Varying features of early age-of-onset "sporadic" and hereditary nonpolyposis colorectal cancer patients

Hereditary Colorectal Cancer Syndromes

Awareness of hereditary colorectal cancer syndromes is important to facilitate their identification because affected patients are at increased risk for early onset, synchronous, and metachronous colorectal malignancies, and certain extracolonic malignancies depending on the syndrome. Identification of an affected individual allows for screening and early interventions for patients and their at-risk kindred. Genetic counseling and testing is important to the care of these patients. As knowledge of the genetic basis of these syndromes grows, unique genotype-phenotype profiles allow clinicians to tailor surveillance and treatment strategies based on individual risk.

Frequency of all types of colorectal tumors in the patients referred to selected hospitals in tehran

Background

Colorectal cancer (CRC) is one of the most common cancers worldwide which is not extensively researched in Iran.

Objectives

The present study aims to investigate the epidemiologic characteristics of CRC in patients referred to selected hospitals of Tehran University of Medical Sciences.

Patients and Methods

In this descriptive-analytic study 218 patients with colorectal cancer were investigated. Data were collected via reviewing recorded pathologic results of patients of these hospitals which then were analyzed by univariant methods.

Results

Among 218 patients, 140 (64.2%) were male and 78 (35.8%) were female. Of all patients, 132 (60.0%) suffered from tumors in rectum; 38 (17.4%) in sigmoid; 12 (5.5%) in descending colon; 10 (4.6%) in transverse colon and 26 (11.9%) in ascending colon and cecum. Tumors were well differentiated in 134 patients (61.5%), moderately in 62 cases (28.4%) and poorly differentiated in 22 patients (10.1%). There was no significant difference between males and females regarding the location and degree of tumor differentiation.

Conclusions

Regarding high prevalence of colorectal cancer in Iran and potential environmental and genetic factors, surveillance must be considered for this disease. Its risk factors such as diet, life style and low physical activity should be evaluated and screening should start at younger ages.

Precancerous lesions in colorectal cancer

Colorectal cancer (CRC) is the third most common cause of cancer death in the world. The incidence rate (ASR) and age distribution of this disease differ between most of African-Middle-Eastern (AMAGE) and North America and Europe for many reasons. However, in all areas, "CRC" is considered as one of the most preventable cancers, because it might develop from variant processes like polyps and IBD in addition to the genetic pathogenesis which became very well known in this disease. We tried in this paper to review all the possible reasons of the differences in incidence and age between the west and AMAGE. Also we reviewed all the mutations that lead to the hereditary and familiar clustering of this disease with the correlations with the surrounding food and environment of different areas. Then, we focused on the precancerous pathology of this disease with special focusing on early detection depending on new endoscopy technology and most important genetic studies. We lastly reviewed the evidence of some of the surveillance and put suggestions about future surveillance programs and how important those programs are on the psychological aspect of the patients and their families.

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.

Mucinous adenocarcinoma showing different clinicopathological and molecular characteristics in relation to different colorectal cancer subgroups

BACKGROUND

Mucinous adenocarcinoma (MAC) is frequently reported to be associated with patients of young-age sporadic colorectal cancer (YSCC) and hereditary nonpolyposis colorectal cancer (HNPCC). This study is aimed to investigate whether the clinicopathological characteristics of MAC of HNPCC patients are distinct from those of YSCC patients.

PATIENTS AND METHODS

Eighty-two HNPCC and 68 YSCC patients recorded in the colorectal cancer registry of Chang Gung Memorial Hospital at Linkou, Taiwan, between January 1, 1995 and December 31, 2001 were included in this study. Clinicopathological and molecular variables of MAC and non-MAC of HNPCC and YSCC patients were compared accordingly.

RESULTS

Compared to non-MAC, MAC significantly showed higher frequencies of poor differentiation (32% vs. 8.2%, p = 0.001), advanced tumor stage (76% vs. 47%, p = 0.002), loss of mismatch repair protein (MMR) expression (74% vs. 44%, p = 0.023), and increased MUC2 expression (98% vs. 61%, p < 0.001). MAC of HNPCC patients showed predominant right-sided colon involvement, whereas MAC of YSCC patients displayed predominance in the left colon (79% vs. 22%, p = 0.001). Among the non-MAC counterparts, more differences were detectable including tumor stage, loss of MMR expression, and increased MUC1 expression. Furthermore, both MAC and non-MAC of YSCC patients showed higher frequencies of advanced tumor stage (81% vs. 62%, p = 0.072). In contrast, the incidence of loss of MMR expression in MAC and non-MAC of HNPCC patients is not significantly different (86% vs. 70%, p = 0.323).

CONCLUSIONS

Significantly different tumor localization was observed between mucinous YSCC (left colon predominance) and mucinous HNPCC (right colon predominance).

Incidence and age distribution of colorectal cancer in Iran: results of a population-based cancer registry

Epidemiologic patterns of colorectal cancer (CRC) in Iran have not been studied adequately. In a recent cancer registry and active cancer surveillance, we collected data on the incidence of colorectal tumors in five provinces of Iran from 1996 to 2000. In total, 2055 were registered in this study. Age-adjusted rates of CRC in Iranian males and females were 8.2 and 7.0/100,000, respectively. Seventeen percent of the cases were younger than 40 years of age at the time of diagnosis. This proportion was similar to proportions seen in many other Middle-Eastern countries, but much higher than those seen in Western countries. A comparison of age-specific rates between Iran and the US showed similar rates in young (<40 years) Iranians and Americans, but much lower rates in older (>/=40) Iranians. We conclude that Iran is still a country with low-risk of CRC, particularly for older individuals. The high proportions of young CRC cases seen in Iran, and probably many neighboring countries, are due to the young age-structure of these countries and relatively low rates of CRC in older individuals.

Mechanisms of microsatellite instability in colorectal cancer patients in different age groups

PURPOSE

The proportion of colorectal cancers located proximal to the splenic flexure increases with age. Colorectal cancers of the microsatellite instability phenotype are preferentially located in the proximal colon. We investigated the location of colorectal cancer with this phenotype in different age groups to determine whether different molecular mechanisms could account for the changes in distribution of colorectal cancers.

METHODS

A representative sample of 230 colorectal cancers from three age groups (<45 years, 60-70 years, >87 years) was selected from a subset of The Upper Midwest Oncology Medical Registries database. Microsatellite instability was determined by polymerase chain reaction using a panel of five microsatellite markers. The presence of new microsatellite alleles at two or more loci was scored as microsatellite instability. Tumors were otherwise considered microsatellite stable. MLH1 and MSH2 expression was determined by immunohistochemistry. Methylation of the MLH1 gene promotor was determined by methylation-specific polymerase chain reaction assay.

RESULTS

The proportion of tumors of the microsatellite instability phenotype was 21 percent in the young group, 15 percent in the middle group, and 33 percent in the old group. More tumors of the microsatellite instability phenotype were proximal compared with microsatellite-stable tumors in all three age groups, but the differences were significant only for the old group. Tumors of the microsatellite instability phenotype in the older group were associated with MLH1 inactivation (24/29 or 83 percent), MLH1 promoter methylation (18/29 or 62 percent), and proximal location (25/29 or 86 percent), while tumors in the young group were associated with MSH2 inactivation (8/18 or 44 percent) and distal location (11/18 or 62 percent).

CONCLUSION

The age-related proximal shift of colorectal cancers is associated with the microsatellite instability phenotype, MLH1 inactivation, and MLH1 promoter hypermethylation.

Clinicopathological and molecular genetic analysis of HNPCC in China

AIM: To explore the clinicopathological and molecular genetic features of hereditary nonpolyposis colorectal cancer (HNPCC) in Chinese population.

METHODS: We collected 16 Chinese HNPCC families from Wenzhou, Zhejiang Province, China. Tumor tissues and peripheral white blood cells were studied using microdissection, microsatellite analysis, immunostaining of hMSH2 and hMLH1 proteins and direct DNA sequencing of hMSH2 and hMLH1 genes.

RESULTS: (1) A total of 50 patients had CRC. Average age at diagnosis of the first CRC was 45.7 years; 40.9% and 28.7% of the CRCs were located proximal to the splenic flexure and in the rectum, respectively. Thirty-eight percent of the colorectal cancer patients had synchronous and metachronous CRC. 34.4% and 25% of the CRCs were poor differentiation cancer and mucinous adenocarcinoma, respectively. Fourteen extracoloni tumors were found, and the hepatic cancer was the most common tumor type. Twenty-one patients whose median survival time was 5.7 years died during 1-23 years. Twenty-nine patients have survived for 1-28 years, 58.6%, 41.4% and 24.1% patients have survived for more than 5, 10 and 15 years, respectively; (2) All nine tumor-tissues showed microsatellite instability (MSI) at more than two loci. Four tumor-tissues lost hMSH2 protein expression and one lost hMLH1 protein expression. Three pathological germline mutations were identified from five genetically analyzed families; two of three mutations had not been reported previously as they were a transition from C to A in exon 14 (codon 743) of hMSH2 and a TTC deletion in exon 14 (codon 530) of hMLH1.

CONCLUSION: Chinese HNPCC have specific clinicopathological features, such as early onset, propensity to involve the proximal colon, and high frequency of multiple CRCs, liver cancer more frequent than endometrial cancer. Chinese HNPCC showed relatively frequent germline mutation of mismatch repair (MMR) genes that correlated closely with high-level MSI and loss of expression of MMR genes protein.

The clinical importance and prognostic implications of microsatellite instability in sporadic cancer

AIMS

The genetic abnormality known as microsatellite instability (MSI), first identified in colorectal cancer in 1993, has subsequently been recognised in other malignancies. These cancers are caused by a defect in the nuclear mismatch repair system, allowing mutations to accumulate with every cellular division. Hereditary Non Polyposis Colon Cancers (HNPCC) and associated malignancies demonstrating MSI have a unique histological appearance, improved prognosis and altered response to chemotherapy and radiotherapy. This review examines the incidence of MSI and its clinical significance in commonly occurring solid malignancies.

METHOD

A medline based literature search was performed using the key words 'Microsatellite Instability' and the name of the specific malignancy being investigated. Additional original papers were obtained from citations in those articles identified in the original medline search.

RESULTS

MSI has been detected in many solid malignancies although the definition of instability applied has been variable. It is most commonly found in sporadic malignancies that also occur in the HNPCC syndrome such as colorectal, stomach, endometrial and ovarian cancer. MSI may impart a favorable prognosis in colorectal, gastric, pancreatic and probably oesophageal cancers but a poor prognosis in non small cell lung cancer. In clinical studies colorectal cancers demonstrating MSI respond better to chemotherapy while in vitro studies using MSI positive cell lines show resistance to radiotherapy and chemotherapy.

CONCLUSION

MSI may be a useful genetic marker in prognosis and could be an influential factor in deciding treatment options. However, in many cancers its significance remains unclear and more evaluation is required.

Clinical characteristics and diagnosis of patients with hereditary nonpolyposis colorectal cancer

AIM: To study the clinical characteristics of hereditary nonpolyposis colorectal cancer (HNPCC) in the Chinese population and discuss the identification and management of the patients with HNPCC.

METHODS: A series of 140 patients with colorectal cancers (CRC) and HNPCC associated tumors from 30 families fulfilling the Amsterdam criteria were analyzed.

RESULTS: A total of 118 patients had CRC. Average age at diagnosis of the first CRC was 45.7 years, 56.8% and 23.4% of the first CRC were located proximal to the splenic flexure and in the rectum respectively. Twenty-three (19.5%) had synchronous and metachronous CRC. Twenty-seven patients were found to have extracolonic tumors. Gastric carcinoma was the most common tumor type in our series (44.4%).

CONCLUSION: The frequency of HNPCC was 2.6% in our series of patients. The main features are an excess of early onset with a propensity to involve the proximal colon, and high frequency of multiple foci. Management and surveillance for these patients should be different from sporadic CRC. Contrary to American and European reports, gastric cancer seems more frequent than endometrial cancer in Chinese. It is necessary to formulate a new HNPCC criterion for Chinese patients.

Pathogenesis and clinical management of hereditary non-polyposis colorectal cancer

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is an inherited genetic condition associated with microsatellite instability; it accounts for around 5 per cent of all cases of colorectal cancer. This review examines recent data on management strategies for this condition.

METHODS

A Medline-based literature search was performed using the keywords 'HNPCC' and 'microsatellite instability'. Additional original papers were obtained from citations in articles identified by the initial search.

RESULTS AND CONCLUSION

The Amsterdam criteria identify patients in whom the presence of an inherited mutation should be investigated. Those with a mutation should be offered counselling and screening. The role of prophylactic surgery has been superseded by regular colonoscopy, which dramatically reduces the risk of colorectal cancer. Screening for extracolonic malignancy is also advocated, but the benefits are uncertain. Chemoprevention may be of value in lowering the incidence of bowel cancer in affected patients, but further studies are required.

A population-based study of the extent of surgical resection of potentially curable colon cancer

BACKGROUND

We attempted to determine factors contributing to the extent of initial curative resection for colon cancer in a population-based cohort. Total abdominal colectomy with ileorectal anastomosis (TAC-IR) may be considered for young patients or those with a colorectal cancer family history to prevent metachronous lesions and facilitate surveillance.

METHODS

All Ontario patients newly diagnosed with colon cancer over 12 months beginning in July 1997 were staged at the time of surgery. The extent of resection was compared with variables, including familial risk obtained from the Ontario Familial Colon Cancer Registry.

RESULTS

Complete staging was possible for 86% of patients. A total of 1223 patients had a potentially curative resection: 17%, 46%, and 36% were stage I, II, and III, respectively. Patients were more likely to receive a TAC-IR if they were < or = 50 years old (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.8-6.6), if they had a synchronous lesion (OR, 28.37; 95% CI, 12.2-61.2), or if they were at a teaching hospital (OR, 2.8; 95% CI, 1.6-4.7), but not if they had a family history (OR,.7; 95% CI,.3- 1.5).

CONCLUSIONS

Young age, teaching hospital, and multiple cancers but not family history were important factors for performing a TAC-IR.

Use of microsatellite analysis in young patients with colorectal cancer to identify those with hereditary nonpolyposis colorectal cancer

BACKGROUND AND OBJECTIVES

The frequency of microsatellite instability (MSI) in young patients with colorectal cancer was evaluated, including reexamination of the medical and family history of each patient, and interviews with the patients to determine any possible new occurrence of hereditary nonpolyposis colorectal cancer (HNPCC) in the patients themselves or their family members.

METHODS

Fifty-three young patients (younger than 40 years of age) with colorectal cancer were selected and investigated. DNA was extracted from paraffin sections and microsatellite analysis was performed.

RESULTS

The frequency of MSI among the young patients with colorectal cancer was 50.9%, which was significantly higher than the rate of 12-21% noted in older patients with colorectal cancer (P < 0.001). For the 24 young patients with colorectal cancer who did not have MSI, only one case of HNPCC kindred and two cases with a family history of cancer were identified. In contrast, among the 20 young patients with colorectal cancer who had MSI, five cases of HNPCC kindred, two cases with metachronous patients with colorectal cancer, and three cases with a family history of cancer were identified.

CONCLUSION

Our results suggest that a defect in the DNA mismatch repair system may play some role in carcinogenesis in young patients with colorectal cancer. Microsatellite analysis and subsequent interviews regarding medical and family history are useful tools for efficiently identifying possible cases of HNPCC among young patients with colorectal cancer.

Colorectal adenocarcinoma in patients under 45 years of age: comparison with older patients in a well-defined French population

PURPOSE

Little is known about colorectal cancer in young patients at a population level, and the behavior, characteristics, and prognosis of such tumors continue to be debated.

METHODS

A population-based series of 4,643 new cases of colorectal adenocarcinomas diagnosed between 1976 and 1996 in C te d'Or, France, was used to describe time trends in incidence, predisposing conditions, location, stage, and treatment and to evaluate the prognosis of such tumors in patients under 45 years of age (n = 146). Prognosis was determined using relative survival rates and predictive factors using a multivariate relative survival model.

RESULTS

Before the age of 45 years, age-standardized incidence rates were 1.9 per 100,000 in males and 1.4 per 100,000 in females. Incidence rates almost doubled from 1976 to 1982 and from 1983 to 1989 in both genders and stabilized thereafter. The frequency of predisposing conditions was significantly higher before the age of 45 years (11.7 vs. 0.4 percent; P < 0.001). TNM Stage III tumors were more frequent in younger patients, and Stage II tumors were more frequent in older patients. The postoperative mortality rate was lower in the 0-to-44 age group, 2.1 percent, compared with 8.4 percent for the 45-and-over age group (P = 0.004). Five-year relative survival rates were 51.9, 49.2, and 41.4 percent, respectively. In both overall and stage-for-stage comparisons, patients before the age of 45 years had a better survival rate than older patients. Gender and stage at diagnosis were the only independent prognostic factors of survival for young patients.

CONCLUSIONS

This study confirms the high frequency of predisposing conditions in young patients and that young age is not a poor prognostic factor for colorectal cancer. This underlines the importance of family screening, aggressive surveillance, and treatment in the young with known predisposing conditions.

Limitations of family cancer history assessment at initial surgical consultation

PURPOSE

Although important for the diagnosis of familial clustering of colorectal cancer and hereditary nonpolyposis colorectal cancer, the accuracy of familial cancer history assessment in the office setting has been questioned. Furthermore, there are few publications describing the optimal method for accurately capturing a family cancer history. The purpose of this study was to determine how well family cancer history is assessed in patients with early age-of-onset colorectal cancer at initial surgical consultation compared with a telephone interview and mailed questionnaire.

METHODS

Medical records of patients 40 years old or younger at the time of colorectal cancer surgery were reviewed for documentation of family cancer history at initial surgical consultation. In addition, family cancer history was solicited from surviving patients or their next of kin by telephone and a mailed questionnaire. The kappa coefficient was used to measure degree of correlation between family cancer history obtained at initial surgical consultation and subsequent telephone interview and questionnaire.

RESULTS

One hundred twenty-five patients were available for analysis. Family cancer history was documented on the initial surgical consultation report in 78 percent of cases. Although 31.2 percent were identified as having no family cancer history at initial surgical consultation, this proportion decreased to 13.5 percent after telephone interviews and questionnaires. Family history assessment at initial surgical consultation also failed to identify 7 of 11 individuals meeting Amsterdam criteria for hereditary nonpolyposis colorectal cancer and 10 of 16 individuals meeting modified clinical criteria for hereditary nonpolyposis colorectal cancer.

CONCLUSIONS

Although family cancer history was commonly obtained during the initial surgical consultation of patients with colorectal cancer, there was a tendency to underestimate the extent of familial cancer. A telephone interview and questionnaire conducted at a later date may reveal a more comprehensive family cancer history. This is an important observation, because individuals identified as high-risk for hereditary nonpolyposis colorectal cancer or familial clustering of colorectal cancer require special consideration with respect to screening, surveillance, and surgical management.