If you do this, kidney cancer will not be scary!

Author: Yang Yong, Chief Physician, Peking University Cancer Hospital

Reviewer: Zhang Yi, Chief Physician, Peking University International Hospital

When we mention "cancer", we always feel it is very scary. However, for most kidney cancers, if they can be detected and treated early, there will be almost no impact on life expectancy.

1. What are the characteristics of kidney cancer? Is it easy to metastasize?

Kidney cancer is a relatively special tumor. 90%, or even about 95%, of kidney cancers are clear cell carcinomas.

Clear cell carcinoma has a characteristic that we call it a relatively indolent cancer. How indolent is it? Without surgery, it is allowed to grow naturally, and it only grows 0.5-1 cm per year.

This type of kidney cancer is not life-threatening if it is detected early. Some patients can live to over 90 years old after timely surgery.

But for other types of kidney cancer, it is different. For example, collecting duct carcinoma, kidney cancer with sarcomatous changes, or renal medullary carcinoma, etc., the tumor of these kidney cancers may not be large, but it can metastasize quickly and easily lead to death.

Therefore, there are two reasons why kidney cancer leads to death: one is that it is diagnosed too late; the second is that the pathological type is too special.

However, no matter what, as long as they receive early diagnosis and early treatment, most kidney cancer patients can achieve long-term survival.

Figure 1 Original copyright image, no permission to reprint

2. Who needs early screening for kidney cancer?

First, people who are in sub-healthy state. Sub-healthy state means that life is very tiring and rest is not good. When in sub-healthy state, the body's immunity is reduced. Such people should pay attention to their health, not only kidney cancer, but also various problems are prone to occur.

Second, smokers. Smoking is one of the risk factors for kidney cancer. Some statistical studies have shown that smokers are 2-4 times more likely to develop kidney cancer than non-smokers.

Third, people with metabolic syndrome. The so-called metabolic syndrome is actually an epidemiological survey conducted by Western countries. Patients with hypertension, high blood lipids, high blood sugar, obesity, etc. generally have a slightly higher incidence of various cancers. For example, people with metabolic syndrome have a lifetime risk of kidney cancer, prostate cancer or bladder cancer that is about 2-3 times higher than other people.

Fourth, people with a family history of kidney cancer. If someone in your family has had kidney cancer, you should pay attention, because there is a kind of hereditary kidney cancer caused by a special gene mutation, and this gene mutation will be passed down from generation to generation.

This type of kidney cancer is quite special, usually bilateral, and although the malignancy of kidney cancer is not very high, it can occur at a very young age. Therefore, if a patient is diagnosed with hereditary kidney cancer caused by a certain gene mutation, his children should start physical examinations very early to detect it early.

3. What is the most commonly used examination method for early screening of kidney cancer?

Early screening for kidney cancer is actually very simple. Just do an ultrasound. If you see nothing on the kidneys during the B-ultrasound, you will be relieved. Generally speaking, if the test results are completely normal, it is enough to do a screening once a year.

Figure 2 Original copyright image, no permission to reprint

But in actual clinical practice, what is more troubling is the discovery of renal cysts by ultrasound examination.

If it is a simple renal cyst, it is generally okay, about 20%-30% of normal people have it. Long-term observation usually does not change much. Some simple renal cysts will grow larger, and surgery can be performed when they are particularly large.

Of course, for older patients, even if the cyst is relatively large, surgery may not necessarily be necessary. It depends on the patient's specific situation.

However, renal cysts are also special. Some renal cysts are not so clean. Something may grow inside the cyst, which may lead to malignant transformation. In addition, malignant tumors related to renal cysts also have a characteristic, that is, as long as the cyst is not broken, it will generally not metastasize. Its malignancy is very low, but once it is discovered, it must be taken seriously and followed up closely.

4. If a high-echo mass is detected by renal ultrasound, should it be removed promptly?

The most common type of high-echo mass in the kidney is a benign tumor, which we call angiomyolipoma or hamartoma. In this case, the diagnosis can usually be confirmed through ultrasound or CT.

If it is difficult to identify, further examination can include abdominal enhanced CT, MRI or PET/CT.

Currently, in clinical practice, 90%-95% of masses found by CT scans can be diagnosed as benign or malignant, cystic or hamartoma, as long as they are larger than 2 cm. However, if the mass is very small, it will be more difficult to diagnose.

Of course, many doctors would recommend temporary observation for such a small mass, because even if it is malignant, it will not affect the patient's prognosis if it is diagnosed and treated when it grows to 2 cm or 3 cm.

If the patient is concerned and is willing to undergo surgery as soon as possible, it does not matter whether the tumor is benign or malignant, and it can be directly removed by performing a partial nephrectomy while preserving the kidney.