Kidney Cancer: Epidemiology and Pathogenesis
Epidemiology
- Incidence & Mortality
- 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 rates are higher in developed countries
- Likely due to increased use of diagnostic imaging
- USA (2021)
- Includes renal pelvis cancers
- Estimated mortality 13,780
- Estimated incidence 76,080
- Canada (2020)
- Includes renal pelvis cancers
- Estimated incidence 7,500
- 10th most commonly diagnosed cancer in Canada
- 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
- Increased use of diagnostic imaging
- Many databases include upper tract urothelial carcinoma with kidney cancer and therefore independent incidence of kidney cancer cannot be assessed
- Survival
- 5-year relative survival (survival relative to population without disease) based on disease stage at diagnosis§:
- Localized: 93%
- Regional: 70%
- Distant: 13%
- All stages: 75%
- Most lethal of all GU malignancies
- 5-year relative survival all stages for§:
- Prostate cancer: 98%
- Bladder: 77%
- 5-year relative survival all stages for§:
- Survival has been increasing (≈1% year since 2004)
- 5-year relative survival (survival relative to population without disease) based on disease stage at diagnosis§:
- Gender
- M:F 3:2
- Overall mortality worse in males
- M:F 3:2
- 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.
- Typical presentation between age 50-70; median age at diagnosis: 64
- Race
- More common in African Americans, American Indian, and Alaska Native populations than Caucasians
Pathogenesis
- 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§
- 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
Questions
- What proportion of RCCs are familial?
- What are the risk factors for RCC?
Answers
- What proportion of RCCs are familial?
- ≈4-6%
- What are the established risk factors for RCC?
- Obesity
- Hypertension
- Smoking
- Acquired cystic disease
- Familial syndrome
Next Chapter: Pathology and Familial Syndromes
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.