Kidney cancer, or renal cancer, refers to any cancer that affects the kidney. Advanced age, obesity and high blood pressure increase the risk of developing kidney cancer. It is one of the most common cancers in adults. There is no single, definitive treatment for kidney cancer, as it depends on the general state of health of the individual as well as the stage and type of cancer. However, treatment may include surgery, immunotherapy, or chemotherapy, among others. This article is about kidney cancer including its causes, diagnosis, treatment and outlook.
Kidney cancer starts in the kidneys, a pair of bean-shaped organs located on either side of the spine, behind the stomach. The kidneys filter excess water, salt and waste from the blood. They then return the filtered blood to the circulatory system and evacuate the waste as urine into the bladder. Cancer begins when cells grow and divide out of control instead of being organized. As a result, cancer cells create masses called tumors. These tumors can then invade and damage nearby tissues and organs or spread to other parts of the body. Kidney cancer affects 1 in 46 men and 1 in 80 women during their lifetime. Also, the average age of diagnosis is usually 64 years old.
Kidney tumors
A person with kidney cancer may have tumors in one or both kidneys. Sometimes kidney tumors are benign, that is, they are not cancerous. They may not spread to other parts of the body. However, they can sometimes grow and cause problems. When these tumors start to cause problems, doctors may recommend removing them.
The different types of kidney cancer
There are different types of kidney cell cancers, including:
Renal cell carcinoma (RCC): This is the most common type of kidney cancer, accounting for up to 90% of cases. It originates in the renal cortex, or the outer layer of the kidney. Doctors can then divide it into several subtypes.
Transitional cell carcinoma: About 5-10% of kidney cancers are of this type. They originate in the renal pelvis, which is the center of the kidney. Doctors may also refer to them as urothelial carcinomas.
Wilms tumor: This type of tumor usually occurs in children and is rare in adults. Doctors may also refer to it as nephroblastoma.
Kidney Cancer Symptoms
Symptoms don’t usually appear in the early stage of kidney cancer, but some people still experience them, especially when the cancer spreads.
Here are some symptoms of kidney cancer:
blood in the urine
side pain that does not go away
a lump in the abdomen
loss of appetite
unexplained weight loss
anemia
Other illnesses can cause similar symptoms. If a person has any of these symptoms, they should contact their doctor.
main causes
Doctors don’t know exactly what causes kidney cancer, but genetic and environmental factors may play a role. In the case of kidney cancer, the cells of the kidney undergo certain changes. Cancer begins when there is a change in the DNA structure of cells, which can trigger their uncontrolled growth. A tumor eventually forms. The changes can activate oncogenes, that is, genes that help cells grow, divide and stay alive. They can also turn off tumor suppressor genes, which control cell division and help cells die in time. If a person has changes in more than one gene, it can cause kidney cancer.
Risk factors
The main risk factor for renal cell carcinoma is smoking cigarettes, pipes and cigars.
Obesity is another major risk factor, especially in women. Experts estimate that quitting smoking and maintaining a moderate weight can halve the incidence of kidney cancer.
Other risk factors may be:
high blood pressure
chronic renal failure
occupational exposure to chemicals such as trichloroethylene
a family history of kidney cancer
advanced age
Disease stages
The stages of kidney cancer are as follows:
Stage 1: The tumor is less than 7 centimeters (cm) in diameter and is only in the kidney.
Stage 2: The tumor is larger than 7 cm but is still in the kidney.
Stage 3: The tumor, regardless of size, has spread outside the kidney. It may have spread to nearby lymph nodes or blood vessels, structures in the kidney that collect urine, or the layer of fatty tissue that surrounds the kidney.
Stage 4: The tumor grows beyond the fatty tissue layer of the kidney and may reach the adrenal gland – which is located above the kidneys – or nearby lymph nodes. Or, the cancer has spread to other parts of the body.
Diagnostic
If a person has symptoms of kidney cancer, the doctor will likely start with:
ask him about his symptoms
inquire about personal and family medical history
perform a physical examination
ask for tests.
Tests
If a doctor suspects a person has kidney cancer, they may order one or more of the following tests:
Blood and urine tests: These tests help rule out other possible causes for the symptoms, such as kidney stones or infection.
Imaging scans: An ultrasound, MRI, or CT scan can help the doctor identify the presence of tumors or changes in the shape of the kidney that could be due to cancer.
Biopsy: For this procedure, the doctor will use imaging technology to guide him in removing a sample of tissue. He will use a needle to take a small sample of kidney tissue to look at under a microscope. Only a biopsy can confirm the presence of cancer.
The doctor may also recommend other tests to check for the presence of transitional cell cancer.
Treatment
A person’s treatment options may depend on:
his general state of health
the type and stage of kidney cancer
personal preferences
previous cancer treatments.
Some options may include:
Surgery
In most cases, surgery is the main treatment for kidney cancer that can be excised. The surgeon may remove part or all of a kidney, as well as the tissue around the tumor. If necessary, he may have to remove lymph nodes and other tissues. A person can function with only one kidney, so removal of an entire kidney is an option.
Laparoscopic surgery, which requires only small incisions, is often possible.
Non-surgical options
A sick or frail person may not be able to undergo surgery. In this case, some non-surgical options can be considered if the cancerous kidney lesion is considered small, usually no larger than 4 cm.
Cryotherapy/cryoablation: Extremely cold gases pass through a probe, creating an “ice ball” at the tip that can destroy the tumour. The procedure can be painful and can cause bleeding, infection, and tissue damage near the tumor.
Radiofrequency ablation: An electric current is passed through the end of a probe to destroy the tumour. It comes with the same risks as cryoablation procedures.
Chemotherapy
Chemotherapy is the use of powerful drugs to attack and kill cancer cells, which can stop or delay the progression of cancer. Doctors only prescribe chemotherapy when other treatments, such as immunotherapy or targeted therapies, have not worked. Kidney cancer cells usually do not respond to chemotherapy, but a small number of people have benefited from it. These drugs often affect the whole body and can have widespread side effects. However, the effects often disappear at the end of the treatment.
Immunotherapy
Immunotherapy boosts the body’s immune system’s ability to fight cancer.
Inhibitory drugs can target certain proteins on the body’s immune cells and modify them to attack cancer cells. An example drug targets the PD-1 protein.
Cytokines, which are small proteins that boost the body’s immune response, may also be an option.
Common side effects are nausea, vomiting, chills, fatigue, and loss of appetite.
Targeted therapy
In targeted therapy, drugs target specific functions or genes that play a role in the development of cancer. They disrupt functions and proteins that are necessary for cancer survival and growth.
An example of such a drug blocks angiogenesis, the process of forming new blood vessels that can feed cancer. Each drug can have its own side effects, but in general, these types of drugs can cause fatigue, low red blood cell count, and sores in the mouth, among other things.
Radiation therapy
Radiation therapy usually cannot cure kidney cancer. However, it can help reduce the size of the tumour, limit the spread of cancer cells and reduce symptoms.
It involves using high-energy beams to kill cancer cells. Side effects are usually nausea and fatigue.
Perspectives
Getting an early diagnosis usually improves a person’s future prospects. Medical experts use past statistics to calculate the likelihood that people with cancer will live at least 5 years after diagnosis, compared to the general population.
For kidney cancer, the following statistics for the 5-year survival rate:
93% for cancers that have not spread beyond the kidneys at the time of diagnosis.
71% for cancer that has reached nearby tissues
14% for cancers that have affected other parts of the body.
Many different factors influence these estimates, including the type of kidney cancer, the person’s age, and general health.
For all stages, the overall 5-year survival rate after diagnosis is 76%.
Résumé
Kidney cancer occurs when cells grow out of control in the kidneys and form tumours. There are different types of kidney cancer, with renal cell carcinoma being the most common. Smoking, obesity, and a family history of kidney cancer can increase the risk of developing kidney cancer. However, doctors are unsure of the specific causes.
Kidney cancer treatment may involve surgery, systemic treatments, or radiation therapy. These approaches are successful for most people, with kidney cancer having an overall survival rate of 76%.