A study led by Baptist Health Miami Cancer Institute shows that patients with TP53, RB1 and PTEN mutated prostate cancer have a lower overall survival rate than patients who are biomarker negative. The results emphasize the importance of genetic testing for all advanced cancer patients, the researchers say.
Rohan Garje, M.D., chief of genitourinary medical oncology at Miami Cancer Institute
“Tumor genetic testing is not universal, but should be,” said Rohan Garje, M.D., chief of genitourinary medical oncology at Miami Cancer Institute. “The identification of the prognostic features it provides is extremely important. But even more than that, we believe information from next-generation sequencing will enable us to better understand which patients may benefit from intensified therapies.”
Dr. Garje presented his research, “Impact of TP53, RB1 and PTEN Mutations on Overall Survival in Metastatic Prostate Cancer: A Multi-center Study Via the Guardian Research Network,” at the ASCO Genitourinary Cancers Symposium in San Francisco in January.
The study used a real-world sample from community oncology centers across the Guardian Research Network. Of the 350 patients with metastatic prostate cancer in the study, 140 were biomarker-positive for either TP53, RB1 or PTEN, and 210 were biomarker negative.
While the biomarker-positive group as a whole had a lower overall survival compared to those without the genetic mutations, a sub-group with a minimum follow-up of four years showed an even greater difference. In the subgroup, the biomarker-positive cohort had a median survival of 35.8 months versus 67.2 months for the biomarker-negative cohort.
Prostate cancer is the second-leading cause of death in American men, according to the American Cancer Society. A number of genetic mutations have been linked to aggressive prostate cancer. Among those, the mutations such as TP53, RB1 and PTEN, which cause the loss of tumor suppressor capabilities, can lead to the likelihood of cancer cells growing and spreading. At the same time, these mutations may make the cancer resistant to certain treatments.
“Unless genetic testing is performed,” Dr. Garje said, “we don’t have the information necessary to tailor treatment to the individual.” Additionally, this information can be utilized in treatment intensification or de-intensification for men with metastatic prostate cancer.
“There’s no doubt that personalized interventions based on genomic profiles hold potential for improving outcomes,” Dr. Garje said. Additional studies based on genomic risk stratification will help physicians further develop customized therapies.