Primary renal cell carcinoma has had a slight increase in annual incidence. This is due to incidental detection with the more frequent use of ultrasound and CT imaging modalities. Often the kidney cancer is picked up at an earlier and smaller stage, where the tumour may be 2-4cm and well localised to the kidney. It is becoming less common to detect very large locally advanced or metastatic renal cell carcinoma.
Larger kidney cancers, well above 8-10cm, can locally invade adjacent structures, or send a tongue of tumour into the renal vein and inferior vena cava. This requires a complex open operative approach. The smaller organ-confined cancers are best dealt with by way of partial nephrectomy, where the kidney cancer, along with a rim of normal healthy surrounding kidney is removed and the defect is sewn up in several layers.
Partial nephrectomy can be performed, either open or robotic assisted, or laparoscopic.
Robotic partial nephrectomy is ideal for cancers up to 4cm in diameter, in certain positions within the kidney, that are amenable, in terms of ease of access during dissection.
It is important to persist with nephron sparing approaches where possible, especially in patients with higher risks of chronic kidney disease, which mostly relates to those with hypertension or diabetes.
Open partial nephrectomy is performed through a retroperitoneal flank, 11th rib incision.
Convalescence using the robotic key hole approach is more rapid with less post operative analgesic requirements than the open approach. Certain central endophytic tumours are not amenable to robotic partial nephrectomy.
Referral to a medical oncologist may be required for advanced renal cell carcinoma, where there are metastases and a Tyrosine-kinase receptor inhibitor or other molecular targeted therapies may be required. Their administration and management of side effects is best left with the oncologist.
Cystic lesions of the kidney are classified based on the Bosniak scoring system and cysts that are simply fluid filled with no irregularities are watched. Renal cysts are common and certain cysts containing enhancing septations or nodularity or soft tissue, may require surgical excision.
In general, it is thought that 70% of kidney tumours detected on ultrasound or CT are malignant renal cell carcinomas, a small proportion of them may be rarer malignancies, such as lymphoma, sarcoma or a metastasis to the kidney from elsewhere. 20-30% of renal tumours are benign. Renal tumour biopsy by way of image guided core needle or fine needle biopsies can be performed by an interventional radiologist for histopathologic confirmation of the type of tumour and its grade. This helps in decision making and allocates suitability to an active surveillance program.
In the elderly co-morbid age group, smaller renal tumours, even if they are malignant, can be watched by way of active surveillance, however renal tumour biopsy is preferable.
Biopsy requires that all blood thinners are temporarily withheld. Radiofrequency ablation (RFA) or cryotherapy, are less invasive methods to either cauterise or freeze a renal tumour and have medium term oncologic efficacy rates of approximately 90-95%, in terms of cancer clearance.