Biochemical relapse free survival rate in patients with prostate cancer treated with external radiotherapy: outcomes obtained at the CMN Siglo XXI Hospital de Oncología, CMN 20 de Noviembre and Hospital General de México of the México City

Abstract

Aim

Biochemical relapse-free survival (bRFS) rate is determined by a cohort of Mexican patients (n=595) with prostate cancer who received treatment with external radiotherapy.

Background

Patients with prostate cancer were collected from CMN Siglo XXI (IMSS), CMN 20 de Noviembre (ISSSTE), and Hospital General de México (HGM). For the IMSS, 173 patients that are treated with three-dimensional conformal radiation therapy (3D-CRT) and 250 with SBRT, for the ISSSTE 57 patients are treated with 3D-CRT and on the HGM 115 patients are managed with intensity modulated radiation therapy (IMRT). The percentage of patients by risk group is: low 11.1%, intermediate 35.1% and high 53.8%. The average follow-up is 39 months, and the Phoenix criterion was used to determine the bRFS.

Materials and methods

The Kaplan–Meier technique for the construction of the survival curves and, the Cox proportional hazards to model the cofactors.

Results

(a) The bRFS rates obtained are 95.9% for the SBRT (7Gy fx, IMSS), 94.6% for the 3D-CRT (1.8Gy fx, IMSS), 91.3% to the 3D-CRT (2.65Gy fx, IMSS), 89.1% for the SBRT (7.25Gy fx, IMSS), 88.7% for the IMRT (1.8Gy fx, HGM) %, and 87.7% for the 3D-CRT (1.8Gy fx, ISSSTE). (b) There is no statistically significant difference in the bRFS rates by fractionation scheme, c) Although the numerical difference in the bRFS rate per risk group is 95.5%, 93.8% and 89.1% for low, intermediate and high risk, respectively, these are not statistically significant.

Conclusions

The RT techniques for the treatment of PCa are statistically equivalent with respect to the bRFS rate. This paper confirms that the bRFS rates of Mexican PCa patients who were treated with conventional vs. hypofractionated schemes do not differ significantly.