Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a type of kidney cancer originating from the proximal convoluted tubule, responsible for approximately 90–95% of kidney cancers in adults. It mainly affects the elderly, particularly men, with a male-to-female ratio of up to 2:1. Initial treatment often involves partial or complete nephrectomy, with a five-year survival rate ranging from 65–90% if the cancer hasn't metastasized.

Signs and Symptoms

RCC typically presents late due to its ability to hide symptoms. Classic symptoms include haematuria (blood in urine), flank pain, and abdominal mass, often indicative of advanced disease. Other symptoms may include weight loss, fever, high blood pressure, night sweats, and malaise. Metastasis often occurs in lymph nodes, lungs, liver, adrenal glands, brain, or bones.

Risk Factors

Lifestyle

Major risk factors include smoking, obesity, and hypertension, accounting for up to 50% of cases. Occupational exposure to chemicals like asbestos and long-term NSAID use are also suspected risk factors. Conversely, moderate alcohol consumption appears protective.

Genetics

Hereditary factors play a minor role, with immediate relatives having a two to fourfold increased risk. Conditions like hereditary papillary renal carcinoma and von Hippel–Lindau disease also increase risk. Patients with acquired cystic kidney disease requiring dialysis are 30 times more likely to develop RCC.

Pathophysiology

RCC originates from the proximal renal tubular epithelium and is an adenocarcinoma. Both sporadic and hereditary subtypes are linked to mutations in chromosome 3, impacting tumour suppressor genes (VHL, TSC) or oncogenes (c-Met).

Diagnosis

Diagnosis involves evaluating signs and symptoms, medical history, and biochemical tests. Imaging tools like ultrasound, CT scanning, and MRI are very important for detecting RCC.

Classification

RCC is classified into several histological subtypes:

• Clear Cell RCC (CCRCC): 60–70%, linked to chromosome 3p alterations.
• Papillary RCC (PRCC): 10–15%, linked to trisomy of chromosomes 7 and 17.
• Chromophobe RCC (ChRCC): 3–5%, linked to loss of chromosomes Y, 1, 2, etc.

Treatment

Surgery

Surgical options include partial nephrectomy for small tumours and radical nephrectomy for larger or more complex tumours. Surgery is often laparoscopic, reducing recovery time.

Percutaneous Ablative Therapies

Techniques like radiofrequency ablation and cryoablation are used for localised tumours, especially in non-surgical candidates.

Targeted Drugs

Medications such as sunitinib, axitinib, and nivolumab target cancer growth factors or enhance the immune response.

Prognosis

Prognosis depends on tumour size, stage, and histological type. The five-year survival rate for localised RCC is 81%, decreasing significantly with metastasis. Early detection improves outcomes, with incidentally diagnosed RCC having better prognosis compared to symptomatic cases.

History

The understanding of RCC has evolved significantly since the first reference in 1613. The classification and pathogenesis were subjects of debate, with the term "renal cell carcinoma" eventually becoming widely accepted, emphasising its origin from renal tubular cells.

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Self-assessment MCQs (single best answer)

What percentage of kidney cancers in adults is accounted for by Renal Cell Carcinoma (RCC)?

Which gender is more commonly affected by RCC?

What is the initial treatment often involved in RCC?

Which symptom is not typically associated with RCC?

Which of the following is a major lifestyle risk factor for RCC?

Which histological subtype of RCC is the most common?

What genetic condition is associated with an increased risk of RCC?

Which imaging tool is not commonly used for diagnosing RCC?

What is the five-year survival rate for localised RCC?

Which targeted drug is used in the treatment of RCC?