TERT Gene Alterations Found in Bladder Cancer
An important discovery regarding the bladder cancer genome was announced during the American Association for Cancer Research (AACR) meeting in Philadelphia, held April 18-22, 2015.
An important discovery regarding the bladder cancer genome was announced during the American Association for Cancer Research (AACR) meeting in Philadelphia, held April 18-22, 2015.
Researchers from the University of Colorado Cancer and the National Cancer Institute have found that the telomerase reverse transcriptase (TERT) gene promoter--which encodes the enzyme telomerase--was altered in 54 cases (69%) of bladder cancer due to alterations that occur after birth. Germline mutations, which are inherited, were found in 56% of bladder cancers of this study group. The TERT alterations frequently coincide with alterations in bladder cancer genes such as the stromal antigen 2 (STAG2) and the lysine-specific demethylase 6A (KDM6A).1
Bladder cancer is diagnosed in 74,000 people annually; about 56,320 in men and 17,680 in women. Approximately 16,000 people die from bladder cancer (about 11,510 men and 4,490 women) annually.
The discovery of which genes mutate early is exciting because it could lead to more specific treatments as the earliest stages, when cancer is more curable. When bladder cancer is caught early (stage 0), the 5-year survival rate is 98%. In stage I, it slightly decreases, to 88%. By the time the cancer is stage IV, the survival rate is 15%.2
"We expect these TERT alterations happen early in the development of bladder cancer as a sort of precursor to the disease itself, and so it may be possible to develop a genetic test that examines urine as a way to screen for the disease," says Dan Theodorescu, MD, PhD, director of the CU Cancer Center and study author.
Somatic alterations were also observed in 15% of tumors in the BRCA1-associated protein-1 (BAP1) gene, which has been observed in the development of bladder cancer. The BAP1 alterations also occurred with KDM6A mutations, and contributed to a high frequency of BRCA pathway defects due to germline and somatic alterations of BRCA1, BRCA2, ATM, and PALB2, according to the press release.
References:
- Sundem G. (2015). Tumor genome sequencing shows the most frequently altered gene in bladder cancer: TERT. University of Colorado Cancer Center.
- American Cancer Society. (2015). What are the key statistics about bladder cancer?
