Author: By Lynda Williams, Senior medwireNews Reporter
medwireNews: For men with poor-prognosis prostate cancer, postponing radiotherapy up to 6 months after initiation of androgen deprivation therapy (ADT) may be feasible, say researchers who found that overall survival (OS) is not adversely affected by the delay.
“[I]f COVID-19 outbreaks continue to occur sporadically during the coming months to years, these data could allow future flexibility about the timing of [radiotherapy] initiation”, suggest Vinayak Muralidhar, from Harvard Medical School in Boston, Massachusetts, USA, and co-workers.
The team collated US National Cancer Database 2004–2014 information for 19,258 men diagnosed with unfavourable intermediate-risk prostate cancer and 44,600 men with high-risk disease, all of whom were treated with external beam radiotherapy and ADT.
Among men with unfavourable intermediate-risk prostate cancer, 10-year OS was 59.2% for the patients who began radiation up to 60 days before beginning ADT and a comparable 57.9%, 62.3% and 58.9% for those whose radiation began 1–60, 61–120 or 121–180 days after ADT initiation, respectively.
Similarly, among men with high-risk or very-high-risk prostate cancer, the 10-year OS rates were a comparable 58.9%, 51.7%, 54.8% and 52.4%, respectively.
Moreover, multivariable analysis found no significant difference between the pre-ADT and post-ADT initiation groups after accounting for factors including age, race, location, Gleason score, prostate-specific antigen level and T stage.
Nor did OS correlate with date of radiotherapy initiation when using a continuous, non-linear model, the team reports in a letter to JAMA Oncology.
“These results validate the findings of 2 prior randomized trials and possibly justify the delay of prostate [radiotherapy] for patients currently receiving ADT until COVID-19 infection rates in the community and hospitals are lower”, write Vinayak Muralidhar et al.
Nevertheless, the researchers caution that study limitations include “the short follow-up period, retrospective design, lack of information about ADT duration, and possible data entry errors in the database.”
Reference
Dee EC, Mahal BA, Arega MA, et al. Relative timing of radiotherapy and androgen deprivation for prostate cancer and implications for treatment during the COVID-19 pandemic. JAMA Oncol; Advance online publication 13 August 2020. doi:10.1001/jamaoncol.2020.3545
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