What Is Clear Cell Renal Cell Carcinoma?

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer, accounting for about 70 to 80 percent of all adult kidney cancers. It begins in the lining of the small filtering tubes inside the kidney and is named for the clear appearance of its cells when viewed under a microscope. This clear look comes from stored fats and carbohydrates within the cancer cells.

Although the exact cause of clear cell renal cell carcinoma is not always known, several risk factors increase the likelihood of developing it. Smoking, obesity, high blood pressure, and certain inherited genetic syndromes, such as von Hippel–Lindau (VHL) disease, are known to raise the risk. Mutations in the VHL gene are especially important in this cancer type, leading to abnormal cell growth and the formation of tumors.

Most cases of clear cell RCC are found in adults over the age of 50, and men are affected more often than women. In many instances, the cancer is discovered incidentally during imaging studies done for other reasons, since early stages may not cause noticeable symptoms. When symptoms do appear, they often include blood in the urine, pain in the side or back, a lump in the abdomen, unexplained weight loss, or fatigue.

Diagnosis typically involves imaging tests such as ultrasound, CT scans, or MRI to visualize the kidney and determine whether a mass is present. A biopsy may be done to confirm the diagnosis and identify the specific subtype of renal cell carcinoma.

Treatment depends on the size and stage of the tumor. When the cancer is confined to the kidney, surgery offers the best chance for cure. Smaller tumors may be removed through partial nephrectomy, which preserves kidney function, while larger or more advanced tumors may require radical nephrectomy, where the entire kidney is removed.

For patients whose cancer has spread beyond the kidney, treatment may involve targeted therapy, immunotherapy, or a combination of both. These modern treatments work by blocking the growth signals that allow cancer cells to multiply or by helping the body’s immune system attack them. Drugs such as pembrolizumab, nivolumab, axitinib, and cabozantinib are commonly used in managing advanced cases.

The outlook for clear cell renal cell carcinoma has improved significantly in recent years thanks to advances in surgery and medical treatments. When detected early, many patients are cured and go on to live healthy lives.

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