The anatomical distribution of colorectal cancer in Korea: evaluation of the incidence of proximal and distal lesions and synchronous adenomas

Resource Use and Costs Associated to the Initial Phase of Treatment for Patients with Colorectal Cancer Receiving Post-Surgery Chemotherapy: A Cost Analysis from a Healthcare Perspective

Background:

To estimate the resource use and costs associated to the initial phase of treatment for colorectal cancer in Iran.

Methods:

A retrospective study was conducted using routinely collected data within Electronic Health Records System (SEPAS), a national database representing public hospitals in Iran between March 20, 2016 and March 19, 2017. Primary end points included healthcare resource use, direct medical and non-medical costs of care in the 12-month study period.

Results:

The study population included 657 patients with colorectal cancer who underwent surgery and the follow-up chemotherapy. We estimated a total direct cost of $21,407 per patient. The results indicated that direct medical costs were primarily driven by inpatient hospital care, followed by surgery, chemotherapy, and diagnostic services.

Conclusion:

The initial 12-month of treatment for colorectal cancer, including surgery and the follow-up chemotherapy, is resource intensive. The total direct costs associated to the disease are remarkable, with Inpatient hospital services being the main contributor followed by surgery and chemotherapy.

Clinicopathologic Features of Colorectal Polyps in Shahid Beheshti University of Medical Sciences (SBMU)

Aim: This study was designed to report epidemiologic findings of polyps in Iranian patients, and predict histology of polyp regarding to demographic and colonoscopic findings. Background: Classification of colorectal polyps had been revised in the past two decades and there is a need for polyp categorization in the Iranian Health System. Patients and methods: In this retrospective study, the medical records of patients with colonoscopic diagnosis of polyp in pathology departments of SBMU affiliated teaching hospitals were reviewed. Patient’s slides evaluated and demographics findings were assessed. The anatomical location, macroscopic appearance including size and histological assessment of all polyps were recorded. Results: From total number of 1106 polyps (detected in 862 patients), adenomatous polyps (638 [57.7%]) were the most prevalent findings, followed by colon mucosal tag (184[16.6%]), hyperplastic and serrated polyps (122[11%]), inflammatory polyps (110[9.9%]), hamartomatous (21[1.9%]), and malignant lesions (13[1.2%]). Multivariate logistic regression showed age (each one year increasing age; odds ratio [OR] = 1.026, 95%confidence interval [CI] = 1.016–1.036, p < 0.0001), location of polyp (right colon; OR = 1.905, 95%CI = 1.366–2.656, p < 0.0001), and polyp size of 5-10 mm (OR = 1.662, 95%CI = 1.214–2.276, p = 0.002), and polyp size of >10 mm (OR = 2.778, 95%CI = 1.750–4.411, p< 0.0001) were independently associated with neoplastic polyps. Also, polyp size of >10 mm (OR= 2.613, 95%CI= 1.083-6.307, p=0.033), tubulovillous pattern of polyp (OR= 3.508, 95%CI= 1.666-7.387, p=0.001) and villous pattern of polyp (OR= 10.444, 95%CI= 4.211-25.905, p<0.0001) were associated with high grade dysplasia in neoplastic polyps. Conclusion: Increased age, location of polyp (right colon), increased size of polyp and villous component of polyp could classify patients in high risk groups.

Clinicopathological Associations of K-RAS and N-RAS Mutations in Indonesian Colorectal Cancer Cohort

BACKGROUND

K-RAS and recently N-RAS gene mutation testing are mandatory requirements prior to anti-epidermal growth factor receptor (EGFR) monoclonal antibody treatment of metastatic CRC. Mutation prevalence and distribution in Indonesian colorectal cancer (CRC) are not known.

METHODS

Combined methods of PCR high-resolution melt (HRM), restriction fragment length polymorphism (RFLP), and direct DNA sequencing were used to genotype exons 2, 3, and 4 of both K-RAS and N-RAS genes for routine clinical testing of CRC patients. Descriptive analytical review of 595 consecutive CRC patients (years 2013 to 2016) was performed to find associations between gene mutations and clinicopathologic features.

RESULTS

This retrospective study revealed overall K-RAS gene mutation in exon 2 (codon 12 and 13) rates being 34.9%. Women (42.5%), stages I and II (43.4%), and well and moderate differentiations (37.7%) had higher frequency of K-RAS exon 2 mutations than men (29%, p = 0.006), stages (III and IV 31.9%, p = 0.05), and poor differentiation (11.8%, p = 0.002), respectively. At later period (2015-2016), 121 of 595 patients were genotyped for the remaining exons 3 and 4 of K-RAS as well as exons 2, 3, and 4 of N-RAS mutations resulting in overall RAS mutation prevalence of 41%. Mucinous histology had highest frequency of N-RAS mutation.

CONCLUSIONS

Combination of PCR HRM with either RFLP or direct DNA sequencing was useful to detect K-RAS exon 2 and extended RAS mutations, respectively. Frequency of all RAS mutations in stage IV Indonesian (41%) was similar among Asians (41-49%), which tend to be lower than western (55%) CRC.

Geographic distribution of the incidence of colorectal cancer in Iran: a population-based study

OBJECTIVES

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer death in the world. The aim of this study was to investigate the provincial distribution of the incidence of CRC across Iran.

METHODS

This epidemiologic study used data from the National Cancer Registry of Iran and the Center for Disease Control and Prevention of the Ministry of Health and Medical Education of Iran. The average annual age-standardized rate (ASR) for the incidence of CRC was calculated for each province.

RESULTS

We found that adenocarcinoma (not otherwise specified) was the most common histological subtype of CRC in males and females, accounting for 81.91 and 81.95% of CRC cases, respectively. Signet ring cell carcinoma was the least prevalent subtype of CRC in males and females and accounted for 1.5 and 0.94% of CRC cases, respectively. In patients aged 45 years or older, there was a steady upward trend in the incidence of CRC, and the highest ASR of CRC incidence among both males and females was in the age group of 80-84 years, with an ASR of 144.69 per 100,000 person-years for males and 119.18 per 100,000 person-years for females. The highest incidence rates of CRC in Iran were found in the central, northern, and western provinces. Provinces in the southeast of Iran had the lowest incidence rates of CRC.

CONCLUSIONS

Wide geographical variation was found in the incidence of CRC across the 31 provinces of Iran. These variations must be considered for prevention and control programs for CRC, as well as for resource allocation purposes.

15-Hydroxyprostaglandin dehydrogenase as a marker in colon carcinogenesis: analysis of the prostaglandin pathway in human colonic tissue

Background/Aims

Cyclooxygenase-2 (COX-2), 15-hydroxyprostaglandin dehydrogenase (15-PGDH), and microsomal prostaglandin E synthase-1 (mPGEs-1) regulate prostaglandin E₂ (PGE₂) expression and are involved in colon carcinogenesis. We investigated the expression of PGE₂ and its regulating genes in sporadic human colon tumors and matched normal tissues.

Methods

Twenty colonic adenomas and 27 colonic adenocarcinomas were evaluated. COX-2 and 15-PGDH expression was quantified by real-time polymerase chain reaction. The expression of PGE₂ and mPGEs-1 was measured using enzyme-linked immunosorbent assay and Western blotting, respectively.

Results

The expression of COX-2, mPGEs-1, and PGE₂ did not differ between the adenomas and matched distant normal tissues. 15-PGDH expression was lower in adenomas than in the matched normal colonic tissues (P<0.001). In adenocarcinomas, mPGEs-1 and PGE₂ expression was significantly higher (P<0.001 and P=0.020, respectively), and COX-2 expression did not differ from that in normal tissues (P=0.207). 15-PGDH expression was significantly lower in the normal colonic mucosa from adenocarcinoma patients than in the normal mucosa from adenoma patients (P=0.018).

Conclusions

Early inactivation of 15-PGDH, followed by activation of COX-2 and mPGEs-1, contributes to PGE₂ production, leading to colon carcinogenesis. 15-PGDH might be a novel candidate marker for early detection of field defects in colon carcinogenesis.

Incidence trends of colorectal cancer in the West of Iran during 2000-2005

BACKGROUND

Colorectal cancer is a main leading cause of cancer death in western countries. Although many studies have been conducted on incidence trends all over the world in recent years, information regarding changes in incidence of colorectal cancer in Iran is insufficient. The present study of colorectal cancer in the west of Iran during recent years was therefore performed.

MATERIALS AND METHODS

The registered data for colorectal cancer cases in National Cancer Registry System were extracted from the Ministry of Health and Medical Education, Center for Disease Control and Management. The codes from 18-21 among cancers were selected for colon and rectum cancers. Incidence rates were standardized directly using WHO population. The significance of incidence rate trends during 2000-2005 was tested through Poisson regression.

RESULTS

762 cases of colorectal cancer were observed during 6 years in this region, with a gender ratio of men to women of 1.2. It increased from 65 cases in 2000 to 213 cases in 2005 or from 1.5 per100,000 per persons per year to 4.8. Significant increasing trends were evident in Kermanshah and Hamadan provinces; however, change did not reach significance in Ilam and Kurdistan provinces.

CONCLUSIONS

Colorectal cancer has an increasing trend in the west of Iran. Although it seems that the increasing rate of colorectal cancer is due to increasing of cancer risk factors, some proportion may be related to the improvement of surveillance systems in Iran.

Colorectal cancers from distinct ancestral populations show variations in BRAF mutation frequency

It has been demonstrated for some cancers that the frequency of somatic oncogenic mutations may vary in ancestral populations. To determine whether key driver alterations might occur at different frequencies in colorectal cancer, we applied a high-throughput genotyping platform (OncoMap) to query 385 mutations across 33 known cancer genes in colorectal cancer DNA from 83 Asian, 149 Black and 195 White patients. We found that Asian patients had fewer canonical oncogenic mutations in the genes tested (60% vs Black 79% (P = 0.011) and White 77% (P = 0.015)), and that BRAF mutations occurred at a higher frequency in White patients (17% vs Asian 4% (P = 0.004) and Black 7% (P = 0.014)). These results suggest that the use of genomic approaches to elucidate the different ancestral determinants harbored by patient populations may help to more precisely and effectively treat colorectal cancer.

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.

Correlation between the EGF gene intronic polymorphism, rs2298979, and colorectal cancer

Colorectal cancer (CRC) is an important disorder that results from genetic and epigenetic alterations in one colonic epithelial cell. Epidermal growth factor (EGF) is critical in the development of tumors in epithelial tissues. Variations in the DNA sequence of the EGF gene may be particularly significant with regard to susceptibility to CRC. The present study aimed to investigate the effect of the EGF gene single nucleotide polymorphism (SNP), rs2298979, on CRC. In this prospective study, 220 samples were collected from patients with CRC and compared with 220 matched healthy controls. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and the result was validated by direct sequencing. A significant correlation was observed between the rs2298979 variant in the EGF gene and CRC. The frequency of the A/G genotype in the control group was higher than in the patients with sporadic CRC [odds ratio (OR), 0.488; 95% confidence interval (CI), 0.307–0.774; P=0.002]. In this study there were no individuals with a G/G genotype. Although the frequency of the G and A alleles was similar in the healthy control and CRC patient groups, individuals with the A/G genotype were less susceptible to CRC compared with those with the A/A genotype.

A comparative overview of general risk factors associated with the incidence of colorectal cancer

Cancers found in colorectal region remain largely localized to the large intestine and rectum. They are derived from the epithelium and are considered to be among the most frequently detected cancers. They are known to occur in approximately 5 % population of the Western world. After metastasis, a patient's 5-year postsurgical survival chances unfortunately fall from 90 to 10 % or even less. Adenocarcinoma, the most common cell type of colon cancer, alone constitutes 95 % of the cases. Lymphoma and squamous cell carcinoma can also be found in some cases. Because 5 % of persons are predisposed to development of colorectal cancer, this disease has often been addressed as an important public health issue. Factors that are known in particular to increase a person's risk to develop this cancer are as follows: an individual's age, dietary habits, any complaint of obesity, diabetes, previous history of cancer or intestinal polyps, personal habit of alcohol consumption and smoking, family history of colon cancer, race, sex, and ethnicity. Since the risk of colorectal cancer is increasing steadily in Kashmir, India, like in some other corners of Asia, exhaustive efforts are being made to find the association of above given and other risk factors with the development of this gastrointestinal tract cancer. Adoption of Western life style, diet mimicry, together with a habit of having physically inactive life style and consumption of red meat in particular can be blamed as being active players to a considerable extent.

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.

Trend of colorectal cancer in Hong Kong: 1983-2006

BACKGROUND AND AIM

The incidence of colorectal cancer (CC) is increasing in many Asian countries, but decreasing in western countries. The present study examined the local incidence of CC in the past few decades.

METHODS

A population based study, using data from Hong Kong (HK) Cancer Registry, was carried out to examine the trends of CC in different age groups in HK. Comparison with other countries was made.

RESULTS

The crude rate of CC in HK increased from 29.6/100,000 in 1983 to 57.1/100,000 in 2006. Age standardized rate (ASR) increased by less than 20%. It was markedly smaller than the 190% increase in crude rate. ASR progressively increased in males. In females, ASR peaked in 1994 and declined in the last decade. In most countries, the risk of CC was higher and increasing in males, but stable or decreasing in females. With respect to age, increasing risk was noted in males above 60 years old and females above 70 years old. However, a declining rate was noted in those below 50 years old. The decrease was over 40% in the 30-34 years group over the past two decades.

CONCLUSIONS

Increasing incidence of CC in HK was mostly in the older and male population, but not in the younger age group.

Epidemiology of colorectal cancer in Asia

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