Hereditary leiomyomatosis and renal cell carcinoma

Facial Features of Hereditary Cancer Predisposition

In the age of telehealth medicine, an individual's facial features may provide the only physical clues signaling the presence of a heritable cancer predisposition syndrome. These syndromes include APC-associated polyposis, Birt-Hogg-Dubé syndrome, CYLD cutaneous syndrome, hereditary leiomyomatosis and renal cell cancer, multiple endocrine neoplasia, neurofibromatosis type 1, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome, and tuberous sclerosis complex 1 and 2, among others. Correctly identifying characteristic features is important for genetic and nongenetic specialists as early detection can enable prompt intervention, improving patient outcomes. Advancements in the availability of genetic testing allow patients and their relatives to have more information about their genetic risk profile than before. These changes in clinical pathways, combined with improvements in screening and risk-reducing treatment, highlight the need to outline the cutaneous and morphologic features of high-risk cancer syndromes for clinicians. In this review, we describe the important facial features of hereditary cancer predisposition, with emphasis on diagnosis, cutaneous and extracutaneous manifestations, and screening.

Cutaneous leiomyosarcoma in a case of hereditary leiomyomatosis and renal cell carcinoma syndrome

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is an autosomal-dominant disorder that results from a germline pathogenic variant in the fumarate hydratase (FH) gene on chromosome 1, characterised by renal cell carcinoma (RCC), cutaneous leiomyoma and uterine leiomyoma. Leiomyosarcomas are reported in less than 1% of those with HLRCC. We report a case of a man in his 30s who had a long-standing plaque excised from the left upper arm after undergoing a radical nephrectomy for a fumarate-deficient RCC, with histological exam revealing a grade 1 leiomyosarcoma. Genetic testing confirmed a heterozygous pathogenic variant in the FH gene. This is a rare case of leiomyosarcoma associated with HLRCC, and our patient remains under surveillance with interval abdominal imaging and skin examination. Leiomyosarcomas are difficult to distinguish clinically from their benign counterpart; therefore, histopathological examination is paramount with a low threshold for excision.

Tricarboxylic Acid Cycle Relationships with Non-Metabolic Processes: A Short Story with DNA Repair and Its Consequences on Cancer Therapy Resistance

Metabolic changes involving the tricarboxylic acid (TCA) cycle have been linked to different non-metabolic cell processes. Among them, apart from cancer and immunity, emerges the DNA damage response (DDR) and specifically DNA damage repair. The oncometabolites succinate, fumarate and 2-hydroxyglutarate (2HG) increase reactive oxygen species levels and create pseudohypoxia conditions that induce DNA damage and/or inhibit DNA repair. Additionally, by influencing DDR modulation, they establish direct relationships with DNA repair on at least four different pathways. The AlkB pathway deals with the removal of N-alkylation DNA and RNA damage that is inhibited by fumarate and 2HG. The MGMT pathway acts in the removal of O-alkylation DNA damage, and it is inhibited by the silencing of the MGMT gene promoter by 2HG and succinate. The other two pathways deal with the repair of double-strand breaks (DSBs) but with opposite effects: the FH pathway, which uses fumarate to help with the repair of this damage, and the chromatin remodeling pathway, in which oncometabolites inhibit its repair by impairing the homologous recombination repair (HRR) system. Since oncometabolites inhibit DNA repair, their removal from tumor cells will not always generate a positive response in cancer therapy. In fact, their presence contributes to longer survival and/or sensitization against tumor therapy in some cancer patients.

Case report: response to immunotherapy and association with the fh gene in hereditary leiomyomatosis and renal cell cancer-associated renal cell cancer

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare autosomal dominant syndrome caused by a germline mutation in the fumarate hydratase (FH) gene that manifests with cutaneous leiomyomas, uterine fibroids, and renal cell cancer (RCC). Patients with HLRCC-associated RCC (HLRCC-RCC) have aggressive clinical courses, but there is no standardized therapy for advanced HLRCC-RCC. In this study, we described a case of aggressive HLRCC in a 33-year-old female who exhibited a novel heterozygous germline insertion mutation in exon 8 of the FH gene (c.1126 C > T; p.Q376*). The patient underwent laparoscopic resection of the right kidney, but metastases appeared within 3 months after surgery. Histological staining of the resected tumor revealed high expression levels of programmed cell death-ligand 1 (PD-L1). Therefore, the patient was treated with immunotherapy. The patient achieved a partial response to immunotherapy, and the treatment of metastatic lesions has continued to improve. A thorough literature review pinpointed 76 historical cases of HLRCC-RCC that had undergone immunotherapy. From this pool, 46 patients were selected for this study to scrutinize the association between mutations in the FH gene and the effectiveness of immunotherapy. Our results indicate that immunotherapy could significantly improve the overall survival (OS) of patients with HLRCC-RCC. However, no influence of different mutations in the FH germline gene on the therapeutic efficacy of immunotherapy was observed. Therefore, our study suggested that immunotherapy was an effective therapeutic option for patients with HLRCC regardless of the type of FH germline mutation.

A new missense mutation c.1240A>G in fumarate hydratase gene leads to uterine leiomyoma associated hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome in Chinese

OBJECTIVE

This study presents a detailed analysis of the clinical and genetic characteristics of uterine leiomyoma associated with Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC), combined with exploration of family history, pathology, and management procedures, supported by thorough evidence collection.

METHODS

Blood samples were collected from the proband, and the pathogenic variant was verified using Sanger sequencing. A comprehensive review of family history, FH deficiency pathology, FH and 2SC immunohistochemistry staining was conducted. Functional evidence was derived from clinical and genetic information, supplemented by a literature collection and mutation was reclassified based on ACMG/AMP guidelines.

RESULTS

The study successfully identifies a novel missense mutation (c.1240A>G; p.Lys414Glu) in exon 9 of FH, with no prior reports in existing databases. The patient's phenotype and family history, coupled with evidence collected from the literature, contribute to the preliminary determination of the variant as likely pathogenic. We also emphasize that the importance of combining FH-deficient morphology and immunohistochemical staining with 2SC for enhanced sensitivity.

CONCLUSION

This research adds a novel missense mutation to the repertoire of FH gene variants, emphasizing its likely pathogenic nature based on a multidimensional analysis of phenotype, family history, and literature evidence. The findings enhance our understanding of the genetic landscape associated with FH and underscore the importance of thorough characterization for accurate variant classification.

Whole-Exome Sequencing Revealed a Pathogenic Germline Variant in the Fumarate Hydratase Gene, Leading to the Diagnosis of Hereditary Leiomyomatosis and Renal Cell Cancer

The diagnosis of hereditary skin tumors is difficult for "old" diagnostic tools such as immunohistochemistry. Whole-exome sequencing analysis as a "new" diagnostic tool enables us to make a final diagnosis in spite of unknown hereditary diseases in the past. Hereditary leiomyomatosis and renal cell cancer are autosomal dominant hereditary cancer syndromes characterized by uterine myomas, cutaneous leiomyomas, and aggressive renal cell cancer. The syndrome is associated with pathogenic germline variants in the fumarate hydratase gene. Herein, we demonstrate a pathogenic germline variant of the fumarate hydratase gene in a 60-year-old woman with multiple cutaneous leiomyomas, leading to the diagnosis of hereditary leiomyomatosis and renal cell cancer. Whole-exome sequencing analysis using genomic DNA extracted from peripheral blood leukocytes revealed one germline variant in the FH gene on chromosome 1 (c.290G>A, p.Gly97Asp). She received total hysterectomy due to uterine myoma, which strongly supported the diagnosis. No tumor was detected in her kidney by computed tomography and ultrasound examination. Genetic examination for the mutation of the fumarate hydratase gene is important in order to reach the correct diagnosis and to detect renal cancer at its early stage.

Comparative Review on Cancer Pathology from Aberrant Histone Chaperone Activity

Histone chaperones are integral to chromatin dynamics, facilitating the assembly and disassembly of nucleosomes, thereby playing a crucial role in regulating gene expression and maintaining genomic stability. Moreover, they prevent aberrant histone interactions prior to chromatin assembly. Disruption in histone chaperone function may result in genomic instability, which is implicated in pathogenesis. This review aims to elucidate the role of histone chaperones in cancer pathologies and explore their potential as therapeutic targets. Histone chaperones have been found to be dysregulated in various cancers, with alterations in expression levels, mutations, or aberrant interactions leading to tumorigenesis and cancer progression. In addition, this review intends to highlight the molecular mechanisms of interactions between histone chaperones and oncogenic factors, underscoring their roles in cancer cell survival and proliferation. The dysregulation of histone chaperones is significantly correlated with cancer development, establishing them as active contributors to cancer pathology and viable targets for therapeutic intervention. This review advocates for continued research into histone chaperone-targeted therapies, which hold potential for precision medicine in oncology. Future advancements in understanding chaperone functions and interactions are anticipated to lead to novel cancer treatments, enhancing patient care and outcomes.

Fumarate hydratase as a metabolic regulator of immunity

Tricarboxylic acid (TCA) cycle metabolites have been implicated in modulating signalling pathways in immune cells. Notable examples include succinate and itaconate, which have pro- and anti-inflammatory roles, respectively. Recently, fumarate has emerged as having specific roles in macrophage activation, regulating the production of such cytokines as interleukin (IL)-10 and type I interferons (IFNs). Fumarate hydratase (FH) has been identified as a control point. Notably, FH loss in different models and cell types has been found to lead to DNA and RNA release from mitochondria which are sensed by cytosolic nucleic acid sensors including retinoic acid-inducible gene (RIG)-I, melanoma differentiation-associated protein (MDA)5, and cyclic GMP-AMP synthase (cGAS) to upregulate IFN-β production. These findings may have relevance in the pathogenesis and treatment of diseases associated with decreased FH levels such as systemic lupus erythematosus (SLE) or FH-deficient kidney cancer.

Prevalence and prognosis of hypoxia-inducible factor-2α (HIF-2α) pathway gene mutations across advanced solid tumors

INTRODUCTION

Hypoxia-inducible factor-2α (HIF-2α) modulates the hypoxic response pathway in tumors; however, mutations in pathways (including SDHA, SDHB, SDHC, SDHD, FH, and VHL genes) that are suspected to activate HIF-2α are poorly understood, with limited understanding of the prevalence and clinical prognosis.

METHODS

This retrospective observational study used a de-identified nationwide (US-based) clinico-genomic database (CGDB) across 15 available tumor types.

RESULTS

Among the 9467 adult patients with advanced/metastatic solid tumors included in the analysis, any mutation at the above-mentioned six genes was observed in 1.8% (95% CI: 1.5-2.1) of patients. The mutation prevalence ranged from 0.05% of SDHD to 0.93% of VHL. When further stratified by tumor type, the prevalence of gene mutation in each tumor type was well below 1%, except for VHL with 44% in renal cell carcinomas (RCC). Excluding RCC, the prevalence of any HIF-2α gene mutations in the study population was 0.9% (95% CI: 0.8-1.2). The median overall survival (OS) from 1 and 2 L therapy among patients with any HIF-2α gene mutation was 14.5 (95% CI: 11.5-24.2) and 9.3 (95% CI: 6.0-18.1) months, respectively, compared with 13.4 (95% CI: 12.9-13.9) and 9.8 (95% CI: 9.3-10.4) months among patients without HIF-2α gene mutations.

DISCUSSION AND CONCLUSIONS

The prevalence of HIF-2α related gene mutations was generally low (<1%) across the 15 solid tumor types, except for VHL in RCC. No significant association between HIF-2α gene mutation status and OS was identified among patients evaluated in this study.

A case report of hereditary leiomyomatosis and renal cell carcinoma (HLRCC)

Leiomyomatosis and renal cell carcinoma (HLRCC) are rare autosomal dominant cancer syndromes characterized by cutaneous leiomyoma, uterine leiomyoma, and renal cell carcinoma (RCC). RCC in HLRCC is an aggressive metastatic tumor that develops at a young age. Here, we report the case of a patient with HLRCC who was diagnosed after the spontaneous rupture of a renal tumor. The patient underwent cytoreductive surgery, followed by combination therapy with the immune checkpoint inhibitor (ICI) nivolumab and cabozantinib, a tyrosine kinase inhibitor (TKI); however, no improvements were achieved.

Fumarate Hydratase-Deficient Leiomyoma of the Uterine Corpus: Comparative Morphologic Analysis of Protein-Deficient Tumors With and Without Pathogenic Germline Fumarate Hydratase Gene Mutations

Deficiency of fumarate hydratase (FH) protein expression in uterine corpus leiomyomas may be attributable to either germline or somatic mutations of the FH gene, the former being definitional for the hereditary leiomyomatosis and renal cell cancer syndrome. The authors assess whether, using previously reported FH-associated morphologic features, FH protein-deficient uterine corpus leiomyomas associated with a pathogenic germline mutations of the FH gene (group 1) are distinguishable from FH protein-deficient uterine corpus leiomyomas without such mutations (and whose FH protein loss is presumed to be attributable to somatic/epigenetic inactivation or other unknown phenomena: group 2). Groups 1 and 2 were compared regarding a variety of clinicopathologic features, including 7 core "FH-associated" tumoral morphologic features: staghorn vasculature; alveolar-type edema; bizarre nuclei; chain-like tumor nuclei; hyaline cytoplasmic globules; prominent nucleoli, intranuclear inclusions, and perinucleolar halos; and prominent eosinophilic/fibrillary cytoplasm. Among 2418 patients diagnosed with uterine corpus leiomyoma during the study period, FH-associated morphologic features were reported in 1.5% (37 patients), and FH immunohistochemistry was performed in 29 (1.19%). Fourteen (48.27%) of the 29 patients showed FH protein deficiency by immunohistochemistry. Twelve patients underwent germline testing, of which 8 (66.7%) were classified as group 1 and 4 (33.3%) as group 2. FH protein-deficient tumors were larger (10.44 vs 4.08 cm, P  =  0.01) and associated with younger patients (42.05 vs 47.97, P  =  0.004) than 370 randomly selected uterine leiomyoma controls. Groups 1 and 2 showed no significant differences in patient age and tumor size. In group 1 tumors, the FH-associated morphologic features were generally present diffusely; all group 1 tumors displayed ≥5 FH-associated features, whereas all group 2 tumors displayed <5 FH-associated features (means 6.5  ±  0.53 vs 3.5  ±  1.00, P < 0.001). Notably, eosinophilic/fibrillary cytoplasm and alveolar-type edema were each significantly more prevalent in group 1 tumors than group 2 tumors (P  =  0.018 for both). No single morphologic feature was found to be completely sensitive and specific in making the distinction between group 1 and 2 tumors. Our findings suggest that groups 1 and 2 are unlikely to be morphologically distinguishable by individual morphologic features. Whether there is a combination of features that can reliably make this distinction is unclear and will require additional studies with larger cohorts.

Multiple cutaneous and uterine leiomyomatosis: Reed's syndrome

Reed's syndrome (RS) is a rare autosomal-dominant disorder characterised by multiple cutaneous and uterine leiomyomas, with a strong tendency for renal cell carcinoma (RCC) development. A woman in her 50s, who had previously undergone total abdominal hysterectomy due to multiple uterine leiomyomas, presented with painful nodules on her trunk and right arm for the past 6 years. These nodules were confirmed as leiomyomas through histopathology. Diagnosis of RS was established through clinicopathological correlation and positive family history, particularly her mother's. Early-onset uterine leiomyomas in patients with a similar family history should raise suspicion for RS, necessitating vigilant long-term follow-up. RCC detection requires mandatory renal imaging. Screening family members and providing genetic counselling are crucial.

Hereditary Renal Cancer Syndromes

Familial kidney tumors represent a rare variety of hereditary cancer syndromes, although systematic gene sequencing studies revealed that as many as 5% of renal cell carcinomas (RCCs) are associated with germline pathogenic variants (PVs). Most instances of RCC predisposition are attributed to the loss-of-function mutations in tumor suppressor genes, which drive the malignant progression via somatic inactivation of the remaining allele. These syndromes almost always have extrarenal manifestations, for example, von Hippel-Lindau (VHL) disease, fumarate hydratase tumor predisposition syndrome (FHTPS), Birt-Hogg-Dubé (BHD) syndrome, tuberous sclerosis (TS), etc. In contrast to the above conditions, hereditary papillary renal cell carcinoma syndrome (HPRCC) is caused by activating mutations in the MET oncogene and affects only the kidneys. Recent years have been characterized by remarkable progress in the development of targeted therapies for hereditary RCCs. The HIF2aplha inhibitor belzutifan demonstrated high clinical efficacy towards VHL-associated RCCs. mTOR downregulation provides significant benefits to patients with tuberous sclerosis. MET inhibitors hold promise for the treatment of HPRCC. Systematic gene sequencing studies have the potential to identify novel RCC-predisposing genes, especially when applied to yet unstudied populations.

Fumarate hydratase (FH) and cancer: a paradigm of oncometabolism

Fumarate hydratase (FH) is an enzyme of the Tricarboxylic Acid (TCA) cycle whose mutations lead to hereditary and sporadic forms of cancer. Although more than twenty years have passed since its discovery as the leading cause of the cancer syndrome Hereditary leiomyomatosis and Renal Cell Carcinoma (HLRCC), it is still unclear how the loss of FH causes cancer in a tissue-specific manner and with such aggressive behaviour. It has been shown that FH loss, via the accumulation of FH substrate fumarate, activates a series of oncogenic cascades whose contribution to transformation is still under investigation. In this review, we will summarise these recent findings in an integrated fashion and put forward the case that understanding the biology of FH and how its mutations promote transformation will be vital to establish novel paradigms of oncometabolism.

Unusual Cutaneous Lesions in a 53-Year-Old Female: A Potential Indicator of Underlying Renal Cell Carcinoma

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare autosomal dominant genetic disorder resulting from mutations in the fumarate hydratase (FH) gene. It is characterised by a predisposition to cutaneous and uterine leiomyomas (fibroids) and an aggressive form of renal cell carcinoma (RCC). We report the case of a 53-year-old female who presented with an unusual rash in the context of a personal and family history of uterine leiomyomas requiring hysterectomy. A skin biopsy confirmed cutaneous leiomyomas and subsequent genetic testing demonstrated a pathogenic heterozygous mutation on exon 7 of the FH gene, confirming a diagnosis of HLRCC. Due to the recognised association with renal cell carcinoma in this syndrome, abdominal imaging was performed, which excluded RCC, and the patient was commenced on lifelong surveillance with annual abdominal magnetic resonance imaging.

Hereditary leiomyomatosis and renal cell cancer linked with FH mutations

The diagnosis of hereditary leiomyomatosis and renal cell cancer was revolutionized over 20 years ago by the establishment of links between fumarate hydratase mutations and the syndrome of cutaneous and uterine leiomyomata, with a risk of potentially fatal renal cell carcinoma. Dermatologists can help with the initial clinical diagnosis and a skin biopsy, as well as long-term clinical screening for leiomyosarcoma.

Hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome in a young patient presenting with a large uterus: A case report and review of the literature

Hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome is a rare genetic disorder caused by a germline mutation in the fumarate hydratase (FH) gene. It is clinically characterized by cutaneous leiomyomas, uterine leiomyomas and renal cell cancer. A 31-year-old woman presented with severe abdominopelvic pain associated with severe menorrhagia which required a visit to the emergency department. Computed tomography (CT) showed a severe enlargement of the uterus with newly diagnosed fibroids. Magnetic resonance imaging (MRI) confirmed the finding of an enlarged uterus with mild left and moderate right hydronephrosis and hydroureter. The patient tried to manage the pain with oral over-the-counter medications and heat pads without significant relief. She was recommended to proceed with total abdominal hysterectomy and bilateral salpingectomy. She tolerated the procedure well and had an uneventful postoperative recovery. Pathology showed morphologic features, including the staghorn vessels, alveolar edema, eosinophilic cytoplasmic inclusions and prominent nucleoli which are characteristics for FH-deficient leiomyomas. Genetic testing was positive for a pathogenic variant in the FH gene associated with HLRCC. This case highlights the importance of proceeding with genetic testing in patients with personal and family history of leiomyomas and unusual pathology findings. Early identification of the syndrome can lead to appropriate screening for renal cell carcinoma.

Investigating Fumarate Hydratase-Deficient Uterine Fibroids: A Case Series

Uterine leiomyomas or uterine fibroids are the most common benign soft tissue tumor in reproductive-aged women. Fumarate hydratase deficient (FH-d) uterine fibroids are a rare subtype that is diagnosed only on pathologic evaluation. FH-d uterine fibroids may be the first indicator of hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. Therefore, identifying and understanding the clinical implication and diagnosis of FH-d uterine fibroids is critical for early diagnosis of HLRCC. This case series investigates the uncommon yet significant condition of FH-d uterine fibroids. We examined the clinical manifestation, diagnostic imaging, and histopathological characteristics of FH-d uterine fibroids in five cases identified at our institution over the last ten years. All diagnoses were confirmed by pathologic evaluation after surgical treatment. Gynecologists and pathologists play a critical role in the early diagnosis of FH-d uterine fibroids and must recognize the relevant clinical and pathologic findings that raise suspicion about this diagnosis. The detection of these cases is largely dependent on the pathologist's ability to recognize unique histopathologic features. Once these characteristics are identified, it should prompt a referral to a gynecologist to consider conducting germline genetic testing. The management of FH-d uterine fibroids necessitates a multidisciplinary approach, including proper genetic screening and regular surveillance, especially for renal tumors.

Fumarase Deficiency and Its Effect on Infertility: A Case Series

Background

Fumarase deficiency is an autosomal recessive condition characterized by severe neurologic abnormalities due to homozygous mutations in the fumarate hydratase (FH) gene. Heterozygous carriers of FH mutations have increased risk of developing uterine fibroids that can be associated with hereditary leiomyomatosis and renal cell cancer (HLRCC). The association between FH mutations and infertility remains uncertain. The objective of our study was to characterize the infertility diagnoses, treatments, and outcomes in women presenting to a fertility center who were found to be carriers of fumarase deficiency based on the presence of heterozygous FH mutations.

Case Presentation

A retrospective case series was conducted including 10 women presenting to an academic fertility center who were found to be FH carriers based on genetic carrier screening. Of the 9 women who were engaged in further workup, 2 had imaging results consistent with uterine fibroids. One woman underwent hysteroscopic myomectomy prior to two courses of ovulation induction with timed intercourse (OI/TIC) followed by one successful cycle of IVF. Of the remaining patients, only 1 woman successfully delivered after a cycle of ovulation induction with intrauterine insemination (OI/IUI). Other patients pursuing OI/IUI, OI/TIC, or monitored natural cycles had unsuccessful experiences.

Conclusion

Patients with infertility who are offered genetic testing should be screened for FH mutations, as the carriers are at risk of developing HLRCC-associated uterine fibroids, which can influence fertility and pregnancy. Additional research is needed to investigate the impacts of FH mutations on infertility.

Hereditary Leiomyomatosis and Renal Cell Cancer: A Case Report of Pilar Leiomyomatosis with History of Kidney Cancer and Review of the Literature

Pilar leiomyoma or piloleiomyoma is a benign neoplasm of the smooth muscle arising from the arrector pili muscle. It manifests as brown to red firm papulonodules with sites of predilection being the face, trunk, and extensor surfaces of the extremities. Histologically, the lesions exhibit ill-defined dermal tumors with interlacing fascicles of spindle cells. Some genodermatoses are characterized by the development of visceral tumors and cutaneous leiomyomatosis such as Reed's syndrome, and hereditary leiomyomatosis and renal cell cancer (HLRCC). A 55-year-old male presented with reddish-brown papules and nodules on the face and upper back, accompanied by sharp episodic pain on the face. He had undergone nephrectomy for renal cancer 9 years ago, and his younger brother had similar cutaneous manifestation. Histopathologic findings were consistent with pilar leiomyoma, showing bundles of smooth muscle tumors in the dermis. Based on the clinical information including clinical features, past medical history, and family history, HLRCC was highly suspected. To confirm the diagnosis, whole exome sequencing was performed using peripheral blood, which revealed a novel point mutation (c.739G>A, p.Glu247Lys) in the fumarate hydratase (FH) gene. We describe a confirmed case of HLRCC, which is a genetic disorder with a potential to cause visceral cancers, which dermatologists might overlook as a benign condition.

A Phase II Trial of Guadecitabine in Children and Adults with SDH-Deficient GIST, Pheochromocytoma, Paraganglioma, and HLRCC-Associated Renal Cell Carcinoma

PURPOSE

Succinate dehydrogenase (dSDH)-deficient tumors, including pheochromocytoma/paraganglioma, hereditary leiomyomatosis and renal cell cancer-associated renal cell carcinoma (HLRCC-RCC), and gastrointestinal stromal tumors (GIST) without KIT or platelet-derived growth factor receptor alpha mutations are often resistant to cytotoxic chemotherapy, radiotherapy, and many targeted therapies. We evaluated guadecitabine, a dinucleotide containing the DNA methyltransferase inhibitor decitabine, in these patient populations.

PATIENTS AND METHODS

Phase II study of guadecitabine (subcutaneously, 45 mg/m2/day for 5 consecutive days, planned 28-day cycle) to assess clinical activity (according to RECISTv.1.1) across three strata of patients with dSDH GIST, pheochromocytoma/paraganglioma, or HLRCC-RCC. A Simon optimal two-stage design (target response rate 30% rule out 5%) was used. Biologic correlates (methylation and metabolites) from peripheral blood mononuclear cells (PBMC), serum, and urine were analyzed.

RESULTS

Nine patients (7 with dSDH GIST, 1 each with paraganglioma and HLRCC-RCC, 6 females and 3 males, age range 18-57 years) were enrolled. Two patients developed treatment-limiting neutropenia. No partial or complete responses were observed (range 1-17 cycles of therapy). Biologic activity assessed as global demethylation in PBMCs was observed. No clear changes in metabolite concentrations were observed.

CONCLUSIONS

Guadecitabine was tolerated in patients with dSDH tumors with manageable toxicity. Although 4 of 9 patients had prolonged stable disease, there were no objective responses. Thus, guadecitabine did not meet the target of 30% response rate across dSDH tumors at this dose, although signs of biologic activity were noted.

Kidney tumors associated with germline mutations of FH and SDHB show a CpG island methylator phenotype (CIMP)

Germline mutations within the Krebs cycle enzyme genes fumarate hydratase (FH) or succinate dehydrogenase (SDHB, SDHC, SDHD) are associated with an increased risk of aggressive and early metastasizing variants of renal cell carcinoma (RCC). These RCCs express significantly increased levels of intracellular fumarate or succinate that inhibit 2-oxoglutarate-dependent dioxygenases, such as the TET enzymes that regulate DNA methylation. This study evaluated the genome-wide methylation profiles of 34 RCCs from patients with RCC susceptibility syndromes and 11 associated normal samples using the Illumina HumanMethylation450 BeadChip. All the HLRCC (FH mutated) and SDHB-RCC (SDHB mutated) tumors demonstrated a distinct CpG island methylator phenotype (CIMP). HLRCC tumors demonstrated an extensive and relatively uniform level of hypermethylation that showed some correlation with tumor size. SDHB-RCC demonstrated a lesser and more varied pattern of hypermethylation that overlapped in part with the HLRCC hypermethylation. Combined methylation and mRNA expression analysis of the HLRCC tumors demonstrated hypermethylation and transcription downregulation of genes associated with the HIF pathway, HIF3A and CITED4, the WNT pathway, SFRP1, and epithelial-to-mesenchymal transition and MYC expression, OVOL1. These observations were confirmed in the TCGA CIMP-RCC tumors. A selected panel of probes could identify the CIMP tumors and differentiate between HLRCC and SDHB-RCC tumors. This panel accurately detected all CIMP-RCC tumors within the TCGA RCC cohort, identifying them as HLRCC -like, and could potentially be used to create a liquid biopsy-based screening tool. The CIMP signature in these aggressive tumors could provide both a useful biomarker for diagnosis and a target for novel therapies.

2022 WUOF/SIU International Consultation on Urological Diseases: Genetics and Tumor Microenvironment of Renal Cell Carcinoma

Renal cell carcinoma is a diverse group of diseases that can be distinguished by distinct histopathologic and genomic features. In this comprehensive review, we highlight recent advancements in our understanding of the genetic and microenvironmental hallmarks of kidney cancer. We begin with clear cell renal cell carcinoma (ccRCC), the most common subtype of this disease. We review the chromosomal and genetic alterations that drive initiation and progression of ccRCC, which has recently been shown to follow multiple highly conserved evolutionary trajectories that in turn impact disease progression and prognosis. We also review the diverse genetic events that define the many recently recognized rare subtypes within non-clear cell RCC. Finally, we discuss our evolving understanding of the ccRCC microenvironment, which has been revolutionized by recent bulk and single-cell transcriptomic analyses, suggesting potential biomarkers for guiding systemic therapy in the management of advanced ccRCC.

Hereditary Leiomyomatosis and Renal Cell Carcinoma: A Case Report and Review of the Literature

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare genetic disorder, and individuals tend to develop multiple cutaneous leiomyomas, uterine leiomyomas, and renal cell cancer (RCC). In our study, we report the first case in Saudi Arabia, to our knowledge - a 28-year-old male with a history of right leg leiomyosarcoma post excision two years back who was referred to us with incidental finding of right kidney mass measuring 1.8x2x2.2 cm who underwent right laparoscopic radical nephrectomy, and histopathology reported it as HLRCC and RCC.

The Pathologic and Molecular Genetic Landscape of the Hereditary Renal Cancer Predisposition Syndromes

It is estimated that 5-8% of renal tumors are hereditary in nature with many inherited as autosomal dominant. These tumors carry a unique spectrum of pathologic and molecular alterations, the knowledge of which is expanding in the recent years. Indebted to this knowledge, many advances in treatment of these tumors have been achieved. In this review, we summarize the current understanding of the genetic renal neoplasia syndromes, the clinical and pathologic presentations, their molecular pathogenesis, the advances in therapeutic implications and targeted therapy.

Rare variant in the fumarate hydratase gene found in patients with clinical features of hereditary leiomyomatosis and renal cell cancer (HLRCC): A case series

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an inherited cancer predisposition syndrome caused by autosomal dominant heterozygous pathogenic variants in the fumarate hydratase (FH) gene. FH pathogenic variant carriers are at an increased risk for cutaneous leiomyomas, renal cell cancer, and uterine fibroids. We present a case series of patients identified at two different medical institutions with clinically diagnostic features of HLRCC and a shared rare variant in the FH gene.

HEREDITARY LEIOMYOMATOSIS AND ACUTE LYMPHOBLASTIC LEUKEMIA: a LINK THROUGH FUMARATE DYSHYDRATASE MUTATION?

BACKGROUND

: Hereditary leiomyomatosis (HL) is an autosomal dominant condition due to a variety of fumarate hydratase (FH) mutations in which individuals tend to develop cutaneous leiomyomas, multiple uterine leiomyomas and are at risk for developing aggressive papillary renal cell carcinoma.

CASE PRESENTATION

: A 26-year-old man with a past history of acute lymphoblastic leukemia (T-ALL) presented with numerous painful light brown papules and nodules spread all over his body except for the head, appearing since infancy. Similar lesions were present in his mother's family. A cutaneous biopsy revealed a cutaneous leiomyoma. His mother died from metastatic uterine neoplasia and his sister suffered from leiomyoma of the uterus. No renal cancer was reported in his family. A heterozygous pathogenic variant was detected in the FH gene.

CONCLUSION

: To our knowledge, this is the first case possibly linking HL and T-ALL through FH deficiency.

Metabolic reprogramming in renal cancer: Events of a metabolic disease

Recent studies have established that tumors can reprogram the pathways involved in nutrient uptake and metabolism to withstand the altered biosynthetic, bioenergetics and redox requirements of cancer cells. This phenomenon is called metabolic reprogramming, which is promoted by the loss of tumor suppressor genes and activation of oncogenes. Because of alterations and perturbations in multiple metabolic pathways, renal cell carcinoma (RCC) is sometimes termed as a "metabolic disease". The majority of metabolic reprogramming in renal cancer is caused by the inactivation of von Hippel-Lindau (VHL) gene and activation of the Ras-PI3K-AKT-mTOR pathway. Hypoxia-inducible factor (HIF) and Myc are other important players in the metabolic reprogramming of RCC. All types of RCCs are associated with reprogramming of glucose and fatty acid metabolism and the tricarboxylic acid (TCA) cycle. Metabolism of glutamine, tryptophan and arginine is also reprogrammed in renal cancer to favor tumor growth and oncogenesis. Together, understanding these modifications or reprogramming of the metabolic pathways in detail offer ample opportunities for the development of new therapeutic targets and strategies, discovery of biomarkers and identification of effective tumor detection methods.

Kidney cancer: from genes to therapy

Renal cell carcinoma incidence is rising worldwide with increasing subtype stratification by the World Health Organization. Each subtype has unique genetic alterations, cell biology changes and clinical findings. Such genetic alterations offer the potential for individualized therapeutic approaches that are rapidly progressing. This review highlights the most common subtypes of renal cell carcinoma, including both hereditary and sporadic forms, with a focus on genetic changes, clinical findings and ongoing clinical trials.

Hereditary Leiomyomatosis and Renal Cell Cancer: Recent Insights Into Mechanisms and Systemic Treatment

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare autosomal dominant hereditary cancer syndrome characterized by a predisposition to cutaneous leiomyomas, uterine leiomyomas, and renal cell carcinoma (RCC). It is known to be caused by germline mutations of the fumarate hydratase (FH) gene, which encodes an enzyme component of the citric acid cycle and catalyzes the conversion of fumarate to L-malate. Currently, there is no standardized treatment for HLRCC, which may be due in part to a lack of understanding of the underlying mechanisms. Here, the underlying molecular mechanisms by which the inactivation of FH causes HLRCC are discussed. Additionally, potential therapeutic pharmacological strategies are also summarized to provide new perspectives for the prevention and treatment of HLRCC.

Papillary renal cell carcinoma: Review

Kidney cancer is the 13th most common malignancy globally, and the incidence is rising. Papillary renal cell carcinoma is the second most common subtype, comprising 10-15% of renal cell carcinomas. Though the histologic features of this subtype were initially described in the 1990's, our understanding of the genetic and molecular characteristics of this disease have rapidly evolved over the past decade. In this review, we summarize the contemporary understanding of the clinical, morphologic, radiographic, and genetic characteristics of papillary renal cell carcinoma, as well as clinical considerations, current options for management, and prognosis.

Targeting Mitochondrial Oncometabolites: A New Approach to Overcome Drug Resistance in Cancer

Drug resistance is the main obstacle for a successful cancer therapy. There are many mechanisms by which cancers avoid drug-mediated death, including alterations in cellular metabolism and apoptotic programs. Mitochondria represent the cell's powerhouse and the connection between carbohydrate, lipid and proteins metabolism, as well as crucial controllers of apoptosis, playing an important role not only in tumor growth and progression, but also in drug response. Alterations in tricarboxylic acid cycle (TCA) caused by mutations in three TCA enzymes-isocitrate dehydrogenase, succinate dehydrogenase and fumarate hydratase-lead to the accumulation of 2-hydroxyglutarate, succinate and fumarate respectively, collectively known as oncometabolites. Oncometabolites have pleiotropic effects on cancer biology. For instance, they generate a pseudohypoxic phenotype and induce epigenetic changes, two factors that may promote cancer drug resistance leading to disease progression and poor therapy outcome. This review sums up the most recent findings about the role of TCA-derived oncometabolites in cancer aggressiveness and drug resistance, highlighting possible pharmacological strategies targeting oncometabolites production in order to improve the efficacy of cancer treatment.

Mitochondrial impairments in aetiopathology of multifactorial diseases: common origin but individual outcomes in context of 3P medicine

Mitochondrial injury plays a key role in the aetiopathology of multifactorial diseases exhibiting a "vicious circle" characteristic for pathomechanisms of the mitochondrial and multi-organ damage frequently developed in a reciprocal manner. Although the origin of the damage is common (uncontrolled ROS release, diminished energy production and extensive oxidative stress to life-important biomolecules such as mtDNA and chrDNA), individual outcomes differ significantly representing a spectrum of associated pathologies including but not restricted to neurodegeneration, cardiovascular diseases and cancers. Contextually, the role of predictive, preventive and personalised (PPPM/3P) medicine is to introduce predictive analytical approaches which allow for distinguishing between individual outcomes under circumstance of mitochondrial impairments followed by cost-effective targeted prevention and personalisation of medical services. Current article considers innovative concepts and analytical instruments to advance management of mitochondriopathies and associated pathologies.

A Non-Hereditary Case of Hereditary Leiomyomatosis and Renal Cell Carcinoma Syndrome

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is believed to result from an autosomal dominant mutation in the fumarate hydratase (FH) gene on chromosome 1. It is characterized by leiomyomas, mainly uterine or cutaneous, and renal cell carcinoma (RCC). The most common type of RCC associated with HLRCC is type II papillary RCC although other types are seen. Of note, chromophobe RCC has not been described in previously documented cases of HLRCC. HLRCC is typically associated with germline mutations with occasional somatic mutations reported, however, to the best of our knowledge, none have yielded the full phenotype until now. Herein, we report a case of a 45-year-old woman who underwent a hysterectomy following a year of heavy vaginal bleeding, yielding a diagnosis of uterine leiomyomas. Eight months later, the patient presented with hematuria and was subsequently found to have a left renal mass. Following a left radical nephrectomy, histologic exam revealed a chromophobe RCC with FH deficiency.

Renal cell carcinoma in young FH mutation carriers: case series and review of the literature

Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC) is an autosomal dominant syndrome caused by heterozygous pathogenic germline variants in the fumarate hydratase (FH) gene. It is characterized by cutaneous and uterine leiomyomas and an increased risk of developing renal cell carcinoma (RCC), which is usually adult-onset. HLRCC-related RCC tends to be aggressive and can metastasize even when the primary tumor is small. Data on children and adolescents are scarce. Herein, we report two patients from unrelated Dutch families, with HLRCC-related RCC at the ages of 15 and 18 years, and a third patient with an FH mutation and complex renal cysts at the age of 13. Both RCC’s were localized and successfully resected, and careful MRI surveillance was initiated to monitor the renal cysts. One of the patients with RCC subsequently developed an ovarian Leydig cell tumor. A review of the literature identified 10 previously reported cases of HLRCC-related RCC in patients aged younger than 20 years, five of them presenting with metastatic disease. These data emphasize the importance of recognizing HLRCC in young patients to enable early detection of RCC, albeit rare. They support the recommendations from the 2014 consensus guideline, in which genetic testing for FH mutations, and renal MRI surveillance, is advised for HLRCC family members from the age of 8–10 years onwards.

Hereditary leiomyomatosis and renal cell cancer syndrome - case report and review of the literature

Hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC) is an exceptionally rare autosomal dominant condition caused by a germline heterozygous mutation of the fumarate hydratase gene. It manifests as multiple piloleiomyomas, associated with numerous, early-onset uterine leiomyomas in female patients, as well as a highly increased risk of renal cell carcinoma (RCC), most often type 2 papillary RCC. HLRCC has been described in association with adrenal cortical hyperplasia, pheochromocytoma, adrenal cortical carcinoma, and other solid tumors, but the exact relationship between these disorders has not yet been clarified. We present a case of HLRCC associated with bilateral adrenal cortical hyperplasia and discuss the pathogenesis, clinical and paraclinical features of HLRCC, as well as the adequate management of these patients.

Hereditary leiomyomatosis and renal cell carcinoma: a case series and literature review

Background

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare genodermatosis characterized by cutaneous leiomyoma (CLM), uterine leiomyoma (ULM) and renal cell carcinoma (RCC). Five HLRCC patients are presented with a compiled database of published HLRCC cases to increase understanding of HLRCC. Furthermore, a surveillance program is suggested. Our review is based on a PubMed search which retrieved case reports and cohort studies published before November 2019. The search yielded 97 original papers with a total of 672 HLRCC patients.

Results

CLMs were present in 474 patients (71.5%), developed at the mean age of 28 years. Five patients had cutaneous leiomyosarcomas. ULMs were present in 356 women (83%), while two had uterine leiomyosarcoma. ULMs were diagnosed at a mean age of 32 years, with the youngest diagnosed at age 17 years. The most common surgical treatment for ULMs was hysterectomy, performed at a mean age of 35 years, with the youngest patient being 19 years old. RCCs were present in 189 patients (34.9%), of which half had metastatic disease. The mean age of diagnosis was 36 years with the youngest patient diagnosed with RCC at the age of 11 years.

Conclusion

We suggest a surveillance program for HLRCC including a dermatological examination once every 2 years, annual magnetic resonance imaging starting at the age of 10 years to monitor for early RCCs, annual gynecological examinations from the age of 15 years and counseling regarding risk of hysterectomy and family planning at the age of 18 years. CLMs are often the earliest manifestation of HLRCC, which is why recognizing these lesions, performing a biopsy, and making a prompt referral to genetic counseling is important in order to diagnose HLRCC early.

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.

Filling the gap between risk assessment and molecular determinants of tumor onset

In the past two decades, a ponderous epidemiological literature has causally linked tumor onset to environmental exposure to carcinogens. As consequence, risk assessment studies have been carried out with the aim to identify both predictive models of estimating cancer risks within exposed populations and establishing rules for minimizing hazard when handling carcinogenic compounds. The central assumption of these works is that neoplastic transformation is directly related to the mutational burden of the cell without providing further mechanistic clues to explain increased cancer onset after carcinogen exposure. Nevertheless, in the last few years, a growing number of studies have implemented the traditional models of cancer etiology, proposing that neoplastic transformation is a complex process in which several parameters and crosstalk between tumor and microenvironmental cells must be taken into account and integrated with mutagenesis. In this conceptual framework, the current strategies of risk assessment that are solely based on the 'mutator model' require an urgent update and revision to keep pace with advances in our understanding of cancer biology. We will approach this topic revising the most recent theories on the biological mechanisms involved in tumor formation in order to envision a roadmap leading to a future regulatory framework for a new, protective policy of risk assessment.

Fumarate hydratase as a therapeutic target in renal cancer

INTRODUCTION

Renal cell carcinoma (RCC) is a heterogeneous group of cancers that can occur sporadically or as a manifestation of various inherited syndromes. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is one such inherited syndrome that predisposes patients to HLRCC-associated RCC. These tumors are notoriously aggressive and often exhibit early metastases. HLRCC results from germline mutations in the FH gene, which encodes the citric acid cycle enzyme fumarate hydratase (FH). FH loss leads to alterations in oxidative carbon metabolism, necessitating a switch to aerobic glycolysis, as well as a pseudohypoxic response and consequent upregulation of various pro-survival pathways. Mutations in FH also alter tumor cell migratory potential, response to oxidative stress, and response to DNA damage.

AREAS COVERED

We review the mechanisms by which FH loss leads to HLRCC-associated RCC and how these mechanisms are being rationally targeted.

EXPERT OPINION

FH loss results in the activation of numerous salvage pathways for tumor cell survival in HLRCC-associated RCC. Tumor heterogeneity requires individualized characterization via next-generation sequencing, ultimately resulting in HLRCC-specific treatment regimens. As HLRCC-associated RCC represents a classic Warburg tumor, targeting aerobic glycolysis is particularly promising as a future therapeutic avenue.

Consideration in the management of renal cell carcinoma during the COVID-19 Pandemic

Introduction:

Recently the COVID-19 pandemic became the main global priority; main efforts and health infrastructures have been prioritized in favor of COVID-19 battle and the treatment of benign diseases has been postponed. Renal cell cancer (RCC) patients configure a heterogenous populations: some of them present indolent cases which can safely have postponed their treatments, others present aggressive tumors, deserving immediate care. These scenarios must be properly identified before a tailored therapeutic choice.

Objectives

We propose a risk- based approach for patients with RCC, to be used during this unprecedented viral infection time.

Materials and Methods:

After a literature review focused in COVID-19 and current RCC treatments, we suggest therapeutic strategies of RCC in two sections: surgical approach and systemic therapy, in all stages of this malignance.

Results:

Patients with cT1a tumors (and complex cysts, Bosniak III/IV), must be put under active surveillance and delayed intervention. cT1b-T2a/b cases must be managed by partial or radical nephrectomy, some selected T1b-T2a (≤7cm) cases can have the surgery postponed by 60-90 days). Locally advanced tumors (≥cT3 and or N+) must be promptly resected. As possible, minimally invasive surgery and early hospital discharge are encouraged. Upfront cytoreduction, is not recommendable for low risk oligometastatic patients, which must start systemic treatment or even could be put under surveillance and delayed therapy. Intermediate and poor risk metastatic patients must start target therapy and/or immunotherapy (few good responders intermediate cases can have postponed cytoreduction). The recommendation about hereditary RCC syndromes are lacking, thus we recommend its usual care. Local or loco regional recurrence must have individualized approaches. For all cases, we suggest the application of a specific informed consent and a shared therapeutic choice.

Conclusion:

In the pandemic COVID -19 times, a tailored risk-based approach must be used for a safe management of RCC, aiming to not compromise the oncological outcomes of the patients.

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.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome: Spectrum of imaging findings

PURPOSE

To retrospectively investigate the radiological presentations of HLRCC-associated renal tumors to facilitate accurate lesion characterization and compare these presentations with simple cysts and characteristics of other subtypes of renal cell carcinoma (RCC) as reported in the literature.

METHODS

The MRI and CT imaging characteristics of 39 pathologically confirmed lesions from 30 patients (20 male, 10 female) with HLRCC syndrome were evaluated by two radiologists. Patients had an average age at diagnosis of 43.8 ± 13.1 years. Lesion characteristics including laterality, homogeneity, diameter (cm), nodularity, septations, T1 and T2 signal intensity, enhancement, and restricted diffusion were recorded. Imaging characteristics of the lesions were further compared to characteristics of benign simple cysts surgically removed at the same time point.

RESULTS

The examined lesions had a mean diameter of 5.06 ± 3.80 cm, an average growth rate of 2.91 × 10^-3 cm/day and an estimated annual growth rate of 1.06 cm/year. 50% of lesions demonstrated nodularity, 65% were mostly T2-hyperintense, 83% demonstrated restricted diffusion in solid portions of the lesions, and 65% had well-defined margins. 76% of patients demonstrated extra-renal manifestations, 53% lymphadenopathy, and 43% distant metastasis.

CONCLUSIONS

Our analysis confirmed that while HLRCC-associated renal lesions demonstrate diversity in imaging presentations, the majority are unilateral and solitary, T2-hyperintense, heterogeneous with well-defined margins, and frequently demonstrate restricted diffusion and nodularity.

Role of the mitochondrial stress response in human cancer progression

IMPACT STATEMENT

Dysregulated mitochondria often occurred in cancers. Mitochondrial dysfunction might contribute to cancer progression. We reviewed several mitochondrial stresses in cancers. Mitochondrial stress responses might contribute to cancer progression. Several mitochondrion-derived molecules (ROS, Ca2+, oncometabolites, exported mtDNA, mitochondrial double-stranded RNA, humanin, and MOTS-c), integrated stress response, and mitochondrial unfolded protein response act as retrograde signaling pathways and might be critical in the development and progression of cancer. Targeting these mitochondrial stress responses may be an important strategy for cancer treatment.

Fumarase-deficient uterine leiomyoma: a case of a rare entity and surgical innovation

We report a case of a 47-year-old female, with strong preoperative clinical and radiological suspicious of uterine leiomyosarcoma who underwent a total abdominal hysterectomy. Despite the final histology concluded as benign uterine leiomyoma, the loss of fumarate hydratase expression of the same specimen still put her at risk of having hereditary leiomyomatosis and renal cell carcinoma syndrome. Intraoperatively, an obstetric vacuum cup was used for uterine manipulation to avoid breaching of the uterine serosa.

Inherited kidney cancer syndromes

PURPOSE OF REVIEW

To describe current paradigms for genetic testing, screening, and treatment of patients with inherited kidney cancer syndromes.

RECENT FINDINGS

We describe various new aspects of hereditary kidney cancer. Recent data now support that hereditary kidney cancer may account for 5-8% of kidney cancers diagnosed. Methods of testing have evolved including the introduction of multigene next-generation sequencing panels. We continue to learn more about the natural history and management of classic hereditary cancer syndromes. New emerging conditions with lower kidney cancer penetrance have been recognized adding the growing list of syndromes associated with kidney cancer development. The surgical management strategies of enucleation remain however systemic therapy options are being explored both for localized and advanced settings.

SUMMARY

Genetic predisposition to kidney cancer is likely more common than once thought. Knowledge of clinical manifestation and genetic testing strategies are needed to properly identify and treat patient and their families.

Oncometabolites in renal cancer

The study of cancer metabolism has evolved vastly beyond the remit of tumour proliferation and survival with the identification of the role of 'oncometabolites' in tumorigenesis. Simply defined, oncometabolites are conventional metabolites that, when aberrantly accumulated, have pro-oncogenic functions. Their discovery has led researchers to revisit the Warburg hypothesis, first postulated in the 1950s, of aberrant metabolism as an aetiological determinant of cancer. As such, the identification of oncometabolites and their utilization in diagnostics and prognostics, as novel therapeutic targets and as biomarkers of disease, are areas of considerable interest in oncology. To date, fumarate, succinate, L-2-hydroxyglutarate (L-2-HG) and D-2-hydroxyglutarate (D-2-HG) have been characterized as bona fide oncometabolites. Extensive metabolic reprogramming occurs during tumour initiation and progression in renal cell carcinoma (RCC) and three oncometabolites - fumarate, succinate and L-2-HG - have been implicated in this disease process. All of these oncometabolites inhibit a superfamily of enzymes known as α-ketoglutarate-dependent dioxygenases, leading to epigenetic dysregulation and induction of pseudohypoxic phenotypes, and also have specific pro-oncogenic capabilities. Oncometabolites could potentially be exploited for the development of novel targeted therapies and as biomarkers of disease.

Case of Hereditary Papillary Renal Cell Carcinoma Type I in a Patient With a Germline MET Mutation in Russia

Hereditary papillary renal carcinoma (HPRC) is a rare autosomal dominant disease characterized by the development of multiple papillary type I renal cell carcinomas. This hereditary kidney cancer form is caused by activating mutations in MET. Descriptions of patients with HPRC are scarce in the world literature, and no cases have been described in open sources in Russia. Here, we describe a 28-year-old female Russian patient with 7 and 10 primary papillary renal cell carcinomas in the left and right kidneys, respectively. The patient did not have a family history of any of the known hereditary cancer syndromes. A comprehensive medical examination was performed in 2016 including computed tomography and pathomorphological analysis. The observed tumors were resected in a two-step surgical treatment. In February 2019, no sign of disease progression was detected in follow-up medical examination. Molecular genetic analysis revealed the germline heterozygous missense variant in MET: c.3328G>A (p.V1110I; CM990852). We have discussed the biological effects of the detected mutation and the utility of DNA diagnostics for treating patients with HPRC.