Universal Point of Care Testing for Lynch Syndrome in Patients with Upper Tract Urothelial Carcinoma

A collaborative review of the microsatellite instability/deficient mismatch repair phenotype in patients with upper tract urothelial carcinoma

OBJECTIVE

To perform a collaborative review of the literature exploring the microsatellite instability/deficient mismatch repair (MSI/dMMR) phenotype in patients with upper tract urothelial carcinoma (UTUC).

METHOD

A collaborative review of the literature available on Medline was conducted by the Cancer Committee of the French Association of Urology to report studies describing the genetic mechanisms, investigation, prevalence and impact of the MSI/dMMR phenotype in UTUC patients.

RESULTS

The predominant genetic mechanism leading to the MSI/dMMR phenotype in UTUC patients is related to the constitutional mutation of one allele of the MMR genes MLH1, MSH2, MSH6 and PMS2 within Lynch syndrome. Indications for its investigation currently remain limited to patients with a clinical suspicion for sporadic UTUC to refer only those with a positive testing for germline DNA sequencing to screen for this syndrome. With regard to technical aspects, despite the interest of MSIsensor, only PCR and immunohistochemistry are routinely used to somatically investigate the MSI and dMMR phenotypes, respectively. The prevalence of the MSI/dMMR phenotype in UTUC patients ranges from 1.7% to 57%, depending on the study population, investigation method and definition of a positive test. Younger age and a more balanced male to female ratio at initial diagnosis are the main specific clinical characteristics of UTUC patients with an MSI/dMMR phenotype. Despite the conflicting results available in the literature, these patients may have a better prognosis, potentially related to more favourable pathological features. Finally, they may also have lower sensitivity to chemotherapy but greater sensitivity to immunotherapy.

CONCLUSION

Our collaborative review summarises the available data from published studies exploring the MSI/dMMR phenotype in UTUC patients, the majority of which are limited by a low level of evidence.

Contemporary Issues in Urothelial Carcinoma of Upper Urinary Tract

Upper urinary tract urothelial carcinoma (UTUC) is an uncommon malignancy involving the renal pelvis and ureter. Careful pathologic analysis plays a critical role in the diagnosis and clinical management of UTUC. In combination with clinical and radiologic evaluation, pathologic features can be used to stratify patients into low-risk and high-risk groups. This risk stratification can help clinicians select the optimal treatment for patients with UTUC, such as kidney-sparing (conservative) treatment, radical nephroureterectomy or ureterectomy, and perioperative systemic therapy. However, due to the technical difficulty of obtaining sufficient tissue from the upper urinary tract, it is often challenging for pathologists to accurately grade the tumor and assess tumor invasion in small biopsy specimens. Although the majority of UTUCs are pure urothelial carcinoma, a considerable subset of UTUCs show histologic subtypes or divergent differentiation. Recent studies have identified genetically distinct molecular subtypes of UTUC by examining DNA, RNA, and protein expression profiles. The prognosis of pT3 UTUC, particularly renal pelvic UC, remains controversial, and several studies have proposed subclassification of pT3 UTUC. Lynch syndrome is a significant risk factor for UTUC, and screening tests may be considered in young patients and those with familial histories of the disease. Despite significant progress in recent years, several issues remain to be addressed in the pathologic diagnosis, molecular classification, and treatment of UTUC.

Novel MSH2 and TSC2 variants in a Chinese family with Lynch syndrome and their synergistic impact in urothelial carcinoma

Lynch syndrome, an autosomal dominant hereditary disease arising from mutations in mismatch repair genes, is linked to the development of multiple tumor types, notably colorectal cancer, endometrial carcinoma and upper urinary tract urothelial carcinoma. In this study, we present the case of a young patient diagnosed with upper urinary tract urothelial carcinoma, notable for a familial history of diverse malignancies. By employing genetic analysis, we verified the presence of Lynch syndrome within the family and detected novel variants, MSH2 p.A604D and TSC2 p.C738Y, utilizing NGS technology. Subsequently, we conducted validation experiments to assess the pathogenicity of the MSH2 and TSC2 variants. We illustrated that the MSH2 variant can result in diminished MSH2 expression, compromised mismatch repair function, and induce resistance to cisplatin in urothelial carcinoma. Furthermore, we substantiated the promotional impact of the identified TSC2 variant on urothelial carcinoma, encompassing proliferation, invasion, and migration. Significantly, we found that the MSH2 p.A604D variant and TSC2 p.C738Y variant synergistically enhance the promotion of urothelial carcinoma.

Consultation on UTUC II Stockholm 2022: diagnostics, prognostication, and follow-up-where are we today?

PURPOSE

To summarise the current knowledge regarding diagnostics, prognostication and follow-up in upper tract urothelial carcinoma (UTUC).

METHODS

A scoping review combined with expert opinion was applied to provide an overview of the current research field. Based on the published literature and the experts' own experience and opinions, consensus was reached through presentations and discussions at the meeting Consultation on UTUC II in Stockholm 2022.

RESULTS

The strongest prognostic factors in UTUC are tumour grade and stage. They are correlated, and grade is used for indirect staging. The diagnostic examinations should include multiphase computed tomography urography (CTU) with corticomedullary phase, and urethrocystoscopy with cytology. If there is no clear diagnosis for clinical decision-making, ureterorenoscopy (URS) with focal cytology and biopsies should be performed. Both WHO classification systems (1973/1999 and 2004/2016) should be used. Novel biomarker tests are not yet widespread nor recommended for the detection of UTUC. Long-term, regular follow-up, including URS in patients who have had organ-sparing treatment, is important to check for tumour recurrences, intravesical recurrences, metastases and progression of the tumour.

CONCLUSION

Proper diagnostics with correct grading of UTUC are necessary for appropriate treatment decisions. The diagnostics should include CTU with corticomedullary phase, urine or bladder cytology, URS with focal barbotage cytology, and biopsies when needed for proper diagnosis and risk stratification. Regular, long-term follow-ups are fundamental, due to the high rate of recurrence and risk of progression.

Diagnosis of patients with Lynch syndrome lacking the Amsterdam II or Bethesda criteria

BACKGROUND

Lynch Syndrome (LS) is an autosomal dominant inheritance disorder characterized by genetic predisposition to develop cancer, caused by pathogenic variants in the genes of the mismatch repair system. Cases are detected by implementing the Amsterdam II and the revised Bethesda criteria, which are based on family history.

MAIN BODY

Patients who meet the criteria undergo posterior tests, such as germline DNA sequencing, to confirm the diagnosis. However, these criteria have poor sensitivity, as more than one-quarter of patients with LS do not meet the criteria. It is very likely that the lack of sensitivity of the criteria is due to the incomplete penetrance of this syndrome. The penetrance and risk of developing a particular type of cancer are highly dependent on the affected gene and probably of the variant. Patients with variants in low-penetrance genes have a lower risk of developing a cancer associated with LS, leading to families with unaffected generations and showing fewer clear patterns. This study focuses on describing genetic aspects of LS cases that underlie the lack of sensitivity of the clinical criteria used for its diagnosis.

CONCLUSION

Universal screening could be an option to address the problem of underdiagnosis.

Prevalence and characteristics of patients with upper urinary tract urothelial carcinoma having potential Lynch syndrome identified by immunohistochemical universal screening and Amsterdam criteria II

BACKGROUND

This study aimed to identify patients with upper urinary tract urothelial carcinoma (UTUC) having potential Lynch syndrome (pLS) by immunohistochemistry (IHC) of DNA mismatch repair gene-related proteins (MMRPs) and Amsterdam criteria II and explore their clinical characteristics.

METHODS

We retrospectively collected the clinical data of 150 consecutive patients with UTUC who underwent surgical resection at our institution between February 2012 and December 2020, and immunohistochemistry (IHC) of four MMRPs (MLH1, MSH2, MSH6, and PMS2) on all UTUC specimens was performed. Patients who tested positive for Amsterdam criteria (AMS) II and/or IHC screening were classified as having pLS and others as non-pLS, and their characteristics were explored.

RESULTS

In this study, 5 (3%) and 6 (4%) patients were positive for AMS II and IHC screening, respectively. Two patient were positive for both AMS II and IHC screening, resulting in 9 (6%) patients with pLS. The pLS group was predominantly female (67% vs. 36%; p = 0.0093) and had more right-sided tumors (100% vs. 43%; p = 0.0009) than the non-pLS group. Of the 6 patients who were positive for IHC screening, 4 showed a combined loss of MSH2/MSH6 (n = 3) and MLH1/PMS2 (n = 1). Other two patients showed single loss of MSH6 and PSM2.

CONCLUSIONS

AMS II and IHC screening identified pLS in 6% of patients with UTUC. The IHC screening-positive group tends to have relatively high rate of combined loss, but some patients have single loss. AMS II may overlook patients with LS, and a universal screening may be required for patients with UTUC as well as those with colorectal and endometrial cancer.

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.

[Urothelial carcinoma of the upper urinary tract]

Urothelial carcinoma of the upper urinary tract (upper tract urothelial carcinoma, UTUC) is less common than bladder carcinoma with nearly identical risk factors and has a poorer prognosis. The standard diagnostic procedure is imaging of the upper urinary tract by computed tomography urography. In cases of diagnostic uncertainty, a diagnostic ureterorenoscopy with biopsy sampling can be performed in addition to urine cytology. Treatment depends primarily on the stage and grading of the tumor. Depending on the extent and localization, organ-preserving treatment or radical nephroureterectomy is indicated. Perioperative systemic treatment in high-risk UTUC can be performed in both neoadjuvant and adjuvant settings, although the current data on neoadjuvant chemo- and immunotherapy do not yet allow standard application. For metastatic disease, a multimodal treatment approach consisting of cisplatin-based or carboplatin-based chemotherapy, immunotherapy, and treatment with enfortumab vedotin can be considered. Salvage surgery, radiotherapy and metastasectomy are available for rare individual cases.

Relative Risk of Bladder and Kidney Cancer in Lynch Syndrome: Systematic Review and Meta-Analysis

Background: The association between Lynch syndrome (LS) and a higher risk of upper tract urothelial carcinoma is well established, but its effect on the risk of bladder and kidney cancers remains controversial. This review aimed to compare the relative risk (RR) of bladder and kidney cancer in confirmed LS germline mutation carriers compared to the general population. Methods: Medline, Embase, Cochrane Central, and Google Scholar were searched on 14 July 2022 for studies published in English that reported on the rates of urological cancer in adults with confirmed LS germline mutation. The quality of included studies was assessed using Cochrane’s tool to evaluate risk of bias in cohort studies. Random effects meta-analysis estimated the pooled relative risk of bladder and kidney cancer in LS carriers compared to the general population. The quality of the overall evidence was evaluated using GRADE. Results: Of the 1839 records identified, 5 studies involving 7120 participants from 3 continents were included. Overall, LS carriers had a statistically significantly higher RR of developing bladder cancer (RR: 7.48, 95% CI: 3.70, 15.13) and kidney cancer (RR: 3.97, 95% CI: 1.23, 12.81) compared to unaffected participants (p < 0.01). The quality of the evidence was assessed as “low” due to the inclusion of cohort studies, the substantial heterogeneity, and moderate-to-high risk of bias. Conclusion: Lynch syndrome is associated with a significant increase in the relative risk of kidney and bladder cancer. Clinicians should adopt a lower threshold for germline mutation genetic testing in individuals who present with bladder cancer. Further studies evaluating the role and cost-effectiveness of novel urine-based laboratory tests are needed. High-quality studies in histologically proven renal cell carcinoma and their underlying germline mutations are necessary to strengthen the association with LS.

French AFU Cancer Committee Guidelines - Update 2022-2024: Upper urinary tract urothelial cancer (UTUC)

INTRODUCTION

The aim was to propose an update of the French Urology Association Cancer Committee (ccAFU) Recommendations on the management of upper urinary tract urothelial carcinomas (UUT-UC).

METHODS

A systematic Medline search was performed between 2020 and 2022, taking account of the diagnosis, treatment options and follow-up of UUT-UC, while evaluating the references with their levels of evidence.

RESULTS

The diagnosis of this rare pathology is based on CTU acquisition during excretion and flexible ureterorenoscopy with histological biopsies. Radical nephroureterectomy (RNU) remains the gold standard for surgical treatment. Nevertheless conservative treatment can be discussed for low risk lesions: tumour of low-grade, with no infiltration on imaging, unifocal<2cm, eligible for full treatment therefore requiring close endoscopic surveillance by flexible ureteroscopy in compliant patients. After RNU, postoperative instillation of chemotherapy is recommended to reduce the risk of recurrence in the bladder. Adjuvant chemotherapy has shown clinical benefits compared to surveillance after RNU for tumours (pT2-T4 N0-3 M0).

CONCLUSION

These updated recommendations should contribute to improving not only patients' level of care, but also the diagnosis and decision-making concerning treatment for UUT-UC.

Clinicopathological characteristics and loss of mismatch repair protein expression in Chinese upper tract urothelial carcinomas

Expression of DNA mismatch repair (MMR) protein (MLH1, PMS2, MSH2, and MSH6) in upper tract urothelial carcinoma (UTUC) has been explored in Western cohorts, but it is rarely reported in Eastern cohorts. We aimed to assess the loss of MMR protein expression among Chinese UTUC patients and study its clinicopathological implications. We enrolled 175 UTUC patients at our center and tested the expression of MMR proteins by immunohistochemistry. Then, we explored these patients' clinicopathological characteristics. We found loss of MMR proteins in 19 (10.9%) of 175 patients in our cohort (6 MSH2 and MSH6, 2 MSH6 alone, 6 MSH2 alone, 3 MLH1 and PMS2, and 2 PMS2 alone). Loss of MMR proteins was not a significant prognostic factor of relapse-free survival for these patients. In addition, patients with lower T stage or with bladder cancer history were more likely to have loss of MMR protein expression. At last, two metastatic patients (MSH2 and MSH6 loss; MSH2 loss) with loss of MMR protein experienced tumor recession after several cycles of anti-PD-1 immunotherapy. In conclusion, this is the largest Chinese UTUC cohort study to date that explores the loss of MMR protein expression. The rate of MMR loss observed was comparable to that in the Western UTUC cohort, supporting universal UTUC screening in China. Furthermore, a subset of advanced UTUCs with MMR protein loss are probably immunogenic, for whom single or combined immunotherapy may be potential therapeutic options in the future.

Prevalence and risk estimation of cancer-predisposing genes for upper urinary tract urothelial carcinoma in Japanese

Upper urinary tract urothelial carcinoma is a rare cancer that has been associated with mismatch repair genes such as MLH1, MSH2, MSH6 and PMS2. In addition, patients with pathogenic variants of cancer-predisposing genes such as BRCA1 and BRCA2 have been reported. However, how cancer-predisposing genes affect the risk of upper urinary tract urothelial carcinoma in the Japanese population remains unclear. Thus, we performed a case-control sequencing study of 27 cancer-predisposing genes in 208 upper urinary tract urothelial carcinoma patients and 37 727 controls. Only MSH6 and MSH2 were observed with a value of P < 0.05. However, there was no difference in the prevalence of pathogenic variants of BRCA1/2, which does not support the use of a poly adenosine diphosphate-ribose polymerase inhibitor in patients with upper urinary tract urothelial carcinoma. Only mismatch repair genes were associated with patients with upper urinary tract urothelial carcinoma, but the prevalence of pathogenic variants in mismatch repair genes was lower than that reported in previous studies from other populations.

Detection of Microsatellite Instability in Colonoscopic Biopsies and Postal Urine Samples from Lynch Syndrome Cancer Patients Using a Multiplex PCR Assay

Identification of mismatch repair (MMR)-deficient colorectal cancers (CRCs) is recommended for Lynch syndrome (LS) screening, and supports targeting of immune checkpoint inhibitors. Microsatellite instability (MSI) analysis is commonly used to test for MMR deficiency. Testing biopsies prior to tumour resection can inform surgical and therapeutic decisions, but can be limited by DNA quantity. MSI analysis of voided urine could also provide much needed surveillance for genitourinary tract cancers in LS. Here, we reconfigure an existing molecular inversion probe-based MSI and BRAF c.1799T > A assay to a multiplex PCR (mPCR) format, and demonstrate that it can sample >140 unique molecules per marker from <1 ng of DNA and classify CRCs with 96−100% sensitivity and specificity. We also show that it can detect increased MSI within individual and composite CRC biopsies from LS patients, and within preoperative urine cell free DNA (cfDNA) from two LS patients, one with an upper tract urothelial cancer, the other an undiagnosed endometrial cancer. Approximately 60−70% of the urine cfDNAs were tumour-derived. Our results suggest that mPCR sequence-based analysis of MSI and mutation hotspots in CRC biopsies could facilitate presurgery decision making, and could enable postal-based screening for urinary tract and endometrial tumours in LS patients.

Microsatellite Instability: From the Implementation of the Detection to a Prognostic and Predictive Role in Cancers

Microsatellite instability (MSI) has been identified in several tumors arising from either germline or somatic aberration. The presence of MSI in cancer predicts the sensitivity to immune checkpoint inhibitors (ICIs), particularly PD1/PD-L1 inhibitors. To date, the predictive role of MSI is currently used in the selection of colorectal cancer patients for immunotherapy; moreover, the expansion of clinical trials into other cancer types may elucidate the predictive value of MSI for non-colorectal tumors. In clinical practice, several assays are used for MSI testing, including immunohistochemistry (IHC), polymerase chain reaction (PCR) and next-generation sequencing (NGS). In this review, we provide an overview of MSI in various cancer types, highlighting its potential predictive/prognostic role and the clinical trials performed. Finally, we focus on the comparison data between the different assays used to detect MSI in clinical practice.

Identification of Germline Mutations in Upper Tract Urothelial Carcinoma With Suspected Lynch Syndrome

Objective

Whole-exon sequencing (WES) is a commercially available tool for hereditary disease testing. However, little is known about hereditary upper-tract urothelial carcinoma (UTUC) in the Chinese population. This study aims to investigate the prevalence of Lynch syndrome (LS) in UTUC patients with high-risk features and identify the germline mutations of genetic predisposition gene mutations in those patients.

Methods

In total, 354 consecutive UTUC patients undergoing surgery were universally recruited, of whom 108 patients under 60 years old or with a personal/family history of cancer underwent universal immunohistochemistry staining to detect the expression of mismatch repair (MMR) proteins (MLH1, MSH2, MSH6 and PMS2). Patients with deficient or weak MMR protein staining or meeting the Amsterdam II criterion were defined as suspected LS patients, who further experienced microsatellite instability (MSI) (BAT25, BAT26, BAT40, D2S123, D5S346, D17S250) detection and performed WES analysis to explore germline pathogenic/likely pathogenic (P/LP) alterations.

Results

Of 108 patients, 90 (83.3%) cases were included due to younger than 60 years, and 18 cases due to personal/family history. IHC staining identified 21 patients with deficient MMR protein staining and 15 cases with weak MMR protein staining. Three cases met the Amsterdam II criterion but with proficient MMR protein staining. Finally, WES analysis was performed in 38 suspected LS patients and P/LP germline mutations were identified in 22 individuals. Genetic testing confirmed 5 LS cases, including 3 cases with novel mutations. MSI-harboring tumor was discovered in 4 LS cases, one of whom had weak MMR protein staining. Germline P/LP variants in DNA damage repair genes were found in 11 cases. In addition, we found that 11 patients had high- or moderate- penetrance P/LP mutations other than MMR genes. The common P/LP variants in high- or moderate-penetrance genes were 4 in ATM, 3 in MSH6 and KIT, and 2 in APC, NF1 and DICER.

Conclusions

We identified approximately 11% of UTUC cases as suspected LS and at least 1.4% patients with confirmed LS-associated UTUC. In addition, broader germline genetic testing could be considered to screen for cancer severity in hereditary UTUC patients.

Immunohistochemical screening of upper tract urothelial carcinomas for Lynch syndrome diagnostics: a systematic review

OBJECTIVE

To review the effect of universal screening of newly diagnosed upper tract urothelial carcinomas (UTUC) for mismatch repair (MMR) protein loss to aid in Lynch syndrome diagnostics.

MATERIALS AND METHODS

Studies were identified through PubMed on December 1^st, 2021. Eligibility criteria were universal immunohistochemical analyses for at least two MMR proteins in unselected, consecutively collected UTUC cohorts. Exclusion criteria included reviews, case-reports, non-English language, and non-humans. Risk of bias was assessed using a modified Newcastle-Ottawa scale. Meta-analyses were performed to compare the association between clinical criteria and Lynch syndrome diagnoses.

RESULTS

From 12 included studies, 1628 surgically removed UTUC from 1626 patients were screened for MMR protein loss. In 11 studies, 140 of the 1559 patients had tumors with loss (9.0%) with 80.7% showing loss of MSH2, MSH6, or both. In 7 studies, genetic testing confirmed Lynch syndrome diagnosis for 20 of 970 patients (2.1%). In 8 studies, 31 patients were given a clinical Lynch syndrome diagnosis (2.6%). In total, 51 assumed or verified Lynch syndrome patients were identified among 1087 patients (4.7%). Meta-analyses of 3 studies showed significant association between previous cancer diagnosis and Lynch syndrome-associated UTUC (p = 0.038).

CONCLUSION

Despite the few studies conducted and lack of genetic testing, current data suggests that universal screening for MMR protein loss in UTUC may result in Lynch syndrome diagnoses in 4.7%. However, for the screening to be effective for Lynch syndrome diagnostics, follow-up investigations such as genetic testing for MMR variants are needed.

Lynch syndrome in urological practice: diagnosis, therapeutic strategies, and screening for upper tract urothelial carcinoma

PURPOSE OF REVIEW

To provide a comprehensive overview of diagnosis, treatment, and screening for upper tract urothelial carcinoma (UTUC) among Lynch syndrome patients.

RECENT FINDINGS

Lynch syndrome is an autosomal dominant disorder resulting from the germline mutation in the mismatch repair (MMR) system. The Lynch syndrome predisposes to early onset of a broad spectrum of tumours, among which UTUC represents the third most frequent malignancy. Since up to 10% of UTUC can be attributed to Lynch syndrome, a correct recognition of this disease provides the opportunity for patients and their relatives to be properly treated for UTUC and to be followed up for other Lynch syndrome-related malignancies.

SUMMARY

UTUC patients less than 65 years, or UTUC patients with personal history of Lynch syndrome-related cancer, or with one first-degree relative (FDR) less than 50 years with Lynch syndrome-related cancer, or two FDRs with Lynch syndrome-related cancer regardless of age should be referred to molecular testing and subsequent DNA sequencing to confirm Lynch syndrome diagnosis. Considering the increased risk of metachronous recurrence, treatments other than radical nephroureterectomy, such as ureteroscopic laser ablation may represent valuable therapeutic strategies. As Lynch syndrome patients exhibit an approximate 14-fold increased risk of developing UTUC compared with general population, expert recommendations are urgently required in order to point out appropriate screening protocols.

Upper Tract Urothelial Carcinoma in the Lynch Syndrome Tumour Spectrum: A Comprehensive Overview from the European Association of Urology - Young Academic Urologists and the Global Society of Rare Genitourinary Tumors

CONTEXT

Upper tract urothelial carcinoma (UTUC) represents the third most frequent malignancy in Lynch syndrome (LS).

OBJECTIVE

To systematically review the available literature focused on incidence, diagnosis, clinicopathological features, oncological outcomes, and screening protocols for UTUC among LS patients.

EVIDENCE ACQUISITION

Medline, Scopus, Google Scholar, and Cochrane Database of Systematic Reviews were searched up to May 2021. Risk of bias was determined using the modified Cochrane tool. A narrative synthesis was undertaken.

EVIDENCE SYNTHESIS

Overall, 43 studies between 1996 and 2020 were included. LS patients exhibited a 14-fold increased risk of UTUC compared with the general population, which further increased to 75-fold among hMSH2 mutation carriers. Patients younger than 65 yr and patients with personal or family history of LS-related cancers should be referred to molecular testing on tumour specimen and subsequent genetic testing to confirm LS. Newly diagnosed LS patients may benefit from a multidisciplinary management team including gastroenterologist and gynaecologist specialists, while genetic counselling should be recommended to first-degree relatives (FDRs). Compared with sporadic UTUC individuals, LS patients were significantly younger (p = 0.005) and exhibited a prevalent ureteral location (p = 0.01). Radical nephroureterectomy was performed in 75% of patients (5-yr cancer-specific survival: 91%). No consensus on screening protocols for UTUC was achieved: starting age varied between 25-35 and 50 yr, while urinary cytology showed sensitivity of 29% and was not recommended for screening.

CONCLUSIONS

Urologists should recognise patients at high risk for LS and address them to a comprehensive diagnostic pathway, including molecular and genetic testing. Newly diagnosed LS patients should be referred to a multidisciplinary team, while genetic counselling should be recommended to FDRs.

PATIENT SUMMARY

In this systematic review, we analysed the existing literature focused on upper tract urothelial carcinoma (UTUC) among patients with Lynch syndrome (LS). Our purpose is to provide a comprehensive overview of LS-related UTUC to reduce misdiagnosis and improve patient prognosis.

Morphological predictors for microsatellite instability in urothelial carcinoma

Introduction

Microsatellite instability occurs due to a series of mutations in the DNA pairing error repair (Mismatch repair; MMR) genes, which can affect germ cells as occurs in Lynch syndrome, whose patients are at high risk of developing multiple cancers. The loss of MMR protein is commonly determined by immunohistochemical studies. Although the relation between microsatellite instability and urothelial carcinomas has been widely studied, its evaluation is not currently performed in the analysis of urothelial carcinomas.

Methods

In this study, the microsatellite status of 139 urothelial carcinomas was analyzed and their clinicopathological characteristics were evaluated. We identified that 10.3% (13 patients) of urothelial carcinomas had loss of MMR protein expression (9 MLH1; 5 MSH2; 2 PMS2; 2 PSH6; n = 139).

Results

Results suggest that these tumors occur more frequently in males, are more frequently located in the bladder or ureters, and present a high tumor grade with a papillary histological pattern that does not infiltrate the lamina propria or, in the case of infiltrating tumors, that grows into perivesical tissues.

Conclusions

We identified patients with the aforementioned tumor characteristics as patients with a high probability of presenting loss of MMR protein expression, and consider that only these patients should undergo further immunohistochemical and molecular techniques for proper diagnosis. Therefore, we propose that the clinicopathological characteristics found in the present study could become possible markers to determine which cases should undergo additional tests.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of urothelial cancer

A number of immunotherapies have been developed and adopted for the treatment of urothelial cancer (encompassing cancers arising from the bladder, urethra, or renal pelvis). For these immunotherapies to positively impact patient outcomes, optimal selection of agents and treatment scheduling, especially in conjunction with existing treatment paradigms, is paramount. Immunotherapies also warrant specific and unique considerations regarding patient management, emphasizing both the prompt identification and treatment of potential toxicities. In order to address these issues, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts in the field of immunotherapy for urothelial cancer. The expert panel developed this clinical practice guideline (CPG) to inform healthcare professionals on important aspects of immunotherapeutic treatment for urothelial cancer, including diagnostic testing, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with urothelial cancer.

A 25 year perspective on advances in the pathologic assessment and diagnosis of urologic cancers

Over the past 25 years, diagnostic categories in genitourinary pathology have changed dramatically. Prostate cancer reporting incorporated numerous new variant categories, recognized the importance of intraductal carcinoma, and introduced the concept of Grade Groups. Pathologic diagnosis of bladder cancer not only added new variant categories, but also modified the grading of non-invasive urothelial neoplasms and refined staging definitions. Kidney cancer classification expanded from a handful of diagnostic categories to a broad array of additional cancer types defined by unique immunohistochemical and molecular findings. Segregation of penile carcinoma by human papillomavirus status more accurately reflected pathogenesis and helped improve prediction of cancer behavior. Testicular pathology research advanced understanding of germ cell tumor subtypes and their impact on patient outcomes. Finally, adrenal gland pathology has evolved to incorporate a broader recognition of morphological variation and risk factors associated with tumor progression. Taken together, changes in pathology over the past quarter century have revolutionized our approach to genitourinary cancers. This review seeks to highlight some of the many significant changes in genitourinary pathology that have occurred during the past 25 years and emphasize impacts on clinical outcomes or therapy, as relevant.

An Update on Immune Checkpoint Therapy for the Treatment of Lynch Syndrome

During the recent years, immune checkpoint-based therapy has proven highly effective in microsatellite instable (MSI) solid tumors irrespective of organ site. MSI tumors are associated with a defective mismatch repair (MMR) system and a highly immune-infiltrative tumor microenvironment—both characteristics of Lynch syndrome. Lynch syndrome is a multi-tumor syndrome that not only confers a high risk of colorectal and endometrial cancer but also cancer in, eg the upper urinary tract, ovaries, and small bowel. Since the genetic predisposition for Lynch syndrome are pathogenic variants in one of the four MMR genes, MLH1, MSH2, MSH6 or PMS2, most of the Lynch syndrome cancers show MMR deficiency, MSI, and activation of the immune response system. Hence, Lynch syndrome cancer patients may be optimal candidates for immune checkpoint-based therapies. However, molecular differences have been described between sporadic MSI tumors (developed due to MLH1 promoter hypermethylation) and Lynch syndrome tumors, which may result in different treatment responses. Furthermore, the response profile of the rare Lynch syndrome cases may be masked by the more frequent cases of sporadic MSI tumors in large clinical trials. With this review, we systematically collected response data on Lynch syndrome patients treated with FDA- and EMA-approved immune checkpoint-based drugs (pembrolizumab, atezolizumab, durvalumab, avelumab, ipilimumab, and nivolumab) to elucidate the objective response rate and progression-free survival of cancer in Lynch syndrome patients. Herein, we report Lynch syndrome-related objective response rates between 46 and 71% for colorectal cancer and 14–100% for noncolorectal cancer in unselected cohorts as well as an overview of the Lynch syndrome case reports. To date, no difference in the response rates has been reported between Lynch syndrome and sporadic MSI cancer patients.

Papillary Renal Cell Carcinoma in Lynch/Muir-Torre Syndrome with Germline Pathogenic Variant in MSH6 and Molecular Analysis: Report of a Case and Review of the Literature

Lynch syndrome (LS) is an autosomal dominant inherited disorder due to pathogenic variations in the mismatch repair genes, which predisposes to malignancies, most commonly colon and endometrial carcinoma. Muir-Torre syndrome is a subset of LS with cutaneous sebaceous adenoma and keratoacanthoma in addition to the malignancies. Renal cell carcinoma (RCC) in patients with LS is extremely rare. Only 26 cases have been reported and among them, only two cases of papillary RCC. We report a case of synchronous papillary RCC and colonic adenocarcinoma in an 85-year-old male with Lynch/Muir-Torre syndrome. The LS was diagnosed when he presented with multiple sebaceous adenomas and genetic testing showed a pathogenic variant in MSH6 mismatch repair gene. A colonoscopy at that time showed multiple tubular adenomas with high-grade dysplasia. He was lost to follow-up and presented with gastrointestinal bleeding after 20 years. A right colonic mass, and a solid mass in the lower pole of the right kidney, was detected by imaging. Right Colectomy showed a T3N0 mucin-producing adenocarcinoma. Right nephrectomy showed a T3a papillary RCC which was microsatellite stable with MSH6, and KRAS mutation. The 36-month follow-up exams showed additional sebaceous neoplasms, and an absence of metastatic carcinoma. Analysis of the reported cases of RCC in LS show clear cell RCC as the most common type. These tumors showed MLH1 mutation most commonly, unlike the urothelial malignancies in LS which involve MSH2. Among the 4 cases of RCC with MSH6 mutation, three were in females, indicating some gender differences.

Diagnosis of Lynch Syndrome and Strategies to Distinguish Lynch-Related Tumors from Sporadic MSI/dMMR Tumors

Simple Summary

Microsatellite instability (MSI) is a hallmark of Lynch syndrome (LS)-related tumors but is not specific, as most of MSI/mismatch repair-deficient (dMMR) tumors are sporadic. Therefore, the identification of MSI/dMMR requires additional diagnostic tools to identify LS. In this review, we address the hallmarks of LS and present recent advances in diagnostic and screening strategies to identify LS patients. We also discuss the pitfalls associated with current strategies, which should be taken into account in order to improve the diagnosis of LS.

Abstract

Microsatellite instability (MSI) is a hallmark of Lynch syndrome (LS)-related tumors but is not specific to it, as approximately 80% of MSI/mismatch repair-deficient (dMMR) tumors are sporadic. Methods leading to the diagnosis of LS have considerably evolved in recent years and so have tumoral tests for LS screening and for the discrimination of LS-related to MSI-sporadic tumors. In this review, we address the hallmarks of LS, including the clinical, histopathological, and molecular features. We present recent advances in diagnostic and screening strategies to identify LS patients. We also discuss the pitfalls associated with the current strategies, which should be taken into account to improve the diagnosis of LS and avoid inappropriate clinical management.

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

International guidelines for the diagnosis of Lynch syndrome (LS) recommend molecular screening of colorectal cancers (CRCs) to identify patients for germline mismatch repair (MMR) gene testing. As our understanding of the LS phenotype and diagnostic technologies have advanced, there is a need to review these guidelines and new screening opportunities. We discuss the barriers to implementation of current guidelines, as well as guideline limitations, and highlight new technologies and knowledge that may address these. We also discuss alternative screening strategies to increase the rate of LS diagnoses. In particular, the focus of current guidance on CRCs means that approximately half of Lynch-spectrum tumours occurring in unknown male LS carriers, and only one-third in female LS carriers, will trigger testing for LS. There is increasing pressure to expand guidelines to include molecular screening of endometrial cancers, the most frequent cancer in female LS carriers. Furthermore, we collate the evidence to support MMR deficiency testing of other Lynch-spectrum tumours to screen for LS. However, a reliance on tumour tissue limits preoperative testing and, therefore, diagnosis prior to malignancy. The recent successes of functional assays to detect microsatellite instability or MMR deficiency in non-neoplastic tissues suggest that future diagnostic pipelines could become independent of tumour tissue.

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.

The Differential Diagnosis of Medullary-Based Renal Masses

CONTEXT.—

Renal malignancies can be divided into cortical- and medullary-based tumors, the latter of which classically infiltrate the renal parenchyma by extending between nonneoplastic structures. Although high-grade cortical tumors can rarely exhibit the same growth pattern, the infiltrative morphology should elicit a differential diagnosis to be considered in each case. However, these diagnoses can be challenging to distinguish, especially on small renal biopsy samples.

OBJECTIVE.—

To provide an overview of the clinical, gross, and microscopic findings; genetic and molecular alterations; and immunohistochemical evaluation of medullary-based renal tumors and other tumor types with overlapping morphologies and growth patterns.

DATA SOURCES.—

Literature review and personal observations were used to compile the information in this review.

CONCLUSIONS.—

Collecting duct carcinoma is a prototypical medullary-based tumor, and although diagnostic criteria exist, it remains a diagnosis of exclusion, especially with ancillary techniques aiding the recognition of established as well as more recently described neoplasms. Other medullary-based malignancies included in the differential diagnosis include renal medullary carcinoma/renal cell carcinoma unclassified with medullary phenotype, fumarate hydratase-deficient renal cell carcinoma, and upper tract urothelial carcinoma. Moreover, other rare entities should be excluded, including metastatic carcinoma, lymphoma, and melanoma. In addition to potential prognostic differences, accurate diagnoses can have important surgical and clinical management implications.

Universal Mismatch Repair Protein Screening in Upper Tract Urothelial Carcinoma

OBJECTIVES

Universal screening of upper tract urothelial carcinoma (UTUC) for Lynch syndrome by mismatch repair (MMR) protein immunohistochemistry (IHC) has been recommended by some investigators. Herein, we assess this recommendation retrospectively by simulating its performance on a retrospective, unselected cohort of UTUCs, with comparison to the established setting of colorectal and endometrial adenocarcinoma.

METHODS

We assessed for complete loss of MMR protein (MLH1, MSH2, MSH6, and PMS2) IHC in 74 consecutive cases of UTUC and then tabulated clinical and pathologic factors. MMR findings from same-institution colorectal and endometrial adenocarcinomas were tabulated for comparison.

RESULTS

We observed loss of at least one MMR protein in 12% in our UTUC cohort (three MSH2/MSH6, three MSH6 only, one MLH1/PMS2, and two PMS2 only). Of these nine cases (seven males, two females, median age 67 years, five associated with colorectal adenocarcinoma), at least three (4% of the overall cohort) proved to be Lynch syndrome. Overall, MMR loss in UTUC was comparable to colorectal (11%; 50 of 471 cases) and endometrial (12%; 12 of 101 cases) adenocarcinomas.

CONCLUSIONS

The rate of MMR loss observed in UTUC was comparable to that in the established setting of colorectal and endometrial adenocarcinomas, supporting universal UTUC screening at our institution and others.

Immune checkpoints and their inhibitors: Reappraisal of a novel diagnostic and therapeutic dimension in the urologic malignancies

Advances in molecular immunology have unveiled some of the complexity of the mechanisms regulating cellular immune responses and led to the successful targeting of immune checkpoints in attempts to enhance antitumor T cell responses. Surgery, chemotherapy, and radiation therapy have been the mainstay of treatment in urologic malignancies. Immune checkpoint molecules such as cytotoxic T-lymphocyte associated protein-4, programmed cell death protein-1, and programmed death-ligand 1 have been shown to play central roles in evading cancer immunity. Thus these molecules have been targeted by inhibitors for the management of cancers forming the basis of immunotherapy. Immunotherapy is now among the first line therapeutic options for metastatic renal cell carcinomas. In advanced bladder cancer, immunotherapy is the standard of care in the second line and the first line for cisplatin ineligible patients. There continues to be ongoing research to identify the role if any of immunotherapy in testicular, prostatic, and penile cancers. The ideal biomarker for response to immunotherapy is still elusive. Although programmed death-ligand 1 immunohistochemical testing has been widely used across the globe as a biomarker for immunotherapy, companion diagnostic tests have inherent issues with testing and reporting and cannot have universal applicability. Additional biomarkers including, tumor mutational burden, deficient mismatch repair, high microsatellite instability, and immune gene expression profiling are being evaluated in various clinical trials. This review appraises the data of immunotherapy in the management of urologic malignancies.

Role of Tumor Mutation Burden Analysis in Detecting Lynch Syndrome in Precision Medicine: Analysis of 2,501 Japanese Cancer Patients

BACKGROUND

Tumor mutation burden (TMB) is the total exonic mutation count per megabase of tumor DNA. Recent advances in precision medicine occasionally detect Lynch syndrome (LS) by germline sequencing for mismatch-repair (g.MMR) genes but not using TMB. The current study analyzes the utility of TMB in detecting LS.

METHODS

Whole-exome sequencing (ion-semiconductor sequencing) was performed for somatic and germline DNA from 2,501 various cancer patients to detect TMB and g.MMR sequencing. MMR IHC was conducted when high TMB (≥10) was detected in LS-related cancers with an additional condition of wild-type BRAF in colorectal cancers. Target sequencing and multiplex ligation-dependent probe amplification (MLPA) were further performed for g.MMR genes in MMR-deficient cancers (TMB-based g.MMR target sequencing). We compared universal sequencing and TMB-based target sequencing in their sensitivity for detecting LS.

RESULTS

LS was detected in 16 (0.6%) of the 2,501 patients: 1.1% (9/826) of colorectal cancer patients, 16.2% (6/37) of endometrial cancer patients, and 14.3% (1/7) of small intestine cancer patients. TMB-based g.MMR target sequencing (81.3%) showed superior sensitivity for detecting LS than universal g.MMR sequencing (56.3%; P = 0.127) but missed 3 LS patients (1 with a low-TMB cancer, 1 with a BRAF-mutant colorectal cancer, and 1 with an MMR-proficient cancer). Ion-semiconductor sequencing could detect single-nucleotide substitutions but not large deletions. POL-mutated cancers showed extremely high TMBs (48.4-749.2).

CONCLUSIONS

g.MMR target sequencing, combined with TMB, somatic BRAF mutation, and MMR IHC is an effective strategy for detecting LS.

IMPACT

TMB can be a biomarker for detecting LS in precision medicine.

Diagnostic challenges and treatment strategies in the management of upper-tract urothelial carcinoma

Upper-tract urothelial carcinoma (UTUC) is a rare disease, posing many challenges for the treating physician due to the lack of strong evidence-based recommendations. However, novel molecular discoveries and a better understanding of the clinical behavior of the disease lead to a continuous evolution of therapeutic landscape in UTUC. The aim of the review is to provide a comprehensive update of the current diagnostic modalities and treatment strategies in UTUC with a special focus on recent developments and challenges. A comprehensive literature search including relevant articles up to August 2020 was performed using the MEDLINE/PubMed database. Despite several technological improvements, accurate staging and outcome prediction remain major challenges and hamper appropriate risk stratification. Kidney-sparing surgery can be offered in low risk UTUC; however, physician and patient must be aware of the high rate of recurrence and risk of progression due to tumor biology and understaging. The value and efficacy of intracavitary therapy in patients with UTUC remains unclear due to the lack of high-quality data. In high-risk diseases, radical nephroureterectomy with bladder cuff excision and template lymph node dissection is the standard of care. Perioperative systemic chemotherapy is today accepted as a novel standard for advanced cancers. In metastatic or unresectable disease, the therapeutic landscape is rapidly changing due to several novel agents, such as checkpoint inhibitors. While several diagnostic and treatment challenges remain, progress in endoscopic technology and molecular knowledge have ushered a new age in personalized management of UTUC. Novel accurate molecular and imaging biomarkers are, however, still needed to guide decision making as tissue acquisition remains suboptimal. Next generation sequencing and novel agents are promising to rapidly improve patient outcomes.

Prevalence of Lynch syndrome among patients with upper urinary tract carcinoma in a Japanese hospital-based population

BACKGROUND

The prevalence of Lynch syndrome and the use of universal tumor screening to identify Lynch syndrome among unselected patients with upper urinary tract urothelial carcinoma, which is associated with Lynch syndrome, have not been closely investigated yet.

METHODS

A total of 166 tumors from 164 upper urinary tract urothelial carcinoma patients were tested for microsatellite instability and expression of mismatch repair proteins (MLH1, MHS2, MSH6 and PMS2) by immunohistochemistry. Genetic testing was performed for patients suspected of having Lynch syndrome. Clinicopathological factors, including familial and personal cancer history associated with mismatch repair deficiency, were evaluated.

RESULTS

The frequency of high-level microsatellite instability and loss of at least one mismatch repair protein was 2.4% (4/164); the microsatellite instability and immunohistochemistry results showed complete concordance. Of these four patients, three were genetically proven to have Lynch syndrome, while the remaining one was highly suggestive for Lynch syndrome based on their personal cancer history. Univariate analysis showed that age<70 years (P = 0.04), ureter as the tumor location (P = 0.052), previous history/synchronous diagnosis of colorectal cancer (P < 0.01) and fulfillment of the criteria per the revised Bethesda guideline (P < 0.01) tended to be or were significantly associated with high-level microsatellite instability/mismatch repair loss.

CONCLUSIONS

The prevalence of Lynch syndrome among unselected upper urinary tract urothelial carcinoma patients was at least 1.8% in our study population. The screening efficacies of the microsatellite instability test and immunohistochemistry appear equivalent. Universal tumor screening may be a valid approach; however, selective screening methods that consider factors associated with mismatch repair loss/high-level microsatellite instability tumors require further investigation.

Lynch syndrome and urologic malignancies: a contemporary review

PURPOSE OF REVIEW

An overview of urologic malignancies in Lynch syndrome and the current state of research.

RECENT FINDINGS

Upper tract urothelial carcinoma (UTUC) is the third most common malignancy in Lynch syndrome. Establishment and utilization of a sensitive and practical screening method for Lynch syndrome in patients presenting with UTUC is overdue. Next-generation sequencing to evaluate for microsatellite instability (MSI) and detect mutations of mismatch repair (MMR) genes may be the future of Lynch syndrome screening. Epidemiologic data and molecular characterization suggest bladder urothelial carcinoma (BUC) and prostate cancer (PCA) as unrecognized components of Lynch syndrome. Small studies suggest that Lynch syndrome may predispose individuals to adrenocortical carcinoma. Testicular cancer literature focuses on characterizing MSI and MMR gene expression as it relates to chemotherapy sensitivity; outcomes suggest a potential avenue to investigate its relationship to Lynch syndrome.

SUMMARY

Patients with Lynch syndrome have an increased risk of urologic malignancies, including UTUC and likely BUC and PCA. BUC and PCA have a lower penetrance than UTUC for unknown reasons. Established Lynch syndrome-associated genitourinary tumors will necessitate the development of methods to diagnose Lynch syndrome in patients presenting with these malignancies, in addition to establishing screening guidelines for patients with Lynch syndrome-associated genitourinary tumors.

Variation in Blood and Colorectal Epithelia's Key Trace Elements Along with Expression of Mismatch Repair Proteins from Localized and Metastatic Colorectal Cancer Patients

Colorectal cancer (CRC) is an increasingly common medical issue affecting millions worldwide, and contribution of the body's trace elements to CRC is arguable. The concentrations and buffered status of selenium, iron, copper, zinc, and phosphorus in blood and large intestinal tissues of CRC patients are, respectively, variable and vital for cell physiology. The aim of this study was to assess selenium, iron, copper, zinc, and phosphorus variations in blood and colorectal epithelia along with examining the expression of mismatch repair proteins in CRC patients with/without metastasis for potential diagnosis/therapy. Concentrations of selenium, iron, copper, zinc, and phosphorus in blood of healthy versus CRC patients and colorectal epithelia (adenocarcinomatous versus non-adenocarcinomatous/control) were measured in 40 CRC patients (55.87 ± 11.9 years old) with/without metastasis before surgery using ICP-OES. Mismatch repair (MMR) protein expression was analyzed through histopathological/immunohistochemistry assays, which was sparse in 5 CRC patient's colorectal tissues (12%). Compared with healthy individuals, blood and colorectal tissue's levels of phosphorus, copper, and iron were significantly higher in the CRC patients, and more pronounced in metastatic CRC patients; conversely, blood and colorectal tissue's selenium levels were significantly lower in metastatic patients. Unlike blood zinc, cancerous colorectal tissue's zinc concentration was significantly lower in CRC patients compared to healthy control cohorts. There was no significant difference on the measured elements in samples from CRC patients with MMR^- compared to CRC patients with MMR⁺. Receiver operating characteristic analysis revealed a correlation of blood iron, zinc, copper, and phosphorus to CRC, and inappropriately low levels of blood and colorectal selenium correlated with exacerbated metastasis. Altered levels of selenium, iron, copper, zinc, and phosphorus in vivo may impact the pathogenesis and detection of CRC, and their diagnostic/therapeutic potential in CRC would be revealing.

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.

Germline mismatch repair gene variants analyzed by universal sequencing in Japanese cancer patients

Background

Lynch syndrome (LS) is the commonest inherited cancer syndrome caused by pathogenic variants of germline DNA mismatch repair (g.MMR) genes. Genome‐wide sequencing is now increasingly applied for tumor characterization, but not for g.MMR. The aim of this study was to evaluate the incidence and pathogenicity of g.MMR variants in Japanese cancer patients.

Methods

Four g.MMR genes (MLH1, MSH2, MSH6, and PMS2) were analyzed by next generation sequencing in 1058 cancer patients (614 male, 444 female; mean age 65.6 years) without past diagnosis of LS. The g.MMR variant pathogenicity was classified based on the ClinVar 2015 database. Tumor MMR immunohistochemistry, microsatellite instability (MSI), and BRAF sequencing were also investigated in specific cases.

Results

Overall, 46 g.MMR variants were detected in 167 (15.8%) patients, 17 likely benign variants in 119 patients, 24 variants of uncertain significance (VUSs) in 68 patients, two likely pathogenic variants in two patients, and three pathogenic variants in three (0.3%) patients. The three pathogenic variants included two colorectal cancers with MLH1 loss and high MSI and one endometrial cancer with MSH6 loss and microsatellite stability. Two likely pathogenic variants were shifted to VUSs by ClinVar (2018). One colon cancer with a likely benign variant demonstrated MLH1 loss and BRAF mutation, but other nonpathogenic variants showed sustained MMR and microsatellite stability.

Conclusions

Universal sequencing of g.MMR genes demonstrated sundry benign variants, but only a small proportion of cancer patients had pathogenic variants. Pathogenicity evaluation using the ClinVar database agreed with MSI, MMR immunohistochemistry, and BRAF sequencing.

Lynch Syndrome in Urologic Malignancies - What Does the Urologist Need to Know?

Lynch Syndrome (LS) entails a defective DNA mismatch repair system, which is the postreplicative proofreading and editing system, ensuring our genome's integrity. LS predisposes to several cancers, most commonly colorectal and endometrial cancers. LS occurs in approximately 1 in 250-1000 people. LS is associated with urological malignancies with upper tract urothelial carcinoma the most common, although still clinically underestimated. Other urologic malignancies possibly associated with LS include bladder, prostate, testis, and renal cell carcinoma. Ascertaining their true prevalence in LS is mandatory for their and their relatives' diagnosis and treatment. Awareness regarding identifying patients at risk for LS through assessment of personal and familial oncologic history is critical among urologists.

Next-Generation Service Delivery: A Scoping Review of Patient Outcomes Associated with Alternative Models of Genetic Counseling and Genetic Testing for Hereditary Cancer

The combination of increased referral for genetic testing and the current shortage of genetic counselors has necessitated the development and implementation of alternative models of genetic counseling and testing for hereditary cancer assessment. The purpose of this scoping review is to provide an overview of the patient outcomes that are associated with alternative models of genetic testing and genetic counseling for hereditary cancer, including germline-only and tumor testing models. Seven databases were searched, selecting studies that were: (1) full-text articles published ≥2007 or conference abstracts published ≥2015, and (2) assessing patient outcomes of an alternative model of genetic counseling or testing. A total of 79 publications were included for review and synthesis. Data-charting was completed using a data-charting form that was developed by the study team for this review. Seven alternative models were identified, including four models that involved a genetic counselor: telephone, telegenic, group, and embedded genetic counseling models; and three models that did not: mainstreaming, direct, and tumor-first genetic testing models. Overall, these models may be an acceptable alternative to traditional models on knowledge, patient satisfaction, psychosocial measures, and the uptake of genetic testing; however, particular populations may be better served by traditional in-person genetic counseling. As precision medicine initiatives continue to advance, institutions should consider the implementation of new models of genetic service delivery, utilizing a model that will best serve the needs of their unique patient populations.

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

Background:

Lynch syndrome is an autosomal dominant disorder that predisposes individuals affected to certain malignancies. Colon and endometrial cancers are the malignancies most highly associated with Lynch syndrome. However, growing body of evidence links Lynch syndrome to urological cancers.

Objective:

This review aims to clarify the type of urological malignancies that fall under the Lynch-associated cancer spectrum.

Methods:

Using PRISMA guidelines, a systematic search between January 1990 to February 2018, was conducted using the MEDLINE database with the application of the following MESH terms: colorectal neoplasms, hereditary nonpolyposis; DNA mismatch repair; urologic neoplasms; kidney pelvis; ureteral neoplasms; urinary bladder; carcinoma, transitional cell; prostatic neoplasms; testicular neoplasms.

Results:

Upper tract urothelial cancers are well established under the Lynch spectrum. Increasing evidence supports its association with prostate cancer. However, there is, inconclusive and limited evidence for an association with bladder and testicular cancer.

Conclusions:

The evidence underpinning certain urological malignancies associated with Lynch syndrome has expanded in recent years. Our review may assist in providing a summary of the current standing in literature. However, we recommend further investigations to better clarify associations, particularly with prostate, bladder and testicular cancer.

Molecular subtype classification of urothelial carcinoma in Lynch syndrome

Lynch syndrome confers an increased risk for urothelial carcinoma (UC). Molecular subtypes may be relevant to prognosis and therapeutic possibilities, but have to date not been defined in Lynch syndrome‐associated urothelial cancer. We aimed to provide a molecular description of Lynch syndrome‐associated UC. Thus, Lynch syndrome‐associated UCs of the upper urinary tract and the urinary bladder were identified in the Danish hereditary nonpolyposis colorectal cancer (HNPCC) register and were transcriptionally and immunohistochemically profiled and further related to data from 307 sporadic urothelial carcinomas. Whole‐genome mRNA expression profiles of 41 tumors and immunohistochemical stainings against FGFR3, KRT5, CCNB1, RB1, and CDKN2A (p16) of 37 tumors from patients with Lynch syndrome were generated. Pathological data, microsatellite instability, anatomic location, and overall survival data were analyzed and compared with sporadic bladder cancer. The 41 Lynch syndrome‐associated UC developed at a mean age of 61 years with 59% women. mRNA expression profiling and immunostaining classified the majority of the Lynch syndrome‐associated UC as urothelial‐like tumors with only 20% being genomically unstable, basal/SCC‐like, or other subtypes. The subtypes were associated with stage, grade, and microsatellite instability. Comparison to larger datasets revealed that Lynch syndrome‐associated UC shares molecular similarities with sporadic UC. In conclusion, transcriptomic and immunohistochemical profiling identifies a predominance of the urothelial‐like molecular subtype in Lynch syndrome and reveals that the molecular subtypes of sporadic bladder cancer are relevant also within this hereditary, mismatch‐repair defective subset.

Therapeutic strategies for upper tract urothelial carcinoma

INTRODUCTION

Many controversies exist regarding the appropriate management of patients with upper tract urothelial carcinoma (UTUC), including staging, surgical management, use of systemic therapy, and prevention of bladder recurrence. Due to the rarity of this condition, high-level evidence is often lacking and in many cases guidelines are extrapolated from existing evidence on urothelial bladder cancer. Areas covered: This review paper summarizes the evidence on proper diagnosis and staging, surgical techniques, prevention of bladder recurrences, the use of local or systemic treatments in both neoadjuvant and adjuvant settings as well as special consideration for hereditary UTUC. Expert commentary: UTUC is a rare malignancy and slow progress is being made in the acquisition of high-quality evidence in this field. Treatments that facilitate preservation of the kidney are being explored such as advanced endoscopic techniques or partial resection of ureteral disease with seemingly acceptable oncological results. Further prospective evidence is needed.

Recent progress in Lynch syndrome and other familial colorectal cancer syndromes

The current understanding of familial colorectal cancer was limited to descriptions of affected pedigrees until the early 1990s. A series of landscape-altering discoveries revealed that there were distinct forms of familial cancer, and most were related to genes previously not known to be involved in human disease. This review largely focuses on advances in our understanding of Lynch syndrome because of the unique relationship of this disease to defective DNA mismatch repair and the clinical implications this has for diagnostics, prevention, and therapy. Recent advances have occurred in our understanding of the epidemiology of this disease, and the advent of broad genetic panels has altered the approach to germline and somatic diagnoses for all of the familial colorectal cancer syndromes. Important advances have been made toward a more complete mechanistic understanding of the pathogenesis of neoplasia in the setting of Lynch syndrome, and these advances have important implications for prevention. Finally, paradigm-shifting approaches to treatment of Lynch-syndrome and related tumors have occurred through the development of immune checkpoint therapies for hypermutated cancers. CA Cancer J Clin 2018;68:217-231. © 2018 American Cancer Society.