Kidney cancer or renal carcinoma usually occurs in older people and accounts for about 2 to 3% of cancers in adults, affecting about twice as many men as women. In adults, the most common type of kidney tumor is renal cell carcinoma, which begins in the cells that line the small tubes within your kidneys. Kidney cancer rarely strikes children and young adults; the exceptions are a pediatric kidney cancer called Wilms tumor and some forms of hereditary kidney cancer syndromes, such as von Hippel-Lindau disease.
Causes of Kidney Cancer
The causes are not known, however external factors, such as smoking and obesity, have been related to a higher incidence of kidney cancer and changing environmental factors as well as population aging has seen an increase in the presentation of this form of cancer.
Signs and Symptoms
Kidney cancer symptoms are often overlooked because tumours are usually slow growing and not suspected until the patient begins to experience symptoms such as blood in the urine, pain, tiredness and a palpable mass. Since back pain is common among people over 40 years of age, such pain is often ignored and the presence of kidney cancer can go undetected. Kidney cancer may also cause high blood pressure.
The risk of developing kidney cancer is four times higher if a close relative has had kidney cancer. Being on dialysis for many years is a risk factor for kidney cancer.
People who have had bladder cancer are more likely to develop kidney cancer, and vice versa. About three per cent of kidney cancer patients have inherited a damaged gene that will make it likely the cancer will also be found in their second kidney.
Not smoking is the most effective way to prevent kidney cancer and it is estimated that the elimination of smoking would reduce the rate of renal pelvis cancer by one-half and the rate of renal cell carcinoma by one-third.
Other factors that may decrease the risk of developing kidney cancer include: maintaining a normal body weight, a diet that is high in fruits and vegetables, especially in bananas and root vegetables such as carrots, maintaining normal blood pressure and limited exposure to environmental toxins.
Diagnosing Kidney Cancer
Cancer of the kidney is most commonly detected with either computed tomography (CT) scan, ultrasound or magnetic resonance imaging (MRI). Cystoscopy can rule out associated bladder cancer. Kidney cancer cells may also break away from the original tumor and spread (or metastasize) to other parts of the body such as the lymph nodes, bones or lungs, with about one third of cases showing metastasis at the time of diagnosis.
Types of Kidney Cancer
Almost 85% of this tumor are renal cell carcinomas. A less common type of kidney is Papillary carcinoma. Other rare kidney cancers include: Renal sarcoma, Collecting Duct carcinoma, Medullary and Chromophobe carcinomas.
Radical nephrectomy with or without the removal of lymph nodes offers the only cure but treatment of kidney cancer may include: surgery, arterial embolization, radiation therapy, biological therapy or chemotherapy depends upon the stage of the disease and the patient’s overall health.
Nephrectomy or removal of the entire organ including the adrenal gland, adjacent lymph nodes and surrounding normal tissue has been the norm, but recent research shows that removal of just the tumor, produces similar survival rates and offers less chance of subsequent renal failure in selected cases.
Scientists have also isolated the gene responsible for VHL disease, and this discovery offers exciting future possibilities for improved diagnosis and treatment of some kidney cancers. Various combinations of interleukin-2, interferon, and other biologic agents and even vaccines developed from cells removed from the kidney cancer are also being investigated.
With prompt and appropriate treatment, the kidney cancer mortality rate is fairly low, unfortunately kidney cancer has a tendency to spread early, especially to the lungs, sometimes before symptoms develop. The five year survival rate is around 90-95% for tumors less than 4 cm. For larger tumors confined to the kidney without venous invasion, survival is still relatively good at 80-85%. If it has metastasized to the lymph nodes, the 5-year survival is around 5 % to 15 %. If it has spread metastatically to other organs, the 5-year survival rate is less than 5 %.
An important factor for those with this form of cancer and for that matter with all cancers is that assertive patients who actively work to overcome cancer often increase the odds of survival, live longer, and enjoy life more.