Today we are going to talk about a very important organ. Our video today is about the kidney. 

The kidneys are the two bean-shaped organs. Each one of them is about the size of a fist. They are located just below the rib cage, one on each side of the spine. 

Our kidneys are responsible for filtering the blood from waste products, drugs and toxins and forming the urine. Healthy kidneys filter about a half cup of blood every minute removing waste and extra water. The urine then flows from the kidney to the bladder through two thin tubes of muscles, one on each side. 

The urinary bladder then stores the urine until it is the right time to urinate. 

The kidneys, ureters, and bladder are parts of the urinary tract. Filtering the blood is a very important job. However, the kidneys are so important for other reasons. In addition to removing extra water and waste from your body, your kidneys also remove acid that is produced by your cells as a byproduct of metabolism and maintain a healthy balance of water, salts, and minerals such as sodium, potassium, calcium, and magnesium in your blood. 

This mineral balance your kidneys keep is very important for the normal function of nerves, muscles, and other tissues. 

The kidneys also produce hormones that:

• Control the blood pressure. 
• Contribute to the production of red blood cells. 
• Keep the bones strong and healthy. 

So, how do the Kidneys work? 

Our kidneys consist of filtering units called the nephrons. Each kidney contains about a million nephrons. And each nephron includes a filter called the glomerulus and the tubule.

All the nephrons work together in a two-step process: the glomerulus filters the blood, and the tubule returns important substances to your blood and removes wastes. 

The glomerulus is a cluster of tiny blood vessels. As the blood enters the nephrons, it flows into the glomerulus. 

The vessels of the glomerulus have thin walls that allow small molecules, waste, and fluids to pass through them into the tubules. While large molecules such as proteins and blood cells stay inside the vessels. 

But how does the blood flow through the kidneys? 

Each organ in our body has a major vessel that supplies it with blood. In the case of the kidney, blood flows into it through the renal artery. It is a large blood vessel that branches into smaller and smaller blood vessels until the blood reaches each nephron. Then the blood is filtered in the nephrons and flows out of the kidney through the renal vein.

This cycle happens many times per day. The blood circulates through the kidneys many times. 

This perfectly organized system always works without you noticing it until there is a problem. 

But what happens if there is a mass in the kidney that is disturbing its functions? And by mass I don't mean a stone or something, I mean what if there is a real mass, a tumor in the kidney? 

Could this happen? 

Unfortunately, yes it can. And this is the main topic of our video today, kidney cancer.

So, what is a Kidney cancer?

A tumor is an abnormal growth in any part of the body. So, likewise, a kidney mass is an abnormal growth in the kidney.

And just like any mass, some of them are benign and some are cancerous.

One in four kidney masses is benign. Besides, the smaller the mass, the more the probability of it being benign. 

Larger masses are more likely to be malignant. 

It is not clear yet what causes kidney cancers. But we know for sure that kidney cancers start when some kidney cells develop some mutation in their DNA. 

The cell DNA contains all the instructions to tell the cell what to do. 

When there is a mutation in the DNA, it starts telling the cell to divide out of control and live beyond its lifespan. The accumulation of these abnormal cells will eventually lead to the formation of the cancer. 

Besides, some of these abnormal cells might break off and spread anywhere else in the body as a metastasis. 

Regardless of the specific causes, researchers have identified some risk factors that increase the risk of kidney cancer, including: 

• Old age. The risk of kidney cancer increases with age.
• Smoking. Smokers have a higher risk of developing kidney cancer, but their risk drops once they quit.
• Obesity. Obese people are at higher risk of developing kidney cancer than people with a normal healthy weight.
• Hypertension. 
• Treatment for kidney failure. People who receive long-term dialysis for chronic kidney failure are at a higher risk of kidney cancer.
• Some inherited syndromes. Some inherited disorders such as von Hippel-Lindau disease, Birt-Hogg-Dube syndrome, tuberous sclerosis complex, hereditary papillary renal cell carcinoma or familial renal cancer have a higher risk of developing kidney cancer.
• Family history of kidney cancer. Kidney cancer risk is higher in people who had a close family member who had it before.
• Radiation. Women who were treated with radiation for reproductive organs cancers may have a slightly increased risk of developing kidney cancer. 
• Workplace exposure to chlorinated chemicals.

But how can someone tell if they have kidney cancer? Are there specific signs and symptoms? 

In its early stages, kidney cancer doesn't have symptoms. But over time, symptoms might develop, and they include:

• Bloody urine, which may appear pink, red, or cola-colored.
• Loss of appetite.
• Fatigue.
• Fever.
• Unintentional loss of weight.
• Pain in the back or the side that doesn't go away.
• A lump or a mass in the kidney area.
• Bone pain.
• Anemia.
• High blood pressure.

There are different types of kidney cancer, including:

• Renal cell carcinoma. This is the most common type of kidney cancer in adults and accounts for 85% of all kidney cancers. It usually develops as a mass in one kidney; however, it can affect both kidneys. The tumor begins in the lining cells of the tubes inside the nephrons. 
• Transitional cell carcinoma. This type accounts for 6% to 7% of all kidney cancers. It usually begins at the area where the ureter connects to the kidney, also known as the renal pelvis area. It can also occur in the ureters or the bladder.
• Renal sarcoma. It is the least common type of kidney cancer. It is somehow rare that it accounts for only 1% of all kidney cancers. It begins in the connective tissue of the kidney and if it is not treated early, it can spread to the nearby organs and bones.
• Wilms tumor. It is the most common type of kidney cancer in children and accounts for about 5% of all kidney cancers.

In addition to the different types of kidney cancer, each type can be staged into different stages.

• Stage I: in this stage, the tumor is only 7 Cm and confined to the kidney. It has not spread to lymph nodes or other tissues.
• Stage II: in this stage, the tumor is larger than 7 Cm but still in the kidney and hasn't spread to lymph nodes or other tissues.
• Stage III: in this stage, the tumor has spread to the major vessels such as the renal vein, to the nearby lymph nodes, or into the surrounding tissue.
• Stage IV: the tumor in this stage spreads outside of the kidney to the adrenal glands, small glands that lie on top of the kidney, or to distant lymph nodes or other organs. 

The tumor itself can also be graded based on how abnormal its cells look when they have a sample of it. 

This system of grading helps surgeons in determining the suitable treatment plan for every stage. 

You must feel worried now, but don't worry. Here are some of the tips to prevent kidney cancer.

If you adopted these healthy tips, you can prevent kidney cancer:

• Stop smoking. Currently, there are many options to quit smoking starting from chewing nicotine gums to support groups. 
• Maintain a healthy weight. You can do workouts or follow a healthy diet to restrict your intake of calories if you are obese.
• Control high blood pressure. Check your blood pressure readings regularly. Discuss with your health care providers options to reduce your blood pressure if it is high. You may also take some medications to lower it, restrict the salt in your diet, and do sports.

Recently, the incidence of kidney cancer seems to be increasing. This is mainly because imaging techniques such as CT scans are being used more in the workup for the diagnosis of renal cancer. Besides, sometimes kidney cancers are accidentally discovered at an early stage when the tumor is still small and confined to the kidney. 

Our role today is to answer most of your questions regarding kidney cancer. Today we have Professor Kim who is a leading professor at Soon Chun Hyang University Hospital in Seoul. He is going to discuss with us everything about kidney cancer from an experienced medical point of view.

Interview

Now, let’s talk about kidney cancer. 

OK.

Are there many types of kidney cancer?

Kidney cancer can be divided into two types – Clear cell RCC and non-Clear cell RCC. The reasons we divide into clear cell and non-clear cell is that clear cell comprises the majority of cases. Last ten years, targeted therapy has advanced a lot. Unlike typical chemotherapy, targeted therapy attacks only the relevant tissue areas. But this only works for clear cell lines and does not work in non-clear cells. So, these days, it is important to determine whether the cancer is clear or not as it will determine the course of treatment. Also, another reason we identify as clear cell and not, is that non-clear cells are not as toxic. People should know that they can be classified as clear and non-clear as it is the current focus. 

What causes kidney cancer?

As we discussed briefly about smoking, smoking has a big direct influence. For Asians, there is little relevance in terms of genetics. For foreigners, there is a marker called von Hippel-Lindau (VHL) gene which is linked to the kidney cancer. It can be said there is a link. Just like lung cancer and bladder cancer, smoking is directly linked as a cause.

In the case of kidney cancer, does it have any obvious signs?

Just like prostate cancer, kidney cancer, people now frequently take screens. Therefore, we find the cancer at an early stage so there is no actual symptom. But before, it was typically discovered at a late stage, where it has spread, so it was called a cancer for internal doctors. The reason it was called that is that when the cancer has spread to organs like the liver or lungs, is that jaundice would appear or lung infections occur. Thus, it was called an internal doctors’ cancer as it affected many organs nearby. Now, as we catch the cancer early on, it is no longer called an internal doctor’s cancer but a radiologist’s cancer. 

And to end with kidney cancer, let’s talk about the kinds of treatment for the case of kidney cancer.

Most important when treating kidney cancer is to remove all the affected areas. First, I will talk about the local cancer. If the cancer is localized in the kidney, it is best to do robotics surgery for the affected areas. If the cancer has spread to other organs such as the lungs, brain, thyroids, the affected tissue must be surgically removed. It is best to do as much as the surgeon can perform since the patient’s wellbeing increases. It is said that anything that is visible should be removed. The surgeon’s role is very important.

Conclusion

Kidney cancer can be divided into two types – Clear cell and non-Clear cell. The reasons we divide into clear cell and non-clear cell is that clear cell comprises the majority of cases. Last ten years, targeted therapy has advanced a lot. Unlike typical chemotherapy, targeted therapy attacks only the relevant tissue areas. But this only works for clear cell lines and does not work in non-clear cells. So, these days, it is important to determine whether the cancer is clear or not as it will determine the course of treatment. Also, another reason we identify as clear cell and not, is that non-clear cells are less aggressive.

Smoking has a big direct influence. For Asians, there is little relevance in terms of genetics. For westerners, there is a marker called von Hippel-Lindau (VHL) gene which is linked to kidney cancer. Like lung cancer and bladder cancer, smoking is directly linked as a cause.

People now frequently take screenings. Therefore, we find the cancer at an early stage so there is no actual symptom. But before, it was typically discovered at a late stage, where it has spread, so it was called a cancer for internal doctors. Now, as we catch the cancer early on, it is no longer called an internal doctor’s cancer but a radiologist’s cancer.

In treating kidney cancer, the skill of the surgeon is important.