1. Genomic landscape of older versus younger men with metastatic castration-resistant prostate cancer.
- Author
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Knox A., Fettke H., Hauser C., Bukczynska P., Ng N., Foroughi S., Graham L.-J., Mahon K., Tan W., Zheng T., Yu J., Dai C., Du P., Jia S., Horvarth L., Kohli M., Azad A., Kwan E., Knox A., Fettke H., Hauser C., Bukczynska P., Ng N., Foroughi S., Graham L.-J., Mahon K., Tan W., Zheng T., Yu J., Dai C., Du P., Jia S., Horvarth L., Kohli M., Azad A., and Kwan E.
- Abstract
Background: Metastatic castration-resistant prostate cancer (mCRPC) disproportionately affects older individuals. While the molecular landscape of mCRPC is well established, less is understood about how genomic alterations differ with age. We compared cell-free DNA (cfDNA) profiles of younger (age<70) and older (age>=70) men with mCRPC and assessed the relative prognostic impact of genomic alterations between age categories. Method(s): Plasma cfDNA from 276 patients across two independent prospective cohorts (Australian, n=123; US, n=153) was sequenced using the PredicineTM cfDNA assay. Genomic alteration frequency (copy number variants and mutations) and circulating tumour DNA fraction (ctDNA%) were compared between age categories using the chi-squared and Wilcoxon rank-sum tests, respectively. Kaplan-Meier survival estimates, and Cox regression analysis were used to assess associations between age, genomic alterations, and overall survival. Result(s): Median age was 72 years (IQR 66-78), with 170 (62%) patients >=70. There was no significant difference in ctDNA% between older and younger patients (median 22% vs 30%, p=0.6). Similarly, no significant difference in alteration frequency was observed in prostate cancer driver genes, including AR (<70 vs >=70: 46% vs 49%, p=0.6), PTEN (39% vs 31%, p=0.2), BRCA2 (29% vs 21%, p=0.13) and ATM (17% vs 14%, p=0.4). The impact of established poor prognostic alterations was evident in both age categories. In an exploratory analysis, certain alterations may have a more pronounced effect in younger patients, including PIK3CA gain (HR 4.2 for <70, HR 1.9 for >=70 years; HR for interaction 2.2, p = 0.03) and MYC gain (HR 3.6 for <70, HR 2.1 for >=70 years; HR for interaction 1.8, p = 0.1). Conclusion(s): The frequency of clinically relevant genomic alterations was comparable between older and younger mCRPC patients. Screening for alterations that confer sensitivity to precision medicine therapies should be considered regardless o
- Published
- 2021