More than 81,000persons are diagnosed with kidney cancer annually in the US.1 It is important to know the risk factors for kidney cancer which may allow you to take preventive actions to lower your probability of having the disease.
As for many diseases, genetics play a vital role in the disease development (DNA mutations in cells of one or both kidneys may result in uncontrolled cell division and proliferation); those with specific genetic cancer syndromes or a family history of kidney cancer are at an increased risk for acquiring the illness. Although the actual causes of a person's kidney cancer is unknown, there are risk factors similar to other types of cancer such as smoking and obesity.
Cigarette smoking increases the risk of renal cell carcinoma (RCC), the risk being proportional to the amount smoked.
Obese and overweight individuals are more likely to develop RCC. Obesity is associated with alterations in some hormones that might result in RCC.
People with high blood pressure are more likely to get kidney cancer. This risk does not seem to be reduced by using medications to control high blood pressure.
A kidney cancer family history is an additional risk factor. Those with a significant family history of renal cell carcinoma (but none of the known genetic diseases) have a greater likelihood of developing this disease.2 This risk is higher for those who have a sibling with the disease. It is unclear if this is due to common genes, an environmental factor that both individuals were exposed to, or both.
Numerous studies indicate that occupational exposure to specific compounds, such as trichloroethylene, increases the risk of RCC.
It is also seen that RCC is almost twice as prevalent in males compared to females. This could be due to men being more likely to smoke and be exposed to cancer-causing substances (at work), which may partially explain the discrepancy.
The reasons for some racial groups having a greater incidence of RCC are unclear; some studies show that African Americans have slightly higher risk compared to Whites.
Certain medications, such as Paracetamol may be associated with increased risk of RCC.
Individuals with chronic renal disease and undergoing dialysis (a procedure used to eliminate toxins from the body when the kidneys are not functioning correctly) were seen to be at high risk of RCC.
As some individuals inherit genes that enhance their likelihood of acquiring particular forms of cancer, genetic and hereditary risk factors must be considered. It is crucial that individuals with genetic causes of RCC see their physicians often, particularly if they have already been diagnosed with RCC. Some physicians advocate routine imaging studies (such as CT scans) to detect new kidney tumours in these patients.
Types of kidney cancer
Renal cell carcinomas (RCC)
RCC is the most prevalent form of adult kidney cancer, accounting for around 85% of diagnosis. This form of cancer originates in the filtration tubules of the kidney's proximal renal tubules. The incidence of RCC demonstrates a male preponderance over females with a ratio of 1.5:1. RCC arises most often during the sixth and seventh decades of life. Initial therapy is often partial or whole removal of the diseased kidney(s). Where the cancer has not metastasized (spread to other organs) or penetrated deeper into the tissues of the kidney, the five-year survival rate ranges from 65 to 90 percent; however, this percentage is significantly reduced when the disease has disseminated. Because the body is so adept at concealing symptoms, patients with RCC are often in late stages of the illness when it is found. Blood in the urine (occurring in 40% of afflicted individuals when they first seek medical assistance), flank discomfort (40%), a mass in the belly or flank (25%), weight loss (33%), fever (20%), elevated blood pressure (20%), night sweats, and feeling generally ill are common first signs of RCC. RCC often metastasizes to the lymph nodes, lungs, liver, adrenal glands, brain, and bones. Immunotherapy and targeted treatment have improved the prognosis for RCC with metastasis.
Benign kidney tumours
Similar to renal cancer, benign kidney tumours exhibit such symptoms, however it is not malignant but may reach a considerable size that causes concern among clinicians. There can be single or multiple tumours on either or both kidneys. The removal of these tumours may include surgery or ablation, similar to malignant tumours. Treatment selections are based on the symptoms caused by the tumours, their size, and the patient's overall health.
Angiomyolipomas are the most prevalent benign tumour and seen mostly among females . They may appear at random, however some are caused by tuberous sclerosis. The symptoms are comparable to those of kidney carcinoma, including discomfort and blood in the urine. If such or more symptoms emerge, they must be monitored and treated properly.
Oncocytomas are uncommon and may develop to enormous sizes. They are more prevalent in males. The causes for these tumours may be genetic disorders such as tuberous sclerosis or Birt-Hogg-Dubé syndrome. In the event where symptoms are suspected, it is important that the patient is monitored. As it is difficult to differentiate oncocytomas from RCC, the clinician may elect to remove the tumour surgically to prevent potential malignancy.
Wilms tumour is a kind of kidney cancer that typically affects children aged 3-4 years. Usually, tumours affect a single kidney, although they might affect both. Over 90% of paediatric kidney malignancies are Wilms tumours. These develop at random and reach a considerable size before they are diagnosed. African-American teenagers are slightly more vulnerable than White teenagers. Certain syndromes (such as WAGR syndrome, Denys-Drash syndrome, or Beckwith-Wiedemann syndrome) and congenital anomalies may further increase risk. Wilms tumours fall into two categories:
- Favourable Wilms tumours are more prevalent, comprising around 90% of the majority of Wilms tumours, and are easier to cure. Under a microscope, the cells of these tumours seem aberrant, but their nuclei (the component of the cell that contains the DNA) are less deformed than the nuclei of the other subtype of Wilms tumours.
- Wilms tumours having anaplastic cellular nuclei are referred to as anaplastic. Anaplasia in the tumour may be either diffuse or localised (anaplastic cells are grouped in one location). Treatment is more challenging for diffuse anaplastic tumours.
The standard treatment for Wilms tumour is a combination of surgery, chemotherapy, and/or radiation therapy. Treatment is effective for nine of ten children with Wilms tumours.
Symptoms of kidney cancer in men
- Low back discomfort or one-sided chronic pressure
- Enlargement on the side or lower back
- Unexplained weight reduction
- Loss of hunger
- Night perspiration
- Testicle enlargement (caused by enlarged veins near the testicle)
- Recurrent fevers that cannot be explained
- Inflammation of the legs or ankles
- Elevated blood pressure
- Anaemia (low red blood cell count)
Female kidney cancer symptoms are identical to male kidney cancer symptoms. These symptoms may suggest a kidney tumour, but they may also be caused by other, less severe health conditions. Some kidney cancer patients exhibit none of these symptoms, while others have wholly distinct symptoms.
Early signs of kidney cancer
Before kidney cancer symptoms become apparent, a laboratory test or imaging scan may disclose a potential diagnosis. For instance, a typical urine test may detect traces of blood that are not visible to the human eye. A computed tomography (CT) scan, which consists of X-rays collected from multiple angles and processed by a computer to create 3D pictures, may also reveal signs of kidney cancer. If dye is injected into a vein prior to the imaging procedure, it may be possible to differentiate between a noncancerous cyst and a solid malignant tumour. Depending on the imaging modality, the probable relevance of light/dark patches on a scan of the kidneys varies greatly and may be indicative of malignancy. In these scans, the dye accumulates and appears as a bright spot in areas where cancer may be present. If the dye cannot reach certain portions of the kidney, such regions may appear as black patches on the pictures. This method facilitates the differentiation between tumours and cysts. The colour does not accumulate in cysts but rather in tumours. In lieu of X-rays, magnetic resonance imaging (MRI) creates comprehensive pictures of the kidneys using a computer and magnetic fields. Gadolinium may be used during an MRI to enhance tumour visibility. Lastly, an ultrasound utilises sound waves to search for indicators of a kidney tumour and establish whether a kidney mass is a fluid-filled cyst (appear as black patches) or a solid tumour (typically malignant kidney tumours are solid and will appear as a brighter area).
How are the symptoms different from that of women?
Men are diagnosed with kidney cancer more commonly than women, and they have a more aggressive histology, bigger tumours, a higher grade and stage, and worse oncological prognosis. Sex steroid hormones and smoking behaviours may play a role in explaining these gender discrepancies. In addition, the expression of genes involved in tumour development and immune response in kidney cancer differs between men and women, which influences the gender-related response to oncological therapies, such as anti-angiogenic drugs and immunotherapy. Gender-related variations have been linked to tumour features, as well as the surgical, functional, and oncological outcomes of RCC. Other critical processes that fully explain the substantial gender-related clinical variations reported in kidney cancer are not yet fully known.3
If the doctor discovers a kidney lesion that may be kidney cancer, it is to assess the extent (stage) of the disease. The doctor may recommend further CT scans or other imaging tests as part of the staging process for kidney cancer. The stages of kidney cancer are denoted by Roman numerals ranging from I to IV, with the lower stages suggesting kidney-confined malignancy. At stage IV, such cancer is considered advanced and could have spread to lymph nodes or other organs.
Blood tests and urine tests
Blood and urine testing are frequently the first diagnostic procedure. Blood and urine tests may provide your physician with insights regarding the cause of your symptoms.
The practice of removing a sample from kidney tissue (biopsy) is not always necessary. In some instances, your physician may suggest a procedure to take a tiny sample of cells (biopsy) out of a questionable location of your kidney. The sample is examined in a laboratory for indications of malignancy.
Your doctor may see a kidney tumour or abnormalities with imaging testing. Ultrasound, X-ray, CT, and MRI are examples of imaging tests.
Surgical removal of the malignancy is generally the first step in treating kidney cancer. For kidney-confined malignancies, that might be the sole necessary therapy. Additional therapies may be indicated if the malignancy has progressed beyond the kidney. Multiple factors, such as the patient's overall health, the type of kidney cancer , progression of the disease, treatment options/choices will influence the optimal course of action.
Most kidney malignancies are first treated with surgery. When feasible, the objective of surgery is to remove the malignancy while maintaining normal kidney function. The following procedures are used to treat kidney cancer:
Removal of the diseased kidney
A full (radical) nephrectomy entails the removal of the whole kidney, a border of healthy tissue, and occasionally the lymph nodes, the adrenal gland, or other organs depending on the metastasis. Nephrectomy may be performed with a single incision in the abdomen or side (open nephrectomy) or through a series of tiny incisions in the abdomen (laparoscopic nephrectomy) (laparoscopic or robotic-assisted laparoscopic nephrectomy).
Surgical removal of the tumour from kidney
This partial nephrectomy also known as kidney-sparing or nephron-sparing surgery, the surgeon will remove only the cancerous tissue and a narrow margin of healthy tissue around it, as opposed to the complete kidney. It may be performed openly, laparoscopically or with robotic help. Commonly used to treat minor kidney malignancies, kidney-sparing surgery may be a possibility if you only have one kidney. When feasible, kidney-sparing surgery is preferable over a total nephrectomy in order to retain kidney function and limit the risk of future consequences, such as renal disease and need for dialysis.
The sort of surgery your surgeon suggests will depend on the stage of your cancer and your general condition.
As scientists understand more about the changes in cancer-causing cells, they have created medications that target a subset of these alterations. These tailored medications are distinct from conventional chemotherapy treatments. They may function when normal chemotherapy medications do not, and their side effects are often distinct. In kidney cancer, where chemotherapy has not been found to be very helpful, targeted medications are proving to be quite useful.
Every one of the targeted medications listed below are effective against advanced kidney malignancies. They may temporarily decrease or halt the development of the tumour, but none of these medications are capable of curing kidney cancer. Typically, targeted medications are administered one at a time. It is not yet known if one of these medications is obviously superior to the others or whether combining them would be more effective than administering them individually.
The targeted medicine sunitinib (Sutent) may also be administered after surgery to reduce the chance of cancer recurrence in patients with a high recurrence risk (adjuvant treatment) The majority of targeted medications (eg. Sutent) used to treat kidney cancer function by inhibiting angiogenesis (development of new blood vessels that feed tumours) or key proteins in cancer cells (called tyrosine kinases) that aid in their growth and survival. This medication is normally used daily for four weeks followed by a break for two weeks. Some physicians may advocate taking it for two weeks followed by one week off to decrease negative effects. The most prevalent adverse effects are nausea, diarrhoea, skin or hair colour changes, mouth ulcers, weakness and low white and red blood cell counts. There is a possibility of fatigue, hypertension, congestive heart failure, haemorrhage, hand-foot syndrome and low thyroid hormone levels.
Immunotherapy is the use of drugs to enhance a patient's immune system's ability to identify and eliminate cancer cells. Multiple immunotherapies may be used to treat kidney cancer. The immune system's capacity to refrain from attacking normal cells in the body is an essential component. The checkpoints are proteins on immune cells that must be activated (or deactivated) in order to initiate an immune response. Occasionally, kidney cancer cells use these checkpoints to elude an attack on the immune system. However, these medications target the checkpoint proteins, restoring the immune response against cancer cells.
One of the most used drugs are Pembrolizumab (Keytruda) and Nivolumab (Opdivo) which are PD-1 inhibitors that target PD-1, a protein on immune system cells (called T cells) that prevents these cells from attacking other cells in the body. By inhibiting PD-1, these medications enhance the immune response against renal cancer cells. This may often decrease or halt the development of malignancies. Pembrolizumab may be administered for one year following surgery to individuals whose cancer has been surgically removed but who have a greater risk of relapse. It may also be administered to patients who have surgery to remove the primary tumour as well as surgery to eliminate metastasis. Pembrolizumab may be used in conjunction with the targeted medication Axitinib or Lenvatinib to treat advanced kidney cancer.
Nivolumab can be administered to patients who develops recurrent kidney cancer after targeted medication therapy as it has been found to extend patients' lives. This medication may be administered in combination with ipilimumab (a CTLA-4 inhibitor) for four doses, followed by nivolumab alone, to patients with advanced kidney cancer who have not received any therapy. This combination has been demonstrated to increase longevity. As the first therapy for patients with advanced kidney cancer, nivolumab may be used with the targeted medication cabozantinib. This combination has been demonstrated to increase lifespan. Nivolumab is administered intravenously (IV) every 2, 3, or 4 weeks. Pembrolizumab is administered intravenously every 3 to 6 weeks. Fatigue, cough, nausea, itching, skin rash, lack of appetite, constipation, joint pain, and diarrhoea may be side effects of PD-1 inhibitors.
Radiation treatment kills the cancer cells with high-energy rays or particles. Occasionally, radiation is used to cure kidney cancer if the patient is unable to undergo surgery or has just one kidney. This mode of treatment is used only if the alternative therapies are seen to be ineffective. When radiation treatment has been used to treat kidney cancer, it is often external beam therapy (EBRT), which concentrates radiation from outside the body on the tumour. If radiation is used to treat a specific location of cancer spread, such as in the lung, it is often stereotactic body radiation treatment (SBRT), a subtype of external beam radiation therapy (EBRT). Radiation treatment is often used to alleviate kidney cancer symptoms such as pain, bleeding, or issues caused by disease spread in patients with kidney cancer (especially to the bones or brain).
Where the radiation travels through the skin, adverse events of radiation treatment may include skin changes (akin to sunburn) and hair loss, as well as nausea, diarrhoea, or fatigue. Typically, the effects are short lived. Radiation may potentially exacerbate the adverse effects of some other therapies.
Chemotherapy (chemo) employs anti-cancer medications either intravenously (IV) or orally (as pills). This therapy may be effective for cancer that has spread (metastasized) to organs other than the kidney since these medications penetrate the bloodstream and reach all the other regions of the body . Chemotherapy is not a traditional treatment for kidney cancer, since kidney cancer cells often do not react well to it. A limited proportion of patients have been demonstrated to benefit from chemotherapy medications such cisplatin, 5-fluorouracil (5-FU), as well as gemcitabine. Nonetheless, chemotherapy is often used only when targeted medicines and/or immunotherapy have failed to treat kidney cancer. Chemotherapy is administered in cycles, with each treatment session followed by a period of rest to enable the body to recuperate. Generally, chemotherapy regimens last a few weeks.
Chemotherapy medications target rapidly proliferating cells, hence are often effective against cancer cells. However, other cells in the body, including the bone marrow (where new blood cells are produced), a lining of the mouth and intestines, and hair follicles, also divide rapidly. Chemotherapy is also likely to disrupt these cells, which may result in certain adverse effects. The adverse effects of chemotherapy vary on the kind of medications used, the dosage, and the duration of treatment. Possible adverse reactions include:
- Hair loss
- Mouth ulcers
- loss of hunger
- sickness and vomiting
- Diarrhoea or bowel irregularity
- Increased likelihood of infection (due to low white blood cell counts)
- Easy bruising or bleeding (due to low blood platelet counts)
- Fatigue (due to low red blood cell counts)
Typically, these adverse effects disappear after therapy is completed. There are often techniques to avoid or mitigate them. For instance, medications may be used to prevent or lessen nausea and vomiting. Chemotherapy medications may individually generate unique side effects. Ask the health care staff about the potential adverse effects of your chemotherapy medications.
Different forms of cancer are caused by various circumstances. Researchers continue to investigate the causes of and methods for preventing kidney cancer. However there is no established method to prevent kidney cancer in its entirety, you may well be able to reduce your risk by:
- Quitting smoking
- Taking measures to reduce the blood pressure
- Keeping a healthy body mass index (BMI)
- Consuming a fruit and vegetable-rich, low-fat diet
Consult a health care provider for further information about your individual cancer risk.
Numerous difficulties may arise as a result of kidney cancer. Occasionally, they may appear even before the diagnosis, although they are often discovered after the tumour has progressed. They may arise as a result of the tumour, its therapy, or metastatic illness.
- Hematuria: Blood in the urine is not the most common indicator of kidney cancer, although it ultimately develops in one-fifth of patients. Timely treatment can often stop excess bleeding and discomfort.
- Pleural Effusion: When kidney cancer spreads to the lungs or lining of the lungs, fluid may collect between the membranes lining the lungs (the pleura). This condition along with the presence of cancer cells is known as malignant pleural effusion. There can even be heavy fluid collection, resulting in severe shortness of breath. During a thoracentesis, a small needle is inserted through the skin of the chest wall and into the pleural cavity to remove fluid. It is possible to treat recurrent pleural effusions with either an indwelling pleural catheter (a shunt that allows for continuous drainage of the fluid) or a procedure in which an irritating substance (talc) is placed between the membranes, causing them to scar together so that fluid can no longer accumulate (pleurodesis).
- Fractures of a Pathological Nature: Pain in the bones may be an early sign of kidney cancer with indication of metastasis. When cancer infiltrates the bone, the bone becomes weak and even brittle (pathologic fractures). When kidney cancer progresses to the lower spine, microfractures in the spine may cause vertebral collapse and spinal cord compression by putting pressure on the nerve roots. This is a medical emergency since it may lead to paralysis in the legs as well as loss of bladder and bowel control. Such bone metastases are often quite destructive, which will require extra attention to pain, possible fractures and nerve compression, hypercalcemia (high blood calcium owing to bone disintegration) and other symptoms. There are various treatments available which will be explained by the clinician.
- Elevated Blood Pressure: The kidneys play a crucial role in maintaining blood pressure. Kidney cancer may cause persistently high blood pressure, and sometimes becomes difficult to regulate (malignant hypertension).
- Hypercalcemia: Blood calcium levels may be raised owing to both a paraneoplastic disease and the destruction of bone that occurs with bone metastases. A high blood calcium level (hypercalcemia) associated with cancer may cause nausea, severe muscular weakness, disorientation, coma, and even death. However, it is curable if properly identified.
- High Number of Red Blood Cells: Even though anaemia is typical in early-stage kidney cancer, a high red blood cell count (erythrocytosis) may develop. This happens when cancer cells release the protein that encourages bone marrow synthesis of red blood cells. The "thicker" blood caused by excessive red blood cells may raise the risk of blood clots, heart attacks, and strokes (more viscous).
- Hepatic Insufficiency: Kidney cancer may impact the liver both via metastasis and as a result of a paraneoplastic condition. Since the liver and kidney both filter the blood, liver and kidney malfunction may lead to the buildup of toxins in the blood which can cause disorientation, personality changes, and other symptoms.
- Medical Complications: The surgical treatment of kidney cancer involves the partial or complete removal of one or both kidneys. This type of surgery may result in cardiac and respiratory events such as stroke, pulmonary embolism (clot breaking off in the leg and spreading to the lungs), pneumonia and damage to the liver, spleen, pancreas, or colon. Additional side effects include abdominal infection and bleeding may develop. If the tumour spreads into the renal vein, The surgical removal will require a vascular disease specialist (such as a heart surgeon).. With the discovery of less invasive surgical procedures such as laparoscopic nephrectomy, there are fewer post-op complications.
- Renal Failure: The partial or complete removal of a kidney can increase the risk of renal failure of the remaining functioning kidney. This is due to the stress exerted on the kidney by many cancer therapies and medications. In the event of renal failure, dialysis may be required (or a kidney transplant, if it is an early stage kidney cancer).
Kidney cancer is one of the most prevalent kinds of cancer, and it mostly affects men. Male kidney cancer is often more aggressive and has a worse prognosis than in females.. Cigarette smoking, hypertension, and obesity are among the recognised kidney cancer risk factors. Males are more likely than females to smoke and have hypertension, which may partially explain the disparity in kidney cancer incidence. There are several treatments available which can be decided by the clinicians depending on the stage and intensity of the kidney cancer.
- Key Statistics About Kidney Cancer. American Cancer Society. [cited 2023 Sep 11]. Available from: https://www.cancer.org/cancer/types/kidney-cancer/about/key-statistics.html
- Risk Factors for Kidney Cancer. American Cancer Society. [cited 2023 Sep 11]. Available from: https://www.cancer.org/cancer/types/kidney-cancer/causes-risks-prevention/risk-factors.html
- Mancini M, Righetto M, Baggio G. Gender-Related Approach to Kidney Cancer Management: Moving Forward. International journal of molecular sciences. 2020 May 10;21(9):3378. [cited 2023 Sep 11] Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7246979/