Hereditary Renal Cancer Syndrome Research Articles

Malignant tumors in tuberous sclerosis complex: a case report and review of the literature

BackgroundTuberous sclerosis complex (TSC) is a rare, autosomal dominant genetic disease that arises from TSC1 or TSC2 genetic mutations. These genetic mutations can induce the development of benign tumors in any organ system with significant clinical implications in morbidity and mortality. In rare instances, patients with TSC can have malignant tumors, including renal cell carcinoma (RCC) and pancreatic neuroendocrine tumor (PNET). It is considered a hereditary renal cancer syndrome despite the low incidence of RCC in TSC patients. TSC is typically diagnosed in prenatal and pediatric patients and frequently associated with neurocognitive disorders and seizures, which are often experienced early in life. However, penetrance and expressivity of TSC mutations are highly variable. Herein, we present a case report, with associated literature, to highlight that there exist undiagnosed adult patients with less penetrant features, whose clinical presentation may contain non-classical signs and symptoms, who have pathogenic TSC mutations.Case presentationA 31-year-old female with past medical history of leiomyomas status post myomectomy presented to the emergency department for a hemorrhagic adnexal cyst. Imaging incidentally identified a renal mass suspicious for RCC. Out of concern for hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome, the mass was surgically removed and confirmed as RCC. Discussion with medical genetics ascertained a family history of kidney cancer and nephrectomy procedures and a patient history of ungual fibromas on the toes. Genetic testing for hereditary kidney cancer revealed a 5’UTR deletion in the TSC1 gene, leading to a diagnosis of TSC. Following the diagnosis, dermatology found benign skin findings consistent with TSC. About six months after the incidental finding of RCC, a PNET in the pancreatic body/tail was incidentally found on chest CT imaging, which was removed and determined to be a well-differentiated PNET. Later, a brain MRI revealed two small cortical tubers, one in each frontal lobe, that were asymptomatic; the patient’s history and family history did not contain seizures or learning delays. The patient presently shows no evidence of recurrence or metastatic disease, and no additional malignant tumors have been identified.ConclusionsTo our knowledge, this is the first report in the literature of a TSC patient without a history of neurocognitive disorders with RCC and PNET, both independently rare occurrences in TSC. The patient had a strong family history of renal disease, including RCC, and had several other clinical manifestations of TSC, including skin and brain findings. The incidental finding and surgical removal of RCC prompted the genetic evaluation and diagnosis of TSC, leading to a comparably late diagnosis for this patient. Reporting the broad spectrum of disease for TSC, including more malignant phenotypes such as the one seen in our patient, can help healthcare providers better identify patients who need genetic evaluation and additional medical care.

Molecular and immune landscape of FH-mutated cancers.

3125 Background: Fumarate Hydratase (FH) encodes an essential enzyme in the TCA cycle. Inactivating germline mutations in FH lead to hereditary leiomyomatosis and renal cell cancer syndrome with risk of development of certain cancers. Sporadic FH mutations have been described in different cancers but implications of somatic mutations on cancer outcomes and survival are not well described. Here, we characterize the molecular landscape of FH-mutant cancers. Methods: Tumors analyzed using NGS (NextSeq, 592 genes; NovaSeq, WES), IHC, and WTS (NovaSeq) (Caris Life Sciences, Phoenix, AZ). PD-L1 tested by 22c3, 28-8 (Agilent) and SP-142 (Spring Biosciences) IHC (>1%). MSI tested by FA, IHC, and NGS. TMB measured by totaling somatic mutations per tumor (TMB-h > 10 mutations/MB). Real-world overall survival was extracted from insurance claims data and calculated from first treatment to last contact using K-M survival curves for molecularly defined cohorts. Statistical significance was determined using chi-square and Wilcoxon rank-sum test, adjusted for multiple comparisons (q<0.05). Results: 3239 FH mutations were seen in 45 tumor types in 3149 FH-mutated tumors. NSCLC, colorectal and endometrial cancers harbored the most mutations. There were 839 pathogenic (P) or likely pathogenic (LP) and 2400 variants of unknown significance (VUS). Some tumors had multiple mutations. The most common mutations: R233H (P; 37), K477dup (LP; 555), and A41V (VUS; 70). VUS had increased TMB-H (40.4% vs 29.8%, q=0.004) and CREBBP mutations (5.1% vs 1.6%, q=0.012) compared to P+LP. A41V-mt tumors had significantly lower TMB-H than other VUS (8.8% vs 41.5%, q=0.002) and lower MSI-H (3.13% vs 3.69% vs 29.4%, q=0.003) and DICER1, PRKDC, FBXW7 mutations (q<0.05) compared to K477dup and R233. The A41V-mt patients had worse survival compared to patients with P+LP (HR: 1.4, 95% CI: 1.0-2.0, p = 0.049) and a trend toward worse survival compared to K477dup and R233H. In patients treated with chemotherapy, A41 was associated with worse survival compared to P+LP (HR: 4.6, 95% CI: 2.0-10.3, p<0.0001) and compared to K477dup and R233 (p<0.01). There was a trend towards worse survival after IO of A41-mt compared to P+LP (HR: 1.99, 95% CI: 0.88-4.5, p = 0.093). Conclusions: FH alterations are found in multiple cancers. A41V was the most common VUS mutation and is associated with a distinct molecular profile compared to K477dup-mt and R233-mt tumors; it was associated with worse survival in all-comers and after chemotherapy compared to P+LP mutations. This highlights the significance of this mutation and the need for further investigation into how this specific and other FH mutations contribute to cancer progression and treatment outcomes.

Molecular and immune landscape of FH-mutated kidney cancer.

382 Background: Hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome is caused by inactivating germline mutations in fumarate hydratase ( FH), predisposing individuals to development of certain cancers. Sporadic FH mutations have been described in different types of cancers, including kidney cancers, but the implications of somatic mutations are not well described. Here, we characterize the molecular landscape of kidney tumors with FH mutations. Methods: Tumors were analyzed using next generation sequencing of DNA (NextSeq, 592 genes and NovaSeq, WES) and RNA (NovaSeq). Immune cell fraction was estimated by immune deconvolution (Quantiseq). Significance was determined by chi-square and Wilcoxon rank sum test and adjusted for multiple comparisons (q-value <0.05). Results: Of 1956 kidney tumors, 31 had somatic pathogenic or likely pathogenic (P+LP; 1.58%) and 21 had variant of unknown significance (VUS; 1.07%) mutations in FH. Among the most commonly co-mutated genes, VHL (29.03% vs 38.1% vs 55.2%) and PBRM1 (9.68% vs 20% vs 29.8%) were less frequently mutated in P+LP compared to VUS and WT tumors; while NF2 (22.6% vs 5% vs 5.65%) was more frequently mutated in P+LP tumors compared to the others. In P+LP tumors, the HIPPO pathway (22.6% vs 4.76% vs 5.62%) was more frequently altered while the chromatin remodeling pathway (25.8% vs 28.6% vs 51.1%) was less frequently altered compared to VUS or WT tumors. P+LP tumors showed decreased NK cell infiltration (q=0.01) compared to VUS and WT tumors. Additionally, there was a trend towards increased CD8+ T cells and CTLA4 and PDCD1 expression in P+LP tumors compared to VUS but not WT tumors. Of the 1,956 kidney tumors, 315 were of clear cell renal cell carcinoma (ccRCC) histology. P+LP (n=4) ccRCC tumors showed a trend towards higher expression of immune checkpoint genes CTLA4 and IDO1 compared to VUS tumors (n=5). VHL expression was higher in P+LP ccRCC compared to VUS ccRCC tumors. P+LP ccRCC tumors showed a trend toward increased CD4+ (2.59% vs 0%) and CD8+ (2.14% vs 0%) T cells as well as T cell inflammation (25% vs 0%) and median Interferon score compared to VUS ccRCC tumors. Conclusions: P+LP FH mutated kidney tumors may have a different mutational and immune landscape than VUS FH mutated and WT tumors. Despite the small sample size, our study highlights potential therapeutic implications that will require further study.[Table: see text]

Hereditary renal cell tumors: Clinicopathologic importance

Hereditary renal cancer syndromes represent approximately 5% of renal malignancies and have distinctive clinical, histopathologic, and genetic features. Next-generation sequencing and other molecular testing methods have uncovered several hereditary renal cancer syndromes. Several autosomal dominant hereditary renal cell carcinoma (RCC) syndromes, including those related to germline pathogenic variants in VHL, BAP1, MITF, MET, FH, TSC1/TSC2, FLCN, SDH, and CDC73 have been confirmed. FH- and BAP1-related RCCs are associated with more aggressive disease. Identifying the clinical and pathological features in these hereditary RCC syndromes is important as, relative to familial cohorts, these patients require early screening and intervention and regular surveillance to improve their clinical prognosis and long-term outcomes. More importantly, identification of these syndromes plays a vital role in personalized management and systemic treatment selection in this modern era of precision medicine. Ongoing studies have demonstrated that treatment based on genetic pathway targeting is a promising approach for hereditary renal cancer management. This review describes updates in the diagnostic criteria for and management of familial kidney cancer syndromes.

Hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC): Genotype and phenotype characteristics in a cohort of 197 patients.

1580 Background: HLRCC is a hereditary condition with autosomal dominant inheritance due to germline mutations in the fumarate-hydratase gene ( FH). It is characterized by skin leiomyomas (SLM) in 48-84% of individuals, uterine leiomyomas (ULM) in 30-72%, renal cysts (RCy) and renal cell cancer (RCC) in 15-34%. We aimed to describe the genetics, the clinical features and the potential genotype-phenotype associations in the largest cohort of FH mutation carriers from Spain. Methods: We performed a multicenter, observational, retrospective study of individuals with genetic or clinical diagnosis of HLRCC. We collected clinical information from medical records. We analyzed genetic variants and looked for genotype-phenotype associations. Statistical analyses were performed by IBM-SPSS Statistics-v.22. Results: We included 197 individuals (113 women, 84 men), 74 index cases and 123 relatives. Twenty-seven different variants were detected, 26 pathogenic (12 missense, 5 frameshift, 4 large-deletions, 3 splice-site and 2 nonsense) and 1 variant of unknown significance (missense). Of 182 patients with full skin examination, 64.8% presented SLM (median age 36 years; range 8-85). ULM were diagnosed in 90.3% of 103 women with gynecologic exam (median age 30 years; range 17- 55). Hysterectomy was performed in 62.9% (median age 34 years; range 21-54). Of 153 patients with radiological records, 37.3 % presented RCy. Nineteen patients (10.9%) presented RCC, 11 males and 8 females (median age 37 years; range 10-67). The histological diagnoses were: 14 papillary, of which 10 were type 2; 3 clear cell carcinoma and 2 unclassified carcinoma. Six tumors had stage I, 2 stage II, 3 stage III, 4 stage IV, and 4 not available. The median overall survival among patients at stages 3-4 was 2.9 years [1.3-4.5]. Patients with missense pathogenic variants showed higher risk of developing SLM (p = 0.043) and ULM (p = 0.002) than those with loss of function variants. Conclusions: In our cohort, the frequency of RCC (10.9%) is lower than that published in cohorts of similar sample size. The most frequent histology was the papillary type-2; however, other histological patterns do not exclude HLRCC. Individuals with missense pathogenic variants show higher incidence of SLM and ULM.

Exploring the hereditary background of renal cancer in Denmark.

BackgroundEvery year more than 800 patients in Denmark are diagnosed with renal cell carcinoma (RCC) of which 3–5% are expected to be part of a hereditary renal cancer syndrome. We performed genetic screening of causative and putative RCC-genes (VHL, FH, FLCN, MET, SDHB, BAP1, MITF, CDKN2B) in RCC-patients suspected of a genetic predisposition.MethodsThe cohort consisted of forty-eight Danish families or individuals with early onset RCC, a family history of RCC, a family history of RCC and melanoma or both RCC- and melanoma diagnosis in the same individual. DNA was extracted from peripheral blood samples or cancer-free formalin-fixed paraffin-embedded tissue.ResultsOne start codon variant of unknown clinical significance (VUS) (c.3G>A, p.Met1Ile) and one missense VUS (c.631A>C, p.Met211Leu) was found in VHL in a patient with RCC-onset at twenty-eight years of age but without other manifestations or family history of von Hippel-Lindau (VHL). Furthermore, in three families we found three different variants in BAP1, one of which was a novel non-segregating missense variant (c.1502G>A, p.Ser501Asn) in a family with two brothers affected with RCC. Finally, we found the known E318K-substitution in MITF in a RCC-affected member of a family with multiple melanomas. No variants were detected in CDKN2B.ConclusionAlthough we did find three VUS’s in BAP1 in three families and a pathogenic variant in MITF in one family, pathogenic germline variants in BAP1, MITF or CDKN2B are not frequent causes of hereditary renal cancer in Denmark. It is possible that the high prevalence of risk factors such as male gender, smoking and obesity has influenced the development of cancer in the patients of the current study. Further investigations into putative predisposing genes and risk factors of RCC are necessary to enable better prediction of renal cancer risk or presymptomatic testing of relatives in hereditary renal cancer families.

Abstract 4611: Uterine leiomyoma driver events in uterine adenomyomas

Abstract Uterine adenomyosis is a condition in which ectopic endometrial glands are present in myometrial stroma surrounded by smooth muscle cell hyperplasia. Foci of adenomyosis growing as a tumor like mass are called adenomyomas. Uterine adenomyomas are common tumors and they share symptoms, including pelvic pain and abnormal bleeding, with uterine leiomyomas. The two tumor types are challenging to distinguish from one another and the diagnosis is usually confirmed only after surgery by pathological evaluation. The molecular background of uterine adenomyomas is not currently well known. In uterine leiomyomas, somatic mediator complex subunit 12 (MED12) mutations, high mobility group AT-hook (HMGA2) protein overexpression, and fumarate hydratase (FH) inactivation are well established as major mutually exclusive driver events covering 80-90% of the tumors. Here, we have analyzed the presence of these changes in a set of 21 uterine adenomyomas. Representative areas of formalin-fixed paraffin embedded archival uterine adenomyoma tissue samples were used to construct a tissue microarray. The HMGA2 overexpression and the FH inactivation were assessed using immunohistochemistry with anti HMGA and 2SC antibodies, respectively. DNA was extracted from the tumor samples to determine the MED12 mutation status by direct sequencing of exons 1 and 2 of the gene. MED12 c.131GA, p.G44D mutation was found in two adenomyoma samples out of 21 (9.5%). Strong positive staining of 2SC indicating FH inactivation was present in one sample which also showed reduced FH protein expression when validated with an independent method using anti-FH immunostaining. Sequencing revealed a frameshift mutation c.911delC, p.P304fs in exon 7 leading to a premature stop codon 25 codons later. The mutation was also found in a separate uterine leiomyoma of the same patient and both tumor samples mostly presented the mutant allele indicating loss of heterozygosity of the wild type allele. This, together with the patient's medical history of previous uterine leiomyomas, indicates the germline origin of the mutation and thus a hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. No changes in HMGA2 expression were detected with all samples presenting normal expression levels. In conclusion, MED12 mutations are present in a subset of uterine adenomyomas. The mutation frequency of 9.5% that was observed here in our adenomyoma sample series is considerably lower than that of 70% in uterine leiomyomas. Our results also suggest that adenomyomas may be linked to HLRCC in which they have not been previously reported. The driver events behind uterine adenomyomas remain mostly unknown and further large-scale studies are warranted to clarify the spectrum of underlying mutations and molecular background of these common tumors. Citation Format: Tuomas A. Heikkinen, Anna Äyräväinen, Janne Hänninen, Terhi Ahvenainen, Ralf Bützow, Annukka Pasanen, Pia Vahteristo. Uterine leiomyoma driver events in uterine adenomyomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4611.

Rare Leiomyoma of the Tunica Dartos: A Case Report with Clinical Relevance for Malignant Transformation and HLRCC.

Background. Genital leiomyomas fall under the broader category of cutaneous leiomyomas, which are rare smooth muscle neoplasms accounting for 5% of all leiomyomas. Genital leiomyomas arising from the dartos muscle are exceedingly rare with fewer than 30 cases reported in the literature. They are typically benign and adequately treated with simple surgical excision; however, previously reported cases of malignant transformation and a possible link to the hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome warrant closer follow-up. Case Presentation. We report a case of a 47-year-old male refugee from Rwanda found to have a mobile, pea-sized, mildly painful scrotal lesion near the left penoscrotal junction and 1.5 cm indeterminate vascular mass in the right kidney. Surgical excision of the scrotal nodule was performed and the diagnosis of a dartoic leiomyoma was rendered. The presence of moderate nuclear atypia, rare mitotic activity, and close surgical margins prompted a wide reexcision. We report the surgical approach, pathologic findings, and clinical follow-up related to this scrotal lesion. Conclusion. Scrotal leiomyomas demonstrate a high rate of recurrence and pose a risk for malignant transformation. They may also indicate an underlying autosomal dominant syndrome associated with increased risk for development of an aggressive form of renal cell carcinoma. When discovered, management should include surgical excision, screening for syndromic features, and routine follow-up.

Are lung cysts in renal cell cancer (RCC) patients an indication for FLCN mutation analysis?

Renal cell cancer (RCC) represents 2–3 % of all cancers and is the most lethal of the urologic malignancies, in a minority of cases caused by a genetic predisposition. Birt–Hogg–Dubé syndrome (BHD) is one of the hereditary renal cancer syndromes. As the histological subtype and clinical presentation in BHD are highly variable, this syndrome is easily missed. Lung cysts—mainly under the main carina—are reported to be present in over 90 % of all BHD patients and might be an important clue in differentiating between sporadic RCC and BHD associated RCC. We conducted a retrospective study among patients diagnosed with sporadic RCC, wherein we retrospectively scored for the presence of lung cysts on thoracic CT. We performed FLCN mutation analysis in 8 RCC patients with at least one lung cysts under the carina. No mutations were identified. We compared the radiological findings in the FLCN negative patients to those in 4 known BHD patients and found multiple basal lung cysts were present significantly more frequent in FLCN mutation carriers and may be an indication for BHD syndrome in apparent sporadic RCC patients.

Hereditary leiomyomatosis and renal cell cancer syndrome: Case report and literature review

Hereditary leiomyomatosis and renal cell cancer syndrome: Case report and literature review

Syndromes that Link the Endocrine System and Genitourinary Tract.

The endocrine system and genitourinary tract unite in various syndromes. Genitourinary malignancies may cause paraneoplastic endocrine syndromes by secreting hormonal substances. These entities include Cushing`s syndrome, hypercalcemia, hyperglycemia, polycythemia, hypertension, and inappropriate ADH or HCG production. The most important syndromic scenarios that links these two systems are hereditary renal cancer syndromes with specific genotype/phenotype correlation. There are also some very rare entities in which endocrine and genitourinary systems are involved such as Carney complex, congenital adrenal hyperplasia and Beckwith-Wiedemann syndrome. We will review all the syndromes regarding manifestations present in endocrine and genitourinary organs.

Abstract 3514: MED12 and FH mutations in HLRCC associated uterine leiomyomas

Abstract Uterine leiomyomas (fibroids) are benign tumors which originate from the smooth muscle cells of the myometrium. Almost 70% of women are affected by these tumors by the age of 50. Even though uterine leiomyomas are benign, they can cause difficult symptoms and are the most common indication for hysterectomy. Most uterine leiomyomas are sporadic and up to 70% of these lesions harbor very specific mutations in MED12 (mediator complex subunit 12). All MED12 mutations observed in uterine leiomyomas have been missense or insertion deletion mutations retaining the open reading frame. Uterine leiomyomas occur also in the context of Hereditary Leiomyomatosis and Renal Cell Cancer syndrome (HLRCC, OMIM # 150800). In addition to uterine leiomyomas, the syndrome predisposes individuals to cutaneous leiomyomas and renal cell cancer. HLRCC is an autosomal dominant syndrome caused by heterozygous germline mutations in FH (fumarate hydratase). The gene is classified as a tumor suppressor and according to Knudson's two-hit hypothesis, syndrome related tumors display biallelic inactivation of FH. Recently, we reported 3/34 uterine leiomyomas from HLRCC patients to harbor somatic mutations in MED12. Loss of heterozygosity (LOH) at the FH locus was assessed from the tumors, and interestingly none of the MED12 mutation positive tumors showed biallelic inactivation of FH through LOH. Exome sequencing of seemingly sporadic uterine leiomyomas revealed also one patient to carry a truncating germline mutation in FH. The FH and MED12 loci from the uterine leiomyomas of this patient were further studied with direct sequencing and LOH assessment. Tumors had different MED12 mutations and none of them harbored a somatic mutation or displayed LOH as a second hit at FH locus. The aim of this study is to clarify the role of MED12 in HLRCC syndrome associated uterine leiomyomas and to analyze whether MED12 mutations and biallelic inactivation of FH are truly mutually exclusive. A tissue microarray including uterine leiomyomas from HLRCC patients will be constructed and FH inactivation will be analyzed with immunohistochemical stainings. Expression analyses of the tumors harboring somatic MED12 mutation and FH mutation in germline will show whether these tumors cluster together with MED12 mutation positive tumors, tumors with biallelic FH inactivation, or if they form a separate cluster. Results of these analyses will reveal if there are two distinct molecular mechanisms behind the development of uterine leiomyomas in HLRCC patients; one dependent on the biallelic inactivation of FH and the other on the altered function of MED12. Citation Format: Kati Kämpjärvi, Netta Mäkinen, Miika Mehine, Jaana Tolvanen, Tuomas Heikkinen, Ralf Bützow, Lauri A. Aaltonen, Pia Vahteristo. MED12 and FH mutations in HLRCC associated uterine leiomyomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3514. doi:10.1158/1538-7445.AM2014-3514

Hereditary leiomyomatosis and renal cell carcinoma.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal-dominant hereditary syndrome, which is caused by germline mutations in the FH gene that encodes the tricarboxylic acid cycle enzyme fumarate hydratase (FH). HLRCC patients are predisposed to develop cutaneous leiomyomas, multiple, symptomatic uterine fibroids in young women resulting in early hysterectomies, and early onset renal tumors with a type 2 papillary morphology that can progress and metastasize, even when small. Since HLRCC-associated renal tumors can be more aggressive than renal tumors in other hereditary renal cancer syndromes, caution is warranted, and surgical intervention is recommended rather than active surveillance. At-risk members of an HLRCC family who test positive for the familial germline FH mutation should undergo surveillance by annual magnetic resonance imaging from the age of 8 years. Biochemical studies have shown that FH-deficient kidney cancer is characterized by a metabolic shift to aerobic glycolysis. It is hoped that through ongoing clinical trials evaluating targeted molecular therapies, an effective form of treatment for HLRCC-associated kidney cancer will be developed that will offer an improved prognosis for individuals affected with HLRCC-associated kidney cancer.

Hereditary renal cell carcinoma: genetics, clinical features, and surgical considerations

Hereditary renal cancer syndromes have been described and have illuminated novel methods to treat sporadic renal cell carcinoma. In this work, we aimed to review the genetic basis, molecular pathology and clinical manifestations of hereditary syndromes, as well as outline principles of surgical management and use of targeted therapy. We performed a comprehensive review of selected peer-reviewed publications regarding hereditary renal cancer syndromes, their genetic basis, and recommendations for surgical management. The major syndromes contributing to hereditary renal cell carcinoma are discussed along with relevant literature guiding their management. The evolving surgical and molecular treatments are discussed. Identification of genetic basis of hereditary carcinomas provides opportunity for targeted therapy of metastatic sporadic renal cell carcinoma. Appropriate and timely surgical management of hereditary renal cancers decreases the possibility of development of metastatic disease, and allows for preservation of renal function despite the need for repeat surgical interventions.

Novel germline c-MET mutation in a family with hereditary papillary renal carcinoma

Hereditary papillary renal carcinoma (HPRC) is a highly penetrant hereditary renal cancer syndrome caused by germline missense mutations in the c-MET proto-oncogene. HPRC is clinically characterized by multiple bilateral papillary renal-cell carcinomas. Here we report a family with a novel missense mutation in c-MET. The original pathology report of four primary kidney cancers (1988-1997) revealed renal-cell carcinoma. A revised report described multiple adenomas and papillary renal-cell carcinomas with focal clear cells and a mixture of type 1 and type 2 pattern, emphasizing the importance of revised pathology examinations in possible hereditary renal-cell carcinomas especially when described before 1997.

Knowledge of hereditary renal cancer syndromes

Renal cell cancer (RCC) is a rare disease that accounts for 2-3% of all solid malignancies. Although its etiology is not known, approximately 4% of RCC occurs in the context of complex hereditary syndromes in which the kidney lesions are associated with other manifestations. Therefore, clinical suspicion is essential for proper diagnosis and management. In this review a practical summary to aid treating physicians in the identification of hereditary RCC syndromes, including von Hippel-Lindau syndrome, hereditary papillary RCC, Birt-Hogg-Dubé syndrome, and hereditary leiomyomatosis RCC, is provided. Early recognition of these specific populations will lead to better care, correct surveillance, and, in the near future, to personalized treatment taking advantage of underlying genetic defects.

Hereditäre Nierenzellkarzinome

Renal cell carcinomas occur in several hereditary tumor syndromes. These renal tumors frequently have a specific histopathological appearance which can be a sign for a hereditary cause of the disease. The genetic alterations responsible for most of these tumor syndromes were identified in recent years. Interestingly, renal cell carcinomas show specific histopathological features in each of the hereditary renal cancer syndromes. Clear cell and often cystic renal cell carcinomas occur in von Hippel-Lindau syndrome (VHL), while oncocytomas and chromophobe renal cell carcinomas are found in the Birt-Hugg-Dube syndrome, often also as hybrid tumors. Well differentiated papillary carcinomas (Type 1 according to the WHO) are found in the hereditary papillary renal cell carcinoma (HPRC). In contrast, poorly diffentiated papillary renal cell carcinomas (Type 2 according to the WHO) occur in combination with leiomyomas and leiomyosarcomas of the skin and uterus in hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC). The various genetic causes for these hereditary tumor syndromes open up new therapeutic possibilities, some of which are already being investigated in clinical studies.

Advances in the Genetics of Familial Renal Cancer

We discuss recent advances in the diagnosis and management of renal cell cancer (RCC) given the enhanced molecular genetics knowledge in this area. A number of hereditary renal cancer syndromes have been described, including von Hippel-Lindau disease, Birt-Hogg-Dubé syndrome, hereditary leiomyomatosis/RCC syndrome, and hereditary papillary renal cancer. Early molecular diagnosis now facilitates the management and prevention of RCC in families. Recommendations for screening in families are discussed.

Hereditary causes of kidney tumours

In most cases of renal cell carcinoma there is no family history of renal cancer and no hereditary cause of the disease. Hereditary renal cancer accounts for about 2-4% of cases. Recognition of this subgroup by clinicians is important because of the possibility of severe medical consequences for patients and their relatives. We review the latest data about different genetic conditions characterized by an increased risk of developing renal cancer and we formulate tools to recognize high-risk families. In general, a positive family history, young age at diagnosis of renal cancer, multiple and/or bilateral renal tumours and combined occurrence of different histological types of renal tumours should raise suspicion of a hereditary renal tumour syndrome. In addition, the presence of specific extrarenal symptoms in patients could assist in differentiating between tumour syndromes. A detailed medical and family history, along with physical examination are key factors to diagnose hereditary renal cancer syndromes. When a genetic predisposition for renal cancer is suspected, referral to a Family Cancer Clinic is warranted to initiate genetic examination and counselling on preventive options.

Abstract 1844: No evidence for genetic factor increasing renal cell cancer risk in Hereditary Leiomyomatosis and Renal Cell Cancer syndrome

Abstract Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a hereditary tumor predisposition syndrome with fumarate hydratase (FH), which encodes a tricarboxylic acid cycle enzyme fumarase, as the predisposing gene. The HLRCC family members carry heterozygous germline mutations of the FH gene and the tumors often harbor a second hit making the growth fumarase deficient. The phenotype includes benign cutaneous and uterine leiomyomas as well as renal cell cancer (RCC). The HLRCC related RCCs usually belong to histological papillary type II subtype and are solitary, unilateral and aggressive. The benign leiomyomas are the most common manifestation of the syndrome affecting almost all FH mutation carriers whereas the renal cell cancer phenotype affects only about 20% of the HLRCC families. Interestingly, majority of the families with multiple renal cell cancer cases have concentrated in Finland and the U.S. Why the malignant phenotype affects only a part of the HLRCC patients is unknown. There is no genotype-phenotype correlation and type or site of the FH mutation does not affect the phenotype. The fumarase enzyme activity levels do not correlate with the phenotype either. Thus it is possible that the appearance of RCC requires, in addition to FH mutation, another genetic factor. To search for such a factor in four Finnish HLRCC families with multiple RCC cases we performed genome wide linkage and/or identical by descent (IBD) analyses. After finemapping procedures the only region compatible with linkage was the FH locus itself in 1q43. The genes of the region were screened but no pathognomonic mutations were found. Although these results do not exclude the existence of a genetic RCC risk modifier in HLRCC, the role of FH mutations behind RCC tumors is emphasized. Counseling and genetic testing should be available for HLRCC family members and the FH mutation carriers should be carefully followed up to enable early detection and treatment of the aggressive cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1844.