The kidneys are paired, bean-shaped, blood filtering organs, which sits on either side of the backbone and are attached to the upper back wall of the abdomen. A kidney in healthy adult measures 10 to 12 cm in length, 5 to 7 cm in width, and 3 cm in thickness and has a mass of approximately 135 to 150 grams.
The kidney is made up of small functional units known as nephrons, which constitute the medulla and cortex of the kidney.
Three layers surround the kidney: an innermost renal capsule made up of dense irregular connective tissue, a middle adipose layer made up of fatty tissue, and an outermost renal fascia (also known as Gerota’s fascia) made up of dense irregular connective tissue.
Adrenal glands are two small glands which are present on top of each kidney. The main functions of the kidneys include excretion of waste material by filtration of blood, maintenance of blood pressure, and production of hormones – renin (that helps in maintaining blood pressure), calcitriol (that helps in maintaining bone density) and erythropoietin (that stimulate the production of red blood cells in bone marrow).
Types of Renal Cell Carcinoma
Renal cell carcinoma (RCC) is the most commonly encountered (90% of the cases) kidney cancer. RCCs are further divided into following subtypes based on their histology (appearance under a microscope):
- clear cell RCC,
- papillary RCC,
- chromophobe RCC,
- multilocular cystic RCC,
- collecting duct RCC,
- medullary carcinoma,
- mucinous tubular,
- spindle cell carcinoma,
- neuroblastoma-associated RCC, and
- unclassified lesions.
Risk Factors/Causes of Kidney Cancer
Kidney cancer, or renal cell carcinoma, has witnessed a downfall in its incidence over the last few decades. But, early kidney cancer still continues to be highly diagnosed in the United States. It has been ascertained that patient education and knowledge of risk factors will foster their avoidance of known risks thereby enabling US to reduce its annual burden of kidney cancer.
Tobacco increases the risk of kidney cancer by about 38%. This has been identified as one of the major risk factors for kidney cancer and cessation of smoking may prevent kidney cancer.
A linear relationship has been established with respect to smoking implicating that the more you smoke, the more severe is your risk, and smoking cessation having a positive effect.
The most pronounced risk factor for kidney cancer according to medical literature is obesity. Not just morbid obesity, overweight individuals have also been found to be positive for the risk of kidney cancer.
A clear relationship has been observed, in that, the more number of years lived with an obese status and tendency towards the higher side of BMI holding a much greater risk than individuals who have recently gained a few pounds.
To prevent this, it is recommended that you indulge in regular physical activity before the establishment of any further risk because once the risk is established losing weight will simply not reverse the risk.
Individuals with diagnosed hypertension and those with chronically elevated blood pressure levels (higher than 140 / 90 mm Hg) are at a greater risk of kidney cancer. Again, a positive relationship has been explained in the literature indicating that the higher your blood pressure and the more the chronicity of your condition, greater is your risk.
Along with regular physical activity, stress management, dietary changes to reduce salt consumption and avoidance of processed food items is recommended to keep your blood pressure levels under control.
It has been found that blood pressure reduction significantly reduces your risk of cancer regardless of weight loss effect.
Overuse of pain-killers
Excessive use of analgesics like phenacetin, and certain diuretics increases the risk of developing kidney cancer.
Heavy metals like cadmium and chemicals like benzidine, pesticides, herbicides, asbestos, and trichloroethylene used in dry cleaning and metal industry, have been found to increase the risk of kidney cancer.
Individuals with a history of end-stage kidney disease, especially those who require repeated dialysis, are at a higher risk of developing kidney cancer.
Individuals with a positive family history for renal cancers or other associated carcinomas such as cancer of the urinary bladder / genitourinary tumours are at an elevated risk of renal cancer.
Family history of kidney cancer in close relatives, especially the first degree relatives increases the risk, that increases with the number of family members affected.
Genetic Cancer Predisposition Syndromes
Following are some examples:
- von Hippel-Lindau syndrome (caused by mutations in the VHL gene);
- hereditary papillary RCC (caused by mutation in the METgene);
- hereditary leiomyoma RCC (caused by mutation in the FH gene);
- Birt-Hogg-Dubé syndrome (BHD, caused by mutation in FLCN gene),
- tuberous sclerosis (caused by mutation in the TSC1 and TSC2 genes); and
- Cowden syndrome (caused by mutation in the PTEN gene).
Other than this, individuals with end stage kidney disease, patients with long – term dialysis, individuals with other comorbid conditions like diabetes and those who have received a kidney transplant are at an elevated risk and need to modulate other risk factors more rigorously.
The risk of kidney cancer increases with the number of child birth cycles of the woman.
In several cohort studies, it has been indicated that women who gave birth are at 40 to 90% higher risk of kidney cancer compared with women who have never.
Red meats including beef, pork and goat meat are known to increase your risk of many cancers, including kidney cancer. Their frequent consumption is regarded to potentiate your risk; however, rare intake may not have a significant effect.
To prevent this, you can indulge in a plant – rich diet with high intakes of vitamin A, C and E, which have found to have a protective effect.
These vitamins are found in fresh fruits and vegetables such as carrots, guava, orange and animal sources like fish and fish oil respectively. You can include them as per your dietary preferences.
Elevated risk has been confirmed in the presence of certain industrial components such as Trichloroethylene, which is a potential carcinogen commonly used as metal degreaser.
So, if you are working at industries dealing with transport equipment, electrical / electronic equipment, automobile, jewellery, appliances, plumbing, glass, paper, print and textiles among others, it is probable that you are often exposed at your work place.
In these conditions, it is essential to follow suitable safety protocol such as the use of personal protective equipment to avoid contact with the skin, eyes and prevent indirect ingestion or inhalation. The use of gloves, masks, face shields, gowns and washing hands before the intake of meals is recommended to avoid this.
Overall, obesity, hypertension, smoking and lack of physical activity are the major risk factors for kidney disorders, which can be modulated through lifestyle changes.
Symptoms and Signs
Local spread may cause:
- Blood in the urine
- Lump in abdomen
- Abdominal discomfort or pain
Distant spread may cause:
- Bone pain
- Headache, vomiting, seizures
Most common sites of spread of kidney cancer are adrenal gland, bone, brain, liver and lung.
Kidney Cancer Investigations
Urine sample is checked for the presence of blood cells (RBCs and WBCs). Apart from this, urine culture and urine cytology are also performed to exclude any possibility of urinary tract infection and transitional cell carcinoma of the lower urinary tract, respectively. These conditions can also produce symptoms similar to that of kidney cancer.
This test can distinguish between solid tumors (appear as a solid mass) and fluid-filled cysts. It can also provide information regarding bilateral kidneys involvement, and ascites (abnormal collection of fluid), if any, and also aids in biopsy from the affected area.
One or more of these investigations are required to stage the disease and assess the reponse to treatment-
- Computed tomography (CT) scan
- Magnetic resonance imaging (MRI) scan
- Positron emission tomography (PET) scan
- Intravenous pyelogram (IVP)
- Bone Scan
Laboratory Tests for Biopsy Samples
Biopsy from the kidney helps to confirm the diagnosis. It also tells about the histopathological type of kidney cancer and may be used for genetic or molecular testing to look for targetable mutations.
Kidney Cancer Staging
Kidneys are a pair of organs located in the back of the abdomen, each of which is 4 to 5 inches long. Their main function is to filter the blood and remove waste from the body and regulate the balance of fluids and electrolytes.
This tube like structure, called ureter carries the urine produced after filtering the blood.
This funnel like structure called renal pelvis is formed by dilated proximal part of the ureter in kidney.
It is formed by convergence of 2-3 major calyces.
These structures called as renal pyramids, consist of tubules that transport urine from cortical or outer part of kidney to the calyces and then to the pelvis and ureter.
This structure called as Adrenal Gland or suprarenal gland is present above the kidney, which produces a number of steroid hormones.
Perirenal fat is the accumulation of fatty tissue that completely surrounds the kidney and is enclosed by a layer called as Renal Fascia. Another name for which is Gerota’s Fascia.
Renal veins are the veins that carry the blood filtered by kidney and ultimately drain into the Inferior Vena Cava.
Renal arteries are the branches of aorta that carry blood from heart to the kidneys for filtration.
Stage 1 kidney cancer includes cases with T1 N0 M0, that is T1 disease without any spread to regional lymph nodes or distant sites.
Stage 2 kidney cancer includes T2 N0 M0 disease, in which disease has not spread to regional nodes and distant sites.
Stage 3 includes cases with T1-2 N1 M0 or T3 N0-1 M0.
When T1 or T2 disease (as discussed above) is present in kidney with involvement of regional lymph nodes, it is called as stage 3 disease.
It also includes cases of T3 disease with or without spread to regional lymph nodes.
Stage 4 includes cases with T4 disease and those with spread of disease to distant sites.
Spread of cancer to distant body organs is called M1 disease. It is also classified as stage 4 disease.
It may spread to liver as shown in diagram below.
Kidney Cancer Survival/Life Expectancy
It is calculated based on whether the disease is Localised, Regional or Distant.
- Cancer is limited to the kidney.
- 5 year survival 93%.
- Cancer has spread to nearby structures or lymph nodes
- 5 year survival 70%.
- Cancer has spread to distant body parts.
- 5 year survival 12%.
Treatment of Kidney Cancer
Treatment of Localised and Locally Advanced Disease
Treatment of Metastatic Disease
Treatment depending on stage
Stage 1T1 N0 M0
Stage 2T2 N0 M0
Stage 3T1-2 N1 M0
Stage 4T4 Any N M0
Surgery for Kidney CancerSurgery provides significantly longer survival and is considered as the treatment of choice for resectable kidney cancers in most cases. Sometimes, surgery is employed in palliative setting to relieve symptoms like bleeding and pain. The following types of surgery may be used for the treatment of Kidney cancer:
- Partial nephrectomy: In this surgery, only the kidney tissue containing cancer is removed with adequate margins leaving the rest of the kidney in place. This surgery is sometimes referred to as nephron-sparing surgery. This is generally preferred in case of early-stage disease where tumor size is small.
- Radical nephrectomy: In this surgery, the entire kidney along with associated adrenal gland, nearby lymph nodes, and fatty tissue surrounding the kidney is removed. This is generally used when cancer affects most of the kidney tissue. Sometimes, the adrenal gland may be spared, especially when tumor involves only the lower part of the kidney.
Arterial Embolization and Ablation in Kidney Cancer
In this technique kidney tumor is destroyed by blocking the blood supply to the tumor cells with the help of inert tiny particles that are injected directly in the artery supplying blood to tumor cells. It is used for small tumors localized to kidney, before surgery to downsize the tumor, or in palliative settings in non-operable tumors.
High-energy radio waves are utilized in radiofrequency ablation (RFA), microwaves are used in microwave ablation (MWA) technique, while very cold gases are used in cryoablation to destroy tumors. It is done for small tumors in patients who cannot tolerate surgery, as it has fewer side effects.
Best Kidney Cancer Specialist in Delhi
Dr Sunny Garg is a renowned Medical Oncologist in New Delhi with an experience of around 10 years of treating kidney cancer patients. He has treated kidney cancer patients with Chemotherapy, Targeted Therapy, Immunotherapy and Personalized Cancer Treatment. He is currently practicing at Manipal Hospital, Dwarka.
Diagnostic modalities available at our hospital include Urinalysis, CT guided Biopsy, Intravenous Pyelogram, Whole Body PET CT, etc. Other treatment facilities for Kidney Cancer available are Partial Nephrectomy, Radical Nephrectomy, Cytoreductive Surgery for Metastatic Disease, Radiation Therapy, etc.
Call +91 9686813020 for appointment.