Researchers found new kidney cancer subtypes

New kidney cancer subtypes

Researchers at the Institute of Urologic Oncology and the Department of Urology at UCLA have discovered a new subtype of clear cell renal cancer. This discovery is a step forward in the development of personalized treatments designed according to the patient. Renal cancer represents about 3% of cancers in adults, and of the types of kidney cancer, renal cell carcinoma is the most common (it means about 80%). Nobody knows exactly what are the causes of kidney cancer but there have been put into question several risk factors such as smoking, obesity, hypertension, occupational exposure to various chemicals etc. It should be noted that there are several types of renal cell carcinoma,  but the most common subtype is clear cell renal carcinoma.

Renal Cancer

Renal tumors generally produce hematuria, that is blood in the urine, or back pain; sometimes the first signs are those due to complications. Besides the classic signs and symptoms ( pain, hematuria, tumor ) there can occur several paraneoplastic syndromes related to hematological, endocrine, cardiovascular system, liver, etc.. Therefore renal cancer patients may have prolonged fever, which does not respond to antibiotic treatment, or various haematological disorders (anemia), hypercalcemia, hypertension, Cushing’s syndrome, etc..

The new subtype of kidney cancer is the result of 10 years of study and experiments on the type of genetic mutations that cause these cancers. Dr. Allan Pantuck, a professor of urology and director of genitourinary oncology at UCLA’s Jonsson Comprehensive Cancer Center, said that there were evaluated thousands of renal cancers operated at UCLA. Generally the final diagnosis is made by pathologists who study biopsies samples under microscope. They also determine the stage of a tumor and the prognosis. But sometimes tumors that are similar under the microscop behave differently and have different prognosis. It is essential to establish the prognosis of a tumor in order to decide the type of treatment (for example, high-risk tumors require more aggressive treatment).

Researchers found that in clear cell renal cancer there were deletions in the short arm of chromosome 3 (3p) and the long arm of chromosome 14 (14q). Short arm of chromosome 3 contains a tumor suppressor gene while  the long arm of chromosome 14 contains a gene involved in hypoxia (HIF1 alpha genes). It was found that the loss of chromosome 3p is associated with a better prognosis, which has implications regarding the choice of treatment. Patients with such mutations do not require aggressive treatment. But patients that have mutations in both chromosome 3 and chromosome 14 have a much worse prognosis.