ESTRO 2024 - Abstract Book

S2326

Clinical - Urology

ESTRO 2024

interval from treatment to diagnosis of 7.81 years (IQR 4.40 – 9.17 years). 6 of 267 patients (2.2%) were classified as having a SM likely (n=3) or possibly (n=3) related to prior radiotherapy. The 10-year risk of any SM was 11.8%. Most common sites of SM included colon, esophagus, lung, and lymphoproliferative, with 3 instances each.

Conclusion:

At a median follow up of 10.13 years, SABR had a superior 10-year FFBF and similar OS to previously reported outcomes for conventional and hypofractionated radiotherapy [3]. The risk of SM after SABR for these patients was similar to that previously described for conventional radiotherapy [4], with only a small proportion of patients experiencing a second primary cancer likely or possibly related to their treatment. Long-term follow up from ongoing phase III studies will be required to confirm these results, and incidence of second primary cancers should be collected.

Keywords: Prostate SABR, Second Malignancy

References:

[1] A. Widmark, A. Gunnlaugsson, L. Beckman, C. Thellenberg-Karlsson, M. Hoyer, M. Lagerlund, J. Kindblom, C. Ginman, B. Johansson, K. Björnlinger, M. Seke, M. Agrup, P. Fransson, B. Tavelin, D. Norman, B. Zackrisson, H. Anderson, E. Kjellén, L. Franzén and P. Nilsson, "Ultra-hypofractionated versus conventionally fractionated radiotherapy for prostate cancer: 5-year outcomes of the HYPO-RT-PC randomised, non-inferiority, phase 3 trial," The Lancet, vol. 394, pp. 385-395, 3 August 2019. [2] N. van As, A. Tree, J. Patel, P. Ostler, H. Van Der Voet, D. A. Loblaw, W. Chu, D. Ford, S. Tolan, S. Jain, J. G. Armstrong, P. Camilleri, K. Kancherla, J. Frew, A. Chan, O. Naismith, G. Manning, S. Brown, C. Griffin and E. Hall, "5 Year Outcomes from PACE B: An International Phase III Randomized Controlled Trial Comparing Stereotactic Body Radiotherapy (SBRT) vs. Conventionally Fractionated or Moderately Hypo Fractionated External Beam Radiotherapy for Localized Prostate Cancer," International Journal of Radiation Oncology, Biology, Physics, vol. 117, pp. e2-e3, 15 November 2023. [3] I. Syndikus, C. Griffin, L. Philipps, A. Tree, V. Khoo, A. J. Birtle, A. Choudhury, C. Ferguson, J. M. O'Sullivan, M. Panades, Y. L. Rimmer, C. D. Scrase, J. Staffurth, C. Cruickshank, S. Hasssan, J. Pugh, D. P. Dearnaley and E. Hall, "10 Year efficacy and co-morbidity outcomes of a phase III randomised trial of conventional vs. hypofractionated high dose intensity modulated radiotherapy for prostate cancer (CHHiP; CRUK/06/016)," Journal of Clinical Oncology, vol. 41, no. 6_suppl, p. 304, 2023. [4] J. Huang, L. L. Kestin, H. Ye, M. Wallace, A. A. Martinez and F. A. Vicini, "Analysis of second malignancies after modern radiotherapy versus prostatectomy for localized prostate cancer," Radiotherapy and Oncology, pp. 81-86, 2011.

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