Evolving treatment strategies for colorectal cancer: A critical review of current therapeutic options

Management of rectal cancer has markedly evolved over the last two decades.New technologies of staging have allowed a more precise definition of tumor extension.Refinements in surgical concepts and techniques have resulted in higher rates of sphincter preservation and better functional outcome for patients with this malignancy.Although,preoperative chemoradiotherapy followed by total mesorectal excision has become the standard of care for locally advanced tumors,many controversial matters in management of rectal cancer still need to be defined.These include the feasibility of a non-surgical approach after a favorable response to neoadjuvant therapy,the ideal margins of surgical resection for sphincter preservation and the adequacy of minimally invasive techniques of tumor resection.In this article,after an extensive search in PubMed and Embase databases,we critically review the current strategies and the most debatable matters in treatment of rectal cancer.

pRB expression in esophageal mucosa of individuals at high risk for squamous cell carcinoma of the esophagus

AIM: To investigate the pRb expression in a large group of patients with history of chronic exposure to the main risk factors for development of squamous cell carcinoma of the esophagus. METHODS: One hundred and seventy asymptomatic individuals at high risk for esophageal squamous cell carcinoma (consumption of more than 80 g of ethanol and 10 cigarettes/d for at least 10 years) underwent upper gastrointestinal endoscopy with biopsies of the esophageal mucosa. As a control group, specimens of esophageal mucosa obtained from 20 healthy subjects were also studied. Immunohistochemical assessment of the tissues was performed using a monoclonal antibody anti-pRB protein. RESULTS: Absence of the pRB staining, indicating loss of RB function, was observed in 33 (19.4%) of the individuals at risk for esophageal cancer, but in none of the healthy controls (P < 0.02). Loss of pRb expression increased in a stepwise fashion according to the severity of the histological findings (P < 0.005): normal mucosa (11/97 or 11.3%), chronic esophagitis (17/60 or 28.3%), low-grade dysplasia (3/10 or 30%), high-grade dysplasia 1/2 or 50%) and squamous cell carcinoma (1/1 or 100%). CONCLUSION: Our findings suggest that abnormal expression of the pRB protein may be implicated in the process of esophageal carcinogenesis. Additional studies are warranted to define the role of the pRBprotein as a biomarker for development of esophageal squamous cell carcinoma in individuals at high risk for this malignancy.

Identification of patients at-risk for Lynch syndrome in a hospital-based colorectal surgery clinic

AIM:To determine the prevalence of a family history suggestive of Lynch syndrome (LS) among patients with colorectal cancer (CRC) followed in a coloproctology outpatient clinic in Southern Brazil.METHODS:A consecutive sample of patients with CRC were interviewed regarding personal and family histories of cancer.Clinical data and pathology features of the tumor were obtained from chart review.RESULTS:Of the 212 CRC patients recruited,61 (29%) reported a family history of CRC,45 (21.2%) were diagnosed under age 50 years and 11 (5.2%) had more than one primary CRC.Family histories consistent with Amsterdam and revised Bethesda criteria for LS were identified in 22 (10.4%) and 100 (47.2%) patients,respectively.Twenty percent of the colorectal tumors had features of the high microsatellite instability phenotype,which was associated with younger age at CRC diagnosis and with Bethesda criteria (P < 0.001).Only 5.3% of the patients above age 50 years had been previously submitted for CRC screening and only 4% of patients with suspected LS were referred for genetic risk assessment.CONCLUSION:A significant proportion of patients with CRC were at high risk for LS.Education and training of health care professionals are essential to ensure proper management.

Lack of correlation between p53 codon 72 polymorphism and anal cancer risk

AIM:To investigate the potential role of p53 codon 72 polymorphism as a risk factor for development of anal cancer. METHODS:Thirty-two patients with invasive anal carcinoma and 103 healthy blood donors were included in the study.p53 codon 72 polymorphism was analyzed in blood samples through polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. RESULTS:The relative frequency of each allele was 0.60 for Arg and 0.40 for Pro in patients with anal cancer, and 0.61 for Arg and 0.39 for Pro in normal controls. No significant differences in distribution of the codon 72 genotypes between patients and controls were found. CONCLUSION:These results do not support a role for the p53 codon 72 polymorphism in anal carcinogenesis.