Age at diagnosis and prognosis among prostate cancer patients treated with radiotherapy: evidenced from three independent cohort studies
Authors: X. Dong, G. Ma, F. Chen
Journal: Annals of Oncology (2018)

We read the paper by Pettersson et al. [1.Pettersson A. Robinson D. Garmo H. et al.Age at diagnosis and prostate cancer treatment and prognosis: a population-based cohort study.Ann Oncol. 2018; 29: 377-385Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar] with great interest. They enrolled 121 392 Swedish prostate cancer patients aged 55–95 years to explore the association between age at diagnosis and prognosis among prostate cancer patients with treatment. They observed that age at diagnosis did not contribute to the prostate cancer death among 14 776 men treated with radiotherapy. However, results from prior studies remain inconclusive [2.D’Amico A.V. Cote K. Loffredo M. et al.Advanced age at diagnosis is an independent predictor of time to death from prostate carcinoma for patients undergoing external beam radiation therapy for clinically localized prostate carcinoma.Cancer. 2003; 97: 56-62Crossref PubMed Scopus (28) Google Scholar, 3.Loeb S. Berglund A. Stattin P. Population based study of use and determinants of active surveillance and watchful waiting for low and intermediate risk prostate cancer.J Urol. 2013; 190: 1742-1749Crossref PubMed Scopus (92) Google Scholar]. Large-scale samples with follow-up information from multiple centers were warranted to address this issue. This study employed two independent prostate cohorts, The Prostate, Lung, Colorectal, and Ovarian (PLCO) and The Surveillance, Epidemiology, and End Results (SEER), to investigate the association between age at diagnosis and prognosis among prostate cancer patients treated with radiotherapy. Patients from the two centers were respectively grouped into five groups on the basis of the ages at diagnosis (age 60–64 reference category). Cox proportional hazard regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment of baseline characteristics. Together, we conducted a meta-analysis to comprehensively assess the role of age at diagnosis in the prognosis of prostate patients underwent radiotherapy. For SEER dataset (application number: 10809-Nov2017, supplementary Table S1, available at Annals of Oncology online), compared with 60–64 years group, the HR (95% CI) of 55–59 group, 65–69 group, 70–74 group, and 75+ group was 1.03 (95% CI: 0.81–1.31, P= 0.80), 0.94 (95% CI: 0.76–1.16, P= 0.56), 1.15 (95% CI: 0.93–1.42, P= 0.18), and 1.90 (95% CI: 1.58–2.28, P= 1.23 × 10−11), respectively, supplementary Table S3, available at Annals of Oncology online. For PLCO dataset (application number: PLCO-361, supplementary Table S2, available at Annals of Oncology online), compared with 60–64 years, the HR (95% CI) of 55–59 group, 65–69 group, 70–74 group, and 75+ group was 0.51 (95% CI: 0.11–2.37, P= 0.39), 0.74 (95% CI: 0.33–1.64, P= 0.45), 1.26 (95% CI: 0.61–2.61, P= 0.53), and 2.24 (95% CI: 1.02–4.94, P= 0.04), respectively, supplementary Table S3, available at Annals of Oncology online. To help elucidate the role of age at diagnosis in the outcome of prostate patients treated with radiotherapy, we performed a meta-analysis with the three center samples (PCBaSe from Pettersson et al. [1.Pettersson A. Robinson D. Garmo H. et al.Age at diagnosis and prostate cancer treatment and prognosis: a population-based cohort study.Ann Oncol. 2018; 29: 377-385Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar], PLCO, and SEER). A total of 74 940 sample were including into this analysis, among which 14 776 came from PCBaSe, 3304 from PLCO, and 56 860 from SEER. The results are summarized in Figure 1. Age at diagnosis 75+ years old contributed to poorer prognosis among patients treated with radiotherapy (HR: 1.59, 95% CI: 1.02–2.48). No significant association between the age at diagnosis and the prognosis of patients with radiotherapy was found among other age groups. Our results suggest that age at diagnosis was not the risk factor for the prognosis of prostate patients underwent radiotherapy, but not 75+ years group. This finding may facilitate counseling regarding the prognostic effect of age at diagnosis for prostate cancer treated with radiotherapy. National Natural Science Foundation of China (81530088 and 81473070 to F.C.), State’s Key Project of Research and Development Program (2016YFE0204900 to F.C.).