To report toxicity from the multicentre phase III randomized trial of Bladder Adjuvant Radiotherapy (BART) after radical cystectomy (RC) and chemotherapy in high-risk muscle-invasive bladder cancer (MIBC).
Patients with non-metastatic urothelial MIBC with ≥1 high-risk feature after RC: pT3-4, pN1-3, nodal yield <10, positive margin, or ≥cT3 downstaged with neoadjuvant chemotherapy; were randomized 1:1 to observation (Obs) or adjuvant radiotherapy (RT) at 4 centres, stratified by pN stage (N0, N+) and chemotherapy (neoadjuvant, adjuvant, none). Stoma-sparing IG-IMRT 50.4Gy/28# was prescribed to the cystectomy bed and pelvic nodes. Acute toxicity (≤3 months of RT/randomization) and late toxicity were assessed per protocol using CTCAE v5.0. Patients progressing within 3 or 6 months of randomization were excluded from acute or late toxicity analysis respectively.
BART trial enrolled 153 patients (Obs=76, RT=77). About half (49%) had pN+. Nearly 90% received chemotherapy (70% neoadjuvant; most commonly gemcitabine plus cisplatin). In the RT arm, 63/77 completed radiotherapy per protocol with no toxicity-related RT termination. Of the 134 patients analyzable for acute toxicity, no difference was observed in grade 3 (Obs 4.2% vs RT 1.6%, p=0.34). Grade 2 effects were higher with RT (17.5% vs 1.1%, p<0.001), mainly diarrhea/enteritis or proctitis. Late toxicity was analyzable for 104 patients (Obs=57, RT=47) with median follow up of 27 months. Grade 3-4 toxicity were about 10% (Obs 10.5% vs RT 8.4%, p=0.62), and cumulative late grade 2+ toxicity was similar in both the groups (17.5% vs 23.3%, p=0.27).
In the largest trial of adjuvant radiotherapy for high-risk urothelial MIBC, severe acute and late toxicity were low and similar with observation or radiotherapy. The oncological outcomes are awaited.
International journal of radiation oncology, biology, physics. 2024 Sep 26 [Epub ahead of print]
Vedang Murthy, Priyamvada Maitre, Ganesh Bakshi, Mahendra Pal, Maneesh Singh, Rakesh Sharma, Duleep Gudipudi, Lincoln Pujari, Himanshu Pandey, Bhavesh Bandekar, Deepa Joseph, Rahul Krishnatry, Reena Phurailatpam, Sadhana Kannan, Amandeep Arora, Dr Ankit Misra, Amit Joshi, Vanita Noronha, Kumar Prabhash, Santosh Menon, Gagan Prakash
Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India. Electronic address: ., Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India., Department of Surgery, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India., Basavatarakam Indo-American Cancer Hospital and Research Institute, Hyderabad, India., Homi Bhabha Cancer Hospital & MPMMMC, Varanasi, India., All India Institute of Medical Sciences, Rishikesh, India., Department of Medical Physics, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India., Clinical Research Secretariat, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India., Department of Medical Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India., Department of Pathology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India.