Adenocarcinoma ; genetics ; pathology ; Adenoma ; genetics ; pathology ; Colonic Polyps ; genetics ; pathology ; Colorectal Neoplasms ; genetics ; pathology ; Humans ; Microsatellite Instability ; Mutation ; Precancerous Conditions ; genetics ; pathology ; Proto-Oncogene Proteins B-raf ; genetics

OBJECTIVETo analyze the mutational features of adenomatous polyposis coli (APC) gene and to explore the effect of mismatch repair (MMR) deficiency on its mutations in hereditary non-polyposis colorectal cancers (HNPCC).

METHODSPCR-based in vitro synthesized protein test (IVSP) assay and sequencing analysis were used to confirm somatic mutations of whole APC gene in 19 HNPCC patients.

RESULTSEleven cases with thirteen mutations were determined. The frequency of APC mutation was 58%(11/19). The exhibiting mutations consisted of 9 frameshift mutations and 4 nonsense ones, indicating the existence of more frameshift mutations (69%). All of frameshift mutations were deletion or insertion of 1-2 bp and most of them (7/9) happened at simple nucleotide repeat sequences, particularly within (A) n tracts (5/9). All of four nonsense mutations resulted from C to T transitions at CpG sites.

CONCLUSIONMutational inactivations of APC gene were detected in more than half of HNPCC patients in this study, indicating that APC mutation is a common molecular event in the tumorigenesis of HNPCC. According to the location of frameshift mutations at simple nucleotide repeat sequences and point mutations at CpG sites, it was suggested that endogenous mechanisms like MMR deficiency might exert an effect on the nature of APC mutations in most HNPCC.

Adenomatous Polyposis Coli ; genetics ; Adenomatous Polyposis Coli Protein ; genetics ; metabolism ; Carcinoma ; genetics ; Colorectal Neoplasms ; genetics ; pathology ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; Genes, APC ; physiology ; Humans

Elderly patients with colorectal cancer have different clincopathological characteristics from younger patients. Colorectal cancers tend to localize in the proximal colon, from cecum to the splenic flexure in the elderly patients. Changes in the stools, rectal bleeding or black stool, abdominal pain, fatigue, weight loss and anemia are the common symptoms. Analysis showed that age is one of independent risk factors for lower completion rates of colonoscopy. Therefore, the choice of diagnosis methods in elderly patients should be careful. Achieving a clear diagnosis and avoiding complications should be considered at the same time. Most colorectal cancers in elderly are highly and moderately differentiated adenocarcinomas and locally advanced, and have less lymphatic and blood metastasis. The proportion of poorly differentiated adenocarcinoma increases with the increase of age, which should be concerned. Multiple colorectal cancers and colorectal cancer with extra-colorectal malignancy are not rare in the elderly patients. The common extra-colorectal tumors consist of gastric cancer, lung cancer, biliary carcinoma, pancreas cancer and malignancy from blood system. Molecular events, such as mutations of KARS, BRAF, TP53 and deficiency of DNA mismatch repair, are more frequent in elderly colorectal cancer patients. Many factors have impact on treatment decision in elderly patients with colorectal cancer, including age, comorbidities, physiological functions of organs and willingness of patients and their relatives. Although surgery is still the main treatment, the proportion of radical surgery is lower and emergency surgery is higher as compared to younger patients. With the development of minimally invasive surgical techniques and advances in anesthesia and perioperative management, laparoscopic surgery has become widespread in elderly patients with colorectal cancer. In addition, more attention should be paid to adjuvant therapy. Comprehensive individualized treatment plan should be taken to improve outcomes.
Adenocarcinoma ; pathology ; Aged ; Colonoscopy ; Colorectal Neoplasms ; diagnosis ; genetics ; pathology ; surgery ; Humans ; Laparoscopy ; Mutation ; Risk Factors

Objective: To investigate the clinicopathological features, immunophenotype, and genetic alterations of rectal adenocarcinoma with enteroblastic differentiation. Methods: Four cases of rectal adenocarcinoma with enteroblastic differentiation were collected at the Affiliated Hospital of Qingdao University, Qingdao, China (three cases) and Yantai Yeda Hospital of Shandong Province, China (one case) from January to December 2022. Their clinical features were summarized. Hematoxylin and eosin stain and immunohistochemical stain were performed, while next-generation sequencing was performed to reveal the genetic alterations of these cases. Results: All four patients were male with a median age of 65.5 years. The clinical manifestations were changes of stool characteristics, bloody stools and weight loss. All cases showed mixed morphology composed of conventional adenocarcinoma and adenocarcinoma with enteroblastic differentiation. Most of the tumors consisted of glands with tubular and cribriform features. In one case, almost all tumor cells were arranged in papillary structures. The tumor cells with enteroblastic differentiation were columnar, with relatively distinct cell boundaries and characteristic abundant clear cytoplasm, forming fetal gut-like glands. Immunohistochemically, the tumor cells were positive for SALL4 (4/4), Glypican-3 (3/4) and AFP (1/4, focally positive), while p53 stain showed mutated type in 2 cases. The next-generation sequencing revealed that 2 cases had TP53 gene mutation and 1 case had KRAS gene mutation. Conclusions: Rectal adenocarcinoma with enteroblastic differentiation is rare. It shows embryonal differentiation in morphology and immunohistochemistry, and should be distinguished from conventional colorectal adenocarcinoma.
Humans ; Male ; Aged ; Female ; Biomarkers, Tumor/metabolism* ; Adenocarcinoma/pathology* ; Colorectal Neoplasms ; Rectal Neoplasms/genetics* ; Cell Differentiation

CD44 is a cell adhesion molecule with numerous isoforms created by mRNA alternative splicing. Expression of CD44 variants has been suggested to play a potential role in tumor progression and metastasis. We designed primers CD44V, CD44V6/7, CD44R1 and CD44V6-10 to analyze and compare the roles of each CD44 variants. Expressions of CD44 variants were investigated in normal colonic mucosa, the lymph nodes which was histopathologically free of cancer cell, and cancer tissues of 44 human colorectal cancer patients by RT-PCR method. The expression of CD44V was observed in 28 out of 39 (71.8%) tumors and 7 out of 11 (63.6%) N1 normal regional lymph nodes, and CD44V6/7 was observed in 28 out of 39 (71.8%) tumors and 9 out of 11 (81.8%) N1 normal regional lymph nodes. The expressions of CD44V and CD44V6/7 were most frequently observed compared with any other CD44 variants. In normal colonic mucosa, the expression of CD44 variants are low but in cancer tissue and its regional lymph node, the expression of CD44V and CD44V6/7 were significantly higher and more frequent than any other CD44 variants (p<0.05). These results suggest that CD44V and CD44V6/7 can be a molecular marker for colorectal cancer and its micrometastasis to the regional normal lymph node.
Alternative Splicing ; Antigens, CD44/genetics* ; Colorectal Neoplasms/pathology ; Colorectal Neoplasms/immunology* ; Gene Expression ; Human ; Lymph Nodes/pathology ; Lymph Nodes/immunology* ; Protein Isoforms/genetics

We analyzed the expression of p21, bcl2, and p53 in normal and different pathologic mucosa of the human colorectum using immunohistochemistry and cold polymerase chain reaction-single strand conformation polymorphism. The topography of normal mucosa showed; bcl2 and p53 expression restricted to basal epithelial cells and p21 expressed only in superficial epithelial cells. This topographic expression was altered in hyperplastic polyps and adenomas. Hyperplastic polyps revealed absence of or weak bcl2 expression and strong p21 expression without topography. In adenomas, whereas bcl2 expression increased and extended to parabasal and superficial dysplastic epithelium, the increase of p21 expression was limited to surface dysplastic epithelium. p53 was weakly expressed throughout the full thickness of dysplastic epithelium. Bcl2 expression in adenomas was stronger than in carcinomas; p53 expression was converse and p21 expression was variable. In carcinomas, this topographic expression was largely abrogated but p53 mutation (36%) was more frequent than in adenomas (2%). In carcinomas, p21 and p53 expression correlated inversely, but there was no relationship with bcl2. These results suggest that there is precisely ordered topographic pattern of p21, bcl2, and wild p53 expression in normal colorectal cells, but this becomes disordered during the early stage of colorectal carcinogenesis.
Colorectal Neoplasms/physiopathology ; Colorectal Neoplasms/pathology ; Colorectal Neoplasms/metabolism* ; Colorectal Neoplasms/genetics ; Cyclins/biosynthesis* ; Human ; Mutagenesis ; Protein p53/genetics ; Protein p53/biosynthesis* ; Proto-Oncogene Proteins c-bcl-2/biosynthesis* ; Time Factors

OBJECTIVETo analyze the relationship of K-ras mutation with the development of liver metastasis in colorectal cancer patients and the survival outcomes.

METHODSFrom 2003 to 2008, 300 patients who underwent colorectal cancer surgery in the Department of General Surgery of Zhongshan Hospital, Fudan University were assigned to different groups, according to the diagnosis and follow-up results. The mutation of exon 2 of K-ras was detected in primary paraffin-embedded lesions by PCR and Pyrosequencing. The association of gene mutation with the development of liver metastasis and its prognosis was studied.

RESULTSAmong 300 cases, the mutations of exon 2 were present in 120 cases(40%). The G13D mutation was more common in metachronous metastasis group than that in synchronous group(17.0% vs. 8.0%, P=0.041). Multivariable regression analysis showed that G13D mutation was an independent risk factor(HR=1.108, 95%CI:1.032-5.062, P=0.048) for metachronous metastasis. Patients with mutated K-ras had a poorer overall survival compared to those without mutated K-ras for patients without liver metastasis(median overall, 65 vs. 72 months, P=0.039), and for patients who received metastasis resection(median disease-free survival 18 vs. 24 months, P=0.048). Multivariable analysis showed that K-ras mutation was an independent risk factors of overall survival(HR=1.561, 95%CI:1.022-6.422, P=0.045) in patients without liver metastasis.

CONCLUSIONDetection of K-ras mutation may predict the development of liver metastasis and prognosis.

Aged ; Colorectal Neoplasms ; genetics ; pathology ; Female ; Genes, ras ; genetics ; Humans ; Liver Neoplasms ; genetics ; secondary ; Male ; Mutation ; Prognosis

Adenocarcinoma ; genetics ; pathology ; Adenoma ; genetics ; pathology ; Cell Cycle Proteins ; biosynthesis ; genetics ; Colorectal Neoplasms ; genetics ; pathology ; Disease Progression ; Humans ; Intracellular Signaling Peptides and Proteins ; Lymph Nodes ; pathology ; Lymphatic Metastasis

INTRODUCTIONSporadic colorectal cancers with BRAF mutations constitute two distinct subgroups of colorectal cancers. Recent studies have linked the presence of the BRAF mutation to a familial inheritance pattern. This was a proof-of-concept study that aimed to examine: (a) the extent of field change in sporadic colorectal cancers with BRAF mutation; and (b) the extent of resection margins required and the pattern of DNA mismatch repair protein loss in these tumours.

METHODSEight microsatellite instability-high tumours with positive BRAF mutation from an existing histopathological database were selected for BRAF mutation and mismatch repair protein analysis.

RESULTSAll the resection margins were negative for BRAF mutation. Three tumours had loss of MLH1 and PMS2 expressions, and five tumours had no protein loss. Six peritumoral tissues were negative and one was positive for BRAF mutation.

CONCLUSIONThe results suggest that any early field change effect is restricted to the immediate vicinity of the tumour and is not a pan-colonic phenomenon. Current guidelines on resection margins are adequate for BRAF mutation-positive colorectal cancers. Any suggestion of a hereditary link to these tumours is likely not related to germline BRAF gene mutations. The pattern of protein loss reinforces previous findings for the two subgroups of BRAF mutation-positive colorectal cancers.

Colorectal Neoplasms ; genetics ; pathology ; Female ; Humans ; Male ; Microsatellite Instability ; Mutation ; Neoplasm Metastasis ; Peritoneal Neoplasms ; pathology ; secondary ; Proto-Oncogene Proteins B-raf ; genetics ; Stomach Neoplasms ; pathology ; secondary

Understanding of the mechanism of colorectal carcinogenesis has been gaining momentum for some years on account of its high incidence and impact on the lives of individuals affected. Different genetic abnormalities have been found in colorectal cancers from different sites. For example, proximal colon cancer is usually related to the nucleotide instability pathway, as microsatellite instability (MSI). However, distal colon cancer is usually associated with specific chromosomal instability (CIN). The development of cancer at the rectum, though similar to that at the colon, displays its own unique features. These differences might be partially attributed to different embryological development and physiological circumstances. Environmental factors such as diet and alcohol intake also differ in their role in the development of tumors in the three segments, proximal colon, distal colon, and rectum. "Proximal shift" of colon cancer has been known for some time, and survival rates of colorectal cancer are higher when rectal cancers are excluded, both of which emphasize the three different segments of colorectal cancer and their different properties. Meanwhile, colonic and rectal cancers are distinctive therapeutic entities. The concept of three entities of colorectal cancer may be important in designing clinical trails or therapeutic strategies. However, the dispute about the inconsistency of data concerning the site-specific mechanism of colorectal carcinoma does exist, and more evidence about molecular events of carcinogenesis and targeted therapy needs to be collected to definitely confirm the conception.
Animals ; Colorectal Neoplasms ; classification ; genetics ; metabolism ; pathology ; Humans ; Neoplasm Staging ; Prognosis ; Risk Factors