Prostate cancer researchers have developed a genetic test to identify which men carry the highest risk of their prostate cancer coming back after localized treatment with surgery or radiotherapy. The findings are published online in Lancet Oncology. The study authors report that the gene test provides a much-needed quick and accurate tool to determine with greater precision which men will do well with local treatment only (surgery or radiation), and which will need extra treatment (chemotherapy and hormone therapy) to ensure the cancer is eradicated.
The predictive test analyzes biopsy tissue taken before treatment starts to identify abnormal genetic characteristics (abnormal DNA) of the prostate cancer and its oxygen content. (Low oxygen, or hypoxia, is a known factor in the spread of prostate cancer.) Together, this information can predict with almost 80% accuracy those prostate cancer patients who are at greatest risk of their disease returning, the study shows.
The researchers developed the genetic test with two groups of patients. In the first group, the team analyzed DNA from initial diagnostic biopsies of 126 men who were treated with image-guided radiotherapy (IGRT) and followed for an average 7.8 years. In the second group, the team used the test on 150 men whose tumors were removed surgically (radical prostatectomy). The genetic test produced similar results in both groups and therefore can be used in patients who choose radiotherapy or surgery as their initial treatment.
The study showed that the men with the best outcomes—lower than 7 percent recurrence of prostate cancer at five years—had low levels of genetic changes and low hypoxia. For men with high levels of genetic changes and high hypoxia, outcomes were worse—more than 50 percent of patients had recurrence. These men, in the future, could be offered intensified treatment as part of a personalized treatment plan. Read the article.Read more