Introduction: the kidneys and their vital role

Our body functions as a well-coordinated, harmonious system, and the kidneys play a crucial role in maintaining the balance. Each human kidney is a bean-shaped organ and varies in size between 9 and 14 cm long, influenced by variations of individual size and gender. They perform several crucial tasks: they filters waste products from the blood (for example, urea and creatinine), regulate fluid volume and maintain the balance of electrolytes, and produce essential hormones which are necessary for the regulation of blood pressure. They also stimulate the bone marrow to produce red blood cells by releasing erythropoietin.¹

Given that the function of the kidneys is vital to good health, it is unsurprising that kidney disease can produce severe health impacts, both of chronic and acute nature.² Among the diseases of the kidney, cancer is the condition that has the potential to be life-threatening and can impact the lives of individuals severely, both mentally and physically. This article reviews the clinical features, its causation, diagnosis, and treatment, and some recommendations for prevention, early diagnosis, and awareness.

Understanding kidney cancer

What is kidney cancer?

Kidney cancer, also known as renal cancer, occurs when abnormal cells start to grow uncontrollably in the kidney tissue. This uncontrollable growth leads to the development of a mass or tumour, which disrupts the delicate structures of the kidney and their function, such as tubules in the nephron or glomerular capsule, which are responsible for the production and transportation of urine. This atypical tissue growth further alters the body's functioning, creating an imbalance.³ If this remains undiagnosed, then cancerous tissue can keep growing continuously, and it can invade the surrounding organs of the abdomen. The cancerous mass can also pass to the lymph nodes of the pelvic region and, through the lymphatic circulation, can cause metastasis in the body. Renal cancer can be classified into the following types based on the structures of the kidney it affects:

The most common types of kidney cancer are: 

• Renal Cell Carcinoma (RCC): It is the most common, accounting for approximately 85% of adult cases. It affects the tubules of the nephrons, which are responsible for the transportation of urine to further parts of the kidney
• Transitional/Urothelial Cell Carcinoma: It originates in the lining of the renal pelvis (where urine collects before entering the ureters) and ureters, an important component of the urinary system
• Wilms’ Tumour: It is also known as Nephroblastoma, and it primarily affects children and is rare in adults⁴

Risk factors

Certain factors can significantly increase the risk of having kidney cancer. ⁵ These include:

• Increasing age (mostly cases are over 60)
• Smoking
• Genetic predisposition or inherited conditions (e.g., Von Hippel-Lindau disease)
• Obesity
• Exposure to certain chemicals (e.g., asbestos, cadmium)
• Hypertension
• Comorbidities such as cardiovascular and endocrine diseases
• Metastasis

Symptoms and warning signs

Similar to many other cancers, in the initial phase, renal cancer does not exhibit any obvious symptoms;  it may go undiagnosed for a long period.⁶ However, as the tumour grows, and pressure builds up in the walls of the kidney, the patient may experience signs and symptoms such as:

• Haematuria (blood in the urine)
• Fatigue
• Pain in the side of the abdomen or in the back
•  Lump or abdominal mass
• Unexplained weight loss
• Sweating
• Frequent fever and night sweats
• Anemia
• Weakness
• Loss of appetite

Early detection of cancer is critical, as treatment can be commenced in the initial phase, and it can significantly improve the outcomes.

From suspicion to diagnosis

How is kidney cancer diagnosed?

When a patient is suspected of having kidney cancer, the physician usually begins the assessment to diagnose the illness early and includes the following diagnostic tests:

• Medical history and physical examination: To rule out the risk factors and pre-existing medical conditions which can lead to the formation of tumours
• Urinalysis: To assess the presence of blood, signs of infection, or protein in the urine, which indicates pathological kidneys
• Blood tests: They include renal function test (RFT), complete blood count (CBC), electrolytes, liver function test (LFT), and thyroid tests
• Imaging studies: Such as ultrasound, CT scans, or MRI, can be used based on the needs of the patient to identify the location and size of a renal tumour
• Biopsy: if all the above-mentioned tests are suspicious for tumour, then biopsy or FNAC (fine needle aspiration cytology) can be executed for the final diagnosis of cancer

Staging kidney cancer

Staging cancer can show how much the disease has spread and help with deciding what treatment to recommend:

• Stage I–II: Tumour is limited to the kidney
• Stage III: Tumour has spread to nearby lymph nodes or blood vessels
• Stage IV: Cancer has spread to distant organs, such as the lungs, liver, or bones

Staging is crucial for predicting prognosis and creating a treatment plan.

Treatment options

The treatment plan for the renal cancer patients is based on multiple factors such as the age of the patient, stage of the cancer, tumour grade, type of cancer, overall health of the patient, kidney function, and presence of metastases.⁷

There are multiple ways to treat cancer, including surgery, chemotherapy, radiation therapy, and immunotherapy_.⁸ Multidisciplinary care is often essential.

Surgical management

Surgery is the primary treatment for localised early-stage kidney cancers. Depending on the tumour’s size and location, one of the following procedures may be performed:

• Partial nephrectomy: Only the tumour and a small part of healthy kidney tissue are removed. This is ideal for smaller tumours and allows the preservation of the function of the remaining kidney
• Radical nephrectomy: It is most commonly used for larger or more aggressive tumours which spread rapidly. In this, the entire kidney, surrounding tissue, and involved lymph nodes are removed as well to remove the tumour completely

Non-surgical therapies

The patients who cannot undergo surgery and patients with advanced or metastatic renal cancer have to be treated non-surgically with the drugs, and the following ways can be employed to achieve the outcome:

• Targeted therapy: These agents block the specific molecules which are involved in the growth of tumours.⁹ Common drugs include tyrosine kinase inhibitors (TKIs) like sunitinib or pazopanib
• Immunotherapy: Agents such as nivolumab and pembrolizumab help to destroy the cancer cells by helping the immune system to recognise the cancer cells¹⁰
• Radiation therapy and chemotherapy: These are used frequently when the cancer has spread or in combination with other treatments, though chemotherapy is less effective for kidney cancer than for other cancers

Prevention and management: t aking control

While some risk factors are unavoidable, lifestyle modifications can significantly reduce the chances of developing kidney cancer. Here are a few things which you can consider doing:

Lifestyle modifications

Prevention is better than a cure. Adopt lifestyle habits that significantly improve health and well-being, and avoid indulging in activities which have proven to be harmful.⁶ 

• Avoid smoking and tobacco use
• Maintain a healthy body weight
• Regular physical activity
• Balanced diet (rich in fruits, vegetables, and whole grains)
• Stay well-hydrated
• Limit alcohol intake
• Manage chronic health conditions, especially high blood pressure and diabetes

Routine health check-ups 

Early detection improves survival rates and reduces the mortality rates from cancer. Diagnosis of most of the tumours occurs incidentally during routine check-ups and can help with the initiation of treatment in the early phase.

• Regular blood and urine tests can detect early signs of any renal pathology
• Imaging studies, such as abdominal ultrasound, CT scans, can help identify tumours
• Continuous observation and management of comorbidities such as hypertension, cardiovascular problems, and diabetes can reduce the workload of the kidneys

Life after kidney cancer: survivorship and follow-up

Recovery does not end after treatment. Patients require ongoing surveillance post-treatment with imaging and lab testing for early detection of recurrence. In addition, patients should make lifestyle changes (quitting smoking/tobacco use, weight management, and blood pressure control) to decrease the suspected risk of recurrence and promote overall health.

Summary

Kidney cancer is a difficult and serious condition that can be both serious and life-threatening if ignored; awareness and early treatment are key. The kidneys are one of the most important and necessary organs for keeping homeostasis, or balance, and the overall health of the body in check, even when affected by the unregulated growth of abnormal cells. Renal Cell Carcinoma (RCC) is the most common form of kidney cancer. Often, kidney cancer is not diagnosed until it is too late, which is why patients must be aware of kidney cancer risk factors as well as signs and symptoms. Advances in diagnostics that utilise imaging studies and biopsies have given physicians better diagnostics and staging.

Thanks to advances in diagnosis and treatment, many people with kidney cancer go on to lead full and active lives. Options range from surgical options (partial or radical nephrectomy) to non-surgical options (targeted drugs, immunotherapy, and minimally invasive techniques, i.e. cryoablation).

Prevention will also play a role in kidney cancer through lifestyle choices and changes, including smoking cessation, maintaining a healthy weight, and attending regular health check-ups to help reduce the risk of kidney cancer.

Follow-up care, ongoing surveillance, and lifestyle changes for kidney cancer survivors are critical in reducing the chance of recurrence or another cancer from developing. Ultimately, kidney cancer is not just a medical condition but an opportunity to take control of your health and be resilient.

Staying informed and vigilant allows individuals the ability to be mono-minded in their journey as it relates to kidney cancer, to face this devastating disease with strength and an undeterred determination. As the saying goes, “It’s not just about fighting cancer, it’s about choosing to live boldly and proactively every day.”