DNA repair genes and prognosis in sporadic forms of urothelial carcinoma of the upper urinary tract

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.

Nectin-4 and DNA mismatch repair proteins expression in upper urinary tract urothelial carcinoma (UTUC) as a model for tumor targeting approaches: an ImGO pilot study

BACKGROUND

Upper urinary tract urothelial carcinoma (UTUC) accounts for only about 5-10% of all urothelial cancers and is characterized by an aggressive and frequently rapidly fatal behavior. However, detailed knowledge of its molecular profile is still lacking.

MATERIALS AND METHODS

We identified, by chart analysis, patients who underwent radical nephroureterectomy or diagnostic biopsy for UTUC between January 2015 and August 2020 at the Santa Maria Hospital of Terni, in Italy. Eligible patients were required to have also adequate clinical informations and follow-up details. The primary objective of the study was to evaluate DNA mismatch repair (MMR) proteins and Nectin-4 immunohistochemical expression in UTUC, looking also for an eventual correlation between these molecular features. The secondary objective was to investigate genomic instability in the case of a MMR protein loss. Expression of proteins was assessed by using immunohistochemistry and microsatellite instability (MSI) performed by next generation sequencing. Nectin-4 expression was reported using an intensity scoring system (score, 0-3+), instead the expression of DNA MMR proteins was indicated as present (no loss) or not present (loss).

RESULTS

Thirty four cases have been evaluated and 27 considered eligible for the study with their tumor samples analyzed. Nectin-4 was found to be expressed in 44% of cases and 18.5% of patients showed defective-MMR phenotype. We found a significant correlation between Nectin-4 expression and MSH2/MSH6 protein loss. Out of 7 patients with DNA MMR proteins loss or equivocal phenotype, 3 showed MSI.

CONCLUSIONS

Our pilot study suggest a possible relationship between Nectin-4 and DNA MMR protein expression in UTUC and a clinically significant correlation between defective MMR phenotype and genomic instability. Because of the possible implications of these data for innovative treatment approaches, the need for further studies in this area is warranted.

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.

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.

Association between DNA mismatch repair gene polymorphisms and platinum-based chemotherapy toxicity in non-small cell lung cancer patients

Background

Chemotherapy toxicity is a serious problem from which non-small cell lung cancer (NSCLC) patients suffer. The mismatch repair (MMR) system is associated with platinum-based chemotherapy toxicity in NSCLC patients. In this study, we aimed to investigate the relationship between genetic polymorphisms in the MMR pathway and platinum-based chemotherapy toxicity in NSCLC patients.

Methods

A total of 220 Chinese lung cancer patients who received at least two cycles of platinum-based chemotherapy were recruited for this study. Toxicity was evaluated in each patient after two cycles of chemotherapy. A total of 44 single nucleotide polymorphisms were selected to investigate their associations with platinum-based chemotherapy toxicity.

Results

MutS homolog 2 (MSH2) rs6544991 [odds ratio (OR) 2.98, 95% confidence interval (CI) 1.20–7.40, P = 0.019] was associated with gastrointestinal toxicity in the dominant model; MSH3 rs6151627 (OR 2.38, 95% CI 1.23–4.60, P = 0.010), rs6151670 (OR 2.05, 95% CI 1.07–3.93, P = 0.031), and rs7709909 (OR 2.38, 95% CI 1.23–4.64, P = 0.010) were associated with hematologic toxicity in the dominant model. Additionally, MSH5 rs805304 was significantly associated with overall toxicity (OR 2.21, 95% CI 1.19–4.09, P = 0.012), and MSH5 rs707939 was significantly associated with both overall toxicity (OR 0.42, 95% CI 0.23–0.76, P = 0.004) and gastrointestinal toxicity (OR 0.44, 95% CI 0.20–0.96, P = 0.038) in the dominant model.

Conclusion

Genetic polymorphisms in the MMR pathway are potential clinical markers for predicting chemotherapy toxicity in NSCLC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40880-016-0175-2) contains supplementary material, which is available to authorized users.

Upper tract urothelial carcinomas: frequency of association with mismatch repair protein loss and lynch syndrome

Increased risk for upper tract urothelial carcinoma is described in patients with Lynch syndrome, caused by germline mutations in mismatch repair genes. We aimed to identify the frequency of mismatch repair protein loss in upper tract urothelial carcinoma and its potential for identifying an association with Lynch syndrome. We queried our database to identify upper tract urothelial carcinomas. Patients were cross-referenced for history of colorectal carcinoma or other common Lynch syndrome-associated neoplasms to enrich for potential Lynch syndrome cases. Tumor histopathologic characteristics were reviewed and each case was analyzed for loss of mismatch repair proteins, MLH1, MSH2, MSH6, and PMS2, by immunohistochemistry. Of 444 patients with upper tract urothelial carcinoma, a subset of 215 (encompassing 30 with upper tract urothelial carcinoma and another common Lynch syndrome-associated neoplasm) was analyzed for loss of mismatch repair protein expression. Of 30 patients with Lynch syndrome-associated neoplasms, six had documented Lynch syndrome, including two with Muir-Torre syndrome. Mismatch repair protein loss was identified in 7% of total upper tract urothelial carcinomas and 30% of patients with Lynch syndrome-associated neoplasms (including all patients with Lynch syndrome/Muir-Torre syndrome). Of patients without history of Lynch syndrome-associated neoplasms, 5 of 184 (2.7%) had loss of mismatch repair protein expression. Twelve cases with mismatch repair protein loss demonstrated loss of MSH2 and MSH6, and 2 had isolated loss of MSH6. MLH1 and PMS2 expression were consistently retained. Although increased intratumoral lymphocytes, inverted growth, pushing tumor-stromal interface, and lack of nuclear pleomorphism were more commonly seen in cases with mismatch repair protein loss, only intratumoral lymphocytes and presence of pushing borders were statistically significant. MLH1 and PMS2 testing appear to have little utility in upper tract urothelial carcinoma; however, mismatch repair protein loss of MSH2 and/or MSH6 by immunohistochemistry seems relatively sensitive and specific for identifying patients with potential Lynch syndrome.

Prognostic Genetic Signatures in Upper Tract Urothelial Carcinoma

Urothelial carcinoma is a highly heterogeneous disease that can arise throughout the entire urothelial lining from the renal pelvis to the proximal urethra. Upper tract urothelial carcinoma (UTUC) is rare, and while it shares many similarities with urothelial carcinoma of bladder (UCB), there are also significant differences between UTUC and UCB regarding clinical management and outcomes. No major advances have been made recently in the development of new systemic therapies for urothelial carcinoma, partly due to the lack of understanding of underlying molecular pathogenetic mechanisms. In the past decade, the emergence of next-generation sequencing has greatly enabled genomic characterization of tumor samples. Researchers are currently exploring a personalized approach to augment traditional clinical decision-making based on genetic alterations. In the present review, we summarize current genomic advances in UTUC and discuss the potential implications of these developments for developing prognostic and predictive biomarkers.