Adjuvant Radiotherapy in Prostate Cancer Patients Treated with Surgery: The Impact of Age and Tumor Characteristics

Pathological stage, surgical margin and lymphovascular invasion as prognostic factors after salvage radiotherapy for post-prostatectomy relapsed prostate cancer - outcomes and optimization strategies

Background

Salvage radiotherapy (sRT) is the main potentially curative treatment after biochemical failure/locoregional relapse post-radical prostatectomy (RP). The aim of the study was to characterize the population who underwent sRT after RP at our Department, to understand the influence of several potential prognosis factors, and to determine possible optimization strategies.

Materials and methods

We retrospectively analyzed patients undergoing sRT at our department between 2012 and 2017, evaluating patient, tumor and treatment characteristics, restaging procedures and clinical outcomes - namely biochemical relapse-free survival (BC-RFS), clinical relapse-free survival (C-RFS), additional hormone therapy-free survival (HT-FS) and overall survival (OS). We assessed potential prognostic factors by univariate and multivariate models (MVA).

Results

We included 277 patients (median age 68 years). Median pre-sRT PSA was > 0.5ng/mL in 54.9%. All underwent prostate bed irradiation. Pelvic lymph nodes were included in 9.7%. Outcome analysis was performed for 264 patients (35.6 months median follow-up). At 3 years, BC-RFS was 61.4%, C-RFS was 81.3%, HT-FS was 79.9% and OS was 96.6%. Most relapses occurred in regional lymph nodes only (47.9% patients who relapsed). On MVA, lymphovascular invasion, advanced pT-stages and negative margins negatively influenced BC-RFS (p = 0.029, p = 0.002 and p < 0.001) and HT-FS (p = 0.001, p = 0.029 and p = 0.002). C-RFS was worsened by lymphovascular invasion (p = 0.009) and negative margins (p = 0.015). These had no effect on OS. BC-RFS and HT-FS were improved when sRT started while PSA ≤ 0.5 ng/mL (p < 0.05).

Conclusion

Lymphovascular invasion, higher pT-stages and negative margins negatively affected prognosis. An early start of sRT (PSA ≤ 0.5 ng/mL) predicted better BC-RFS and HT-FS.

Non-cancer mortality in elderly prostate cancer patients treated with combination of radical prostatectomy and external beam radiation therapy

BACKGROUND

To test for rates of other cause mortality (OCM) and cancer-specific mortality (CSM) in elderly prostate cancer (PCa) patients treated with the combination of radical prostatectomy (RP) and external beam radiation therapy (EBRT) versus RP alone, since elderly PCa patients may be over-treated.

METHODS

Within the Surveillance, Epidemiology and End Results database (2004-2016), cumulative incidence plots, after propensity score matching for cT-stage, cN-stage, prostate specific antigen, age and biopsy Gleason score, and multivariable competing risks regression models (socioeconomic status, pathological Gleason score) addressed OCM and CSM in patients (70-79, 70-74, and 75-79 years) treated with RP and EBRT versus RP alone.

RESULTS

Of 18,126 eligible patients aged 70-79 years, 2520 (13.9%) underwent RP and EBRT versus 15,606 (86.1%) RP alone. After propensity score matching, 10-year OCM rates were respectively 27.9 versus 20.3% for RP and EBRT versus RP alone (p < .001), which resulted in a multivariable HR of 1.4 (p < .001). Moreover, 10-year CSM rates were respectively 13.4 versus 5.5% for RP and EBRT versus RP alone. In subgroup analyses separately addressing 70-74 year old and 75-79 years old PCa patients, 10-year OCM rates were 22.8 versus 16.2% and 39.5 versus 24.0% for respectively RP and EBRT versus RP alone patients (all p < .001).

CONCLUSION

Elderly patients treated with RP and EBRT exhibited worrisome rates of OCM. These higher than expected OCM rates question the need for combination therapy (RP and EBRT) in elderly PCa patients and indicate the need for better patient selection, when combination therapy is contemplated.

Predictors of urinary and rectal toxicity after external conformed radiation therapy in prostate cancer: Correlation between clinical, tumour and dosimetric parameters and radical and postoperative radiation therapy

OBJECTIVE

To determine rectal and urinary toxicity after external beam radiation therapy (EBRT), assessing the results of patients who undergo radical or postoperative therapy for prostate cancer (pancreatic cancer) and their correlation with potential risk factors.

METHOD

A total of 333 patients were treated with EBRT. Of these, 285 underwent radical therapy and 48 underwent postoperative therapy (39 cases of rescue and 9 of adjuvant therapy). We collected clinical, tumour and dosimetric variable to correlate with toxicity parameters. We developed decision trees based on the degree of statistical significance.

RESULTS

The rate of severe acute toxicity, both urinary and rectal, was 5.4% and 1.5%, respectively. The rate of chronic toxicity was 4.5% and 2.7%, respectively. Twenty-seven patients presented haematuria, and 9 presented haemorrhagic rectitis. Twenty-five patients (7.5%) presented permanent limiting sequela. The patients with lower urinary tract symptoms prior to the radiation therapy presented poorer tolerance, with greater acute bladder toxicity (P=0.041). In terms of acute rectal toxicity, 63% of the patients with mean rectal doses >45Gy and anticoagulant/antiplatelet therapy developed mild toxicity compared with 37% of the patients with mean rectal doses <45 Gy and without anticoagulant therapy. We were unable to establish predictors of chronic toxicity in the multivariate analysis. The long-term sequelae were greater in the patients who underwent urological operations prior to the radiation therapy and who were undergoing anticoagulant therapy.

CONCLUSIONS

The tolerance to EBRT was good, and severe toxicity was uncommon. Baseline urinary symptoms constitute the predictor that most influenced the acute urinary toxicity. Rectal toxicity is related to the mean rectal dose and with anticoagulant/antiplatelet therapy. There were no significant differences in severe toxicity between radical versus postoperative radiation therapy.