3330 - Secondary Lung Tumor in Localized Prostate Cancer Treated with Radiotherapy ± Androgen Depletion Therapy: Long-Term Data from Two Phase III Trials
Presenter(s)
A. Nabid1, N. Carrier2, E. Vigneault3, A. G. Martin4, J. P. Bahary5, T. V. Nguyen6, P. Vavassis7, M. A. Brassard8, B. Bahoric9, R. Archambault10, F. Vincent11, R. Bettahar12, M. Duclos13, D. R. Wilke14, and L. Souhami15; 1CIUSSS de l'Estrie - CHUS, Sherbrooke, QC, Canada, 2Centre hospitalier universitaire de Sherbrooke, Sherbrooke, QC, Canada, 3Centre Intégré Cancérologie et Centre de recherche CHU de Québec Université Laval, Quebec City, QC, Canada, 4CHU de Québec – Université Laval, Québec, QC, Canada, 5Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Montreal, QC, Canada, 6Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada, 7Maisonneuve-Rosemont Hospital, Montreal, QC, Canada, 8Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-Saint-Jean, Chicoutimi, QC, Canada, 9Département de radio-oncologie, Jewish General Hospital, Montreal, QC, Canada, 10Centre Intégré de Santé et de Services Sociaux de l'Outaouais, Gatineau, QC, Canada, 11Centre hospitalier regional de Trois-Rivieres, Trois-Rivieres, QC, Canada, 12CSSS Rimouski-Neigette, Rimouski, QC, Canada, 13Cedars Cancer Center, Montreal, QC, Canada, 14Department of Radiation Oncology, QE2 Cancer Centre, Nova Scotia Health, Halifax, NS, Canada, 15McGill University Health Centre, Montreal, QC, Canada
Purpose/Objective(s): To establish the incidence and related outcomes of a secondary lung tumor (SLT) in a cohort of localised prostate cancer patients (pts) treated with radiotherapy (RT) ± androgen depletion therapy (ADT) in two Phase 3 trials.
Materials/Methods: From October 2000 to September 2010, 630 pts with high-risk prostate cancer (HRPCa) treated with ADT and RT and 600 with intermediate risk prostate cancer (IRPCa) treated with RT with or without ADT entered 2 randomized trials. SLT and outcomes were compiled until October 2025. IRPCa and HRPCa were compared with Fisher exact test for categorical variables or Mann-Whitney test for continuous variables. SLT was reported in a follow up case report form by each participating institution investigator.
Results: With a median follow-up of 17.4 years, the crude rate of SLT was 8.4% (103/1230). Median age at randomisation was 71 years and SLT occurred at a median age of 76 years [IQR 72-82]. 21 pts received RT alone and 84 RT+ADT.
Patient’s characteristics for age, Zubrod performance scale and comorbidities were similar between HRPCa and IRPCa and different for clinical stage and Gleason score. There was no significant difference in the incidence of SLT between pts treated to the prostate alone in IRPCa 54/600 (9.0%) or to a larger field of RT including the whole pelvis in HRPCa 49/630 (7.8%), p=0.434. 24/103 pts with SLT had initial chronic obstructive pulmonary disease. Tobacco consumption data was available in 87/103 pts (84.5%) and, of these, 82 pts (94.3%) were smokers. Pathology, available in 65/103 pts (64%), was reported as adenocarcinoma in 26, squamous cell in 22, large cell in 6, poorly differentiate in 3 and small cell in 8. SLT occurred gradually over a long period of time (0.1 to 19.5 years) post randomisation with a median time of 7.1 years (IQR:3.8–10.8). At the time of the SLT diagnosis, 84 pts (81.6%) had no biochemical failure (BF), 14 had BF (13.6%) but no evidence of metastatic disease, and 5 with BF and metastatic disease (4.6%). For the 103 pts, the median survival time was 9.2 years (95% CI 8.22-11.57) from randomisation and 10.6 months (IQR 7.1-14.8 months) after diagnosis of SLT. No significant difference in death rate between IRPCa and HRPCa. 92/103 pts (89.3%) had died, SLT was considered the cause of death in 76 (82.6%), prostate cancer in 5 pts (5.4%) and the remaining 11 pts (12.0%) dying from other causes.Conclusion: In pts with localized prostate cancer treated with RT ± ADT, the incidence of a second lung tumor is relatively high, appearing lately and remains the leading cause of death in this group of pts. Prostatic or pelvic radiotherapy appears to play no causative role in these second neoplasms. Considering the potential impact on prostate cancer survivorship, our findings underscore the need to integrate tobacco prevention approaches, appropriate surveillance/screening strategies and educational structured guidelines in our prostate cancer care routine for this group of patients.