Genetic basis of bilateral renal cancer: implications for evaluation and management

Differential VHL mutation patterns in bilateral clear cell RCC distinguishes between independent primary tumors and contralateral metastatic disease

OBJECTIVE

To evaluate whether bilateral, multifocal clear cell renal cell carcinoma (ccRCC) patients can be differentiated by VHL mutation analysis into cases that represent either multiple independently arising primary tumors, or a single primary tumor which has spread ipsilaterally as well as to the contralateral kidney. The nature of kidney cancer multifocality outside of known hereditary syndromes is as yet poorly understood.

MATERIALS AND METHODS

DNA from multiple tumors per patient were evaluated for somatic VHL gene mutation and hypermethylation. A subset of tumors with shared VHL mutations were analyzed with targeted, next-generation sequencing assays.

RESULTS

This cohort contained 5 patients with multiple tumors that demonstrated a shared somatic VHL mutation consistent with metastatic spread including to the contralateral kidney. In several cases this was substantiated by additional shared somatic mutations in ccRCC-associated genes. In contrast, the remaining 14 patients with multiple tumors demonstrated unique, unshared VHL alterations in every analyzed tumor, consistent with independently arising kidney tumors. None of these latter patients showed any evidence of local spread or distant metastasis.

CONCLUSION

The spectrum of VHL alterations within evaluated bilateral, multifocal ccRCC tumors from a single patient can distinguish between multiple independent tumor growth and metastasis. This can be performed using currently available clinical genetic tests and will improve the accuracy of patient diagnosis and prognosis, as well as informing appropriate management.

Genomic Analysis Reveals Heterogeneity Between Lesions in Synchronous Primary Right-Sided and Left-Sided Colon Cancer

Background: The synchronous primary right-sided and left-sided colon cancer (sRL-CC) is a peculiar subtype of colorectal cancer. However, the genomic landscape of sRL-CC remains elusive. Methods: Twenty-eight paired tumor samples and their corresponding normal mucosa samples from 14 patients were collected from the Second Affiliated Hospital of Harbin Medical University from 2011 to 2018. The clinical-pathological data were obtained, and whole-exome sequencing was performed based on formalin-fixed and paraffin-embedded samples of these patients, and then, comprehensive bioinformatic analyses were conducted. Results: Both the lesions of sRL-CC presented dissimilar histological grade and differentiation. Based on sequencing data, few overlapping SNV signatures, onco-driver gene mutations, and SMGs were identified. Moreover, the paired lesions harbored a different distribution of copy number variants (CNVs) and loss of heterozygosity. The clonal architecture analysis demonstrated the polyclonal origin of sRL-CC and inter-cancerous heterogeneity between two lesions. Conclusion: Our work provides evidence that lesions of sRL-CC share few overlapping mutational signatures and CNVs, and may originate from different clones.

The hallmarks of cancer: relevance to the pathogenesis of polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a progressive inherited disorder in which renal tissue is gradually replaced with fluid-filled cysts, giving rise to chronic kidney disease (CKD) and progressive loss of renal function. ADPKD is also associated with liver ductal cysts, hypertension, chronic pain and extra-renal problems such as cerebral aneurysms. Intriguingly, improved understanding of the signalling and pathological derangements characteristic of ADPKD has revealed marked similarities to those of solid tumours, even though the gross presentation of tumours and the greater morbidity and mortality associated with tumour invasion and metastasis would initially suggest entirely different disease processes. The commonalities between ADPKD and cancer are provocative, particularly in the context of recent preclinical and clinical studies of ADPKD that have shown promise with drugs that were originally developed for cancer. The potential therapeutic benefit of such repurposing has led us to review in detail the pathological features of ADPKD through the lens of the defined, classic hallmarks of cancer. In addition, we have evaluated features typical of ADPKD, and determined whether evidence supports the presence of such features in cancer cells. This analysis, which places pathological processes in the context of defined signalling pathways and approved signalling inhibitors, highlights potential avenues for further research and therapeutic exploitation in both diseases.

Familial renal cancer as an indicator of hereditary leiomyomatosis and renal cell cancer syndrome

Hereditary Leiomyomatosis and Renal Cell Carcinoma (HLRCC) is a hereditary condition which typically presents with cutaneous and uterine leiomyomata. Papillary type II renal cell carcinoma and other less common histologic subtypes of renal cancer have been reported in HLRCC. We describe the case of a 31-year-old man in which the pathology review of his renal carcinoma and a positive family history of renal carcinoma allowed for the identification of a pathogenic mutation in the FH gene (c.698G>A;p.R233H) confirming the diagnosis of HLRCC. Recognition of this syndrome allowed for appropriate surveillance as well as identification of at-risk family members. Pathology review is essential for accurate diagnosis of a hereditary cancer syndrome in the setting of familial renal cancer.

Bilateral renal cell carcinoma in a child

Renal cell carcinoma is a rare renal tumor in the pediatric population with an incidence of 0.1-0.3%. We report on the first case of bilateral renal clear cell carcinoma that was treated by partial nephrectomies. We performed a complete genetic evaluation to exclude a family inheritance and we looked at the deletions associated with the possible histologic subtypes of renal cell carcinoma. The patient had no evidence of recurrence after 80-month follow-up and her renal function remained normal.

Incidence of multiple sporadic renal cell carcinomas in patients referred for renal radiofrequency ablation: implications for imaging follow-up

OBJECTIVE

The objective of our study was to report the incidence of multiple sporadic primary renal cell carcinomas (RCCs) in patients referred for radiofrequency ablation (RFA).

MATERIALS AND METHODS

A retrospective search identified 162 patients (104 men and 58 women; mean age, 74 years) without a history of von Hippel-Lindau disease with a total of 175 tumors treated with RFA for biopsy-proven primary renal malignancies at our institution from 1998 to 2009. Three groups of patients with multiple RCCs were identified: patients with a history of nephrectomy for RCC who had been referred for RFA of a new renal tumor, patients who presented with multiple renal tumors at the time of referral for RFA, and patients who were shown to have developed a new renal tumor on follow-up imaging after RFA.

RESULTS

Twenty-eight patients (17%) had multiple biopsy-proven RCCs. Eighteen patients (11%) had undergone prior nephrectomy for surgically proven RCC. The mean interval between prior nephrectomy and RFA referral was 122 months (range, 12-456 months). Seven patients (4%) without a history of nephrectomy presented with two biopsy-proven RCCs at RFA referral. Three patients (2%) who had not undergone nephrectomy and had a solitary RCC at the time of RFA had developed a new biopsy-proven RCC separate from the original treatment site on follow-up imaging after RFA. The mean time to diagnosis from the initial RFA treatment was 52 months (range, 25-89 months).

CONCLUSION

Imaging surveillance of patients referred for renal RFA may be important not only to assess treatment success but also to detect new RCCs.

The impact of germline BHD mutation on histological concordance and clinical treatment of patients with bilateral renal masses and known unilateral oncocytoma

PURPOSE

Managing oncocytoma in the setting of bilateral renal masses is a challenging scenario. Nevertheless, to our knowledge the pathological concordance of an oncocytic neoplasm in 1 kidney with tumors in the contralateral kidney is not known. We evaluated the influence of germline Birt-Hogg-Dubé mutation on concordance rates to assist in managing these cases.

MATERIALS AND METHODS

We reviewed the records of patients at the National Institutes of Health between 1983 and 2009 who had bilateral renal masses, known pathology bilaterally and oncocytoma or an oncocytic neoplasm in at least 1 kidney. Oncocytoma or an oncocytic neoplasm in 2 renal units was considered concordant. Demographic, pathological and clinical data were collected.

RESULTS

The population consisted of 40 patients, including 23 with and 17 without a diagnosis of Birt-Hogg-Dubé syndrome. Patients with the syndrome were younger (p <0.01) but there were no other differences between the 2 groups. However, patients with the syndrome had statistically lower histological concordance between bilateral masses than patients without the diagnosis (Fisher's exact test p <0.01). Also, the 8 patients without Birt-Hogg-Dubé syndrome who had multifocal renal masses showed 100% oncocytoma concordance between renal units.

CONCLUSIONS

Of patients with bilateral renal masses those with Birt-Hogg-Dubé syndrome have significantly lower histological concordance than those without the syndrome. Patients with Birt-Hogg-Dubé syndrome should be monitored and treated differently than those without detected genetic mutations, especially patients with multifocal oncocytomas. Genetic testing for Birt-Hogg-Dubé should be considered in the treatment algorithm of patients with bilateral renal masses and known oncocytoma.

Tumor biology and prognostic factors in renal cell carcinoma

In the past 15 years, there has been an increased understanding of the tumor biology of renal cell carcinoma (RCC). The identification of vascular endothelial growth factor (VEGF), its related receptor (VEGFR), and the mammalian target of rapamycin as dysregulated signaling pathways in the development and progression of RCC has resulted in the rational development of pharmaceutical agents capable of specifically targeting key steps in these pathways. Clinical trials have demonstrated survival benefit with these agents, particularly in clear cell RCC patients. However, metastatic RCC will progress in all patients, resulting in a critical need to determine patient risk and optimize treatment. The goal of this article is to highlight the significant breakthroughs made in understanding the critical genetic alterations and signaling pathways underlying the pathogenesis of RCC. The discovery of prognostic factors and development of comprehensive nomograms to stratify patient risk and predictive biomarkers to facilitate individualized treatment selection and predict patient response to therapy also are reviewed.

Long-term management of bilateral, multifocal, recurrent renal carcinoma

Patients with bilateral multifocal renal cell carcinoma are at increased risk of developing locally recurrent or de novo tumors after nephron-sparing procedures. When dealing with recurrent renal masses the options are limited to observation, total nephrectomy, ablation, or repeat surgical intervention. The main reason for recurrence after nephron-sparing surgery is likely to be the presence of multifocal disease, which is identified in 4.3-25.0% of radical nephrectomy specimen. Bilateral renal involvement is seen in almost 90% of cases of multifocal renal carcinoma, and conversely the majority of patients with bilateral disease will have multifocal tumors. Many patients who are treated for multifocal disease, therefore, require subsequent surgical interventions. The outcome data for repeat renal interventions demonstrate reasonable functional and oncologic outcomes despite higher rates of perioperative complications. Our own results support the use of reoperative renal surgery rather than total nephrectomy and renal replacement therapy.

The changing face of renal-cell carcinoma

The present decade can be credited with the improved understanding of renal-cell carcinoma (RCC), its local and systemic management, and various controversies from diagnosis to types of various available interventions. The old paradigms and dogmas are no longer accepted as "the best way" without evidence, and many "old" principles are cautiously questioned. These notions have resulted in new knowledge, questions, arguments, and treatment options. This article will describe the "changing face of RCC" over the past several years and will briefly summarize the major changes and issues in the field of renal oncology. The discussed topics include improved molecular understanding of RCC, management of small renal masses, the safety and accuracy of renal mass biopsy, the emerging role of molecular imaging, the importance of maximal renal preservation, and the evolving role of laparoscopy, robotics, and ablation.

Renal cell carcinoma

Renal Cell Carcinoma (RCC) has the highest mortality rate of the genitourinary cancers and the incidence of RCC has risen steadily. If detected early, RCC is curable by surgery although a minority are at risk of recurrence. Increasing incidental detection and an ageing population has led to active surveillance as an option for patients with small renal masses. RCC is heterogeneous and comprises several histological cell types with different genetics, biology and behavior. The identification of the genes predisposing to inherited syndromes with RCC has provided much of our knowledge of the molecular basis of early sporadic RCC. Many of the oncogenes and tumor suppressor genes that are mutated leading to pathway dysregulation in RCC remain to be elucidated. Global studies of copy number, gene sequencing, gene expression, miRNA expression and gene methylation in primary RCC will lead towards this goal. The natural history of RCC indicated by candidate precursor lesions, multifocal or bilateral disease, growth rate of small renal masses under surveillance, and high risk populations provide insight into the behavior of this disease. The use of molecular markers for early detection and prognosis merits more attention with ongoing advances in omics technologies. This review focuses on early RCC, that is disease confined within the renal capsule.