Early and late toxicity profiles of patients receiving immediate postoperative radiotherapy versus salvage radiotherapy for prostate cancer after prostatectomy

Risk of severe late toxicity after radiotherapy following radical prostatectomy - a nationwide study

BACKGROUND

Severe side-effects are rare but may occur years after radiation therapy following radical prostatectomy. We sought to estimate the long-term risks of severe late toxicities in an unselected, nationwide, cohort.

METHODS

The study population comprised all men undergoing radical prostatectomy between 1997-2016 in the Prostate Cancer database Sweden (PCBaSe) (n=40,962). By (1:2) matching, two cohorts were created: 2789 men exposed to postoperative radiation and 5578 nonexposed men with comparable age, comorbidities and year of surgery. Cumulative incidences and rate ratios were calculated for the following outcomes: symptoms and interventions of the urinary or intestinal tract demanding inpatient care, secondary malignancies and non-prostate cancer mortality.

RESULTS

The largest differences were seen for late toxicities affecting the urinary tract. The 10-year cumulative incidences among those exposed to postoperative radiation versus the surgery only group were: 17.8% versus 10.5% for procedures of the urinary tract (difference 7.3%, 95% confidence interval [CI] 4.4 to 10.3; relative risk [RR] 1.74, 95% CI 1.47 to 2.05); 6.0% versus 1.2% for hematuria (difference 4.8%, 95% CI 3.1 to 6.5; RR 6.50 95% CI 4.31 to 10.10); and 2.4% versus 1.1% for bladder cancer (difference 1.4%, 95% CI 0.4 to 2.3; RR 2.71 95% CI 1.72 to 4.33). The groups were similar regarding intestinal toxicity, other secondary malignancies, and non-prostate cancer mortality. Adjustments for preoperative tumor risk factors did not importantly affect the rate ratios.

CONCLUSION

Severe late toxicity after postoperative radiation following radical prostatectomy predominately affects the bladder and can appear many years after radiotherapy.

Predictors of Patient-Reported Incontinence at Adjuvant/Salvage Radiotherapy after Prostatectomy: Impact of Time between Surgery and Radiotherapy

BACKGROUND

Baseline urinary incontinence (UI) strongly modulates UI recovery after adjuvant/salvage radiotherapy (ART/SRT), inducing clinicians to postpone it "as much as possible", maximizing UI recovery but possibly reducing efficacy. This series aims to analyze the trend of UI recovery and its predictors at radiotherapy start.

METHODS

A population of 408 patients treated with ART/SRT enrolled in a cohort study (ClinicalTrials.gov #NCT02803086) aimed at developing predictive models of radiation-induced toxicities. Self-reported UI and personality traits, evaluated by means of the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-SF) and Eysenck Personality Questionnaire - Revised (EPQ-R) questionnaires, were assessed at ART/SRT start. Several endpoints based on baseline ICIQ-SF were investigated: frequency and amount of urine loss (ICIQ3 and ICIQ4, respectively), "objective" UI (ICIQ3 + 4), "subjective" UI (ICIQ5), and "TOTAL" UI (ICIQ3 +4 + 5). The relationship between each endpoint and time from prostatectomy to radiotherapy (TTRT) was investigated. The association between clinical and personality variables and each endpoint was tested by uni- and multivariable logistic regression.

RESULTS

TTRT was the strongest predictor for all endpoints (p-values ≤ 0.001); all scores improved between 4 and 8 months after prostatectomy, without any additional long-term recovery. Neuroticism independently predicted subjective UI, TOTAL UI, and daily frequency.

CONCLUSIONS

Early UI recovery mostly depends on TTRT with no further improvement after 8 months from prostatectomy. Higher levels of neuroticism may overestimate UI.

A Ten-year-long Update on Radiation Proctitis Among Prostate Cancer Patients Treated With Curative External Beam Radiotherapy

This comprehensive synopsis summarizes the most relevant information obtained from a systematic analysis of studies of the last decade on radiation proctitis, one of the most feared radioinduced side effects among prostate cancer patients treated with curative external beam radiotherapy. The present review provides a useful support to radiation oncologists for limiting the onset or improving the treatment of radiation proctitis. This work shows that the past decade was a harbinger of significant new evidence in technological advances and technical tricks to avoid radiation proctitis, in addition to dosimetric perspectives and goals, understanding of pathogenesis, diagnostic work-up and treatment. We believe that a well-rounded knowledge of such an issue is fundamental for its appropriate management.

Adjuvant versus early salvage radiotherapy: outcome of patients with prostate cancer treated with postoperative radiotherapy after radical prostatectomy

Background

Adjuvant (ART) and salvage radiotherapy (SRT) are two common concepts to enhance biochemical relapse free survival (BCRFS) in patients with prostate cancer (PC). We analyzed differences in outcome between ART and SRT in patients with steep decline of PSA-levels after surgery to compare outcome.

Methods

We evaluated 253 patients treated with postoperative RT with a median age of 66 years (range 42–85 years) treated between 2004 and 2014. Patients with additive radiotherapy due to PSA persistence and patients in the SRT group, who did not achieve a postoperative PSA level <0.1 ng/mL were excluded. Hence, data of 179 patients was evaluated. We used propensity score matching to build homogenous groups. A Cox regression model was used to determine differences between treatment options. Median follow-up was 32.5 months (range 1.4–128.0 months).

Results

Early SRT at PSA levels <0.3 ng/mL was associated with significant longer BCRFS than late SRT (HR: 0.32, 95%-CI: 0.14–0.75, p = 0.009). Multiple Cox regression showed pre-RT PSA level, tumor stage, and Gleason score as predictive factors for biochemical relapse. In the overall group, patients treated with either ART or early SRT showed no significant difference in BCRFS (HR: 0.17, 95%-CI: 0.02–1.44, p = 0.1). In patients with locally advanced PC (pT3/4) BCRFS was similar in both groups as well (HR: 0.21, 95%-CI:0.02–1.79, p = 0.15).

Conclusion

For patients with PSA-triggered follow-up, close observation is essential and early initiation of local treatment at low PSA levels (<0.3 ng/mL) is beneficial. Our data suggest, that SRT administered at early PSA rise might be equieffective to postoperative ART in patients with locally advanced PC. However, the individual treatment decision must be based on any adverse risk factors and the patients’ postoperative clinical condition.

Study registration

The present work is approved by the Ethics Commission of the Technical University of Munich (TUM) and is registered with the project number 320/14.