Kidney cancer

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Dr Daleen Geldenhuys educates us on kidney cancer and the treatment thereof.

Kidney cancer, commonly known as renal cell carcinoma (RCC), originates within the renal cortex (outer layer of the kidney as opposed to the urine collecting system), and constitutes 80 to 85% of primary renal tumours. Urothelial carcinomas of the renal collecting system accounts for approximately 8% of kidney tumours, and other tumours, such as oncocytomas, collecting duct tumours, and renal sarcomas, are rare. Nephroblastoma (Wilms tumour) is a primitive tumour common in children (5 to 6% of paediatric malignancies). Note, the information below is not directed to childhood cancers.

Kidney cancer often presents late in the course of the disease, usually with a very large mass sometimes more than 20cm in size. Patients often experience referred back pain and the diagnoses are delayed. Earlier cancer may be detected incidentally after an investigation for a different problem, or found if the patient sees macroscopic blood in the urine (red urine).

Two management categories

We divide the presentation of RCC into two management categories.

• Localised disease – This includes Stage 1, 2, and 3. 
• Advanced disease – This includes tumour invading beyond Gerota’s fascia (covering capsule of both the kidney and the adrenal gland above it) or extending into the ipsilateral (same side) adrenal gland and metastatic disease to the rest of the body. RCC can grow in any micro environment and all complaints should be thoroughly investigated not to miss an unusual lesion.

Treatment for localised disease

Surgery is curative in most patients with RCC who don’t have metastases. Surgery is therefore the preferred treatment for patients with Stages 1, 2, and 3.

Treatment may require a radical nephrectomy (removal of the entire kidney), although a partial removal to preserve part of the kidney, is preferred for appropriately selected patients. 

The choice of surgical procedure depends upon the extent of disease, as well as patient-specific factors, such as age and comorbidity. The incision is usually on the left or right side of the upper abdomen, starting at the back and not the convention midline approach as is used for bowel surgery. A minimally invasive approach, such as laparoscopy, can also be done if the tumour is smaller.

In carefully selected patients who present with a resectable primary tumour and a concurrent single metastasis (Stage 4), surgical resection of the metastasis, in conjunction with removal of the kidney may be done.

Other use of treatment 

Other procedures, such as cryotherapy or radiofrequency ablation, may be an alternative for patients with relatively small renal masses who aren’t surgical candidates. 

Bilateral RCC is more common among patients with inherited conditions (von Hippel-Lindau disease and tuberous sclerosis) and papillary RCC. Surgery is recommended but should involve sparing as much of the kidneys as possible during the initial therapy. Losing a big part of the kidney may have lifelong dialysis as a complication.

Active surveillance may be an option for non-surgical candidates such as older adult patients and for those with significant comorbidity. Most small tumours grow slowly and don’t become symptomatic or metastasise. Observation with periodic re-evaluation is a reasonable option.

RCC isn’t sensitive to chemotherapy, so immunotherapy and targeted therapy are the systemic treatments of choice. 

Adjuvant therapy after surgeryis recommended for high-risk patients only and the treatment of choice is immunotherapy for a year, three weekly infusions, rather than observation. We offer active surveillance after nephrectomy to patients who are at lower risk for disease recurrence.

Targeted therapies, such as sunitinib, sorafenib and other drugs in this class, haven’t yet demonstrated recurrence or survival benefits.

Treatment for advanced disease

Patients often present with Stage 4 disease and many patients who initially are resectable eventually experience recurrence. 

Immunotherapy, targeted agents, surgery, and radiation all may have a role depending on the extent of disease, sites of involvement, and patient-specific factors. Surgery is important for debulking of disease (large tumours).

Although RCC has been characterised as a radioresistant tumour, conventional and stereotactic radiation (focused on one area) are frequently useful to treat a single or limited number of metastases. In these settings, the indication of radiation is similar to that in metastases from other tumour types.

Examples of situations where radiation is useful include painful bone metastases, brain metastases and painful recurrences in the area where the kidney used to be.

Treating RCC consists of a multi-modality approach and even in Stage 4 disease, changing the therapy may improve survival and quality of life. Treatment needs to be individualised and a multi-disciplinary team provides the best care.

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