Systematic Review: An Update on the Spectrum of Urological Malignancies in Lynch Syndrome

Predictive tissue markers in testicular germ cell tumors: Immunohistochemical expression of MLH1 and REV-7 proteins

PURPOSE

Testicular Germ Cell Tumors (TGCTs) are the most frequent solid malignancies in young adult men. Regardless of differences in their cell of origin, all TGCTs are considered highly curable malignancies. However, approximately 3-5% of all TGCTs do not respond to platinum-based chemotherapies. The purpose of our paper is to investigate whether immunohistochemical expression of MLH1 and REV-7 can be used as predictive tissue markers for TGCTs.

MATERIAL AND METHODS

The main demographic and clinicopathological characteristics of 64 male patients with TGCTs who underwent orchiectomy from 2007 to 2022 were retrospectively obtained from two large Oncology Clinics in Greece. Both patients with chemosensitive and chemoresistant disease were included. Immunohistochemical staining for MLH1 and REV-7 proteins was applied in specimens of these patients.

RESULTS

31 seminomas and 33 non-seminomas were included. 48 patients had chemosensitive disease, while 16 had chemoresistant disease. 53 specimens showed preserved MLH1 expression, while 11 specimens had lost MLH1 expression. Expression of MLH1 was only significantly associated with patients' age. 16 specimens showed positive REV-7 expression, while 48 specimens were REV-7 negative. Interestingly, 50% of patients with chemoresistant disease and 16,7% of patients with chemosensitive disease were REV-7 positive. This difference was statistically significant. Moreover, REV-7 positivity was significantly associated with chemoresistance, various clinicopathological parameters and patients' prognosis and survival.

CONCLUSION

Loss of MLH1 expression was only found to be significantly associated with lower patients' age. Positive immunohistochemical REV-7 expression was significantly associated with various clinicopathological parameters, while it was also associated with significantly lower survival and greater hazard. REV-7 positive percentages were significantly higher in patients with chemoresistant disease. Our findings imply that immunohistochemical staining for REV-7 could potentially be used as a predictive tissue marker for TGCT tumors. Moreover, targeting of REV-7 protein, could represent a potential therapeutic strategy for chemoresistant TGCT cases. The implementation of well-designed studies on a larger scale is of utmost importance, in order to draw safer conclusions. Additional studies are needed so as to draw safer conclusions.

Association of a novel frameshift variant and a known deleterious variant in MMR genes with Lynch syndrome in Chinese families

BACKGROUND

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome. This condition is characterized by germline variants in DNA mismatch repair (MMR) genes, including MLH1, MSH2, MSH6, and PMS2. In this study, we analyzed the molecular defects and clinical manifestations of two families affected with CRC and proposed appropriate individual preventive strategies for all carriers of the variant.

METHODS

We recruited two families diagnosed with CRC and combined their family history and immunohistochemical results to analyze the variants of probands and those of other family members by using whole exome sequencing. Subsequently, gene variants in each family were screened by comparing them with the variants available in the public database. Sanger sequencing was performed to verify the variant sites. An online platform ( https://www.uniprot.org ) was used to analyze the functional domains of mutant proteins.

RESULTS

A novel frameshift variant (NM_001281492, c.1129_1130del, p.R377fs) in MSH6 and a known deleterious variant (NM_000249.4:c.1731G > A, p.S577S) in MLH1 were identified in the two families with CRC. Using bioinformatics tools, we noted that the frameshift variant reduced the number of amino acids in the MSH6 protein from 1230 to 383, thereby leading to no MSH6 protein expression. The silent variant caused splicing defects and was strongly associated with LS. 5-Fluorouracil-based adjuvant chemotherapy is not recommended for patients with LS.

CONCLUSIONS

The novel frameshift variant (MSH6, c.1129_1130del, p.R377fs) is likely pathogenic to LS, and the variant (MLH1, c.1731G > A, p.S577S) has been further confirmed to be pathogenic to LS. Our findings underscore the significance of genetic testing for LS and recommend that genetic consultation and regular follow-ups be conducted to guide individualized treatment for cancer-afflicted families, especially those with a deficiency in MMR expression.

Clinicopathological characteristics, molecular landscape, and biomarker landscape for predicting the efficacy of PD-1/PD-L1 inhibitors in Chinese population with mismatch repair deficient urothelial carcinoma: a real-world study

Urothelial carcinoma (UC) with deficient mismatch repair (dMMR) is a specific subtype of UC characterized by the loss of mismatch repair (MMR) proteins and its association with Lynch syndrome (LS). However, comprehensive real-world data on the incidence, clinicopathological characteristics, molecular landscape, and biomarker landscape for predicting the efficacy of PD-1/PD-L1 inhibitors in the Chinese patients with dMMR UC remains unknown. We analyzed 374 patients with bladder urothelial carcinoma (BUC) and 232 patients with upper tract urothelial carcinoma (UTUC) using tissue microarrays, immunohistochemistry, and targeted next-generation sequencing. Results showed the incidence of dMMR UC was higher in the upper urinary tract than in the bladder. Genomic analysis identified frequent mutations in KMT2D and KMT2C genes and LS was confirmed in 53.8% of dMMR UC cases. dMMR UC cases displayed microsatellite instability-high (MSI-H) (PCR method) in 91.7% and tumor mutational burden-high (TMB-H) in 40% of cases. The density of intratumoral CD8+ T cells correlated with better overall survival in dMMR UC patients. Positive PD-L1 expression was found in 20% cases, but some patients positively responded to immunotherapy despite negative PD-L1 expression. Our findings provide valuable insights into the characteristics of dMMR UC in the Chinese population and highlights the relevance of genetic testing and immunotherapy biomarkers for treatment decisions.

Japanese Society of Medical Oncology/Japan Society of Clinical Oncology/Japanese Society of Pediatric Hematology/Oncology-led clinical recommendations on the diagnosis and use of immunotherapy in patients with DNA mismatch repair deficient (dMMR) tumors, third edition

BACKGROUND

Clinical trials have reported the efficacy of immune checkpoint inhibitors in the treatment of mismatch repair-deficient (dMMR) advanced solid tumors. The accumulated evidence of tumor agnostic agent has been made since PD-1 inhibitor was approved and used in clinical practice. Therefore, we have revised the guideline "Japan Society of Clinical Oncology provisional clinical opinion for the diagnosis and use of immunotherapy in patients with deficient DNA mismatch repair tumors, cooperated by Japanese Society of Medical Oncology, First Edition".

METHODS

Clinical questions regarding medical care were formulated for patients with dMMR advanced solid tumors. Relevant publications were searched by PubMed and Cochrane Database. Critical publications and conference reports were added manually. Systematic reviews were performed for each clinical question for the purpose of developing clinical recommendations. The committee members identified by Japan Society of Clinical Oncology (JSCO), Japanese Society of Medical Oncology (JSMO), and Japanese society of pediatric hematology/oncology (JSPHO) voted to determine the level of each recommendation considering the strength of evidence, expected risks and benefits to patients, and other related factors. Thereafter, a peer review by experts nominated from JSCO, JSMO, and JSPHO and the public comments among all societies' members were done.

RESULTS

The current guideline describes two clinical questions and eight recommendations for whom, when, and how MMR status should be tested.

CONCLUSION

In this guideline, the committee proposed eight recommendations for performing MMR testing properly to select patients who are likely to benefit from immunotherapy.

Gender-specific counselling of patients with upper tract urothelial carcinoma and Lynch syndrome

PURPOSE

Lynch syndrome (LS) is an autosomal dominant genetic syndrome resulting in a wide spectrum of malignancies caused by germline mutations in mismatch repair genes (MMR). Gene mutations have different effects and penetrance between the two genders. The aim of this review is to offer a gender-specific evidence-based clinical guide on diagnosis, screening, surveillance, and counselling of UTUC patients with LS.

METHODS

Using MEDLINE, a non-systematic review was performed including articles between 2004 and 2022. English language original articles, reviews, and editorials were selected based on their clinical relevance.

RESULTS

Upper tract urothelial carcinoma (UTUC) is the third most common malignancy in Lynch syndrome. Up to 21% of new UTUC cases may have unrecognized LS as the underlying cause. LS-UTUC does not have a clear gender prevalence, even if it seems to slightly prefer the male gender. The MSH6 variant is significantly associated with female gender (p < 0.001) and with gynecological malignancies. Female MSH2 and MLH1 carriers have higher rates for endometrial and ovarian cancer with respect to the general population, while male MSH2 and MLH1 carriers have, respectively, higher rate of prostate cancer and upper GI tract, or biliary or pancreatic cancers. Conflicting evidence remains on the association of testicular cancer with LS.

CONCLUSION

LS is a polyhedric disease, having a great impact on patients and their families that requires a multidisciplinary approach. UTUC patients should be systematically screened for LS, and urologists have to be aware that the same MMR mutation may lead to different malignancies according to the patient's gender.

Systematic review of reported association studies of monogenic genes and bladder cancer risk and confirmation analysis in a large population cohort

Objectives

To evaluate which of previously reported monogenic genes are associated with increased bladder cancer risk, we reviewed published papers on associations of genes and bladder cancer risk and performed a confirmation study of these genes in a large population-based cohort.

Subjects and methods

A systematic review of published papers prior to June 2022 was performed first to identify all genes where germline mutations were associated with bladder cancer risk. The associations of these candidate genes with bladder cancer risk were then tested among 1695 bladder cancer cases and 186 271 controls in the UK Biobank (UKB). The robust SKAT-O, a gene-based analysis that properly controls for type I error rates due to unbalanced case-control ratio, was used for association tests adjusting for age at recruitment, gender, smoking status, and genetic background.

Results

The systematic review identified nine genes that were significantly associated with bladder cancer risk in at least one study (p < 0.05), including MUTYH, MSH2, MSH6, MLH1, ATM, BRCA2, ERCC5, TGFB1 and CHEK2. When pathogenic/likely pathogenic mutations were aggregated within each gene, the association was confirmed for three genes in the UKB at p < 0.0056 (Bonferroni correction for nine tests), including CHEK2, ATM and BRCA2, all also known to be associated with hereditary breast cancer. Suggestive evidence of association was found for two other genes, including MLH1 (p = 0.006) and MSH2 (p = 0.007), both known to be associated with Lynch syndrome. Among these five genes, the bladder cancer risks range from 1.60 (ATM) to 4.88 (MLH1), and mutation carrier rates in cases range from 0.06% (MSH2) to 2.01% (CHEK2).

Conclusion

This study provides statistical evidence for association of previously reported genes and bladder cancer risk and has clinical utility for risk assessment and genetic counselling.

Somatic hits in mismatch repair genes in colorectal cancer among non-seminoma testicular cancer survivors

BACKGROUND

Non-seminoma testicular cancer survivors (TCS) have an increased risk of developing colorectal cancer (CRC) when they have been treated with platinum-based chemotherapy. Previously we demonstrated that among Hodgkin lymphoma survivors (HLS) there is enrichment of rare mismatch repair (MMR) deficient (MMRd) CRCs with somatic hits in MMR genes. We speculate that this phenomenon could also occur among other cancer survivors. We therefore aim to determine the MMR status and its underlying mechanism in CRC among TCS (TCS-CRC).

METHODS

Thirty TCS-CRC, identified through the Dutch pathology registry, were analysed for MMR proteins by immunohistochemistry. Next-generation sequencing was performed in MMRd CRCs without MLH1 promoter hypermethylation (n = 4). Data were compared with a male cohort with primary CRC (P-CRC, n = 629).

RESULTS

MMRd was found in 17% of TCS-CRCs vs. 9% in P-CRC (p = 0.13). MMRd was more often caused by somatic double or single hit in MMR genes by mutation or loss of heterozygosity in TCS-CRCs (3/30 (10%) vs. 11/629 (2%) in P-CRCs (p < 0.01)).

CONCLUSIONS

MMRd CRCs with somatic double or single hit are more frequent in this small cohort of TCS compared with P-CRC. Exposure to anticancer treatments appears to be associated with the development of these rare MMRd CRC among cancer survivors.

Case Report: Potential Predictive Value of MMR/MSI Status and PD-1 Expression in Immunotherapy for Urothelial Carcinoma

Immune checkpoint inhibitors (ICIs) have shown encouraging outcomes against Lynch syndrome (LS)-associated colorectal cancer (CRC) and endometrial cancer with mismatch repair deficient/microsatellite instability-high (dMMR/MSI-H). However, there is as yet no clarity on the safety and efficacy of immunotherapy combined with chemotherapy in LS-associated urothelial carcinoma (UC). Here, we report a patient with recurrent and metastatic LS-associated UC who achieved sustained response to programmed death protein 1 (PD-1) inhibitor combined with chemotherapy over 31 months, during which the side effects of immunotherapy could be controlled and managed. Our findings indicate that the dMMR/MSI status and PD-1 expression in UC may have potential predictive value for the response to PD-1-targeted immunotherapy. Our case supports the inclusion of such combination and/or monotherapy for UC in clinical studies and using dMMR/MSI status and PD-1 expression as potential predictive biomarkers for assessment of the therapeutic response.

Uptake and outcomes of small intestinal and urinary tract cancer surveillance in Lynch syndrome

BACKGROUND

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome associated with increased risk of multiple cancers. While colorectal cancer surveillance decreases mortality in LS and is recommended by guidelines, there is lack of evidence for the efficacy of surveillance for extra-colonic cancers associated with LS, including small intestinal cancer (SIC) and urinary tract cancer (UTC). Given the limited evidence, guidelines do not consistently recommend surveillance for SIC and UTC, and it remains unclear how often individuals will choose to undergo and follow through with extra-colonic surveillance recommendations.

AIM

To study factors associated with SIC and UTC surveillance uptake and outcomes in LS.

METHODS

This is an IRB-approved retrospective analysis of individuals with LS seen at a tertiary care referral center. Included individuals had a pathogenic or likely pathogenic variant in MLH1, MSH2, MSH6, PMS2, or EPCAM, or were a confirmed obligate carrier, and had at least one documented visit to our center. Information regarding SIC and UTC surveillance was captured for each individual, and detailed personal and family history was obtained for individuals who had an initial LS management visit in our center’s dedicated high-risk LS clinic between January 1, 2017 and October 29, 2020. During these initial management visits, all patients had in-depth discussions of SIC and UTC surveillance with 1 of 3 providers experienced in LS management to promote informed decision-making about whether to pursue SIC and/or UTC surveillance. Statistical analysis using Pearson’s chi-squared test and Wilcoxon rank-sum test was completed to understand the factors associated with pursuit and completion of SIC and UTC surveillance, and a P value below 0.05 was deemed statistically significant.

RESULTS

Of 317 individuals with LS, 86 (27%) underwent a total of 105 SIC surveillance examinations, with 5 leading to additional work-up and no SICs diagnosed. Additionally, 99 (31%) patients underwent a total of 303 UTC surveillance examinations, with 19 requiring further evaluation and 1 UTC identified. Of 155 individuals who had an initial LS management visit between January 1, 2017 and October 29, 2020, 63 (41%) chose to undergo SIC surveillance and 58 (37%) chose to undergo UTC surveillance. However, only 26 (41%) and 32 (55%) of those who initially chose to undergo SIC or UTC surveillance, respectively, successfully completed their surveillance examinations. Individuals with a pathogenic variant in MSH2 or EPCAM were more likely to initially choose to undergo SIC surveillance (P = 0.034), and older individuals were more likely to complete SIC surveillance (P = 0.007). Choosing to pursue UTC surveillance was more frequent among older individuals (P = 0.018), and females more frequently completed UTC surveillance (P = 0.002). Personal history of cancer and family history of SIC or UTC were not significantly associated with electing nor completing surveillance. Lastly, the provider discussing SIC/UTC surveillance was significantly associated with subsequent surveillance choices.

CONCLUSION

Pursuing and completing SIC/UTC surveillance in LS is influenced by several factors, however broad incorporation in LS management is likely unhelpful due to low yield and frequent false positive results.

When to Consider Lynch Syndrome in Non-Colon and Non-Endometrial Malignancies

Lynch syndrome (LS) is a common genetic syndrome characterized by pathogenic mutations of DNA mismatch repair genes resulting in a hereditary predisposition to cancer. While typically associated with colonic and endometrial cancer, LS additionally influences the development of many other malignancies. The Amsterdam II and Revised Bethesda Guidelines are the established clinical criteria for diagnosing LS. These guidelines are based on the most general characteristics of LS and do not address specific characteristics of the less commonly LS-associated malignancies. For individuals that present initially with a non-colon and non-endometrial malignancy, recommendations and guidelines on when to consider screening for LS are limited. Therefore, it is essential that clinicians are familiar with distinct LS-associated patient- and tumor-specific characteristics, especially of the less common LS-associated cancers, so that LS's diagnosis is not missed. In this review article, we focus on extra-colonic and extra-endometrial LS-associated cancers, paying particular attention to any established or currently investigated cancer features that help raise suspicion for LS and potentially lead to its earlier diagnosis. This review will also discuss current guidelines specific to each LS-associated malignancy.

Lynch Syndrome: Its Impact on Urothelial Carcinoma

Lynch syndrome, known as hereditary nonpolyposis colorectal cancer (HNPCC), is an autosomal-dominant familial cancer syndrome with an increased risk for urothelial cancer (UC). Mismatch repair (MMR) deficiency, due to pathogenic variants in MLH1, MSH2, MSH6, and PMS2, and microsatellite instability, are known for development of Lynch syndrome (LS) associated carcinogenesis. UC is the third most common cancer type in LS-associated tumors. The diversity of germline variants in the affected MMR genes and their following subsequent function loss might be responsible for the variation in cancer risk, suggesting an increased risk of developing UC in MSH2 mutation carriers. In this review, we will focus on LS-associated UC of the upper urinary tract (UUT) and bladder, their germline profiles, and outcomes compared to sporadic UC, the impact of genetic testing, as well as urological follow-up strategies in LS. In addition, we present a case of metastatic LS-associated UC of the UUT and bladder, achieving complete response during checkpoint inhibition since more than 2 years.

Bladder Cancer: A Review

IMPORTANCE

Bladder cancer is a common malignancy in women and is the fourth most common malignancy in men. Bladder cancer ranges from unaggressive and usually noninvasive tumors that recur and commit patients to long-term invasive surveillance, to aggressive and invasive tumors with high disease-specific mortality.

OBSERVATIONS

Advanced age, male sex, and cigarette smoking contribute to the development of bladder cancer. Bladder tumors can present with gross or microscopic hematuria, which is evaluated with cystoscopy and upper tract imaging depending on the degree of hematuria and risk of malignancy. Non-muscle-invasive tumors are treated with endoscopic resection and adjuvant intravesical therapy, depending on the risk classification. Enhanced cystoscopy includes technology used to improve the detection of tumors and can reduce the risk of recurrence. Patients with high-risk non-muscle invasive tumors that do not respond to adjuvant therapy with the standard-of-care immunotherapy, bacille Calmette-Guérin (BCG), constitute a challenging patient population to manage and many alternative therapies are being studied. For patients with muscle-invasive disease, more aggressive therapy with radical cystectomy and urinary diversion or trimodal therapy with maximal endoscopic resection, radiosensitizing chemotherapy, and radiation is warranted to curb the risk of metastasis and disease-specific mortality. Treatment of patients with advanced disease is undergoing rapid changes as immunotherapy with checkpoint inhibitors, targeted therapies, and antibody-drug conjugates have become options for certain patients with various stages of disease.

CONCLUSIONS AND RELEVANCE

Improved understanding of the molecular biology and genetics of bladder cancer has evolved the way localized and advanced disease is diagnosed and treated. While intravesical BCG has remained the mainstay of therapy for intermediate and high-risk non-muscle-invasive bladder cancer, the therapeutic options for muscle-invasive and advanced disease has expanded to include immunotherapy with checkpoint inhibition, targeted therapies, and antibody-drug conjugates.

Comprehensive genetic analysis of pediatric germ cell tumors identifies potential drug targets

To elucidate the molecular pathogenesis of pediatric germ cell tumors (GCTs), we performed DNA methylation array analysis, whole transcriptome sequencing, targeted capture sequencing, and single-nucleotide polymorphism array analysis using 51 GCT samples (25 female, 26 male), including 6 germinomas, 2 embryonal carcinomas, 4 immature teratomas, 3 mature teratomas, 30 yolk sac tumors, and 6 mixed germ cell tumors. Among the 51 samples, 11 were from infants, 23 were from young children, and 17 were from those aged ≥10 years. Sixteen of the 51 samples developed in the extragonadal regions. Germinomas showed upregulation of pluripotent genes and global hypomethylation. Pluripotent genes were also highly expressed in embryonal carcinomas. These genes may play essential roles in embryonal carcinomas given that their binding sites are hypomethylated. Yolk sac tumors exhibited overexpression of endodermal genes, such as GATA6 and FOXA2, the binding sites of which were hypomethylated. Interestingly, infant yolk sac tumors had different DNA methylation patterns from those observed in older children. Teratomas had higher expression of ectodermal genes, suggesting a tridermal nature. Based on our results, we suggest that KIT, TNFRSF8, and ERBB4 may be suitable targets for the treatment of germinoma, embryonal carcinomas, and yolk sac tumors, respectively.

Yasuo Kubota et al. report a multi-omic analysis of pediatric germ cell tumors from 51 patients ranging in age from 2 months to 19 years. They identify unique methylation, expression, and mutational patterns for each of the main subtypes and propose potential target genes for treatments against the three main subtypes.

Application Areas of Traditional Molecular Genetic Methods and NGS in relation to Hereditary Urological Cancer Diagnosis

Next generation sequencing (NGS) is widely used for diagnosing hereditary cancer syndromes. Often, exome sequencing and extended gene panel approaches are the only means that can be used to detect a pathogenic germline mutation in the case of multiple primary tumors, early onset, a family history of cancer, or a lack of specific signs associated with a particular syndrome. Certain germline mutations of oncogenes and tumor suppressor genes that determine specific clinical phenotypes may occur in mutation hot spots. Diagnosis of such cases, which involve hereditary cancer, does not require NGS, but may be made using PCR and Sanger sequencing. Diagnostic criteria and professional community guidelines developed for hereditary cancers of particular organs should be followed when ordering molecular diagnostic tests for a patient. This review focuses on urological oncology associated with germline mutations. Clinical signs and genetic diagnostic laboratory tests for hereditary forms of renal cell cancer, prostate cancer, and bladder cancer are summarized. While exome sequencing, or, conversely, traditional molecular genetic methods are the procedure of choice in some cases, in most situations, sequencing of multigene panels that are specifically aimed at detecting germline mutations in early onset renal cancer, prostate cancer, and bladder cancer seems to be the basic solution for molecular genetic diagnosis of hereditary cancers.

A Novel Splice-Site Mutation in MSH2 Is Associated With the Development of Lynch Syndrome

Lynch syndrome (LS) is an inherited autosomal dominant disorder caused by germline mutations of mismatch repair (MMR) genes, including MSH2, MSH6, PMS2, and MLH1. This study aimed to analyze the molecular defects and clinical manifestations of an affected family and propose appropriate individual prevention strategies for all mutation carriers. A novel splicing mutation (c.1661+2 T>G) was identified in the MSH2 gene, which was found to co-segregate among affected family members by Whole exome sequencing (WES). RT-PCR analysis confirmed that c.1661+2 T>G could produce 3 transcripts, including 1 normal transcript and 2 aberrant transcripts. The 2 aberrant transcripts resulted in premature termination at the 6th nucleotide codon of MSH2 exon 11, so that the predicted products of the mutant MSH2 mRNAs were truncated proteins of 505 amino acids (with all of exon 10 deleted) and 528 amino acids (with a deletion of 82-nucleotides in exon 10), resulting in the loss of the interaction domain, the ATP domain and post-translationally modified residues. Quantitative RT-PCR (qRT-PCR) analysis showed that MSH2 mRNA levels in all patients were reduced to only 1/4 of the control levels. Our study reveals that a novel splicing mutation (c.1661+2 T>G) in the MSH2 gene causes LS and reaffirms the importance of genetic testing for LS.

The emerging landscape of germline variants in urothelial carcinoma: Implications for genetic testing

Urothelial carcinoma (UC) of the bladder and upper tract (ureter, renal pelvis) is one of the most frequently occurring malignancies. While the majority of UC are chemically induced by smoking, accumulating evidence from genetic studies have demonstrated a small, but consistent impact of heritable gene variants and family history of UC on the development of the disease. Beyond the established association between upper tract UC and germline mismatch DNA repair defects as a defining feature of Lynch syndrome, newer investigations focusing on moderate- and high-risk cancer-related gene variants in DNA damage repair and other signaling pathways are expanding our knowledge on the heritable genetic basis of UC, opening new avenues in the breadth of genetic testing and in clinical counseling of these patients. Overcoming existing challenges in the interpretation of uncertain findings and family cascade testing may help expand our testing approach and guidelines. Following the paradigm of other tumor types, such as breast and ovarian cancers, germline genetic testing, particularly when combined with somatic testing, has the potential to directly benefit affected UC patients and their families in the future through therapeutic targeting (i.e. with poly(ADP-ribose)) polymerase inhibitors, immune checkpoint inhibitors) and genetically informed screening/surveillance, respectively.

Genomic characterization for familial cases with urothelial carcinoma

In this report, we present familial cases of urothelial carcinoma. To investigate the possibility of hereditary urothelial cancer, we performed semiconductor-based next-generation DNA sequencing. A woman in her 80s who had bladder and left ureteral cancer was hospitalized in Sapporo Shirakaba-dai Hospital due to consciousness disturbance. Radiographic evaluation revealed multiple liver metastases and she died 38 days later. Needle necropsy was done for a left ureteral tumor that continued to her bladder tumor and for liver metastases. At the same time, her son in his 60s, who also had muscle-invasive bladder cancer, was admitted to Sapporo Medical University Hospital and underwent neoadjuvant chemotherapy followed by laparoscopic radical cystectomy. DNA was isolated from both cancers and normal controls in each case and analyzed by massive parallel sequencing of 409 cancer-related genes using a targeted, multiplex PCR approach followed by semiconductor sequencing. Somatic mutations of KMT2C and KMT2D were detected in the mother's tumor. Copy number gains of FGFR1, IkBKB, NFkB2, FGFR2, and FLT3 and copy number losses of IGF2R and TP53 were also found in her cancer. In her son's tumor, somatic mutations of FGFR3 and EP300 were identified. Copy number gains of IkBKE/MAPK1/PARP1, EGFR, BRAF, IRS2, MAPK2K1, IGF1R, and ERBB2 and copy number loss of TP53 were also found in his cancer. There were no germline gene mutations related to familial urothelial carcinoma. Although somatic mutation of TP53 was a common feature, these cases with urothelial carcinoma might not be the result of a heredity syndrome.

Confirmation of damaging effect of MSH2 c.2634+1G>C mutation on splicing, its classification and implications for counseling

INTRODUCTION

Lynch syndrome (LS) is predisposing mainly to colorectal and endometrial carcinomas, but also to urinary tract cancers. LS association with upper urinary tract carcinomas is known, but its association with bladder cancer is not so clear. Confirmation of pathogenicity of detected mutations in LS-associated genes is required for adequate counseling.

MATERIAL AND METHODS

Tested young female has family history of two early colorectal and two bladder carcinomas. NGS sequencing revealed MSH2 splice site mutation c.2634+1G>C, which was confirmed by Sanger sequencing. MSH2 cDNA part containing potential splicing change was sequenced. in silico softwares were used to predict the effect of detected mutation on splicing and protein structure. ACMG Guidelines were used for mutation classification.

RESULTS

in silico softwares predict damaging effect of detected mutation on splicing and loss of protein-binding domains. cDNA sequencing confirmed this mutation causes exon 15 excision. ACMG Guidelines classify this mutation as Pathogenic.

DISCUSSION

MSH2 c.2634+1G>C mutation was not reported previously as LS associated. We confirmed its damaging effect on splicing. in silico tools predict consequent loss of protein domains implicating disrupted protein function. Our results suggest that this mutation should be classified as Pathogenic, and indicate inclusion of bladder cancer in LS cancer spectrum.

Japan Society of Clinical Oncology provisional clinical opinion for the diagnosis and use of immunotherapy in patients with deficient DNA mismatch repair tumors, cooperated by Japanese Society of Medical Oncology, First Edition

Background

Novel therapeutic agents have improved survival outcomes in patients with advanced solid tumors. In parallel, the development of predictive biomarkers to identify patients who are likely to benefit from a certain treatment has also contributed to the improvement of survival. Recently, clinical trials have reported the efficacy of immune checkpoint inhibitors in the treatment of mismatch repair-deficient (dMMR) advanced solid tumors. In Japan, a PD-1 inhibitor for dMMR advanced solid tumors, regardless of the primary tumor site, has been approved. However, there are some issues related to administering immune checkpoint inhibitors in the clinical practice setting, making it necessary to develop the guidelines.

Methods

Clinical questions (CQs) regarding medical care were formulated for patients with dMMR advanced solid tumors, and evidence to the CQs was collected by manual search to prepare recommendations. Then, the committee members voted to determine the level of each recommendation considering the strength of evidence, expected risks and benefits to patients, and other factors.

Results

The current guideline, which we consider a provisional clinical opinion at this point, describes the 11 requirements to be considered in terms of patients for whom dMMR testing is recommended, the timing and methods of dMMR testing, and clinical care systems required to perform dMMR testing properly and to administer immune checkpoint inhibitors safely.

Conclusion

This provisional clinical opinion proposes the requirements for performing dMMR testing properly to select patients who are likely to benefit from immune checkpoint inhibitors and administering them safely.

Electronic supplementary material

The online version of this article (10.1007/s10147-019-01498-8) contains supplementary material, which is available to authorized users.