ESTRO 2022

Session Item

Sunday

May 08

16:55 - 17:55

Room D1

Urology

Co-Chair: Nejla Fourati, Tunisia;

Chair: , Germany

Session Code: 2520

Session Type: Proffered Papers

Track: Clinical

17:05 - 17:15

Multi-institutional outcomes of Gleason grade group 5 prostate cancers treated with EBRT and ADT

Vedang Murthy, India

Presentation Number: OC-0606

Abstract

Abstract Title:

Multi-institutional outcomes of Gleason grade group 5 prostate cancers treated with EBRT and ADT

Authors:

Vedang Murthy¹, Srinivas Chilukuri², Indranil Mallick³, Priyamvada Maitre⁴, Amiya Agarwal⁵, Arun Singh Moses⁶, Francis James⁷, Kushal Narang⁸, Tejinder Kataria⁸, AK Anand⁹, Deb Narayan Dutta¹⁰, Swarupa Mitra¹¹, Simon Pavamani¹², Suman Mallick¹³, Nilesh Mahale¹⁴, Manish Chandra¹⁵, Anand Narayan¹⁶, Tanweer Shahid¹⁷, Madhu Sairam¹⁸, V Kannan¹⁹, Sarthak Mohanty²⁰, Trinanjan Basu²¹, Chandni Hotwani²², Bharath G²³

¹Tata Memorial Centre, Radiation Oncology, Mumbai, India; ²Apollo Proton Cancer Centre, Radiation Oncology, Chennai, India; ³Tata Medical Centre, Radiation Oncology, Kolkata, India; ⁴Tata Memorial Centre, Radiation Oncology, Kolkata, India; ⁵Tata Memorial Centre, Radiation oncology, Mumbai, India; ⁶Tata medical centre, Radiation oncology, Kolkata, India; ⁷RCC, Raiation Oncology, Trivandrim, India; ⁸Medanta, Radiation oncology, Gurugram, India; ⁹Max Hospital, Radiation Oncology, Delhi, India; ¹⁰Amrita Institute of Medical Sciences, Radiation oncology, Kochi, India; ¹¹Rajiv Gandhi Cancer Institute, Radiation oncology, New Delhi, India; ¹²CMC, Radiation oncology, Vellore, India; ¹³Narayan Super speciality hospital, Radiation oncology, Howrah, India; ¹⁴Nirali Memorial Radiation Centre and Bharat Cancer Hospital, Radiation oncology, Surat, India; ¹⁵Jupiter Hospital, Radiation oncology, Thane, India; ¹⁶GKNM Hospital, Radiation oncology, Coimbatore, India; ¹⁷Apollo Gleneagles Hospital, Radiation oncology, Kolkata, India; ¹⁸Kovai Medical Centre, Radiation oncology, Coimbatore, India; ¹⁹Hinduja Hospital, Radiation oncology, Mumbai, India; ²⁰Sterling Cancer Hospital, Radiation oncology, Rajkot, India; ²¹HCG Cancer Centre, Radiation oncology, Mumbai, India; ²²Alexis Multispeciality Hospital, Radiation oncology, Nagpur, India; ²³Yashoda Cancer Institute, Radiation oncology, Hyderabad, India

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Purpose or Objective

Patients with Gleason grade group(GG) 5 are known to have a significantly higher risk of biochemical failure(BF), distant metastases, and death compared to patients with lesser GGs. This study reports multi-institutional clinical outcomes of patients with non-metastatic GG5 treated with long-term ADT and high-dose external beam radiation image guided radiotherapy (RT).

Material and Methods

19 cancer centres were requested to report outcomes of non-metastatic GG5 prostate cancers treated with curative intent external beam radiation(EBRT), and with a minimum follow up of 18 months from the end of ADT. The key outcomes that were assessed were biochemical progression free survival(bPFS), metastases free survival(MFS) and overall survival(OS), acute and late gastrointestinal(GI) and genitourinary(GU) toxicities. The univariate(UVA) and multivariate analyses(MVA) to study the impact of prognostic factors were performed using log-rank and Cox proportional hazard model respectively.

Results

A total of 462 patients from 19 institutes were included in the study. 81% had T3/T4 disease, 31% had node-positive disease, 58% had Gleason 4+5, 30% had 5+4 and 12% had 5+5 disease. A third had PSMA PET-CT scan for staging and 77% had it for restaging at BF. The median duration of ADT was 24 months and 21% underwent surgical castration. The median EQD2 dose of RT was 75Gy, with 66% receiving either moderate or extreme hypofractionation and 71% receiving pelvic nodal RT. At a median follow-up of 4.6 years the 5 year bPFS, MFS and OS were 73.1%, 77.4% and 90.5% respectively. The 5-year prostate cancer-specific mortality was 6.7%. On UVA, primary Gleason 5 pattern, and pelvic node positivity were associated with worse bPFS and MFS; and medical castration with worse MFS. On MVA, only the primary Gleason 5 pattern was associated with worse outcomes with respect to all 3 endpoints (HR=0.49, 0.622, 0.469). Of the 115 patients who had a BF, the site of uptake on PSMA PET CT was prostate only, pelvis and distant in 19%, 23% and 84% respectively. Acute grade >2 GI and GU toxicities were noted in 21.9% and 31.9% respectively while late grade 2, 3 GI and GU toxicities were 12.1% and 3%; and 20.6% and 4.1% respectively.

Conclusion

Despite a high proportion of patients with advanced disease and GG5, high dose EBRT alone with long-term ADT leads to low rates of metastases and death from prostate cancer. The primary Gleason pattern 5 is associated with poor clinical outcomes compared to primary Gleason 4. The reported acute and late toxicities in a non-trial, community setting were comparable to the previously published prospective studies.