similar; but certain potential pro-oncogenic pathogens were different. These results suggested that the mucosa-associated microbiota is dynamically associated with CRC, which may provide evidences for microbiota-associated diagnostic, prognostic, preventive, and therapeutic strategies for CRC.

Gender-associated genomic differences in colorectal cancer: clinical insight from feminization of male cancer cells

Gender-related differences in colorectal cancer (CRC) are not fully understood. Recent studies have shown that CRC arising in females are significantly associated with CpG island methylator phenotype (CIMP-high). Using array comparative genomic hybridization, we analyzed a cohort of 116 CRCs (57 males, 59 females) for chromosomal copy number aberrations (CNA) and found that CRC in females had significantly higher numbers of gains involving chromosome arms 1q21.2–q21.3, 4q13.2, 6p21.1 and 16p11.2 and copy number losses of chromosome arm 11q25 compared to males. Interestingly, a subset of male CRCs (46%) exhibited a “feminization” phenomenon in the form of gains of X chromosomes (or an arm of X) and/or losses of the Y chromosome. Feminization of cancer cells was significantly associated with microsatellite-stable CRCs (p-value 0.003) and wild-type BRAF gene status (p-value 0.009). No significant association with other clinicopathological parameters was identified including disease-free survival. In summary, our data show that some CNAs in CRC may be gender specific and that male cancers characterized by feminization may constitute a specific subset of CRCs that warrants further investigation.

Observations on the epidemiology of gastrointestinal and liver cancers in the Asia-Pacific region

Gastric cancer (GC) has long been thought to be an Asian type of cancer that is broadly associated with poverty, whereas colorectal cancer (CRC) has been thought to be a Western type of cancer associated with affluence. The incidence of GC has declined dramatically in the West but has a very high incidence in East Asia. The age-standardized incidence rates (ASR) have also declined. The decrease in the incidence of GC is associated with the decrease in the prevalence of Helicobacter pylori (H. pylori) infection worldwide. The discrepancy between a high H. pylori infection rate and a low GC incidence is seen chiefly among southern Asians of Indian origin and has been aptly termed the "Indian enigma". CRC is a new emerging cancer in this region. Some of the highest CRC ASR have been reported from Asian countries, in many of which it has now surpassed that of GC. Liver cancer is also an important cancer in the Asia-Pacific region. The highest ASR worldwide is reported from the Asian countries of Mongolia, Korea and Japan. The predominant underlying etiology across the region has been hepatitis B virus infection, except in Japan, where hepatitis C is an important cause of hepatocellular carcinoma (HCC). With mass vaccination of hepatitis B at birth and improved public health measures in many countries, hepatitis B and C are set to decline with time. However, the exponential increase in obesity and consequent non-alcoholic fatty liver disease portends a future epidemic of fatty liver-related HCC.

Inflammatory Bowel Disease-related Colorectal Cancer in the Asia-Pacific Region: Past, Present, and Future

Patients with inflammatory bowel disease (IBD) are at an increased risk of developing colorectal cancer (CRC), and key contributing factors include chronic colonic inflammation and the extent and duration of disease. This increase in risk is more likely to result from chronic inflammation of the colonic mucosa than from any clearly defined genetic predisposition. However, globally, the true magnitude of this risk is debatable, since results from different studies are heterogeneous in terms of geographical and methodological variables. The prevalence of IBD-related CRC in the Asia-Pacific region ranges from 0.3% to 1.8% and a recent study found that the cumulative incidence of IBD-related CRC is comparable to that in Western countries. However, the CRC mortality rate in the Asia-Pacific region is on the rise compared with that in Western countries, and a few Asian countries show particularly rapid upward trends in CRC incidence. Although our understanding of the molecular and clinical basis for IBD-related CRC has improved substantially, our means of prevention, endoscopic surveillance, chemoprevention, and prophylactic surgery remain modest at best. Furthermore, published data on IBD-related CRC in the Asia-Pacific region is lacking, and this review addresses many aspects including epidemiology, natural history, etiopathogenesis, morphology, and biological behaviors of IBD-related CRC and sporadic CRC in the Asia-Pacific region. In this review, we will also discuss the risk factors for CRC in IBD patients, endoscopic technology screening, and surveillance programs and management strategies for IBD-related CRC.

Analysis of KRAS mutations in cases of metastatic colorectal cancer at a single institution in Tochigi, Japan

OBJECTIVE

Colorectal cancer patients bearing wild-type KRAS benefit from anti-epidermal growth factor receptor (EGFR) antibody treatment. Since clinical studies showed the efficacy of anti-EGFR antibody treatment for metastatic colorectal cancer (mCRC), we analyzed KRAS mutations in mCRC to gain insight into the association between these mutations and clinicopathological characteristics.

METHODS

KRAS mutations were analyzed in 109 tissue samples of mCRC using amplification refractory mutation system-Scorpion (ARMS/S) assay (68 samples) and direct sequencing (41 samples).

RESULTS

In the ARMS/S assay, 36.5 and 7.4% of mCRCs harbored mutations at codons 12 and 13, respectively. In direct sequencing, corresponding values were 24.4 and 19.5%. Overall, 37.6% (codon 12/13, 25.7/11.9%) of mCRCs harbored KRAS mutations. No significant differences were found between KRAS mutations and clinicopathological variables. Among mCRC patients <65 years of age, the incidence of KRAS mutations at codon 13 was significantly higher in female than male patients (p = 0.035).

CONCLUSION

The incidence of KRAS mutations in mCRC was similar to that of non-mCRC as previously reported. KRAS codon 13 mutations might be associated with younger female patients with mCRC, but further investigation is necessary to clarify the association between this type of mutation and metastatic potential in female CRC patients.

Hospital-based colorectal cancer survival trend of different tumor locations from 1960s to 2000s

Background

Our aim is to explore the trend of association between the survival rates of colorectal cancer (CRC) and the different clinical characteristics in patients registered from 1960s to 2000s. We hypothesized that the survival rate of CRC increases over time and varies according to anatomic subsites.

Methods

Information from a total of 4558 stage T_(1-4)N_(1-2)M₀ CRC patients registered from 1960s to 2008 were analyzed. The association of CRC overall survival with age, gender, tumor locations, time, histopathology types, pathology grades, no. of examined lymph nodes, the T stage, and the N stage was analyzed. The assessment of the influence of prognostic factors on patient survival was performed using Cox’s proportional hazard regression models.

Results

From 1960 to 2008, the studied CRC patients included 2625 (57.6%) and 1933 (42.4%) males and females, respectively. These included 1896 (41.6%) colon cancers, and 2662 (58.4%) rectum cancers. The 5-year survival rate was 49%, 58%, 58%, 70%, and 77% for the time duration of 1960s, 1970s, 1980s, 1990s and 2000s, respectively. An increased 5-year survival rate was observed in the colon cancer and rectum cancer patients. Patients older than 60 years of age were more likely to develop colonic cancer (sigmoid) than rectum cancer (49.2% vs. 39.9%). The Cox regression model showed that only rectum cancer survival was related to time duration.

Conclusion

The overall survival and 5-year survival rates showed an increase from the 1960s to 2000s. There is a trend of rightward shift of tumor location in CRC patients.

Prognostic implication of the CpG island methylator phenotype in colorectal cancers depends on tumour location

BACKGROUND

Colorectal cancer (CRC) is usually categorised as proximal or distal CRC. Recently, many researchers have tried to determine the molecular heterogeneity of CRCs along bowel subsites. However, the differential effects of the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) on the clinical outcome according to tumour location are not well-known.

METHODS

We analysed clinicopathologic and molecular characteristics, including CIMP, MSI, KRAS and BRAF mutations, in 734 CRCs according to bowel subsites. And the prognostic value of CIMP and MSI was analysed according to tumour location.

RESULTS

We found a linear increase of female predominance, T, N category, stage, differentiation, absence of luminal necrosis, tumour -infiltrating lymphocytes, Crohn's-like lymphoid reaction, serration and mucin production from the rectum to caecum. CpG island methylator phenotype -high and MSI-high gradually increased from the rectum to caecum. CpG island methylator phenotype is a poor prognostic factor of overall survival (hazard ratio (HR): 4.13, 95% confidence interval (CI): 1.27-13.46) and disease-free survival (HR: 2.90, 95% CI: 1.04-8.08) in rectal cancers.

CONCLUSION

Clinicopathologic and molecular profiles of CRCs gradually change along bowel subsites, and the prognostic implication of CIMP is different according to tumour location.

Clinicopathological patterns and challenges of management of colorectal cancer in a resource-limited setting: a Tanzanian experience

Background

Colorectal cancer is one of the most common cancers worldwide and its incidence is reported to be increasing in resource-limited countries, probably due to the acquisition of a western lifestyle. However, information regarding colorectal cancer in Tanzania and the study area in particular is limited. This study was conducted in our local setting to describe the clinicopathological pattern of colorectal cancer and highlight the challenging problem in the management of this disease.

Methods

This was a retrospective study of histologically confirmed cases of colorectal cancer seen at Bugando Medical Center between July 2006 and June 2011. Data were retrieved from patients’ files and analyzed using SPSS computer software version 17.0.

Results

A total of 332 colorectal cancer patients were enrolled in the study, representing 4.7% of all malignancies. Males outnumbered females by a ratio of 1.6:1. The median age of patients at presentation was 46 years. The majority of patients (96.7%) presented late with advanced stages. Lymph node and distant metastasis at the time of diagnosis was recorded in 30.4% and 24.7% of cases, respectively. The rectosigmoid region was the most frequent anatomical site (54.8%) involved and adenocarcinoma (98.8%) was the most common histopathological type. The majority of adenocarcinomas (56.4%) were moderately differentiated. Mucinous and signet ring carcinomas accounted for 38 (11.6%)and 15 (4.6%) patients, respectively. Three hundred and twenty-six (98.2%) patients underwent surgical procedures for colorectal cancer. Only 54 out of 321 (16.8%) patients received adjuvant treatment. Postoperative complication and mortality rates were 26.2% and 10.5%, respectively. The overall median duration of hospital stay was 12 days. Only nine out of 297 survivors (3.0%) were available for follow-up at the end of 5 years. Cancer recurrence was reported in 56 of 297 survivors (18.9%). Data on long-term survival were not available as the majority of patients were lost to follow-up.

Conclusions

Colorectal cancer is not uncommon in our environment and shows a trend towards a relative young age at diagnosis and the majority of patients present late with advanced stage. There is a need for screening of high-risk populations, early diagnosis and effective cost-effective treatment and follow-up to improve outcome of these patients.

Subsite-specific dietary risk factors for colorectal cancer: a review of cohort studies

Objective. A shift in the total incidence from left- to right-sided colon cancer has been reported and raises the question as to whether lifestyle risk factors are responsible for the changing subsite distribution of colon cancer. The present study provides a review of the subsite-specific risk estimates for the dietary components presently regarded as convincing or probable risk factors for colorectal cancer: red meat, processed meat, fiber, garlic, milk, calcium, and alcohol. Methods. Studies were identified by searching PubMed through October 8, 2012 and by reviewing reference lists. Thirty-two prospective cohort studies are included, and the estimates are compared by sex for each risk factor. Results. For alcohol, there seems to be a stronger association with rectal cancer than with colon cancer, and for meat a somewhat stronger association with distal colon and rectal cancer, relative to proximal colon cancer. For fiber, milk, and calcium, there were only minor differences in relative risk across subsites. No statement could be given regarding garlic. Overall, many of the subsite-specific risk estimates were nonsignificant, irrespective of exposure. Conclusion. For some dietary components the associations with risk of cancer of the rectum and distal colon appear stronger than for proximal colon, but not for all.

Colorectal cancer screening in Asia

INTRODUCTION

The incidence and mortality of colorectal cancer are rapidly rising in several countries in Asia. However, screening guidelines are lacking.

SOURCES OF DATA

Review of literature and local data published in peer review journals.

AREAS OF AGREEMENT

The incidence, anatomical distribution and mortality of colorectal cancer among Asian populations are comparable to those in Western countries. Flat and depressed colonic lesions are not uncommon. Male gender, smoking, obesity, metabolic syndrome and family history are risk factors for colorectal cancer. Certain ethnic groups in Asia have increased susceptibility to colorectal cancer. Faecal occult blood test, flexible sigmoidoscopy and colonoscopy are recommended options for colorectal cancer screening in Asia. Regular screening should start at the age of 50 years.

AREAS OF CONTROVERSY

The optimal screening method in Asia remains unclear. Faecal immunochemical test has been suggested as the first choice of screening test in countries with limited resources. The role of nurse endoscopists in performing endoscopic procedures for colorectal cancer screening in Asia has not been defined.

GROWING POINTS

There is low public awareness and little support by health authorities for screening and prevention of this emerging disease.

AREAS TIMELY FOR DEVELOPING RESEARCH

Screening for colorectal cancer should be a national health priority in most Asian countries. Studies on barriers to screening, education of the public and engagement of family physicians are important strategies in promoting colorectal cancer screening. With more health-care support, increased public acceptance and better access to the general population, colorectal cancer screening in Asia can be rewarding.

Distribution trends of colorectal adenoma and cancer: a colonoscopy database analysis of 11,025 Chinese patients

BACKGROUND AND AIM

A left-to-right shift of colorectal cancer (CRC) has been reported in Western studies. However, few Asian studies have investigated the anatomic distribution of colorectal adenoma and CRC. We aimed to describe the time trends in the distribution of colorectal adenoma and CRC in a Chinese population.

METHODS

A colonoscopy database was reviewed, and all consecutive patients with lower gastrointestinal symptoms who underwent colonoscopy from 1998 to 2009 were identified. Data, including patients' sex, age, symptoms, and the number and anatomic locations of colorectal adenoma and CRC, were documented.

RESULTS

A total of 11,025 patients were included in the final analysis; 1012 and 363 patients were diagnosed with colorectal adenoma and CRC, respectively. Overall, there were more distal than proximal adenomas (54.4% vs 37.9%), and the proportion of proximal adenomas remained stable from 1998-2006 to 2007-2009 (38.2% vs 37.6%). Similarly, there were more distal than proximal CRC (56.5% vs 42.4%), and the proportion of proximal CRC declined from 45.8% in 1998-2006 to 38.4% in 2007-2009. Colorectal adenoma and CRC were equally distributed among both sexes. For elderly patients (> 50 years), there was a non-significant trend towards more proximal adenoma and CRC.

CONCLUSIONS

The present study suggests no distal-to-proximal shift of colorectal adenoma and CRC among the Chinese population in Shanghai over the past 12 years. The distribution pattern of colorectal adenoma and CRC of Chinese patients is different from that of Western patients, who had more colorectal lesions located in the distal part.

Improvement of long-term survival of colorectal cancer in Japanese-Americans of Hawaii from 1990 to 2001

BACKGROUND

To compare the long-term survival of colorectal cancer (CRC) during two 6-year periods using patients with similar characteristics of the same ethnicity in Hawaii.

METHODS

A retrospective review of Japanese-American patients in Hawaii with CRC surgically resected and followed more than 5 years in a single institution. Patients were divided into two groups by date that patients had surgery: Group 1; 1990-1995, and Group 2; 1996-2001 (introduction of newer chemotherapy, aggressive surgery for liver metastases including radiofrequency thermal ablation).

RESULTS

A total of 344 patients in Group 1 (median age 69.5 years) and 330 patients in Group 2 (median age 71.7 years) were included. There were no differences between two groups in gender, age, anatomic site, carcinoembryonic antigen, tumor size, histologic grade, and TNM stage distribution, including pT, pN, and pM status. Overall 5-year survival rate difference approached significance between two groups (Group 1: 73.2% vs. Group 2: 78.9%; p = 0.097). Particularly, there was significant difference in stage IV patients (Group 1; 8.7% vs. Group 2: 26.0%; p = 0.030) and histologic grade 3 (Group 1; 41.67% vs. Group 2: 67.73%; p = 0.032). Subgroup analyses showed significant difference (p < 0.05) for more advanced cancers (larger tumor, node positive, metastatic disease, poorly differentiated cancer).

CONCLUSIONS

In this study of patients with the same ethnicity, the better survival outcome in latter (Group 2) patients suggests improvement of treatment, especially for patients with more advanced and metastatic cancer (stage IV).

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.

Sex differences in epidemiological, clinical and pathological characteristics of colorectal cancer

Sex significantly influences the clinical and pathological characteristics of colorectal cancer (CRC). These include differences in incidence and mortality rates, clinical presentations including age, emergency surgery for complications from CRC, screening participation rates, site, stage and treatment utilization, histopathology and survival. Environmental, behavioral and biological factors contribute to the differential risk. Recent advances in the molecular biology of CRC, specifically in microsatellite status, estrogen hormone and estrogen receptor beta, have led to greater understanding of the effect of estrogen in colorectal carcinogenesis. Estrogen may preferentially protect against microsatellite unstable cancers through its effect on selected molecular targets; however, the exact pathways have not been elucidated. Recognition of important sex disparities in these areas may lead to the implementation of specific measures to diminish these differences and facilitate equitable distribution of health resources. Identifying specific molecular targets on CRC that interact with estrogen may stimulate research to improve the overall outcomes of all patients with CRC.

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.

Trends in colorectal cancer incidence by subsite in Osaka, Japan

To date, the time trends of left-to-right shift of colorectal cancer incidence have been reported in Western countries. In the present study, we calculated the average annual number of colorectal cancer incidence and the age-adjusted colorectal rates, and examined the change of subsite distribution using the data from the Osaka Cancer Registry between 1974 and 2003. Mucosal carcinoma cases were excluded from the analyses. The proportions of right colon cancer among all colorectal cancer cases were consistently increased; from 21.5% in 1974-78 to 25.6% in 1999-2003 among men, and from 28.2% in 1974-78 to 36.8% in 1999-2003 among women. The age-adjusted incidence rates of right colon cancer among men and women recently levelled off, while the rates of left colon and rectal cancers showed a declining trend. Among women, right colon cancer was more common in the elderly than in the young. The change of subsite distribution seemed to be associated with population aging, changes of life style and the development of total colonoscopy. Careful monitoring is necessary to confirm these findings.

Clinical and pathologic outcomes of colorectal cancer in a multi-ethnic population

BACKGROUND & AIMS

The influence of birthplace on the clinical and pathologic outcomes of colorectal cancer (CRC) in Australia is unknown. Addressing inequalities in health care provision in immigrant groups may improve the overall quality of CRC care.

METHODS

The South Western Sydney Colorectal Tumour Group registry prospectively collects data on new patients with CRC from a population of 800,000. Survival data were cross-linked with the New South Wales population death registry.

RESULTS

From 1997 to 2004 there were 1496 patients (55% males) who were recruited and grouped according to country of birth: Australia, 64%; Southern Europe, 19%; Asia, 12%; and the Middle East, 5%. Significant heterogeneity in CRC characteristics was found, especially in Asians. Compared with Australians, Asians were diagnosed at a younger age (median age, 64 vs 70 y; P < .001, 25.6% were younger than 50 years vs 9.5%; P < .001), had fewer poorly differentiated cancers (8.9% vs 17.7%; P = .004), and fewer metastatic cancers (12.1% vs 21.0%; P = .001). Being Asian-born was associated with improved overall survival independent of age, emergency surgery, grade, and stage (hazard ratio, 0.66; 95% confidence interval, 0.47-0.93; P = 0.02). CRC screening was especially low among Asian- and Middle Eastern-born patients. Complications and treatment were not affected by birthplace, indicating no differences in the provision or acceptance of care based on birthplace.

CONCLUSIONS

Despite an equitable distribution of resources, we found significant heterogeneity in presentations and outcomes according to birthplace, with improved survival in Asian-born patients. The lower rates of screen-detected CRC in Asian- and Middle Eastern-born patients and their younger ages at diagnosis indicate that targeted screening strategies may need to be implemented.

Câncer ano-reto-cólico: aspectos atuais IV - câncer de cólon - fatores clínicos, epidemiológicos e preventivos

O câncer colorretal tem alta incidência populacional e alto índice de mortalidade, com diferenças pouco relevantes entre os povos de diversas nações, como atestam os estudos epidemiológicos dessa doença. Embora a abordagem médico-cirúrgica do câncer colorretal tenha sido favorecida pelos novos conhecimentos adquiridos com a engenharia genética, pelos progressos que aprimoraram o tratamento, principalmente na área de neo-adjuvância, com as inovações nos aparelhos de radioterapia e com a constante introdução de novas e potentes substâncias quimioterápicas, o prognóstico da doença continua sombrio. Todavia, dados colhidos em estudos sobre a biologia do tumor - sua origem, crescimento e desenvolvimento e comportamento biológico - têm acenado para a possibilidade de cura quando os métodos preventivos, em prática, facilitam a abordagem precoce da lesão. Nesse contexto, o câncer colorretal é passível de cura, podendo, inclusive dispensar, para tanto, o tratamento adjuvante ou aliviar o paciente da abordagem cirúrgica mutilante. Assim, o maior esforço posto em ação no início desse século está sendo representado pelos movimentos de educação popular em massa para a prevenção do câncer de reto e dos cólons com incentivo para o teste de sangue oculto nas fezes.

Efficacy of chromoendoscopy with indigocarmine for the detection of ascending colon and cecum lesions

OBJECTIVE

Previous data suggest that routine chromoendoscopy may increase detection rates of diminutive or flat lesions. The aim of this study was to evaluate the usefulness of chromoendoscopy in the ascending colon and cecum, where the incidence of diminutive or flat lesions is high.

MATERIAL AND METHODS

Between June 2006 and September 2006, a total of 316 consecutive patients were prospectively enrolled in this study. The patients were randomly divided into two groups (control group: 158 patients, chromoendoscopy group: 158 patients). If the quality of bowel preparation was poor or cecal intubation was not achieved, the patient was excluded from the study. In the control group, the ascending colon and cecum were observed twice without chromoendoscopy. In the chromoendoscopy group, the cecum and ascending colon were reinspected following staining with indigocarmine solution after conventional examination of the cecum and ascending colon. Finally, a total of 151 and 149 patients were enrolled in the control and chromoendoscopy groups, respectively.

RESULTS

The chromoendoscopy group differed significantly from the control group in the number of additionally detected polyps (control: 14 versus chromoendoscopy: 62, p<0.001) and in the number of patients with additionally detected polyps (control: 12 versus chromoendoscopy: 50, p<0.001). Multivariate analysis revealed that detection of polyps after indigocarmine spraying was independently associated with a high body mass index and older age (p = 0.045 and p = 0.006, respectively).

CONCLUSIONS

With chromoendoscopy using indigocarmine, more polyps can be detected in the ascending colon and cecum as compared with using conventional colonoscopy.

Occupational physical activity and risk for cancer of the colon and rectum in Sweden among men and women by anatomic subsite

Inverse association between physical activity and colon cancer is well established, at least in men. We investigated the association of occupational physical activity with subsite-specific colorectal cancer risk. On the basis of occupational titles from the Swedish nationwide censuses in 1960 and 1970, we defined a cohort of women and men with the same work-related physical demands in 1960 and 1970. Incidence of colon and rectum cancer during 1971-1989 was ascertained through linkages to the Cancer Register. Relative risks (RRs) were estimated through Poisson regression. The risk for colon cancer increased with decreasing occupational physical activity. RR among sedentary women and men was 1.2 and 1.3 (P for trend=0.08 and <0.001). For men, the risks for proximal and distal colon cancer increased by 20 and 40% (P for trend=0.005 and <0.001). Inactivity seemed to be particularly associated with descending colon cancer (RR =2.4, P for trend<0.001). In women, the inverse association with activity was concentrated to proximal parts of colon; RR for cancer in the proximal and transverse colon among sedentary women was 1.4 and 2.0 (P for trend <0.07 and <0.01). Cancer of the rectum was not associated with activity in either sex. We confirmed the well-known inverse relationship between activity and risk of colon cancer but not rectal cancer in both sexes. Data suggest that the physical activity-related variation in risk among women is greatest in the proximal and middle parts of the colon, whereas the corresponding peak in men seems to be more distal. Sex-specific anatomic and motility differences of the colon might contribute to this subsite difference.

Improved survival in young women with colorectal cancer

BACKGROUND

Studies have reported the effect of gender in the context of assessing predictors of survival from colorectal cancer (CRC); however, few have specifically addressed the impact of gender on the clinical and pathological outcomes of CRC. Appreciation of gender disparities may assist in the implementation of measures to address these differences, and improve the overall outcomes of patients with CRC.

METHODS

The South Western Sydney Colorectal Tumour Group registry, which encompasses a population in excess of 800,000, prospectively collects data on new patients with CRC. Data from 1997 to 2004 were collected, including demography, site, grade, histopathology, stage, treatment, and survival.

RESULTS

In total, 2,050 consecutive patients (44% women) with CRC were analyzed. Compared to men, women were older (median 69 yr, range 27-95 yr vs 67, range 22-92 yr, P= 0.001), had more emergency surgery for CRC-related complications (18.8%vs 15.1%, P= 0.03), had more proximal cancers (42.2%vs 31.5%, P < 0.001), had more poorly differentiated cancers (16.9%vs 12.9%, P= 0.01), and had fewer radiotherapy treatments for Dukes B and C rectal cancers (36.4%vs 48.1%, P= 0.02). Young women (aged 50 yr and below) had significantly better overall survival compared to young men; in this group, female gender predicted improved overall survival independent of age, emergency surgery, site, grade, and stage (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.25-0.86, P= 0.01). Similarly, young women had significantly better cancer-specific survival (HR 0.46, 95% CI 0.25-0.85, P= 0.01). However, older women (aged over 50 yr) had worse survival independent of age, emergency surgery, site, grade, and stage (HR 1.38, 95% CI 1.14-1.68, P= 0.001). There were no gender differences in screening, histopathology, stage, or utilization of chemotherapy.

CONCLUSIONS

This study demonstrated an opposing effect of gender on overall and cancer-specific survival at either side of the age of 50 yr. The protective effect of estrogen on CRC may be an important factor. Women had a greater proportion of emergency surgery, which was related to the predominance of proximal cancers in this gender. Women also had more proximal cancers, thereby limiting flexible sigmoidoscopy as a screening test.

A randomised controlled trial of a new 2 litre polyethylene glycol solution versus sodium picosulphate + magnesium citrate solution for bowel cleansing prior to colonoscopy

BACKGROUND

A new 2 L polyethylene glycol (PEG) solution containing ascorbic acid (Asc) and electrolytes (Moviprep) has been developed for bowel cleansing.

OBJECTIVES

To compare the efficacy, safety and acceptability of PEG + Asc versus sodium picosulphate + magnesium citrate in patients scheduled to undergo colonoscopy.

DESIGN AND METHODS

This single blind, parallel group pilot study included 65 adult male and female patients. A blinded assessment of cleansing was made for each bowel segment by the colonoscopist and the scores determined an overall grading of bowel cleansing. Patients completed a questionnaire on the acceptability of the preparation.

RESULTS

Successful bowel preparation was reported in 84.4% of patients who received PEG + Asc and 72.7% of patients who received sodium picosulphate + magnesium citrate (treatment difference +11.6, 95% CI -11.2, +34.5; p = 0.367). Patients were more likely to have a higher overall quality of bowel cleansing with PEG + Asc (p = 0.018), with specifically better cleansing in the ascending colon (p = 0.024) and caecum (p = 0.003) compared with patients who received sodium picosulphate + magnesium citrate. The adverse event profile of the two treatments was similar, with headache and gastrointestinal effects being the most commonly reported. Some patient acceptability results favoured sodium picosulphate + magnesium citrate for those patients who had experience of previous bowel preparation, but were similar for those patients who had not had a previous bowel preparation.

CONCLUSIONS

PEG + Asc provided effective bowel cleansing, which was equivalent to that of sodium picosulphate + magnesium citrate in terms of grading cleansing as overall success or failure. In the proximal colon (ascending colon and caecum) PEG + Asc provided significantly better cleansing to that achieved with sodium picosulphate + magnesium citrate.

Changing trends in gastrointestinal disease in the Asia-Pacific region

The new millennium has seen distinct changes in the pattern of gastrointestinal disease in the Asia-Pacific region. These changes are important as more than half of the world's population come from the region and therefore impact significantly on the global disease burden. The highest incidence of gastric cancer (GCA) has been reported from Asia and GCA remains a very important cancer. However time-trend studies have shown a decrease in GCA incidence in several countries in Asia. A rise in cardio-esophageal cancers as seen in the West has not been reported. On the other hand, colorectal cancer has been steadily increasing in Asia with age-standardized incidence rates of some countries approaching that of the West. The pattern of acid-related diseases has also changed. Gastroesophageal reflux disease is a fast emerging disease with an increasing prevalence of reflux esophagitis and reflux symptoms. The prevalence of peptic ulcer disease has at the same time declined in step with a decrease in H. pylori infection. Many of the changes taking place mirror the Western experience of several decades ago. Astute observation of the epidemiology of emerging diseases combined with good scientific work will allow a clearer understanding of the key processes underlying these changes. With rapid modernization, lifestyle changes have been blamed for an increase in several diseases including gastroesophageal reflux disease, nonalcoholic fatty liver disease and colorectal cancer. A worrying trend has been the increase in obesity among Asians, which has been associated with an increase in metabolic diseases and various gastrointestinal cancers. Conversely, an improvement in living conditions has been closely linked to the decrease in GCA and H. pylori prevalence.

Diet, gender, and colorectal neoplasia

The association between diet and colorectal cancer has been studied in depth for many decades, with equivocal results. It has been hypothesized that cancers arising in the distal and proximal colon have different pathologies, and therefore different risk factors. As such, it is possible that diet-related factors might influence colorectal neoplasia differently depending on the subsite. Recent evidence indicates that women may be more likely to develop proximal cancers than men. Additionally, the link between certain dietary factors and colorectal neoplasia in women seems to vary by menopausal status. Given these observations, women may be affected differently than men by diet-related factors. The objective of this article was therefore to review the data for diet and colorectal adenomas and cancer, and then attempt to address the potential differences in the association of diet-related factors and colorectal neoplasia in men and women. For total energy intake, selenium, and fiber, it seems that there may be slightly stronger effects in men as compared with women, whereas calcium and folate seem to affect both sexes similarly. With regard to vitamin D and colorectal cancer, women may exhibit stronger associations than men. Perhaps the most evidence for a sex-specific effect is observed for obesity, where more substantial direct relationships between body size and colorectal neoplasia have been reported for men than for women. However, this observation may be influenced by the differential effects in women by menopausal status. Further research on sex-specific dietary effects is warranted.

Changes in disease pattern and treatment outcome of colorectal cancer: a review of 5,474 cases in 20 years

BACKGROUND AND AIMS

Colorectal cancer (CRC) is the third most common cause of cancer-related death in Taiwan. During the past 20 years, several advances have improved the treatment outcome and quality of life of CRC patients. The purpose of this study was to identify the changes in the clinicopathological features and outcome of CRC over this period.

MATERIALS AND METHODS

Based on the computerized database of the Taipei Veterans General Hospital, between January 1981 and December 2000, 5,474 CRC patients were identified and divided into 2 groups based on the date of treatment (1981-1990 and 1991-2000). The clinicopathological features, outcome, and prognostic factors were analyzed and compared.

RESULTS/FINDINGS

The age at onset of cancer was 61 years in the 1980s group and 66 years in the 1990s group. The frequency of rectal tumors decreased from 50% in the 1980s group to 44% in the 1990s group. Tumor, nodes, metastasis (TNM) stage distribution, surgical mortality, and anastomosis leakage were similar in the two groups. However, the 5-year overall survival rate was better in the 1990s group (56%) than that in the 1980s group (50%, P = 0.001). For rectal cancer patients, the local recurrence rate was lower in the 1990s group (6%) than that in the 1980s group (10%, P < 0.01). In stage III CRC, the 5-year overall survival rate was significantly higher in the 1990s group (54%) than that in the 1980s group (48%, P = 0.011). TNM stage was the most important independent prognostic factor for overall and disease-free survivals, followed by differentiation grade, CEA level, and treatment period.

INTERPRETATION/CONCLUSION

Advances in surgical technique and more standard use of chemotherapy have improved CRC outcome.

The changing distribution of colorectal cancer in Barbados: 1985-2004

PURPOSE

Recent reports have suggested a shift to the right in older female patients of colon cancer. This is believed to be representative of more accessible national endoscopic screening programs.

METHODS

We report the demographic shift in colorectal cancer based on an analysis of resection specimens during four five-year time periods from 1985 to 2004 at the University Hospital, Barbados. Differences in population-based colorectal cancer incidence, age, gender, site, stage, and presentation (emergency vs. elective) are analyzed.

RESULTS

A total of 1,014 specimens obtained from 993 patients were analyzed, showing a progressive population-based increase in colorectal cancer in Barbados during this 20-year time period. There was an increase in right-sided tumors (P < 0.0001) without a concomitant decline in left-sided tumors. There was a significant increase in Dukes A cancers (P < 0.0001) without gender predilection. During the time period, there was a significant reduction in right-sided tumors presenting as emergencies (P < 0.005) without an effect of stage or gender.

CONCLUSIONS

There has been a steady increase in both right-sided and left-sided colonic cancers without gender predilection. The increase in early-stage tumors and reduction in emergency presentations during the latter part of the study suggests value in instituting a formal national colonoscopic screening program to assess its prospective effect on these parameters.

Increasing prevalence of advanced colonic polyps in young patients undergoing colonoscopy in a referral academic hospital in Hong Kong

AIM: To investigate the distribution and frequency of advanced polyps over eight years.

METHODS: 6424 colonoscopies were reviewed during the study period 1998 to 2005. The study period was subdivided into period I: 1998 to 2001 and period II: 2002-2005.

RESULTS: 1856 polyps (33% advanced polyps) and 328 CRCs were detected. The mean ages of the patients with advanced polyps and cancer were 69.2 ± 12.0 and 71.6 ± 13.8 years, respectively. Advanced polyps were mainly left sided (59.5%). Advanced polyps were found in patients ≤ 60 years from 17.7% in periodI to 26.3% in period II (P < 0.05), especially in male subjects ≤ 60 years (21.6% vs 31.6%, P < 0.05). Advanced tubulovillous polyps rose from 21.5% in period I to 29.5% in period II (P < 0.05). Whereas cancers in male patients ≤ 60 years were similar in both periods: 23.2% vs 16.5% (P > 0.05).

CONCLUSION: Advanced polyps increased significantly in the younger male group in the most recent period and there seems to be a shift towards a proximal location.