Kidney cancer, also known as renal cancer, occurs when cells within the kidneys undergo abnormal changes and begin to multiply uncontrollably, forming a tumor. While often starting as a single growth in one kidney, it can occasionally affect both organs. Renal cell carcinoma (RCC) is the most common type, accounting for about 85-90% of all adult kidney cancer cases.
Sporadic Versus Hereditary Kidney Cancer
Most kidney cancers are considered sporadic, meaning they develop without an inherited genetic cause. These cases arise from random genetic mutations that accumulate over a person’s lifetime, influenced by factors like aging, lifestyle choices, or environmental exposures. Sporadic kidney cancers account for about 90% of all kidney cancer diagnoses.
A smaller percentage of kidney cancers, 5-8%, are classified as hereditary. These cases are linked to specific inherited genetic mutations. Unlike sporadic cancers, hereditary kidney cancers present at an earlier age and may involve multiple tumors or affect both kidneys. The presence of an inherited mutation increases the risk of developing cancer, though it does not guarantee that an individual will develop the disease.
Specific Inherited Kidney Cancer Syndromes
Several distinct inherited genetic syndromes increase an individual’s susceptibility to kidney cancer.
Von Hippel-Lindau (VHL) Disease
This autosomal dominant disorder is caused by mutations in the VHL gene. It is associated with a higher risk of developing clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer. Individuals with VHL disease can also develop tumors in other organs, including the brain, spinal cord, and eyes.
Hereditary Papillary Renal Carcinoma (HPRCC)
This syndrome is linked to mutations in the MET gene. It leads to an increased risk of papillary kidney cancer, which grows at a slower rate.
Birt-Hogg-Dubé (BHD) Syndrome
Caused by mutations in the FLCN gene, BHD syndrome is characterized by skin lesions, lung cysts, and an increased risk of developing various types of kidney tumors, including chromophobe and oncocytoma-like renal cell carcinomas.
Hereditary Leiomyomatosis and Renal Cell Carcinoma (HLRCC)
Associated with mutations in the FH gene, HLRCC raises the risk of developing aggressive forms of papillary type 2 renal cell carcinoma, as well as benign skin and uterine tumors.
Succinate Dehydrogenase (SDH)-deficient Renal Cell Carcinoma
This syndrome is caused by mutations in one of the SDHA, SDHB, SDHC, or SDHD genes. It can lead to the development of specific types of kidney tumors, as well as paragangliomas and pheochromocytomas.
Genetic Testing and Family Risk Assessment
Genetic testing for hereditary kidney cancer is considered in situations suggesting an inherited risk. This includes individuals diagnosed with kidney cancer at a younger age, those with multiple tumors in one kidney, or individuals who have tumors in both kidneys. A strong family history of kidney cancer or other associated tumors also suggests genetic evaluation.
The process begins with genetic counseling, where a specialist reviews an individual’s personal and family medical history to assess the likelihood of an inherited syndrome. If a hereditary risk is suspected, genetic testing involves analyzing a blood or saliva sample to identify specific gene mutations linked to kidney cancer syndromes. Understanding family history, including the types of cancers and ages of diagnosis among relatives, helps guide decisions about which genes to test. Identifying a specific genetic mutation can inform the affected individual’s care and allow for risk assessment and potential testing for other family members.
Monitoring and Care for Inherited Risk
For individuals identified with an inherited risk of kidney cancer, ongoing surveillance is a key part of their care strategy. The primary goal of monitoring is the early detection of tumors, which can improve treatment outcomes. This involves regular imaging studies, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, to visualize the kidneys and surrounding structures. The frequency and type of imaging are tailored to the specific genetic syndrome and individual risk factors.
Beyond imaging, a comprehensive care plan may include preventative strategies for overall health. This can involve lifestyle modifications, such as maintaining a healthy weight, managing blood pressure, and avoiding smoking, all of which are recognized risk factors for kidney cancer. While these measures do not eliminate the inherited risk, they can contribute to overall well-being and potentially reduce the impact of other contributing factors. The specific monitoring protocols and preventative recommendations are individualized, based on the identified genetic mutation and the associated cancer risks.