Seven FAQs about Kidney Cancer

Author: Dong Dexin, Department of Urology, Peking Union Medical College Hospital

In recent years, due to the increase in life expectancy and the advancement of various diagnostic and treatment technologies, kidney cancer seems to be more and more common. Kidney cancer is the most common malignant tumor of the kidney. Many kidney cancer patients have no obvious symptoms in their daily lives and are often discovered accidentally during physical examinations. This can't help but arouse people's special attention to the kidneys.

"Kidney" is the key. What is kidney cancer?

Why does kidney cancer occur quietly?

I have kidney cancer. Is there any hope?

Is it necessary to have a kidney transplant?

.....

"Union Medical Journal" specially invited young editor Dong Dexin, deputy chief physician of the Department of Urology at Peking Union Medical College Hospital, to popularize common questions about kidney cancer. Seven questions and seven answers will help you easily understand things about "kidney cancer".

1. What is kidney cancer? Renal cell carcinoma (RCC), also known as renal adenocarcinoma, is a malignant tumor originating from the renal parenchyma urinary tubular epithelial system, accounting for 80% to 90% of renal malignant tumors. It is the most common malignant tumor of the kidney and one of the most common malignant tumors in the urinary system.

Figure 1. Left normal kidney, right renal cancer cross-section

1. Who is prone to kidney cancer? Kidney cancer is the malignant tumor with the highest mortality rate in the urinary system, accounting for 2% to 3% of adult malignant tumors and about 20% of pediatric malignant tumors. Studies have shown that more men suffer from kidney cancer than women, with a ratio of about 2:1; and the incidence of kidney cancer is closely related to age. The older you are, the higher the incidence of kidney cancer is, and the peak age is 40 to 55 years old. In addition, the incidence of kidney cancer has obvious regional differences, with European and American countries being significantly higher than Asian countries, and cities being higher than rural areas.

Figure 2 The incidence and mortality of kidney cancer in the United States are increasing year by year

However, the cause of kidney cancer is still not fully understood. Existing studies show that it may be related to genetics, smoking, obesity, hypertension and antihypertensive drugs. Patients with chronic kidney disease who require long-term dialysis treatment are also at high risk of kidney cancer.

1. Is kidney cancer hereditary? Kidney cancer is hereditary to a certain extent. There is a type of kidney cancer called hereditary kidney cancer, which accounts for 2%-4% of the total number of kidney cancers, including VHL disease, tuberous sclerosis, BHD syndrome, hereditary leiomyoma and renal cell carcinoma syndrome-related kidney cancer, hereditary papillary renal cell carcinoma, etc., all of which have specific gene abnormal mutations. However, people do not need to worry too much. Compared with hereditary kidney cancer, the most common kidney cancer in clinical practice is kidney cancer caused by non-genetic factors, also known as sporadic kidney cancer.

1. What are the clinical manifestations of kidney cancer? The typical manifestations of kidney cancer are the "triad", namely hematuria, back pain and mass. When kidney cancer invades the renal pelvis, there will be hematuria; the pain is mainly caused by the increase of kidney cancer mass and the swelling of renal capsule. If the blood clot blocks the ureter, it will be colic.

In addition to kidney-related manifestations, about one-third of patients have systemic symptoms, such as fever, hypertension, rapid erythrocyte sedimentation rate, anemia, abnormal liver function, hypercalcemia, polycythemia, varicocele, etc.

Therefore, when the above symptoms occur, you must seek medical attention in time and receive active treatment.

5. What examinations do patients with kidney cancer often need? B-ultrasound is the preferred screening method for kidney cancer. Most patients are first discovered by ultrasound. In addition, CT or MRI examinations are also necessary to help confirm the diagnosis. For a small number of patients with difficult diagnosis or inoperable advanced stage, puncture biopsy is also required to help clinicians make a diagnosis through pathological results.

1. How should kidney cancer be treated? (1) Surgery: Radical nephrectomy, partial nephrectomy, palliative nephrectomy, etc., which can be performed by open or laparoscopic surgery. Different surgical methods and approaches are used depending on the patient, condition, and other circumstances.

(2) Minimally invasive treatment: radiofrequency ablation/cryotherapy/high-energy focused ultrasound, which are mostly palliative treatments or for patients who cannot tolerate surgery.

(3) Adjuvant therapy: biological therapy (Immunotheapy), targeted therapy (TKI/mTOR), immunotherapy PD-1/PD-L1, etc. For advanced metastatic renal cell carcinoma, molecular targeted drugs can significantly improve the patient's objective response rate and survival rate.

(4) Other treatments: renal artery embolization, etc.

Figure 3 Molecular targeted drug therapy mechanism

1. What is the prognosis of kidney cancer? (1) The prognosis of kidney cancer needs to be comprehensively evaluated based on clinical staging, pathological grade and the patient's general condition. Early stage, low malignancy and good physical condition are signs of a good prognosis of kidney cancer. Conversely, late stage, high malignancy and poor physical condition generally indicate a poor prognosis.

(2) For advanced metastatic renal cell carcinoma, the treatment prognosis is based on the criteria of the International Metastatic Renal Cancer Database (IMDC). The lower the score, the better the prognosis, and the higher the score, the worse the prognosis.

Figure 4 Risk factors affecting the prognosis of advanced metastatic renal cancer

In short, only by knowing ourselves and the enemy can we win every battle. On the basis of fully understanding kidney cancer, what we need to do most is to develop good hygiene and eating habits, not eat moldy, rotten, pickled food, eat a light diet, exercise regularly, improve the body's immunity, and pay attention to the early prevention and treatment of kidney disease, so as to stay away from kidney cancer and maintain a healthy body.

About the Author

Dong Dexin

Doctor of Medicine, Associate Chief Physician and Associate Professor of Urology Department, Peking Union Medical College Hospital.

Research direction: renal surgery, urinary system tumors and laparoscopic minimally invasive surgery. Specializes in the comprehensive diagnosis and treatment of renal tumors, advocates laparoscopic partial nephrectomy with nephron preservation; specializes in laparoscopic minimally invasive surgery and transurethral minimally invasive surgery.

Academic part-time positions: Young member of the Andrology and Sexual Medicine Physicians Branch of the Chinese Medical Association; member of the Urology Branch of the Beijing Medical Award Foundation; editorial board member of the Journal of Urology (electronic version); young editorial board member of the Peking Union Medical College Journal. Senior visiting scholar at the Queen Mary Hospital of the University of Hong Kong and Hong Kong Sanatorium and Hospital in 2018. Short-term visiting scholar at the University of Southern California School of Medicine in 2016. Visiting scholar at the Affiliated Hospital of National Taiwan University and the Affiliated Hospital of Taiwan University of Chinese Medicine in 2015. Champion of the surgical group of the 4th CARS Renal Cancer All-round Doctor National Finals in 2020. Published nearly 50 papers in Chinese and English, including 10 SCI papers as the first author. Obtained 1 invention patent and 1 utility model patent.

Acknowledgements: Dong Dexin, the author of this issue of the Health Science Action column of Peking Union Medical College Journal