FINDINGS

A UCLA-led study found treatments that reduce the danger of being diagnosed with a cancer reoccurrence based on rising prostate-specific antigen (PSA) levels after radiotherapy, commonly known as biochemical reoccurrence, don’t necessarily improve a patient’s long-term overall survival.

The team of investigators found that while biochemical reoccurrence was related to the next risk of death, it still didn’t meet the factors to be a reliable surrogate endpoint for overall survival. As defined by the FDA, a clinical final result directly measures whether people in a trial feel or function higher, or live longer. A surrogate endpoint is a selected, relatively early final result that reliably predicts for a clinical final result that happens within the longer-term.

Biochemical recurrences occur much earlier within the disease course than metastases or survival, and will potentially be the best surrogate endpoint for prostate cancer. Subsequently, the team evaluated whether biochemical reoccurrence could possibly be a useful surrogate endpoint for death. This has implications for not only designing clinical trials, but additionally for evaluating the advantage of various types of treatment intensification and for counseling patients.

One reason for our finding could possibly be that many patients within the study died from causes unrelated to prostate cancer. The strength of the correlation between biochemical reoccurrence and overall survival varied depending on how deaths from non-cancer-related causes were accounted for. Nonetheless, it will be significant to notice that we looked specifically at death, and never at quality of life. Definitely, biochemical reoccurrence could impact quality of life. Unfortunately, high-level data tracking this are lacking, and it’s something our group, and others, are hoping to explore further.”

Dr. Amar Kishan, associate professor of radiation oncology on the David Geffen School of Medicine at UCLA and researcher on the UCLA Health Jonsson Comprehensive Cancer Center, and senior writer of the study

BACKGROUND

Biochemical reoccurrence develops in almost one-third of men with prostate cancer after treatment with prostatectomy or radiation therapy for localized prostate cancer. It often occurs early on in the midst of prostate cancer and indicates the cancer could be coming back. For this reason, it has been theorized to be a possible marker to predict a patient’s overall survival final result. Nonetheless, previous analyses have yielded conflicting conclusions about whether or not biochemical reoccurrence could possibly be a reliable predictor of overall survival for patients treated for prostate cancer.

METHOD

The researchers collected and analyzed data from 11 different studies evaluating radiation therapy dose escalation, the usage of androgen deprivation therapy and androgen deprivation therapy prolongation to guage the potential of biochemical reoccurrence as a predictor of survival. Overall, 10,741 patients were included within the evaluation.

IMPACT

Despite the potential of using biochemical reoccurrence as a possible marker to predict overall survival in patients with prostate cancer, the outcomes of the study indicates that it mustn’t be the essential focus or primary measure in future clinical trials for localized prostate cancer. As an alternative, metastasis-free survival, which refers back to the period without cancer spreading to other parts of the body, is a more suitable endpoint for future trials involving radiation therapy in localized prostate cancer cases.

AUTHORS

The senior and corresponding writer is Kishan. The co-first authors are Tahmineh Romero from UCLA and Dr. Soumyajit Roy from Rush University Medical Center. The whole list of authors could be present in the journal article.

JOURNAL

The study was published within the Journal of Clinical Oncology.

FUNDING

The work was supported partly by grants from the Prostate Cancer National Institutes of Health Specialized Programs of Research Excellence (P50CA09213), the Department of Defense (PC210066), the Prostate Cancer Foundation and the American Society for Radiation Oncology.