BIOLOGY OF RENAL CELL CARCINOMA Flashcards
RCC is the most common malignancy that originates from which part of the kidney?
CORTEX
What is the most common subtype of RCC?
ccRCC
How many % does ccRCC comprise among the other histologic subtypes?
75-85%
What is the most common and most lethal subtype of RCC?
ccRCC
What type of gene is commonly lost in ccRCC?
pVHL gene
ccRCC is an aggressive cancer that arises from what part of the nephron?
proximal tubular epithelium
What are the 3 histomorphologic subtypes of RCC?
- ccRCC (CLEAR CELL)
- pRCC (PAPILLARY TYPE 1 & 2)
- chRCC (CHROMOPHOBE)
What subtype constitute 10-20% of RCC?
PAPILLARY TYPES 1&2
What subtype is the least common & constitute 5% of RCC?
CHROMOPHOBE
What is the first pathway identified as being altered in ccRCC?
HIF−hypoxia pathway
What are the other 4 metabolic abnormalities responsible for paraneoplastic syndromes in RCC?
- Warburg effect (aerobic glycolysis) 2. arginine synthetic abnormalities (due to arginosuccinate synthetase-1 [ASS1] deficiency)
- Glutamine pathway reprogramming
What is the most recent therapy that has shown considerable promise in treating ccRCC?
immune checkpoint inhibitors
What 5 metabolic pathways are upregulated in ccRCC?
- aerobic glycolysis
- carnitine and lipid synthesis
- reductive carboxylation
- glutathione oxidized glutathione (GSH/GSSG) pathway
- tryptophan metabolism
What 2 metabolic pathways are downregulated in ccRCC?
- UREA CYCLE
- TCA CYCLE
What is the pathology in RCC?
METABOLIC REPROGRAMMING
What are the 3 genetic abnormalities in ccRCC?
1.VHL gene
2. epigenetic regulators and chromatin remodeling genes
3. disruption of PI3K-AKT-mTOR signaling
What are comprise the majorityof ccRCC cases?
SPORADIC
What % of ccRCC is linked to Hereditary diseases?
2-3%
Mutations in this gene are associated with more than 80% of sporadic ccRCC cases?
VHL gene
What is the most important function of VHL protein (pVHL)?
polyubiquitination of a variety of proteins, including HIF 1 and 2
What is the second most common type of mutation in ccRCC?
epigenetic regulators which are involved in regulation of chromatin maintenance and remodeling
What are the epigenetic regulator genes?
- polybromo 1 (PBRM1)
- BRCA-associated protein-1(BAP1)
- SET domain–containing 1 (SETD1)
Deficiency of this mTOR pathway protein is associated with more aggressive ccRCC tumors
PTEN DEFICIENCY
What proteins are involved in cell proliferation signaling and have been identified in up to 28% of RCC patients?
mTOR PATHWAY PROTEINS
What are the 4 mTOR pathway proteins?
- PTEN
- AKT
- PIK3CA
- mTOR
What is the 2nd most common RCC which is also of proximal tubule origin?
pRCC
What type of pRCC is characterized by MET proto-oncogene−activating mutations?
TYPE 1
What type of pRCC is linked to activation of the NRF2 antioxidant response element pathway as the result of augmented oxidative stress?
TYPE 2
What type of pRCC portends a worse prognosis?
TYPE 2
chRCC is a rare cancer that originates from which part of the nephron?
COLLECTING DUCT
What RCC is similar to benign oncocytomas?
chRCC
What type of RCC is linked with whole-chromosome losses and germline mutations in the folliculin gene (FLCN) found in the autosomal dominant Birt-Hogg-Dubé syndrome?
chRCC
What is the most frequent mutation in sporadic cases of chRCC?
downregulation of p53 tumor suppressor signaling and loss of function of PTEN leading to PI3K-driven cell proliferation
ChRCC is more common in what population?
YOUNGER FEMALES
What is the least aggressive of all RCC types?
chRCC
What is the clinical presentation of RCC?
occult disease and often present with a late and more advanced stage at the time of diagnosis
How many % of patients have metastatic disease or advanced local disease at the time of presentaion?
25%
How many % of patients are diagnosed based on incidental findings in abdominal radiologic imaging?
50%
What has been identified as a negative prognostic factor for RCC?
Hypercalcemia
RCC typically presents at what age group?
60 to 70 years
What are the 5 risk factors for RCC?
- male gender
- obesity
- tobacco use
- DM
- HTN
What population tends to have better survival in RCC?
OBESE
(protective effect of brown fat)
What lowers RCC risk?
alcohol exposure
What 2 factors predispose ESKD patients to develop RCC?
- Cystic disease
- prolonged dialysis dependency
What is the risk of ESKD patients to develop RCC?
100-fold increased risk