1
|
Prognostic Value and Immunohistochemical Analysis of Mismatch Repair Deficiency in Patients with Stage II and III Colorectal Carcinoma-A Single-Center Study. ACTA ACUST UNITED AC 2020; 56:medicina56120676. [PMID: 33302424 PMCID: PMC7762610 DOI: 10.3390/medicina56120676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/01/2020] [Accepted: 12/04/2020] [Indexed: 12/24/2022]
Abstract
Background and objectives: Deficient mismatch repair (MMR) status is associated with good prognosis but poor therapeutic response to adjuvant chemotherapy in patients with colorectal cancer. However, there are some opposed arguments considering therapeutic outcomes in patients with evidenced MMR deficiency in colorectal cancer. The aim of the study was the investigation of prognostic value and immunohistochemical analysis of the MMR-deficiency tumors. Materials and Methods: The study enrolled 104 patients with resected stage II and III colorectal cancer samples from the period 2018–2019. Results: The tumors with deficient MMR status were significantly associated with age up to 50 years and right-sided localization (p < 0.001). During the follow-up period of 22.43 ± 6.66 months, 21 patients (20.2%) died, whereas 14 patients (13.5%) had relapses. The loss of mutL homologue 1/postmeiotic segregation increased 2 (MLH1/PMS2) expression, compared to proficient MMR tumors, was associated with shorter disease-free survival in patients with lymphovascular invasion (p < 0.05), perineural invasion (p < 0.01), stage III (p < 0.05) and high-grade tumor (p < 0.05). Conclusions: This retrospective pilot study of a single-center cohort of patients with stage II and III colorectal cancer highlights the clinical importance of using immunohistochemistry (IHC) analysis as a guide for diagnostic algorithm in a country with limited resources, but with a high prevalence of colorectal carcinoma in the young patients. MMR-deficiency tumors compared with proficient MMR colorectal cancer was not shown to be a significant predictor of disease-free and overall survival.
Collapse
|
2
|
Worldwide variation in lynch syndrome screening: case for universal screening in low colorectal cancer prevalence areas. Fam Cancer 2020; 20:145-156. [PMID: 32914371 DOI: 10.1007/s10689-020-00206-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/01/2020] [Indexed: 02/07/2023]
Abstract
To perform a systematic assessment of universal Lynch syndrome (LS) screening yield in colorectal cancer (CRC) patients around the world. Universal screening for LS is recommended in all CRC patients. However, the variation in yield of LS screening in the setting of significant global variation in CRC prevalence is unknown. A systematic review of articles in the MEDLINE database was performed to identify studies performing universal screening for LS. All cases with microsatellite instability (MSI-H) or missing one or more proteins on immunohistochemistry (IHC) were considered screening positive. The overall pooled yield of universal LS screening in 97 study arms from 89 identified studies was 11.9% (5649/47545) and the overall pooled percentage of confirmed LS patients was 1.8% (682/37220). LS screening positivity varied significantly based on geographic region (Kruskal Wallis test, p < 0.001) and reported 5-year CRC prevalence in the country (Fisher's exact, p < 0.001). Significant inverse correlation was found between LS screening positivity and 5-year CRC prevalence (Pearson correlation, r = - 0.56, p < 0.001). The overall yield of LS screening was 15.00% (382/2553) and rate of confirmed LS was 7.7% (113/1475) in LS screening done in patients ≤ 50 years (16 studies). There is significant geographic variation in LS screening positivity with higher yield in countries with lower prevalence of CRC. Our results highlight the importance of universal LS screening in younger patients and low CRC prevalence countries.
Collapse
|
3
|
Soliman NA, Morsia DF, Helmy NAH. Immunohistochemical Expression of MMR Proteins with Clinicopathological Correlation in Colorectal Cancer in Egypt. Open Access Maced J Med Sci 2019; 7:1608-1617. [PMID: 31210809 PMCID: PMC6560288 DOI: 10.3889/oamjms.2019.357] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Microsatellite instability (MSI) is the genetic pathway underlying 15% of sporadic colorectal carcinoma (CRC) and hereditary non-polyposis CRC. MSI-H CRC has a distinct clinicopathological characteristic including excess mucin and signet ring component, proximal colon, Crohn's like reaction, lymphocytic infiltration, and better survival. AIM This research aims to screen Egyptian CRC patients for MSI status by IHC testing of expression of the MMR proteins in correlation to its clinicopathological features. MATERIAL AND METHODS Immunohistochemistry study for mismatch repair proteins (MMR) was done on 115 cases of CRC. Their expressions were assessed and correlated to clinicopathological parameters in an attempt to obtain the most significant predictors of MSI. RESULTS MSI (low and high) represents 67% of the study cases. The most frequent expression pattern was combined loss of MLH, and PMS2 (38% of MSI) followed by a combined loss of MSH2, and MSH6 (29% of MSI). There was significant correlation of expression pattern of MMR proteins with the laterality, lymphovascular emboli, perineural invasion, grade, T stage, N stage, signet ring component, tumor infiltrating lymphocyte, and peritumoral lesion (0.014, 0.035, 0.012, 0.033, 0.013, 0.000, 0.041, 0.012, and 0.009 respectively). Proximal location (right sided) and lower grade, higher nodal stage, and marked TIL were selected as predictors of MS-H CRC (0.005, 0.031, 0.025, and 0.000 respectively). CONCLUSION All clinicopathological and histological parameters should be assessed in CRC for the sake of predicting MSI. The optimal approach to MSI evaluation is (IHC) assessment of MMR proteins.
Collapse
Affiliation(s)
- Nahed A. Soliman
- Department of Pathology, Faculty of Medicine, Helwan University, Helwan 11795, Egypt
- Department of Pathology, Faculty of Medicine, University of Mansoura, Mansoura 35516, Egypt
| | - Deaa Fekri Morsia
- Department of Pathology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | | |
Collapse
|
4
|
Tan WJ, Hamzah JL, Acharyya S, Foo FJ, Lim KH, Tan IBH, Tang CL, Chew MH. Evaluation of Long-Term Outcomes of Microsatellite Instability Status in an Asian Cohort of Sporadic Colorectal Cancers. J Gastrointest Cancer 2018; 49:311-318. [PMID: 28550452 DOI: 10.1007/s12029-017-9953-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE Microsatellite instability in colorectal cancer (CRC) and its long-term outcomes remains poorly studied in Asians. We investigate the prognostic significance of microsatellite instability in an Asian population and assess its clinical impact in patients who undergo adjuvant chemotherapy. METHODS Six hundred fifty-four consecutive CRC patients who underwent surgical resection between January 2010 and December 2012 were recruited. Survival was estimated using the Kaplan-Meier approach. Univariate Cox proportional hazard models were used to estimate the hazard ratios for variables associated with survival. A subgroup analyses was performed for stage III patients who underwent chemotherapy to evaluate the prognostic significance of microsatellite instability in this group. RESULTS Five hundred ninety-one (90.4%) patients were microsatellite stable (MSS) while 63 (9.6%) were microsatellite instable (MSI). Three years recurrence-free survival (RFS) and disease-specific survival (DSS) were 83.7 versus 73.7% (p = 0.295) and 87.1 versus 91.2% (p = 0.307) in MSS and MSI tumors, respectively. Among stage III patients who received adjuvant therapy, MSI status was found to be an adverse prognostic factor for RFS (HR 2.74 (95% CI 1.43-5.26), p = 0.002). This remained significant on multivariate analysis (HR 2.38 (95% CI 1.15-4.93), p = 0.018). Adjuvant chemotherapy was associated with survival benefit for patients with MSS tumors (HR 0.35, 95% CI 0.17-0.69, p = 0.002) but not MSI tumors (HR 0.67, 95% CI 0.08-8.15, p = 0.750). CONCLUSIONS MSI status is not a prognostic indicator in the general CRC population but appears to be an adverse prognostic indicator for RFS in stage III CRC patients who received adjuvant chemotherapy.
Collapse
Affiliation(s)
- Winson Jianhong Tan
- Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore.
| | - Julie Liana Hamzah
- Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore
| | - Sanchalika Acharyya
- Centre for Qualitative Medicine, DUKE NUS Graduate Medical School, Singapore, Singapore
| | - Fung Joon Foo
- Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore
| | - Kiat Hon Lim
- Department of Pathology, Singapore General Hospital, Singapore, Singapore
| | - Iain Bee Huat Tan
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - Choong Leong Tang
- Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore
| | - Min Hoe Chew
- Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore
| |
Collapse
|
5
|
Goshayeshi L, Ghaffarzadegan K, Khooei A, Esmaeilzadeh A, Rahmani Khorram M, Mosannen Mozaffari H, Kiani B, Hoseini B. Prevalence and clinicopathological characteristics of mismatch repair-deficient colorectal carcinoma in early onset cases as compared with late-onset cases: a retrospective cross-sectional study in Northeastern Iran. BMJ Open 2018; 8:e023102. [PMID: 30166308 PMCID: PMC6119423 DOI: 10.1136/bmjopen-2018-023102] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES Lynch syndrome (LS), a genetically inherited autosomal disorder, increases the incidence of colorectal carcinoma (CRC). We aimed to perform a universal strategy to assess the prevalence and clinicopathological characteristics of early onset CRCs at high risk of LS versus late-onset ones in the Iranian population. SETTING A local population-based study from Northeastern Iran. PARTICIPANTS 321 consecutive CRCs and pathology specimen screened between 2013 and 2016. PRIMARY AND SECONDARY OUTCOME MEASURES Retrospectively, information regarding the clinical criteria was obtained by interviewing the patients with CRC or, their families. Pathologists tested tumours with immunohistochemistry (IHC) staining of four mismatch repair (MMR) proteins (MLH1, MSH2, MSH6 and PMS2). Tumours with absent IHC staining of MLH1 were tested for BRAF mutations to exclude sporadic CRCs. Prevalence of early onset CRCs at high risk of LS and familial CRC type X were assessed as primary and secondary outcome measures, respectively. RESULTS Of 321 CRCs (13/123 (10.57%), early onset vs 21/198 (10.6%) late-onset) were detected to be MMR-deficient (dMMR). Nine early onset cases and 14 late-onset ones with a loss of MLH1 underwent testing for the BRAF mutation, none of the early onset and four (2.02%) late-onset were recognised as sporadic. The difference in the outcome of IHC-analysis between early and late-onset CRCs at high risk of LS was not statistically significant (p=0.34). Majority of the suspected LS tumours from early onset patients had arisen in distal part (8/11 (72.72%) vs 8/14 (57.14%)), all of which were occurred in the rectum or sigmoid. CONCLUSION Clinically, these findings suggest that in case of limitation for BRAF testing, the practitioner in Iran may consider managing early onset dMMR cases like LS until access to BRAF testing becomes available to them, before germline testing to accurately diagnose LS.
Collapse
Affiliation(s)
- Ladan Goshayeshi
- Gastroentrology and Hepatology Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Kamran Ghaffarzadegan
- Pathology Department, Education and Research Department, Razavi Hospital, Mashhad, Iran
| | - Alireza Khooei
- Department of Pathology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Abbas Esmaeilzadeh
- Gastroentrology and Hepatology Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Gastroenterology and Hepatology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahla Rahmani Khorram
- Medical Student, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hooman Mosannen Mozaffari
- Gastroentrology and Hepatology Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Gastroenterology and Hepatology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Behzad Kiani
- Department of Medical Informatics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Benyamin Hoseini
- Department of Health Information Technology, Neyshabur University of Medical Sciences, Neyshabur, Iran
| |
Collapse
|
6
|
Hashmi AA, Ali R, Hussain ZF, Faridi N, Khan EY, Bakar SMA, Edhi MM, Khan M. Mismatch repair deficiency screening in colorectal carcinoma by a four-antibody immunohistochemical panel in Pakistani population and its correlation with histopathological parameters. World J Surg Oncol 2017. [PMID: 28651545 PMCID: PMC5485685 DOI: 10.1186/s12957-017-1158-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Microsatellite instability (MSI) operates as the second major pathway in the colorectal carcinogenesis. Although genetic testing remains the gold standard for the detection of MSI, the College of American Pathologists (CAP) recommends an initial immunohistochemical workup with a four-antibody panel (MLH1, PMS2, MSH2, and MSH6) to screen for a defective mismatch repair system. An increased trend towards young age colorectal carcinoma (CRC) has been noticed in our population over recent years; however, neither screening for MSI by immunohistochemistry (IHC)/genetic testing was done nor were its morphological features studied. We aimed to determine the frequency of mismatch repair deficiency (dMMR) by loss of IHC expression of the aforementioned enzymes in CRC patients and its correlatation with clinicopathologic parameters. Methods This was a retrospective study conducted at Liaquat National Hospital, Karachi, between 2012 and 2015. A total of 100 cases of CRC were included in the study that underwent surgical resection. IHC stains using antibodies MLH1, PMS2, MSH2, and MSH6 were performed by DAKO EnVision method on representative tissue blocks. The results were interpreted by senior histopathologists and correlated with clinico-pathological parameters. Results A total of 100 cases of CRC were studied that included 51 males and 49 females. Thirty-four percent (n = 34) of the patients showed loss of IHC staining for MMR markers. Combined loss of expression for MLH1/PMS2 were observed in 16% (n = 16) of the cases. Loss of MSH2/MSH6 were seen in 6% (n = 6) of the cases. Loss of expression for all markers were noted in 7% (n = 7) of the cases. There were 5% (n = 5) of the cases that showed isolated loss of MLH1 only. The tumors with dMMR status were significantly associated with right-sided location (p = 0.013), exhibited intra-tumoral lymphocytosis (p = 0.007), and lymphovascular invasion (p = 0.043). No significant association was seen with gender, age, tumor stage, grade, or other morphological features. Conclusion The frequency of mismatch repair deficiency in CRC patients was found to be 34% in Pakistani population which warrants further genetic testing to exclude Lynch syndrome. Moreover, right-sided location and intra-tumoral lymphocyte count may be used to identify patients who may need further workup.
Collapse
Affiliation(s)
- Atif Ali Hashmi
- Histopathology department, Liaquat National Hospital and Medical College, Karachi, Pakistan
| | - Rabia Ali
- Histopathology department, Liaquat National Hospital and Medical College, Karachi, Pakistan
| | - Zubaida Fida Hussain
- Histopathology department, Liaquat National Hospital and Medical College, Karachi, Pakistan
| | - Naveen Faridi
- Histopathology department, Liaquat National Hospital and Medical College, Karachi, Pakistan
| | - Erum Yousuf Khan
- Histopathology department, Liaquat National Hospital and Medical College, Karachi, Pakistan
| | | | - Muhammad Muzzammil Edhi
- Surgery department, Rhode Island Hospital and Brown University, Providence, Rhode Island, USA
| | - Mehmood Khan
- Medicine department, Dhaka University, Dhaka, Bangladesh.
| |
Collapse
|
7
|
Prevalence and clinicopathologic/molecular characteristics of mismatch repair-deficient colorectal cancer in the under-50-year-old Japanese population. Surg Today 2017; 47:1135-1146. [PMID: 28258479 DOI: 10.1007/s00595-017-1486-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/12/2017] [Indexed: 02/07/2023]
Abstract
PURPOSE To clarify the prevalence and clinicopathologic/molecular characteristics of mismatch repair (MMR)-deficient colorectal cancer in the young Japanese population. METHODS Immunohistochemical analyses for MMR proteins (MLH1, MSH2, MSH6, and PMS2) were performed in formalin-fixed paraffin-embedded sections prepared from the resected CRC specimens of 119 consecutive patients aged <50 years old, who underwent resection of the primary tumor at our institution between 1996 and 2015. Analyses for somatic BRAF V600E mutation, somatic hypermethylation of the MLH1 promoter, and germline MMR gene mutations were undertaken where indicated. RESULTS MMR protein loss was found in 10 patients (8.4%), 7 (5.9%) of whom were subsequently identified to have Lynch syndrome (LS). The remaining 3 patients were categorized as having sporadic MMR-deficient CRC (n = 2) or "possible LS (n = 1)". In multivariate logistic regression analysis, the presence of tumor-infiltrating lymphocytes (P < 0.01), right-sided location of the tumor (P = 0.01), and a history of LS-associated tumors in the first-degree relatives (P < 0.01) were identified as independent factors predictive of MMR-deficient CRC. CONCLUSION These results are of value in the clinical management of patients with the early onset CRC under circumstances where universal tumor screening approaches for LS are still not available, like in Japan.
Collapse
|
8
|
Manne U, Jadhav T, Putcha BDK, Samuel T, Soni S, Shanmugam C, Suswam EA. Molecular Biomarkers of Colorectal Cancer and Cancer Disparities: Current Status and Perspective. CURRENT COLORECTAL CANCER REPORTS 2016. [PMID: 28626361 DOI: 10.1007/s11888-016-0338-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This review provides updates on the efforts for the development of prognostic and predictive markers in colorectal cancer based on the race/ethnicity of patients. Since the clinical consequences of genetic and molecular alterations differ with patient race and ethnicity, the usefulness of these molecular alterations as biomarkers needs to be evaluated in different racial/ethnic groups. To accomplish personalized patient care, a combined analysis of multiple molecular alterations in DNA, RNA, microRNAs (miRNAs), metabolites, and proteins in a single test is required to assess disease status in a precise way. Therefore, a special emphasis is placed on issues related to utility of recently identified genetic and molecular alterations in genes, miRNAs, and various "-omes" (e.g., proteomes, kinomes, metabolomes, exomes, methylomes) as candidate molecular markers to determine cancer progression (disease recurrence/relapse and metastasis) and to assess the efficacy of therapy in colorectal cancer in relation to patient race and ethnicity. This review will be useful for oncologists, pathologists, and basic and translational researchers.
Collapse
Affiliation(s)
- Upender Manne
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, Wallace Tumor Institute, University of Alabama at Birmingham, Room # 420A, 1530 3rd Avenue South, Birmingham, AL 35294, USA
| | - Trafina Jadhav
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Wallace Tumor Institute, University of Alabama at Birmingham, Room # 430A, 1530 3rd Avenue South, Birmingham, AL 35294, USA.,Present address: Division of Cardiovascular Medicine, Vanderbilt University, 1215 21st Avenue South, Medical Center East, Suite 5050, Nashville, TN 37232-8802, USA
| | - Balananda-Dhurjati Kumar Putcha
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Wallace Tumor Institute, University of Alabama at Birmingham, Room # 430A, 1530 3rd Avenue South, Birmingham, AL 35294, USA.,Present address: 2502 East Woodlands, Saint Joseph, MO 64506, USA
| | - Temesgen Samuel
- Department of Pathobiology, College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA
| | - Shivani Soni
- Department of Biological Sciences, Alabama State University, Room # 325, Life Science Building, 1627, Hall Street, Montgomery, AL 36104, USA
| | - Chandrakumar Shanmugam
- Wallace Tumor Institute, University of Alabama at Birmingham, Room # 430A, 1530 3rd Avenue South, Birmingham, AL 35294, USA.,Present address: Department of Pathology, ESIC Medical College and Hospital, Sanathnagar, Hyderabad, Telangana 500 038, India
| | - Esther A Suswam
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Pathology, Wallace Tumor Institute, University of Alabama at Birmingham, 1720 2nd Avenue South, # 410C, Birmingham, AL 35294-3300, USA
| |
Collapse
|
9
|
Richman S. Deficient mismatch repair: Read all about it (Review). Int J Oncol 2015; 47:1189-202. [PMID: 26315971 PMCID: PMC4583524 DOI: 10.3892/ijo.2015.3119] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/29/2015] [Indexed: 12/20/2022] Open
Abstract
Defects in the DNA mismatch repair (MMR) proteins, result in a phenotype called microsatellite instability (MSI), occurring in up to 15% of sporadic colorectal cancers. Approximately one quarter of colon cancers with deficient MMR (dMMR) develop as a result of an inherited predisposition syndrome, Lynch syndrome (formerly known as HNPCC). It is essential to identify patients who potentially have Lynch syndrome, as not only they, but also family members, may require screening and monitoring. Diagnostic criteria have been developed, based primarily on Western populations, and several methodologies are available to identify dMMR tumours, including immunohistochemistry and microsatellite testing. These criteria have provided evidence supporting the introduction of reflex testing. Yet, it is becoming increasingly clear that tests have a limited sensitivity and specificity and may yet be superseded by next generation sequencing. In this review, the limitations of diagnostic criteria are discussed, and current and emerging screening technologies explained. There is now useful evidence supporting the prognostic and predictive value of dMMR status in colorectal tumours, but much less is known about their value in extracolonic tumours, that may also feature in Lynch syndrome. This review assesses current literature relating to dMMR in endometrial, ovarian, gastric and melanoma cancers, which it would seem, may benefit from large-scale clinical trials in order to further close the gap in knowledge between colorectal and extracolonic tumours.
Collapse
Affiliation(s)
- Susan Richman
- Department of Pathology and Tumour Biology, Leeds Institute of Cancer and Pathology, St. James University Hospital, Leeds, LS9 7TF, UK
| |
Collapse
|