Does the presence of the triad of kidney cancer indicate that it is already in the late stage? What is related to the prognosis of kidney cancer?

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

Reviewer: Lu Wenhong, Researcher, Institute of Science and Technology, National Health Commission

At present, the true cause of kidney cancer is not particularly clear. Epidemiological surveys conducted abroad have found that metabolic syndrome is related to tumors. For example, patients with high blood pressure, high blood lipids, high blood sugar, and obesity generally have a slightly higher incidence of various tumors.

Among urinary tract tumors, the risk of kidney cancer, prostate cancer, and bladder cancer in patients with metabolic syndrome is about 2-3 times higher than that of the normal population. This risk is a statistical concept. For each individual, it is also necessary to evaluate other risk factors and the individual's immunity.

At present, no relevant research on kidney cancer prevention has been carried out, mainly because the single factor correlation of kidney cancer is not significant, so there is a lack of targeted kidney cancer prevention methods. In general, maintaining a healthy mentality and lifestyle is good for the body. In addition, it is also very important to detect tumors early.

Kidney cancer usually has no symptoms in its early stages, so if you discover it early, you must have a physical examination on time. When kidney cancer shows the triad of symptoms, i.e. a mass felt in the abdomen, hematuria, and back pain, it generally indicates that it is in the advanced stage.

Figure 1 Original copyright image, no permission to reprint

Low back pain is very common. It is not necessarily related to the kidneys or caused by tumors. For example, hydronephrosis caused by stones or obstruction, or other reasons, can cause low back pain. If low back pain is related to activity, it can be relieved by rest. In this case, it is likely caused by skeletal muscles. Low back pain caused by kidney cancer has nothing to do with activity. The low back pain persists and it hurts even when lying down to rest. Therefore, a preliminary judgment can be made based on clinical symptoms.

Kidney cancer is a tumor of the renal cortex, which is at a certain distance from the renal pelvis. Hematuria may occur only when the tumor grows to a certain extent and invades the renal pelvis. Therefore, hematuria in kidney cancer indicates that the tumor is in a relatively advanced stage. If a mass can be felt in the kidney area, it means that the tumor has grown to a certain extent, which is generally in a relatively advanced stage. Symptoms that are more advanced than the triad are metastasis, such as metastasis to the bones, causing bone pain, metastasis to the lungs and liver, causing discomfort in the corresponding parts.

The survival period of kidney cancer is related to the stage of the tumor. The earlier the treatment, the longer the survival period. It is also related to individual factors, the choice of treatment plan and other factors.

Kidney cancer is a relatively special tumor. More than 90% of them are clear cell carcinomas, which are relatively inert tumors with a natural growth rate of 0.5-1 cm per year. This type of kidney cancer is not life-threatening if it is discovered early. Other rare special types of kidney cancer, such as collecting duct carcinoma and renal medullary carcinoma, are not large tumors, but they will quickly metastasize, have a poor prognosis, and a short survival period. In general, as long as kidney cancer is diagnosed early, most people can achieve long-term survival.

Figure 2 Original copyright image, no permission to reprint

Generally speaking, for T1 renal cancer, the tumor is small, less than 7 cm, and is confined to the kidney. With radical resection surgery, the 10-year survival rate can reach over 90%. Once the tumor breaks through the kidney and invades surrounding organs, the 5-year survival rate will drop to around 50%. Once surrounding lymph nodes or distant metastasis occurs, the 5-year survival rate will be less than 20%.

As people pay more attention to health and do more physical examinations, most of the kidney cancers found in clinical practice are within three to five centimeters, and the prognosis is relatively good, unless it is a special type of kidney cancer that metastasizes in the early stage.

Early kidney cancer detected through early cancer screening usually has a relatively small tumor. Eighty to ninety percent of cases are treated with partial resection, or kidney-sparing surgery, which completely removes the tumor and part of the kidney tissue, leaving the affected kidney intact. If recurrence occurs, 90% will recur within 3 years after surgery, with a higher probability of recurrence. The rest will recur within 5 years, and the probability of recurrence after 5 years is very low.

The current international kidney cancer guidelines recommend that CT scans be performed at least once a year to monitor for recurrence and that lifelong follow-up examinations be performed. Generally, ultrasound examinations should be performed at least every six months within 5 years after surgery, and enhanced CT scans should be performed once a year.