Genotypic and Phenotypic Characteristics of Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome in Korean Patients

AKR1B10 Is a New Sensitive and Specific Marker for Fumarate Hydratase-Deficient Renal Cell Carcinoma

Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a rare and distinct subtype of renal cancer caused by FH gene mutations. FH negativity and s-2-succinocysteine (2SC) positivity on immunohistochemistry can be used to screen for FH-deficient RCC, but their sensitivity and specificity are not perfect. The expression of AKR1B10, an aldo-keto reductase that catalyzes cofactor-dependent oxidation-reduction reactions, in RCC is unclear. We compared AKR1B10, 2SC, and FH as diagnostic biomarkers for FH-deficient RCC. We included genetically confirmed FH-deficient RCCs (n = 58), genetically confirmed TFE3 translocation RCCs (TFE3-tRCC) (n = 83), clear cell RCCs (n = 188), chromophobe RCCs (n = 128), and papillary RCCs (pRCC) (n = 97). AKR1B10, 2SC, and FH were informative diagnostic markers. AKR1B10 had 100% sensitivity and 91.4% specificity for FH-deficient RCC. The nonspecificity of AKR1B10 was shown in 26.5% of TFE3-tRCCs and 21.6% of pRCCs. 2SC showed 100% sensitivity and 88.9% specificity. However, nonspecificity for 2SC was evident in multiple RCCs, including pRCC, TFE3-tRCC, clear cell RCCs, and chromophobe RCCs. FH was 100% specific but 84.5% sensitive. AKR1B10 served as a highly sensitive and specific diagnostic biomarker. Our findings suggest the value of combining AKR1B10 and 2SC to screen for FH-deficient RCC. AKR1B10+/2SC+/FH- cases can be diagnosed as FH-deficient RCC. Patients with AKR1B10+/2SC+/FH+ are highly suspicious of FH-deficient RCC and should be referred for FH genetic tests.

A Missense Mutation c.1132G > A in Fumarate Hydratase (FH) Leads to Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC) Syndrome and Insights into Clinical Management in Uterine Leiomyomata

BACKGROUND

HLRCC syndrome is a hereditary cancer predisposition syndrome caused by heterozygous germline pathogenic variant of the fumarate hydratase (FH) gene and characterized by cutaneous leiomyomas (CL), uterine leiomyomas (UL), and renal cell carcinoma (RCC). Loss of function variant of FH gene inactivates the Kreb's cycle enzyme activity and predisposes individuals with such variant to the development of HLRCC.

METHODS

Next-generation sequencing (NGS) and Sanger confirmation were given to family members accessible. Following that, a functional study in vitro was performed to further confirm the pathogenicity of the variant. FH-Wild type (FH-WT) and FH-mutant (FH-MUT) (E378K) plasmid were constructed and transfected into 293T and uterine leiomyoma cell lines, respectively. Proliferation assessment was executed to show how this mutation affects the growth of uterine leiomyoma. qPCR and Western blotting were performed to investigate the change of transcription and translation of FH with mutation (E378K), and FH enzyme assay activity were tested in 293T cells with mutation and wild-type plasmids.

RESULTS

Here, we presented two families with the same missense variant (c.1132G > A) that has not been reported as a germline mutation in hereditary uterine leiomyomas before and classified as VUS in gene databases. Our in vitro experiments supported the pathogenicity of this missense variant, especially in uterine leiomyomata.

CONCLUSIONS

According to the American College of Medical Genetics (ACMG) guideline, the E378K variant was classified as likely pathogenic (with evidence PS4_support, PS3_support, PM2_support, PP1, PP3 and PP4 evidence). Further insights into clinical management in uterine leiomyomata were discussed and should be practiced in gynecological clinical settings.

The spectrum of clinical and genetic findings in hereditary leiomyomatosis and renal cell cancer (HLRCC) with relevance to patient outcomes: a retrospective study from a large academic tertiary referral center

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant condition attributed to pathogenic variants in fumarate hydratase (FH) and presents with cutaneous leiomyomas (CLMs), uterine leiomyomas (ULMs) and renal cell cancer (RCC). The objective of this study was to characterize the spectrum of clinical and genetic findings in HLRCC at a large academic tertiary care referral center with a focus on dermatologic manifestations. Fifty-seven patients, 41 female and 16 male, with 27 unique pathogenic or likely-pathogenic FH variants were identified from 38 families. Mean age of HLRCC diagnosis was 44.4 years (range 8-82). CLMs were the primary reason for referral in 49.1% (n=28). CLMs were present in 43/56 patients who underwent full skin examination. Three of these 56 patients were diagnosed with cutaneous leiomyosarcoma. Incidence of ULMs was 37/41 female patients; no uterine leiomyosarcomas were observed. RCC was observed in 6/57 patients (mean age of diagnosis: 47.3 years (range 28-79)). CLMs predated RCC in the 3 patients diagnosed with both. Dermatologists have an opportunity to recognize cutaneous manifestations of HLRCC, including cutaneous leiomyomas and rarely cutaneous leiomyosarcomas, and refer for genetic evaluation to provide definitive diagnosis. Identification of HLRCC can promote family cascade testing and screening for RCC.

Family History of Cancers Increases Risk of Renal Cell Carcinoma in a Chinese Population

Purpose

To explore the impact of family history (FH) on renal cell carcinoma (RCC) and its pathological subtype clear cell RCC (ccRCC) in a Chinese population; a significant association has previously been determined not only in familial cancer syndrome but also in sporadic cases in western populations.

Methods

Consecutive patients with kidney tumors from October 2017 to May 2021 at a tertiary hospital in Shanghai were enrolled in the study. Demographic and clinical information was collected, including age, gender, FH (positive or negative, types of cancers, degree of relatives, etc.), pathological diagnosis, and Fuhrman grades.

Results

A positive FH of any cancer was observed in 26.5% of the RCC patients, while only 16.8% patients with benign kidney tumor were found to have a positive FH. A strong correlation was observed between FH of any cancers in first-degree relatives and RCC (odds ratio [OR]=4.60, 95% confidence interval [CI]: 1.95–10.85, P=5.50×10⁻⁵) or ccRCC (OR=4.63, 95% CI: 1.95–11.02, P=9.63×10⁻⁵). In subgroup analysis, FH of digestive cancers was significantly associated with RCC (OR=4.42, 95% CI: 1.35–14.51, P=0.005) or ccRCC (OR=4.14, 95% CI: 1.25–13.75, P=6.84×10⁻⁴). Similar results were found in multivariate analyses. However, no significant association was observed between FH and age at onset.

Conclusion

FH was an independent risk factor for RCC and ccRCC in this Chinese population. FH of any cancer in first-degree relatives and FH of digestive cancers were found to be the most significant risk factors for kidney cancers.

Clinicopathological and molecular characteristics of fumarate-hydratase-deficient uterine smooth muscle tumors: A single-center study of 52 cases

AIMS

The fumarate hydratase (FH) gene germline mutations cause hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC), predisposing carriers to uterine and cutaneous leiomyomas and renal cell carcinoma (RCC). In this study, we aim to investigate morphology and the correlation between FH mutation in FH-deficient (FH-d) uterine smooth muscle tumors (uSMTs).

METHODS AND RESULTS

We conducted immunohistochemical staining in 161 cases of uSMTs to detect FH deficiency. We identified 52 (52/161, 32%) cases of FH-d, including 34 leiomyomas with bizarre nuclei, 10 uSMTs of uncertain malignant potential (STUMPs), 4 cellular leiomyomas, 3 usual type leiomyomas, and 1 leiomyosarcoma. Patients with FH-d were aged 24-67 years (median, 40 years). The most common FH-d morphological features included staghorn-shaped blood vessels (87%), bizarre nuclei (81%), alveolar pattern edema (65%), macronucleoli surrounded by a halo (65%), cytoplasmic eosinophilic globules (56%), and chain-like distribution of smooth muscle cells (52%). A targeted next generation sequence was performed in 11 of 52 FH-d tumors. Five (5/11, 45%) cases were found with FH germline mutations, including four leiomyomas with bizarre nuclei and one STUMP. The median age of patients with germline FH mutation was 30 years. The germline mutations including three pathogenic, one likely pathogenic, and one rare uncertain clinical significance variants.

CONCLUSIONS

Our results revealed that FH-d uSMTs usually exhibit the distinct morphology features and high frequency of FH germline mutations. The combination of predictive morphology evaluation, FH immunotype and molecular testing is helpful for the screening of HLRCC in uSMTs.