A territory-wide real-world efficacy and toxicity analysis of abiraterone acetate versus docetaxel in 574 Asian patients with metastatic hormone-sensitive prostate cancer.

INTRODUCTION: Abiraterone acetate (ABI) or docetaxel (DOC), in addition to androgen-deprivation therapy (ADT), are current treatment options for metastatic hormone-sensitive prostate cancer (mHSPC). No randomized head-to-head trial has compared these 2 mHSPC treatments, and real-world data regarding their outcomes in Asian patients are lacking. PATIENTS AND METHODS: The medical records of mHSPC patients who began upfront ABI or DOC treatment in addition to ADT at seven public oncology centers in Hong Kong between 2015 and 2021 were reviewed. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), prostate-specific antigen (PSA) response, and toxicities. Kaplan-Meier and multivariate Cox regression analyses were performed. RESULTS: A total of 574 patients were included, of whom 419 received DOC and 155 received ABI. The median follow-up duration was 22.4 (DOC group: 23.8; ABI group: 17.3) months. The ABI group demonstrated significantly better PFS than the DOC group (not reached vs. 15.1 months: hazard ratio = 0.37; 95% confidence interval = 0.28-0.50; P < .001). No significant OS difference was observed (P = .58). Failure to achieve a ≥ 90% decline in PSA level at 3 months and failure to achieve an undetectable PSA nadir were each associated with unfavorable PFS and OS. Patients who received DOC had a higher rate of febrile neutropenia, whereas those who received ABI had higher rates of grade ≥ 3 hypokalemia and elevated alanine transaminase. Treatment discontinuation due to toxicities was more common in the DOC (3.6%) than the ABI (0.6%) group. CONCLUSION: In Asian mHSPC patients, upfront ABI + ADT was associated with better PFS than DOC + ADT, with no significant OS difference. PSA kinetics may help stratify the prognosis for treatment intensification. Toxicity profiles were different, with a higher rate of toxicity-related treatment discontinuation in the DOC group.

Neoadjuvant short-course radiotherapy or chemoradiation plus consolidative chemotherapy followed by radical operation for locally advanced rectal cancer.

Introduction: Limited evidence compares short-course radiotherapy (SCRT) and long-course chemoradiotherapy (LCCRT), both of which are followed by consolidative chemotherapy before radical rectal surgery. We conducted a retrospective cohort study to assess treatment response, survival outcomes, and toxicity in patients with locally advanced rectal cancer. Materials and methods: Patients (cT3-4 and/or N+) treated with SCRT or LCCRT, consolidative chemotherapy, or total mesorectal excision between 2013 and 2021 were identified. the cause-specific cumulative incidence of disease-related treatment failure, locoregional recurrence, distant metastases, and overall survival were evaluated using flexible parametric competing risk analysis and Kaplan-Meier methods, adjusted for treatment regimens and clinicopathological factors. A pathological complete response (pCR), tumor downstaging, and toxicity have been reported. Results: Among the 144 patients, 115 (80%) underwent curative rectal surgery. The LCCRT and SCRT groups achieved pCR in 10 (18%) and seven (12%) patients, respectively (odds ratio, 1.68; 95% confidence interval [CI], 0.59-4.78). The adjusted cause-specific hazard ratio for disease-related treatment failure with LCCRT versus SCRT was 0.26 (95% CI, 0.08-0.87). Three-year cumulative probability of disease-related treatment failure was 10.0% and 25.6% for LCCRT and SCRT, respectively. No significant differences in T-downstaging, N-downstaging, significant pathologic downstaging (ypT0-2N0), locoregional failure, distant metastasis, or overall survival were found. Late rectal toxicity occurred in 10 (15%) LCCRT and two (3%) SCRT patients, respectively. Conclusion: LCCRT with consolidative chemotherapy demonstrated improved disease-related treatment failure compared with SCRT, despite higher late rectal toxicity. Further research is needed to assess the long-term oncologic outcomes and toxicity.

Early toxicities of ultrahypofractionated stereotactic body radiotherapy for intermediate risk localized prostate cancer using cone-beam computed tomography and real-time three-dimensional transperineal ultrasound monitoring.

PURPOSE: Image-guided radiotherapy (IGRT) is central to the safe and effective delivery of ultrahypofractionated (UF) stereotactic body radiotherapy (SBRT) for localized prostate cancer. However, the optimal IGRT modality remains uncertain. We aim to study the safety of performing UF-SBRT using cone-beam computed tomography (CBCT) and real-time transperineal ultrasound (TPUS) monitoring. MATERIALS AND METHODS: We retrospectively review the medical records of 26 patients who had received UF-SBRT for intermediate risk localized prostate cancer in our institution from October 2018 to December 2020. All patients were treated with SBRT without fiducial marker and received 35-40 Gy to the clinical target volume in 5 fractions over 2-5 weeks. CBCT was used to correct for interfraction displacement while intrafraction displacement of the prostate gland was monitored using Elekta Clarity Autoscan TPUS with 4 mm isotropic warning level. All patients also received neoadjuvant and concurrent androgen deprivation therapy for a total of 6 months. The primary endpoints were incidence of acute toxicities and patient reported urinary toxicities in terms of the International Prostate Symptom Score: before (IPSS1), at the completion of (IPSS2), and at 3-6 months (IPSS3) after SBRT. RESULTS: All men were treated and followed up for at least 3 months after SBRT. Patients experienced transient worsening of their urinary symptoms at the end of SBRT but they usually recovered in 3-6 months afterwards. The median IPSS1, IPSS2, and IPSS3 were 12, 12.5, and 8, respectively. One patient developed grade 3 rectal bleeding which was related to underlying hemorrhoid. No other grade 3-4 acute toxicity was observed. CONCLUSION: It appears safe to deliver UF-SBRT without fiducial marker for prostate cancer patients using CBCT and non-invasive hybrid imaging modalities for positioning and tracking. Longer follow-up is necessary to monitor the treatment efficacy and long-term toxicities.