Relationship between delay in radiotherapy and biochemical control in prostate cancer

The aim of this study was to investigate whether a delay in radiotherapy is associated with a poorer biochemical control for prostate cancer.

The time to treatment (TTT) from diagnosis of prostate cancer to radiotherapy was analyzed with respect to prostate-specific antigen (PSA) control in 1024 hormone-naive patients. The Kaplan-Meier PSA control curves for patients with TTT less than the median were compared with those for patients with TTT greater than the median in 3 predefined risk groups. Statistical significant differences in PSA control were further analyzed using Cox multivariate analysis with pretreatment PSA, Gleason score, T stage, and radiotherapy dose as covariates.

The median TTT and median follow-up are 3.7 months and 49 months respectively. Patients with a longer TTT have a statistically significant better PSA control than patients with a shorter TTT if they have intermediate- or high-risk disease. However in multivariate analysis TTT was not found to be significant in predicting PSA control, with pretreatment PSA and Gleason score emerging as highly significant in predicting PSA failure in both intermediate- and high-risk disease.

In this study in prostate cancer patients in British Columbia, there was no evidence that a longer time interval between diagnosis and radiotherapy was associated with poorer PSA control.