Assessment of Risk of Hereditary Predisposition in Patients With Melanoma and/or Mesothelioma and Renal Neoplasia

Prevalence of CDKN2A, CDK4, POT1, BAP1, MITF, ATM, and TERT Pathogenic Variants in a Single-Center Retrospective Series of Patients With Melanoma and Personal or Family History Suggestive of Genetic Predisposition

INTRODUCTION

Approximately 20%-45% of familial melanoma (FM) cases are associated with genetic predisposition.

OBJECTIVES

This single-center retrospective study aimed to assess the frequency of pathogenic variants (PV) in the main melanoma-predisposing genes in patients with cutaneous melanoma and investigate the clinical predictors of genetic predisposition.

METHODS

Patients included were those diagnosed with cutaneous melanoma at the Dermatology Unit of the University Hospital of Verona, Italy, from 2000 to 2022, presenting at least one of the followings: multiple melanomas (≥ 3); personal/family history of pancreatic cancer (PC) (up to 2nd-degree relatives); ≥ 2 1st-degree relatives with melanoma; ≥ 1 1st-degree relatives with early-onset (<45 years) melanoma and tested for CDKN2A, CDK4, POT1, BAP1, MITF, ATM, and TERT.

RESULTS

During the study period, 35 out of 1320 patients (2.7%) underwent genetic testing. Four patients (11.4%) harbored a PV in a melanoma-predisposing gene, three in CDKN2A (8.6%), and one in MITF (2.9%). Variants currently classified as being of unknown clinical significance (VUS) were detected in CDKN2A (N = 1), MITF (N = 1), and ATM (N = 2). Family history of PC and ≥5 melanomas, personal history of ≥50 nevi, and ≥4 melanomas were significantly associated with PV in tested genes (P < 0.05).

CONCLUSIONS

The prevalence of PV in predisposing genes in FM was lower than previously reported in Italian registries. Possible reasons include deleterious variants in untested intermediate/low-penetrance genes or yet-to-be-discovered high-penetrance genes and environmental risk factors. A family history of PC, a high number of nevi and melanomas predict a monogenic predisposition to melanoma.

BRCA1-associated protein 1: Tumor predisposition syndrome and Kury-Isidor syndrome, from genotype-phenotype correlation to clinical management

The BAP1 tumor suppressor gene encodes a deubiquitinase enzyme involved in several cellular activities, including DNA repair and apoptosis. Germline pathogenic variants in BAP1 have been associated with heritable conditions including BAP1 tumor predisposition syndrome 1 (BAP1-TPDS1) and a neurodevelopmental disorder known as Kury-Isidor syndrome (KURIS). Both these conditions are caused by monoallelic, dominant alterations of BAP1 but have never been reported in the same subject or family, suggesting a mutually exclusive genotype-phenotype correlation. This distinction is extremely important considering the early onset and aggressive nature of the types of cancer reported in individuals with TPDS1. Genetic counseling in subjects with germline BAP1 variants is fundamental to predicting the effect of the variant and the expected phenotype, assessing the potential risk of developing cancer for the tested subject and the family members who may carry the same variant and providing the multidisciplinary clinical team with the proper information to establish precise surveillance and management protocols.

Genomic analysis of spermatocytic tumors demonstrates recurrent molecular alterations in cases with malignant clinical behavior

Spermatocytic tumor (ST) is a rare type of germ cell tumor that occurs exclusively in the postpubertal testis and typically affects elderly men. Most STs are benign, but rare cases exhibit aggressive clinical behavior, often in association with transition to sarcomatoid histology. Limited molecular analyses have been performed on STs; therefore, their genomic and epigenomic features remain incompletely described. Twenty-seven samples from 25 individual patients were analyzed with a combination of DNA sequencing panels, genomic methylation profiling, SNP array, isochromosome (12p) [i(12p)] FISH, and immunohistochemistry. The series included five metastasizing tumors (three with sarcomatoid transformation, one anaplastic, and one conventional) and 20 non-metastasizing tumors (14 anaplastic and six conventional). Anaplastic tumors comprised a monomorphic population of intermediate-sized neoplastic cells, as previously described. Multiomic analyses demonstrated that there were two genomic subgroups of STs: one with diploid genomes and hotspot RAS/RAF variants and the other with global ploidy shift and absence of recurrent mutations. Relative gain of chromosome 9 was a consistent finding in both subgroups. A comparison of metastasizing and non-metastasizing cases demonstrated that aggressive behavior was associated with the acquisition of pathogenic TP53 mutations and/or relative gains of 12p/i(12p). In cases with sarcomatoid transformation, TP53 mutations seem to underlie the transition to sarcomatoid histology. Genomic methylation analysis demonstrated that aggressive cases with gains of 12p cluster closer to pure seminomas than to STs without gains of 12p. In conclusion, STs include two genomic subgroups, characterized by global ploidy shifts without recurrent mutations and diploid genomes with RAS/RAF hotspot mutations, respectively. Biologic progression was associated with relative gains of 12p and TP53 mutations. The findings in STs with relative gains of 12p suggest that they may exhibit biologic characteristics akin to those seen in germ cell neoplasia in situ-related germ cell tumors rather than non-germ cell neoplasia in situ-derived STs. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Hereditary Renal Cell Carcinoma Syndromes

Up to 5% of renal cell carcinomas (RCCs) can be associated with a known hereditary RCC syndrome. In addition to the well-characterized RCC syndromes, there are also emerging syndromes associated with increased RCC risk. In the last few years, consensus guidelines have outlined recommendations for who should be referred for genetic evaluation, and what screening should be done for early detection of RCC. Although much progress has been made, work is still needed-guidelines are still mostly based on expert opinion and the role of emerging genetic associations will need to be clarified.

Case report: Mesothelioma and BAP1 tumor predisposition syndrome: Implications for public health

BRCA-1 associated protein 1 (BAP1) tumour predisposition syndrome (TPDS) is a hereditary condition characterised by germline mutation of the tumour suppressor BAP1. This disorder is associated with the development of various benign and malignant tumours, mainly involving the skin, eyes, kidneys, and mesothelium. In this article, we report the case of a man recruited through the Apulia (Southern Italy) Mesothelioma Regional Operational Centre of the National Register of Mesotheliomas, who suffered from uveal melanoma, renal cancer, and mesothelioma, and a familial cluster of BAP1 germline mutations demonstrated by molecular analyses. The family members of the proband developed multiple malignancies. As tumours arising in this context have specific peculiarities in terms of clinical behaviour, identification of this condition through appropriate genetic counselling should be considered for adequate primary, secondary, and tertiary prevention measures for offspring.