1. Introduction
Kidney cancer, also called renal cancer, arises from the malignant transformation of renal parenchymal cells. The most common form is renal cell carcinoma (RCC), originating from the renal tubular epithelium. It represents one of the top urological malignancies worldwide and is increasingly detected incidentally due to widespread imaging.
2. Types of Kidney Cancer
A. Renal Cell Carcinoma (≈90%)
- Clear Cell RCC – Most common; associated with VHL gene mutation
- Papillary RCC – Type 1 and Type 2 variants
- Chromophobe RCC
- Collecting Duct (Bellini duct) carcinoma – Rare, aggressive
B. Non–Renal Cell Tumors
- Transitional Cell Carcinoma (Renal pelvis)
- Wilms Tumor (Nephroblastoma) – Pediatric
- Renal Sarcoma
- Lymphoma (secondary involvement)
3. Pathogenesis
- Genetic mutations lead to dysregulated cell proliferation and angiogenesis
- VHL gene inactivation → ↑ HIF → ↑ VEGF → tumor vascularization
- Risk factors promote chronic renal injury and oxidative stress
Major Risk Factors
- Smoking
- Obesity
- Hypertension
- Chronic kidney disease
- Long-term dialysis
- Occupational exposure (cadmium, asbestos)
- Genetic syndromes (VHL, Birt-Hogg-Dubé)
4. Clinical Features
- Often asymptomatic (early stages)
- Classic triad (late):
- Weight loss, fever, anemia
- Paraneoplastic syndromes (polycythemia, hypercalcemia)
5. Laboratory Diagnosis
A. Blood Tests
B. Urine Examination
- Microscopic or gross hematuria
- Urine cytology (especially for pelvic tumors)
C. Imaging (Diagnostic Backbone)
D. Histopathology
- Image-guided renal biopsy (selected cases)
- Immunohistochemistry (PAX8, CD10, CK7)
6. Treatment
A. Surgical Management
- Partial nephrectomy (localized tumors)
- Radical nephrectomy (advanced disease)
B. Targeted Therapy
- Tyrosine kinase inhibitors (Sunitinib, Sorafenib)
- VEGF inhibitors
C. Immunotherapy
- Immune checkpoint inhibitors
- Nivolumab
- Pembrolizumab
- Ipilimumab
D. Radiotherapy
E. Chemotherapy
- Limited role (ineffective in most RCC)
7. Prevention
- Smoking cessation
- Weight control and a healthy diet
- Blood pressure management
- Occupational safety
- Regular follow-up for high-risk individuals
- Genetic counseling for familial syndromes
8. Prognosis
- Depends on stage and histological subtype
- Early-stage disease has favorable outcomes
- Metastatic RCC has improved survival with immunotherapy
9. Keynotes
- Clear cell RCC is the most common subtype
- CT scan is the diagnostic gold standard
- Surgery is the primary curative treatment
- RCC is resistant to conventional chemotherapy
- Immunotherapy has revolutionized advanced disease management
Further Readings
- https://www.mayoclinic.org/diseases-conditions/kidney_cancer/symptoms-causes/syc-20352664
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5850086
- https://www.mdpi.com/1422-0067/25/16/9060
- https://www.verywellhealth.com/how-kidney_cancer-is-diagnosed-4160378
- https://www.mykidneycancerteam.com/resources/types-of-kidney_cancer-renal-cell-carcinoma-papillary-chromophobe-and-more
- https://www.kidneycancercanada.ca/guide/understanding-kidney_cancer
- https://www.mayoclinic.org/diseases-conditions/kidney_cancer/diagnosis-treatment/drc-20352669
- https://www.cancerresearchuk.org/about-cancer/kidney_cancer/stages-types-grades/types-grades
- https://www.canceraustralia.gov.au/cancer-types/kidney_cancer/types-kidney-cancer
- https://cancerconsult.care/en/articles/conditions/kidney_cancer/kidney-cancer-diagnosis
- https://healthlibrary.osfhealthcare.org/Library/News/34,17768-1
- https://www.hopkinsmedicine.org/health/conditions-and-diseases/kidney-renal-cancer-introduction
- https://www.cancercenter.com/cancer_types/kidney-cancer/stages
- https://www.webmd.com/cancer/bladder-cancer/urothelial-carcinoma
