Discordant DNA mismatch repair protein status between synchronous or metachronous gastrointestinal carcinomas: frequency, patterns, and molecular etiologies

This study aims at examining the frequency, patterns and molecular etiologies of such inter-tumoral MMR discordances. We analyzed a cohort of 2159 colorectal cancer (CRC) patients collected over a 5-year period and found that 1.3% of the patients (27/2159) had  ≥ 2 primary CRCs, and 25.9% of the patients with ≥ 2 primary CRCs (7/27) exhibited inter-tumoral MMR discordance. We then combined the seven MMR-discordant CRC patients with three additional MMR-discordant GIT carcinoma patients and evaluated their discordant patterns and associated mol ecular abnormalities. The 10 patients consisted of 3 patients with Lynch syndrome (LS), 1 with polymerase proofreading-associated polyposis (PAPP), 1 with familial adenomatous polyposis (FAP), and 5 deemed to have no cancer disposing hereditary syndromes. Their MMR discordances were associated with the following etiologies: (1) PMS2-LS manifesting PMS2-deficient cancer at an old age when a co-incidental sporadic MMR-proficient cancer also occurred; (2) microsatellite instability-driven secondary somaticMSH6-inactivation occurring in only one —and not all—PMS2-LS associated MMR-deficient carcinomas; (3) “compound LS” with germline mutations in two MMR genes manifesting different tumors with deficiencies in different MMR proteins; (4) PAPP or FAP syndrome-associated MMR-proficient cancer co-occurring metachronously with a somatic MMR-deficient cancer; and (5) non-syndromic patients...
Source: Familial Cancer - Category: Cancer & Oncology Source Type: research

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It has been>15 years since universal microsatellite instability (MSI) or mismatch repair (MMR) testing has been recommend for all cases of colorectal carcinoma.1 MSI/MMR testing is a proven prognostic marker and can help identify patients with possible hereditary cancers (Lynch syndrome).2,3 More recently, checkpoint inhibition therapy has been found to be effective in tumors that demonstrate MSI, making MSI/MMR testing a pan-cancer therapeutic biomarker.4 Given its importance, multiple organizations, including the American Society of Clinical Oncology, Association for Molecular Pathology, College of American Pathologis...
Source: Gastroenterology - Category: Gastroenterology Authors: Tags: Editorial Source Type: research
c Samuel Aguiar Junior Edenir Inez Palmero José Cláudio Casali-da-Rocha Dirce Maria Carraro Giovana Tardin Torrezan Lynch syndrome (LS) is a hereditary cancer-predisposing syndrome associated most frequently with epithelial tumors, particularly colorectal (CRC) and endometrial carcinomas (EC). The aim of this study was to investigate the relationship between sarcomas and LS by performing clinical and molecular characterization of patients presenting co-occurrence of sarcomas and tumors from the LS spectrum. We identified 27 patients diagnosed with CRC, EC, and other LS-associated tumors who had ...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Article Source Type: research
Lynch syndrome (LS) is an autosomal dominant disease caused by a germline mutation in DNA mismatch repair genes which increases the risk of several cancers such as endometrial and colorectal cancers. However, there are only a few reports of peritoneal malignancies in patients with LS. Herein, we report the first case of a primary peritoneal low-grade serous carcinoma in a woman with LS and provide a literature review of peritoneal malignancies in patients with LS. The patient was a 72-yr-old gravid 2 para 2 Japanese woman with a germline mutation in MLH1. She had a history of colon cancer and endometrial cancer and was tre...
Source: International Journal of Gynecological Pathology - Category: Pathology Tags: PATHOLOGY OF THE UPPER TRACT: CASE REPORTS Source Type: research
In conclusion, somatic mutational signatures suggest that conventional MMR status of tumor tissues is likely to underestimate the significance of the predisposing MMR defects as contributors to breast tumorigenesis in LS. PMID: 32292574 [PubMed]
Source: Oncotarget - Category: Cancer & Oncology Tags: Oncotarget Source Type: research
Mismatch repair deficiency (MMRD) is involved in the initiation of both hereditary and sporadic tumors. MMRD has been extensively studied in colorectal cancer and endometrial cancer, but not so in other tumors, such as ovarian carcinoma. We have determined the expression of mismatch repair proteins in a large cohort of 502 early-stage epithelial ovarian carcinoma entailing all the 5 main subtypes: high-grade serous carcinoma, endometrioid ovarian carcinoma (EOC), clear cell carcinoma (CCC), mucinous carcinoma, and low-grade serous carcinoma. We studied the association of MMRD with clinicopathologic and immunohistochemical ...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research
We present a 47-year-old woman with an MLH1 gene mutation (G133X 397G>T) who presented with menorrhagia. Eleven family members have this mutation, 6 with carcinoma: 5 colorectal and 1 with a gynecologic primary of unknown type. Colonoscopy and endoscopy were unremarkable. Positron emission and computed tomography revealed a 3 cm anterior dome bladder mass without additional extrauterine disease or uterine connection. She underwent partial cystectomy, laparoscopic hysterectomy, bilateral salpingo-oophorectomy, and lymphadenectomy. The uterus demonstrated a dedifferentiated endometrioid adenocarcinoma, immunohistochemical...
Source: Applied Immunohistochemistry and Molecular Morphology - Category: Chemistry Tags: Online Articles: Case Reports Source Type: research
Muir-Torre syndrome is a rare subtype of Lynch syndrome characterized by coincidence of skin neoplasm and visceral malignancies. Here, we report a case of this rare disease, whose diagnosis of the syndrome was first suspected by the pathologist. This was a 60-yr-old woman who presented with an axillary skin nodule, which was diagnosed as basal cell carcinoma. Further inquiry revealed that she was hospitalized for evaluation of a recurrent vaginal stump endometrial carcinoma. Histologic workup and immunohistochemistry for mismatch repair proteins of both the skin and vaginal tumor suggested the possibility of Muir-Torre syn...
Source: International Journal of Gynecological Pathology - Category: Pathology Tags: Pathology of the Corpus: Case Reports Source Type: research
io PR Abstract It is paramount to identify patients whose cancer is associated with genetic susceptibility to the disease, since their long-term management depends on it. Anatomical and molecular pathologists play a key role in the process. Indeed, their diagnosis supports or even sometimes warrants germline genetic testing. For example, a colorectal cancer with mismatch repair protein expression loss suggests Lynch syndrome, while a rare type of renal cell carcinoma with fumarate hydrate expression loss is highly evocative of hereditary leiomyomatosis and renal cell carcinoma syndrome. Similarly, the presence of ...
Source: Annales de Pathologie - Category: Pathology Authors: Tags: Ann Pathol Source Type: research
An estimated 130,000 individuals are diagnosed with colorectal carcinoma each year, and approximately 50,000 will die from this disease, making colorectal carcinoma the third leading cause of cancer deaths in the United States.1 Heritable forms of colorectal carcinoma are common. These heritable conditions may manifest as a polyposis or as colorectal carcinoma. In this review, the pathology of hamartomatous polyps will be discussed with particular emphasis on clues that should alert pathologists to the possibility of a polyposis syndrome.
Source: Diagnostic Histopathology - Category: Pathology Authors: Tags: Mini-symposium: Gastrointestinal/Hepato-Pancreato-Biliary Pathology Source Type: research
Conclusions: Our results suggest that transcriptional patterns are indicative for TMM pathway activation with subtle differences between TEL and ALT mechanisms in a CRC subtype-specific fashion. Sequencing data potentially provide a suited measure to study alterations of telomere length and of underlying transcriptional regulation. Further studies are needed to improve this method.
Source: Frontiers in Oncology - Category: Cancer & Oncology Source Type: research
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