Kidney Cancer: Epidemiology and Pathogenesis
Epidemiology
Many databases include upper tract urothelial carcinoma with kidney cancer and therefore independent incidence of kidney cancer cannot be assessed
- GLOBOCAN includes ICD-9 C65 - "Malignant neoplasm of renal pelvis" with kidney cancer
Incidence
- Incidence has been increasing due to (2):
- Increased use of diagnostic imaging
- Greatest increase has been in small, clinically localized renal amsses which now represent > 40% of incident tumours.
- Increased prevalence of risk factors (e.g. obesity), see below
- Worldwide
- Incidence rates are higher in developed countries
- Likely due to increased use of diagnostic imaging
- Incidence rates are higher in developed countries
- US[1]
- Includes renal pelvis cancers
- Estimated incidence 2023: 81,800 (2022: 79,000)
- Canada[2]
- Includes renal pelvis cancers
- Estimated incidence 2020: 7,500
- 10th most commonly diagnosed cancer in Canada
Mortality
- 5-year relative survival (survival relative to population without disease) based on disease stage at diagnosis[5]:
- Localized: 93%
- Regional: 70%
- Distant: 13%
- All stages: 75%
- Most lethal of all GU malignancies
- 5-year relative survival all stages for[6]:
- Prostate cancer: 98%
- Bladder: 77%
- 5-year relative survival all stages for[6]:
- Survival has been increasing (≈1% year since 2004)
Gender
- Incidence M:F 1.75:1[7]
- Overall mortality worse in males
Age
- Typical presentation between age 50-70; median age at diagnosis: 64
- RCC in children and young adults is more likely to be symptomatic, locally advanced, high grade, and of unfavorable histologic subtypes.
- Children and young adults may respond better to surgical therapy and aggressive approach and formal lymphadenectomy has been recommended at the time of radical nephrectomy
- RCC in children and young adults is more likely to be symptomatic, locally advanced, high grade, and of unfavorable histologic subtypes.
Race
- More common in Blacks, American Indian, and Alaska Native populations than Whites
Risk Factors
Acquired
- Majority of cases are believed to be sporadic
- Established risk factors (5):
- Obesity
- Accounts for ≈30% of incident cases
- Obese patients are more likely to develop RCC but these tumours are more likely to be low-grade, early stage tumours
- Smoking
- Accounts for ≈20% of incident cases
- Hypertension
- Familial syndromes
- Accounts for ≈4-6% of incident cases[8]
- Chronic renal failure
- Controversial; however, patients on maintenance dialysis also are reported to have an increased risk
- It has been suggested to delay screening for kidney cancer in patients on dialysis and without other major comorbidities until the 3rd year on dialysis.
- Controversial; however, patients on maintenance dialysis also are reported to have an increased risk
- Obesity
- Other risk factors (5):
- Family history of renal malignancy (without familial syndrome)
- Exposure to chlorinated solvents
- Retroperitoneal radiation
- Diet
- Moderate alcohol intake, consumption of fruits and (cruciferous) vegetables, and a diet rich in fatty fish are believed to reduce the risk of RCC
- Acquired cystic renal disease
- No increased risk of RCC in patients with autosomal dominant polycystic kidney disease
Inherited
Familial Renal Cell Carcinoma Syndromes
- All are autosomal dominant
- Account for ≈4-6% of cases of RCC overall
Syndrome | Gene | Clinical Manifestations |
Von Hippel-Lindau (VHL) | VHL | HIPPPEEL
|
Hereditary Papillary Renal Carcinoma (HPRCC) | c-MET |
|
Hereditary Leiomyomatosis and RCC (HLRCC)* | Fumarate hydratase |
|
Birt-Hogg-Dube (BHD) | Folliculin |
|
Succinate Dehydrogenase RCC* | SDHB/C/D (encoding subunits of the Krebs cycle enzyme succinate dehydrogenase) |
|
Tuberous Sclerosis Complex (TSC) | TSC1/2 |
|
Cowden/PTEN Syndrome Associated RCC | PTEN |
|
BAP-1 tumour predisposition syndrome[9] | BAP1 |
|
*Renal cancers associated with these syndromes are typically more aggressive |
Von Hippel-Lindau Disease
- Incidence 1:30,000-1:40,000
- RCC develops in 35-70% of VHL patients and is distinctive for early age (median 40) of onset and bilateral and multifocal involvement
- Mutation: VHL
- VHL is a tumor suppressor gene, for both familial and sporadic ccRCC, at chromosome 3p25-26
- VHL mutation is most common genetic mutation in sporadic RCC[10]
- Under normal conditions, the VHL complex targets hypoxia-inducible factors (HIF) for degradation, keeping levels of HIF low. HIF regulates response to hypoxia, starvation, and other stresses
- In the absence of VHL, HIF accumulates and leads to overexpression of vascular endothelial growth factor (VEGF), the primary angiogenic growth factor in RCC, contributing to the neovascularity associated with ccRCC.
- Production of erythropoietin (EPO) is closely associated with circulating oxygen levels. During conditions of hypoxia, hypoxia-inducible factor-1-alpha (HIF-1-a) is upregulated increasing EPO transcription. HIF-1-a is then rapidly degraded by proteases upon restoration of normal oxygen tension.
- VHL is a tumor suppressor gene, for both familial and sporadic ccRCC, at chromosome 3p25-26
- Pheochromocytoma manifestations of VHL are restricted to certain families (type 2 VHL)
- Patients suspected of having VHL, or the appropriate relatives of those with documented disease, should strongly consider genetic evaluation.
- Patients with germline mutations of the VHL gene can be offered screening to identify major manifestations of VHL at a pre-symptomatic phase
- RCC is most common cause of death in VHL patients
Hereditary Papillary Renal Cell Carcinoma (HPRCC)
- Tumours tend to be less aggressive than their sporadic counterparts
- Most of the mutations in HPRCC have been found in the tyrosine kinase domain of met and lead to constitutive activation of the receptor for hepatocyte growth factor
Hereditary leiomyomatosis and RCC syndrome (HLRCC)
- Almost all individuals with this syndrome will develop cutaneous leiomyomas and uterine fibroids (if female), usually manifesting at the age of 20-35 years.
- A high proportion of women have had a hysterectomy for fibroids before formal diagnosis of HLRCC.
- Only a minority (20%) of HLRCC patients develop RCC
- Penetrance for RCC in HLRCC is lower than for the cutaneous and uterine manifestations
- Unlike other familial syndromes, tumours with this syndrome tend to be unilateral, solitary, and more aggressive; therefore, prompt surgical management is indicated
Tuberous Sclerosis Complex (TSC)
- Classic triad:
- Seizures
- Adenoma sebaceum
- Intellectual disability
- May not be present due to variable penetrance of the TSC mutation
- 50% of patients with TSC develop AMLs
Questions
- What proportion of RCCs are familial?
- What are the clinical manifestations of VHL?
- What gene is mutated and what are the clinical manifestations of HRPCC, HLPCC, Burt-Hogg-Dube, Tuberous Sclerosis Complex?
- Explain the pathway of VHL and HIF and role in RCC pathophysiology
- What are the risk factors for RCC?
Answers
- What proportion of RCCs are familial?
- ≈4-6%
- What are the clinical manifestations of VHL?
- Hemangioblastoma
- Increased risk of ccRCC
- Paraganglioma
- Pheochromocyoma
- Pancreatic cysts and neuroendocrine tumours
- Ear endolymphatic tumour
- Epididymal cysts
- Ligament, broad tumours
- What gene is mutated and what are the clinical manifestations of HRPCC, HLPCC, Burt-Hogg-Dube, Tuberous Sclerosis Complex?
- HRPCC: c-met; clinical manifestations: type I papillary RCC
- HLPCC: fumarate hydratase; clinical manifestations; type II papillary RCC, cutaneous leiyomyoma and uterine leiyomyoma
- Burt-Hogg-Dube: folliculin; clinical manifestations: pneumothorax, pulmonary cysts, skin fibrofolliculuomas, chromophobe RCC and other renal tumours
- Tuberous sclerosis complex: TSC1 and TSC2; clinical manifestations: adenoma subaceum, shagreen spots, AMLs, ccRCC, retinal hamartomas, CNS lesions, epilepsy, mental retardation, cardiac lesions, teeth lesions, gum lesions, bone cysts, pulmonary lymphangiomyomatosis
- Explain the pathway of VHL and HIF and role in RCC pathophysiology
- Under normal conditions, VHL targets hypoxia-induced factor (HIF) for degradation. In the absence of VHL due to mutation, HIF accumulates resulting in increased expression of VEGF, the primary angiogenic growth factor for RCC
- What are the established risk factors for RCC?
- Obesity
- Hypertension
- Smoking
- Acquired cystic disease
- Familial syndrome
Next Chapter: Pathology
References
- Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 57
- Campbell, Steven C., et al. "Renal Mass and Localized Renal Cancer: Evaluation, Management, and Follow-Up: AUA Guideline Part I." The Journal of urology (2021): 10-1097.