Understanding Kidney Cancer: Causes, Types, and Treatments
Kidney cancer, mainly renal cell carcinoma, is a common and often asymptomatic disease diagnosed through imaging. It has genetic, environmental, and lifestyle risk factors, including smoking, obesity, and genetic mutations such as VHL. Treatment ranges from surgical removal to immunotherapy. Early detection improves prognosis, but advanced cases have limited response to therapies. Understanding the causes, types, and treatment options is vital for effective management and improving patient outcomes.
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Learn about kidney cancer, also known as renal cell carcinoma
Kidney cancer, predominantly metastatic renal cell carcinoma, is the most prevalent kidney malignancy in adults. Often asymptomatic, it is typically discovered incidentally during imaging procedures. When symptoms do occur—afflicting around 20% of patients—they include flank pain, visible blood in urine, and abdominal swelling.
The development of this cancer involves genetic and environmental factors. Unfortunately, it has a poor outlook due to resistance to chemotherapy and radiation therapy.
Ranked as the 14th leading cause of cancer worldwide, it accounts for about 2-3% of all new cancer diagnoses.
In populations of 100,000, approximately 15 cases are diagnosed yearly, with men being more affected than women. The incidence is 15 times higher in Europe, North America, and Australia compared to Africa and Asia. Kidney cancer is more common after transplantation, especially among native recipients, being a hundred times more frequent than in dialysis patients. Pre-transplant dialysis also correlates with increased risk.
Patients over 64 tend to have a poorer response to treatment, and age-related increases are observed. Obesity raises risk, with every additional 5 kg increasing the chance by 24-34%. Tobacco use also significantly elevates risk, especially among males.
Genetic mutations play a crucial role, notably involving the VHL gene, which normally suppresses tumors. The inactive VHL gene is linked to early-onset renal cancer and familial cases. Some common gene mutations are associated with specific subtypes, such as clear cell carcinoma and papillary variants.
Major types include clear cell renal carcinoma, making up 80% of cases, and papillary carcinoma, prevalent among transplant patients. Chromophobe carcinoma is rare, constituting about 5%.
Risk factors encompass tobacco smoke, high BMI, high blood pressure, and exposure to certain chemicals like asbestos and trichloroethylene. Chronic hepatitis C, kidney failure, familial syndromes such as Tuberous Sclerosis, and acquired cystic kidney disease also increase risk.
A family history significantly raises the likelihood of developing renal cancer, with genetic syndromes like VHL, hereditary leiomyomatosis, Birt-Hogg-Dube syndrome, and SDH mutations playing a part.
Treatment varies based on tumor size and spread. Small, localized tumors are often treated with partial nephrectomy, while larger ones may require radical removal. Cytoreductive surgery is an option in metastatic cases. Immunotherapy, including VEGF and mTOR inhibitors, offers promising outcomes, especially for advanced disease.
Diagnosis involves physical exams, medical history, blood tests—including serum creatinine, calcium, lactate dehydrogenase—and imaging such as CT scans of the abdomen, pelvis, and chest. MRI helps assess tumor extension, particularly into the vena cava. Biopsy is useful for small tumors but less so for larger masses. Imaging guides staging and treatment planning, with a significant portion of patients diagnosed at an early or localized stage, though some present with metastasis.
