If you have 2.5-centimeter cancer in your right kidney, the mere existence of the "cancer" would scare you and keep you awake at night.

From the viewpoint of modern medicine, however, you don’t have to worry much about cancer with a size of four centimeters or less that exists only in the kidney.

"If it's around 2.5 cm, it's stage 1 or stage 1A (when the tumor is up to four cm in diameter or less)," said Dr. Min Kyung-eun, a professor of urology at Kyung Hee University Hospital at Kangdong, on the YouTube channel with the same name as his hospital. "You don’t have to worry much about kidney cancer (if you undergo follow-up surveillance as an outpatient after partial resection).”

In the case of kidney cancer, active surveillance is also used when the tumor is small and less malignant. However, in most cases, surgery is performed for kidney cancer because it is often highly malignant and likely to recur or metastasize later.

Still, even when surgery is necessary, removing 2.5-centimeter cancer in the kidney does not result in the complete loss of a kidney as in the past.

"For smaller cancers, we don't remove the entire kidney like we used to," Professor Min explained, "We often perform a partial nephrectomy, which removes only the tumor to preserve kidney function."

If the 2.5-centimeter cancer exists only within the kidney, no further treatment is needed beyond a partial nephrectomy.

"Patients are discharged from the hospital five to seven days after surgery, and outpatient follow-up is performed after discharge," Professor Min said. "Patients who undergo partial nephrectomy do not need additional radiotherapy or medication. They only need to continue outpatient follow-up to check for recurrence or metastasis."