Renal tumours - adults

Question 1

What is the most common kidney cancer in adults?

Answer 1

Renal cell carcinoma = 90%

80% of these are made up of clear cells

Question 2

Where do renal cell carcinomas arise from?

Answer 2

Proximal tubular epithelium

Question 3

Discuss the basic histology of a renal cell carcinoma

Answer 3

• Highly vascular
• Most are composed of large cells with clear cytoplasm

Question 4

What are the risk factors for RCC

Answer 4

• Smoking
• Male
• Aged 55-84
• Black/ American Indian
• Obesity
• Hypertension
• Family hx

Question 5

Discuss the clinical features of RCC

Answer 5

• Often asymptomatic
• Haematuria, loin pain and a flank mass may be present
• 5% have polycythemia 30% have hypertension due to the tumour secreting renin
• 30% will have anaemia due to depression of EPO
• Rarely a left sided varicocele may be present if left side renal vein tumours obstruct the drainage of the left testicular vein

Question 6

Discuss treatment of RCC

Answer 6

• Generally resistant to chemotherapy and xRT
• Nephrectomy remains first line unless the tumours are bilateral or the contralateral kidney is functioning poorly
• Nephrectomy recommended if mets present as this has been show to cause met regression
• Local ablation therapy for small renal masses <4cm or a tumour confined to the kidney

Question 7

Discuss Heng criteria for RCC

Answer 7

0 risk factors = 75% survival at 2 years

1-2 risk factors = 53% survival at 2 years

3+ risk factors = 7% survival at 2 years

Question 8

What is the mainstay (non surgical) treatment for RCC?

Answer 8

Tyrosine kinase inhibitors

Sunitinib has a 30-40% response rate

Pazopanib is similar to sunitinib but is better tolerated

Question 9

How do tyrosine kinase inhibitors work?

Answer 9

Tyrosine kinase are needed to turn proteins on and off

In cancer, TKIs block kinases that allow the proliferation of cancer cells via angiogenesis and other growth factors

Orally active, small molecules that exhibit antitumor activity by targeting enzymes that play a critical role cellular functions, including modulation of growth factor signaling, proliferation, carcinogenesis, and cell differentiation

Question 10

Discuss polycystic kidney disease

Answer 10

Most common inherited cause of serious kidney disease

PKD1 and PKD2 - cause mutations in PKD 1 and 2 respectively

PKD accounts for 10% on dialysis

De novo = 5% cases

Can be autosomal dominant or recessive - dominant = more common

Males more seriously affected

Presentation: flank pain, renal colic, haematuria, nocuria as kidneys cannot concentrate urine, stones are 2x common, 80% develop liver cysts, 6% - 16% develop berry aneurysms, mitral valve prolapse

Management = supportive, most deaths occur due to CVD so lifestyle measures are very important, HTN control, treat UTIs, analgesia for renal colic

50% PKD1 patients ESRD @60yrs

50% PKD2 patients ESRD @75yrs

Question 11

Other types of kidney cancer

Answer 11

Urothelial cancer: aka transitional cell carcinoma, 5-10% kidney cancers in adults, begins in renal pelvis, treated in the same way as bladder cancer

Lymphoma

Sarcome

Question 12

Most common cell types in renal cancer

Answer 12

Clear cell = 70%: responds well to immunotherapy

Papillary = 10-15%: often treated with surgery if localised, if metastasised treated with angiogenesis blockers e.g. bevacizumab

Medullary: very aggressive - associated with sickle cell disease

Question 13

Clinical presentation of renal cancer

Answer 13

Haematuria, lon pain, abdominal mass, endocrine effect e.g. low EPO, kidneys dont make active vitamin D so PTH rises to get more calcium in the blood (secondary hyperparathyroidism),