Kidney cancer

Overview

Kidney cancer may strike both adults and children. The majority of kidney malignancies are renal cell carcinoma (RCC), also known as renal adenocarcinoma. Although symptoms do not normally occur in the early stages of kidney cancer, some patients do have them, especially as the illness spreads. In most situations, surgery is the primary treatment for excised kidney carcinoma.

 

What is kidney cancer?

Kidney cancer is a kind of cancer that begins in the kidney's cells. Renal cell carcinoma (RCC) is the most frequent kind of kidney cancer, accounting for approximately 90% of all occurrences. Typically, only one kidney is damaged, although cancer can grow in both kidneys in rare situations.

With over 76,000 new cases identified each year, kidney cancer is one of the top ten most frequent malignancies in the United States. Men are diagnosed with kidney cancer at a higher rate than women. Kidney cancer may affect anybody, although it is more frequent among African Americans, American Indians, and Alaska Natives. Kidney cancer can occur at any age, although it is more frequent in older persons (those greater than 75 years old). The earlier you are detected with kidney cancer, the greater your odds of survival.

 

The kidneys

The kidneys are two bean-shaped organs that are roughly the size of a fist. They are linked to the abdomen's upper back wall and are protected by the lower rib cage. One kidney is to the left of the backbone, while the other is on the right. The superior pole and inferior pole of each kidney are terms used to describe the upper and bottom sections of each kidney.

Each kidney has a little organ called an adrenal gland on top of it. Each kidney and adrenal gland are encased in fat and a thin, fibrous layer called Gerota's fascia.

The primary function of the kidneys is to eliminate excess water, salt, and waste materials from the blood that enters the renal arteries. These compounds degrade into urine. Urine gathers in the middle of each kidney, known as the renal pelvis, and then exits the kidneys via long, slender tubes known as ureters. The ureters go to the bladder, which stores urine until you urinate.

The kidneys also have other jobs:

• They help control blood pressure by making a hormone called renin.
• They help make sure the body has enough red blood cells by making a hormone called erythropoietin. This hormone tells the bone marrow to make more red blood cells.

Our kidneys are essential, yet humans can function with only one. Many people in the United States have regular, healthy lives despite having only one kidney. Some people may not have functioning kidneys and must rely on a medical treatment known as dialysis to survive. The most popular type of dialysis employs a specially constructed machine that filters blood in the same way as a human kidney would.

 

Types of kidney cancer

Renal cell carcinoma

The most frequent kind of kidney cancer is renal cell carcinoma (RCC), also known as renal cell cancer or renal cell adenocarcinoma. Renal cell carcinomas account for approximately 9 out of 10 cases of kidney cancer. Although RCC normally develops as a single tumor within a kidney, it is possible to have two or more tumors in one kidney or even tumors in both kidneys at the same time.

RCC is classified into numerous subgroups based on how the cancer cells appear in the lab. Knowing your RCC subtype can help you decide on therapy and can also assist your doctor assess if your cancer is caused by an inherited genetic condition.

 

Clear cell renal cell carcinoma

The most prevalent kind of renal cell cancer. This kind of cancer affects around 7 out of every 10 patients with RCC. The cells that make up clear cell RCC seem exceedingly pale or transparent in the lab.

 

Papillary renal cell carcinoma

This is the second most prevalent kind, accounting for approximately one in every ten RCCs. In some, if not most, of these tumors, little finger-like projections (called papillae) arise. Some clinicians refer to these malignancies as chromophilic because the cells absorb specific dyes and appear pink under a microscope.

 

Chromophobe renal cell carcinoma

This subtype accounts for approximately 5% (5 instances out of 100) of RCCs. These cancer cells are likewise pale, like clear cells, but they are considerably bigger and have certain specific characteristics that may be identified when examined closely.

 

Rare types of renal cell carcinoma

These subtypes are very rare, each making up less than 1% of RCCs:

• Collecting duct RCC
• Multilocular cystic RCC
• Medullary carcinoma
• Mucinous tubular and spindle cell carcinoma
• Neuroblastoma-associated RCC

 

Unclassified renal cell carcinoma

Renal cell cancers are occasionally labeled as unclassified because their appearance does not fit into any of the other categories or because more than one type of cancer cell is present.

 

Other types of kidney cancers

Other types of kidney cancers include transitional cell carcinomas, Wilms tumors, and renal sarcomas.

• Transitional cell carcinoma: 

Transitional cell carcinomas (TCCs), also known as urothelial carcinomas, account for 5 to 10% of all kidney malignancies.

Transitional cell carcinomas begin in the lining of the renal pelvis rather than the kidney itself (where the ureters meet the kidneys). This lining is made up of transitional cells, which resemble the cells that line the ureters and bladder. When examined closely in the lab, cancers formed from these cells resemble other urothelial carcinomas, such as bladder cancer. These malignancies, including bladder cancer, are frequently associated to cigarette smoking and occupational exposure to cancer-causing substances.

TCC patients frequently exhibit the same signs and symptoms as renal cell cancer patients, including blood in the urine and, in some cases, back discomfort.

• Wilms tumor (nephroblastoma): Nephroblastomas nearly always arise in childhood. This form of cancer is extremely uncommon in adults. 
• Renal sarcoma: Renal sarcomas are an uncommon kind of kidney cancer that starts in the kidney's blood vessels or connective tissue. They account for fewer than one percent of all kidney malignancies. 
• Benign (non-cancerous) kidney tumors Some kidney tumors are harmless (non-cancer). This means they do not spread to other regions of the body, but they can still develop and create issues. Benign kidney tumors can be removed or destroyed using many of the same procedures used for kidney cancer, such as surgery or radiofrequency ablation. Many factors influence treatment options, including the size of the tumor and if it is producing symptoms, the number of tumors, whether tumors are in both kidneys, and the person's overall health.
• Angiomyolipoma: The most frequent benign kidney tumor is angiomyolipoma. They are more common in women. They can appear sporadically or in persons with tuberous sclerosis, a genetic disorder that affects the heart, eyes, brain, lungs, and skin. These tumors are made up of various connective tissues (blood vessels, smooth muscles, and fat). If they aren't producing any symptoms, they may usually be ignored. They may need to be treated if they start producing difficulties (such as discomfort or bleeding).
• Oncocytoma: Oncocytomas are rare benign kidney tumors that can develop to be extremely big. They are more common in men and do not generally spread to other organs, thus surgery is frequently used to treat them.

 

Types of kidney cancer cells

Doctors can better plan treatment if they know what sort of cell makes up a kidney tumor. More than 30 distinct kinds of kidney cancer cells have been discovered by pathologists. A pathologist is a physician who specializes in the interpretation of laboratory tests and the evaluation of cells, tissues, and organs to diagnose illness. Before surgery, computed tomography (CT) scans or magnetic resonance imaging (MRI) cannot always distinguish between benign, indolent, and malignant renal cortical tumors.

The following are the most prevalent forms of kidney cancer cells. The grade of a tumor, in general, relates to the degree of differentiation of the cells, not how quickly they develop. Differentiation describes how closely cancer cells resemble healthy ones. The higher the grade, the greater the likelihood that the cells may spread or metastasis over time.

• Clear cell. Clear cells make up over 70% of kidney malignancies. Clear cells range in growth rate from moderate (grade 1) to quick (grade 2). (grade 4). Clear cell kidney carcinoma is very responsive to immunotherapy and targeted treatment.
• Papillary. Papillary kidney cancer accounts for 10% to 15% of all cases of kidney cancer. It is classified into two subtypes: type 1 and type 2. Surgery is frequently used to treat localized papillary kidney carcinoma. If papillary kidney carcinoma develops or metastasizes, blood vessel blocking medicines are frequently used to treat it. Immunotherapy is still being studied as a treatment for metastatic papillary cancer. For metastatic papillary malignancies, many clinicians prescribe therapy through a clinical trial.
• Sarcomatoid features. Under the microscope, each of the kidney cancer tumor subtypes (clear cell, chromophobe, and papillary, among others) can exhibit highly disordered characteristics. Pathologists frequently refer to them as "sarcomatoid." This is not an unique tumor subtype, but when these characteristics are observed, clinicians recognize that this is a particularly aggressive form of kidney cancer. Immunotherapy treatment possibilities for persons with sarcomatoid tumors are being researched scientifically.
• Medullary. Although this is a rare and severe malignancy, it is nonetheless classified as a renal cortical tumor. It is more frequent among Black individuals and is strongly linked to sickle cell illness or sickle cell trait. A person with sickle cell trait has inherited one copy of the sickle cell gene from a parent. Based on preliminary research, chemotherapy in combination with blood vessel inhibitors is now indicated as a therapeutic option, and clinical trials are underway to better clarify treatment choices.
• Collecting duct: Collecting duct carcinoma is more common in adults aged 20 to 30. It starts in the kidney's collecting ducts. As a result, collecting duct carcinoma is linked to transitional cell cancer . Even with systemic chemotherapy and surgery, this is a tough malignancy to treat well over time.
• Chromophobe. Chromophobe cancer is another uncommon malignancy that can cause indolent tumors that seldom spread but can be severe if they do. Clinical trials are being conducted to determine the most effective treatments for this form of cancer.
• Oncocytoma. This is a kind of kidney cancer that grows slowly and seldom, if ever, spreads. For big, bulky tumors, surgery is the preferred therapy.
• Angiomyolipoma. Angiomyolipoma is a benign kidney tumor with a distinct look on a CT scan and under a microscope. It is less likely to develop and spread in most cases. Surgery or, if the tumor is modest, active surveillance are commonly used to treat it. Significant bleeding is uncommon; however, it is more common in pregnant and premenopausal women. In rare cases, an aggressive variant of angiomyolipoma known as epithelioid may enter the renal vein and inferior vena cava and migrate to surrounding lymph nodes or organs such as the liver.

 

Risk Factors of Kidney Cancer

A risk factor is something that enhances the likelihood of contracting a disease. Some risk factors can be modified (for example, smoking), whereas others cannot (your gender or family history). Having a risk factor, or even numerous risk factors, does not guarantee that you will get kidney cancer, but it does raise your chances.

• Risk factors for kidney cancer include:
• Smoking
• Being overweight (obese)
• High blood pressure
• Gender - about twice as many men as compared to women develop kidney cancer
• Being on dialysis treatment for advanced chronic kidney disease
• Family members with kidney cancer
• Long-term use of a pain-relieving drug called phenacetin
• Certain rare genetic diseases, such as von Hippel-Lindau disease, Birt Hogge Dube syndrome, and others
• History of long-term exposure to asbestos or cadmium

You may be able to reduce your chance of developing kidney cancer by avoiding risk factors that are under your control. Stopping smoking, for example, may reduce the risk, as may reducing body weight and high blood pressure.

 

What Are the Symptoms of Kidney and Renal Pelvis Cancers?

A person with kidney or renal pelvic cancer may or may not exhibit any of the following symptoms. The same symptoms might also be caused by other factors. Consult your doctor if you have any of these symptoms.

• Blood in the urine.
• A lump or swelling in the kidney area or abdomen.
• Lower back pain or pain in the side that doesn’t go away.
• Feeling tired often.
• Fever that keeps coming back.
• Not feeling like eating.
• Losing weight for no reason that you know of.
• Something blocking your bowels.
• A general feeling of poor health.

 

Kidney Cancer Diagnosis

Over half of all kidney masses are discovered by coincidence. They are frequently discovered during routine screening or when you visit your doctor for another reason. If your doctor suspects you have kidney issues, he or she may refer you to a urologist. A urologist is a specialist in the urinary system.

There are no normal laboratory tests available to detect kidney masses. Many tests may be used by your doctor to discover more about your kidneys. Here are some examples of exams and processes you can encounter:

• Physical exam and history
• Basic or complete metabolic panel (CMP) to check organ function
• Complete blood count (CBC) to check the blood for signs of disease
• Urinalysis to check for infection, blood and protein in urine
• Serum creatinine levels or other kidney function tests to check if the kidneys are getting rid of waste
• Ultrasound to get images of your kidneys
• CT scan and MRI to help diagnose and stage kidney masses
• Bone scan and chest x-ray to find out if the cancer has spread
• Kidney mass biopsy to help find out what type of tumor you have

 

Grading and Staging

A tumor grade indicates how aggressive the cancer cells in your body are. A tumor stage indicates how far the cancer has spread. Grades 1 through 4 indicate increasing severity, with "1" being the lowest and "4" being the greatest. Higher grade and more advanced stage cancers are typically bigger and more aggressive. Tumor size aids in determining the likelihood of cancer developing.

 

Management of Kidney Cancer

The primary aims of treating kidney masses are to cure the malignancy and preserve renal function as much as possible. Protecting renal function is especially critical for people who only have one kidney or who have another type of kidney illness.

Some people will never require surgery. Surgery may be the best option for others. In some cases, a biopsy of the tumor may be recommended to learn more about its potential aggressiveness. Your doctor may then propose one of four therapy options. They are as follows: 

    1. Active Surveillance

Your doctor will visit you at regular intervals for testing and imaging as part of active monitoring (taking pictures of inside your body). For tiny masses smaller than 3 cm (approximately 1.2 inches) in size, active surveillance is suggested. The objective is to halt progression while avoiding the dangers and side effects of previous therapies. Your visits will be scheduled every three, six, or twelve months as needed. Chest x-rays, CT scans, and ultrasounds may also be performed. The frequency with which you see your doctor will be determined by the size and stage of your tumor, as well as your age and general medical condition.

    2. Ablation

Your surgeon may suggest ablation if your tumor is modest (T1a, mass less than three centimeters in size). Ablation uses high heat or cold to eliminate the tumor. Before ablation, your doctor may perform a biopsy to let a pathologist to examine the tumor cells closely to determine the presence of malignancy.

• Cryoablation (cold ablation) is the process of destroying tumor cells by passing extremely cold gases via a probe.
• Radiofrequency ablation (hot ablation) is performed by inserting a tiny, needle-like probe into the skin to reach the tumor. An electric current is sent through the probe's tip, heating the tumor and destroying the cells.

 

    3. Partial Nephrectomy

The kidney is removed during a nephrectomy. The term "partial nephrectomy" refers to a procedure in which the doctor removes the tumor and the sick portion of the kidney while leaving the healthy portion intact. If your tumor is T1a (4cm or smaller), your doctor may recommend a partial nephrectomy. If the tumor looks to be contained and amenable to this surgical method, a partial nephrectomy can be performed.

    4. Radical Nephrectomy

The entire kidney is removed during a radical nephrectomy. This is done if your kidney tumor is showing indications of malignancy, is very big, or is aggressive. If one of your kidneys fails, your body may operate normally with only one.

Both forms of nephrectomy may commonly be performed using laparoscopic surgery, although depending on the size and features of the tumor, traditional open surgery may be required. During laparoscopy, your surgeon creates a tiny incision in your belly and inserts a thin, lighted tube to examine the kidney.

 

Care Management

A radiologist, urologist, nephrologist, pathologist, and medical oncologist are likely to be on your health care team. These experts will work with you to weigh all of your options and discuss the risks and advantages of therapy. If you have a family history of kidney malignancies, genetic counseling may be indicated.

Discuss your treatment options with your health care team in an open and honest manner.

 

After Treatment

It is critical to maintain contact with your health care physician and keep follow-up appointments. These check-ups are necessary to monitor tumor regrowth. Following the initial therapy, your doctor may repeat several of the tests used to diagnose the kidney tumor. A healthy lifestyle might be beneficial. If you are currently using tobacco, attempt to quit. Limit your alcohol consumption and consume a well-balanced diet. Exercise and attempt to stay under prescribed weight limits.

 

Prognosis for kidney cancer

A doctor cannot forecast the exact course of a disease since it is dependent on each person's unique circumstances. However, based on the type of kidney cancer you have, the test findings, the rate of tumor growth, as well as your age, fitness, and medical history, your doctor may offer you a prognosis, or the expected fate of the condition. Most of the time, the earlier kidney cancer is detected, the better the prognosis.

 

Conclusion 

Kidney cancer is cancer that begins in the kidneys. It occurs when healthy cells in one or both kidneys proliferate uncontrollably and create a lump. Symptoms may include blood in the urine, an abdominal mass, or a back ache. Surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy are all options for treatment.