Impact of Treating Physician on Radiation Therapy Related Severe Toxicities in Men with Prostate Cancer

Helical Tomotherapy Versus 3-Dimensional Conformal Radiation Therapy in High-Risk Prostate Cancer: A Phase 3 Randomized Controlled Trial

PURPOSE

We present long-term outcomes from a phase 3 randomized controlled trial that compared helical tomotherapy with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of high-risk prostate cancer.

METHODS AND MATERIALS

Newly diagnosed patients with high-risk prostate cancer were randomly allocated to receive radical radiation therapy (RT) using 3D-CRT or helical tomotherapy. In both arms, patients received an initial dose of 46 Gy in 23 fractions to the prostate and pelvic lymph nodes, followed by an additional boost to the prostate of 32 Gy in 16 fractions. RT was combined with 3 years of adjuvant androgen deprivation. The primary endpoint was late (>90 days since RT initiation) rectal toxicity.

RESULTS

Overall,123 patients were randomly assigned to either the 3D-CRT (n = 60) or tomotherapy (n = 63) arms. The median follow-up was 161 months. Overall, the proportion of patients with grade ≥ 2 late rectal toxicity was 8.3% (95% CI, 3.1-19.1; n = 5) in the 3D-CRT arm and 11.1% (95% CI, 5.0-22.2; n = 7) in the tomotherapy arm with no significant between-arm difference (P = .83). There was no significant difference (P = .17) in the proportion of patients with late grade ≥ 2 genitourinary toxicity:10.0% (95% CI, 4.1-21.2) in the 3D-CRT arm and 20.6% (95% CI, 11.9-33.0) in the tomotherapy arm. There was no significant difference in the hazard of biochemical progression or death between the 2 groups (hazard ratio for the tomotherapy arm: 0.72; 95% CI, 0.46-1.15; P = .17).

CONCLUSIONS

In this phase 3 trial, the overall incidence of grade ≥ 2 rectal toxicity was low and was not significantly different between the 2 arms. There was no significant evidence of improved biochemical progression-free survival in patients treated with tomotherapy. These findings should be interpreted considering the possibility of type II errors due to limited sample size and low event rates.

Assessment of rectal toxicities after radiation therapy for localized prostate cancer: experience of the Akanda Cancer Institute in Gabon

Background

The purpose was to evaluate the incidence of acute and late rectal toxicities and their correlation with the clinical and dosimetric parameters of patients who underwent curative radiotherapy for localized prostate cancer at the Akanda Cancer Institute, Gabon.

Materials and methods

Between 2013 and 2021, a cohort of 46 patients with clinically localized stage cT1c-T4 prostate cancer was treated with three-dimensional conformal radiation therapy (3D-CRT) at the national cancer institute with doses ranging from 66 to 80 Gy. Post-radiation gastrointestinal (GI) toxicities were classified and graded according to the Common Terminology Criteria for Adverse Events CTCAE v4.0.

Results

In our study, 17.4% (8/46) developed acute GI. Grades 1 and 3 acute GI complications were seen in 13.0% (6/46) and 4.3% (2/46), respectively. No patient developed acute grade 2 or grade higher than 3 complications. Late GI side effects were limited. The median time to the development of late GI Grade ≥ 1 toxicities was 12 months (range: 9-19 months). 10.9% (5/46) had experience late GI. Among them, grade 1 and 2 were seen in 6.5% (3/46), and 4.3% (2/46), respectively. There was no grade 3 or higher complications. Statistically, we did not find any correlation between the presence of rectal toxicity and clinical factors or the presence of comorbidity. On the dosimetric level, the Mann-Whitney statistical test found a correlation between the presence of late GI toxicity and rectal volume irradiated at the prescribed dose (p = 0.02).

Conclusion

Despite the high radiation doses involved, our results showed an acceptable complication rate.

Association of Short-term Patient-reported Outcomes With Long-term Oncologic Outcomes in Localized Prostate Cancer Patients Treated With Radiation Therapy and Androgen Deprivation Therapy in a Randomized Controlled Trial

PURPOSE

Both oncologic outcomes and patient-reported outcomes are pivotal in prostate cancer (PCa). However, it remains unknown if there is any association between these 2 outcomes. In this secondary analysis of a randomized controlled trial, we investigated the association of short-term changes in patient-reported outcome with long-term event-free survival (EFS) and metastasis-free survival (MFS) in localized PCa.

METHODS AND MATERIALS

Localized PCa patients with a Gleason score ≤7, clinical stage T1b to T3a, and prostate-specific antigen (PSA) <30 ng/mL were randomized to neoadjuvant and concurrent androgen deprivation therapy (ADT) for 6 months starting 4 months before prostate radiation therapy or concurrent and adjuvant ADT for 6 months starting simultaneously with radiation therapy. Patient-reported symptom burden was evaluated using the European Organisation for Research and Treatment of Cancer quality of life questionnaire (QLQ)-PR.25. Clinically meaningful deterioration (CMD) was defined as a ≥10-point worsening at any time within 10 months postrandomization regardless of subsequent improvement. Landmark analyses were performed to determine the association of CMD of urinary and bowel symptoms separately with EFS and MFS in patients who responded to the baseline questionnaire, were alive, and were event free at 10 months.

RESULTS

Overall, 393 patients had responded to the baseline QLQ. One patient died, and 1 patient had failure within 10 months. Therefore, 391 patients were eligible for the landmark analyses. After adjusting for age, Gleason score, PSA, performance status, and treatment group, CMD of urinary symptoms was associated with worse EFS (hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.21-2.65) and MFS (HR, 1.69; 95% CI, 1.11-2.57). Considering deaths as competing events, CMD of urinary symptoms was associated with a significant increase in the relative incidence of progression (subdistribution HR, 2.42; 95% CI, 1.12-5.20). However, no association was found between CMD of bowel symptoms and EFS or MFS.

CONCLUSIONS

In this study, short-term CMD of urinary symptoms was associated with significantly inferior EFS and MFS and an increase in the relative incidence of progression. Further investigations are needed to explore the biological rationale of such association in the context of ADT and radiation therapy.

Association of Baseline Patient-reported Health-related Quality of Life Metrics with Outcome in Localised Prostate Cancer

AIMS

Although health-related quality of life (HR-QoL) outcomes are pivotal in oncology, the prognostic significance of patient-reported HR-QoL metrics is largely undefined in localised prostate cancer. We report the association of baseline HR-QoL metrics with overall survival and toxicity in localised prostate cancer.

MATERIALS AND METHODS

This was a secondary analysis of a phase III randomised controlled study conducted in a single-payer health system. Patients with Gleason score ≤7, clinical stage T1b-T3a and prostate-specific antigen <30 ng/ml were randomised to neoadjuvant and concurrent androgen deprivation therapy (ADT) for 6 months starting 4 months before prostate radiotherapy or concurrent and adjuvant ADT for 6 months starting simultaneously with prostate radiotherapy. HR-QoL scores were estimated using the European Organisation for Research and Treatment of Cancer QoL questionnaire. A multistate Markov model was used to determine the association of baseline HR-QoL metrics with overall survival and a multilevel multivariable Cox regression was used to determine the association with the incidence of delayed-onset grade ≥3 radiotherapy-related toxicities. To adjust for multiple analyses, P < 0.025 was considered as statistically significant.

RESULTS

Overall, 393 patients with baseline HR-QoL data were included in this analysis: 194 in the neoadjuvant arm and 199 in the adjuvant arm. Baseline financial difficulty (hazard ratio 1.020, 95% confidence interval 1.010-1.030, P = 0.02) and dyspnoea (hazard ratio 1.020, 95% confidence interval 1.003-1.030, P = 0.01) were associated with inferior overall survival. Baseline dyspnoea was associated with a higher incidence of grade ≥3 toxicity (hazard ratio 1.020, 95% confidence interval 1.010-1.030, P = 0.023).

CONCLUSION

In a cohort of localised prostate cancer patients treated with radiotherapy and short-term ADT, a 10-point higher baseline financial difficulty or dyspnoea was associated with a 20% increased risk of death. With each 10-point increase in baseline dyspnoea, we noted a 20% increase in the associated risk of grade ≥3 delayed-onset radiotherapy-related toxicity.