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Evolving Intersection Between Inherited Cancer Genetics and Therapeutic Clinical Trials in Prostate Cancer: A White Paper From the Germline Genetics Working Group of the Prostate Cancer Clinical Trials Consortium.

ABSTRACT:

Purpose

Advances in germline genetics, and related therapeutic opportunities, present new opportunities and challenges in prostate cancer. The Prostate Cancer Clinical Trials Consortium Germline Genetics Working Group was established to address genetic testing for men with prostate cancer, especially those with advanced disease undergoing testing for treatment-related objectives and clinical trials.

Methods

The Prostate Cancer Clinical Trials Consortium Germline Genetics Working Group met monthly to discuss the current state of genetic testing of men with prostate cancer for therapeutic or clinical trial purposes. We assessed current institutional practices, developed a framework to address unique challenges in this population, and identified areas of future research.

Results

Genetic testing practices in men with prostate cancer vary across institutions; however, there were several areas of agreement. The group recognized the clinical benefits of expanding germline genetic testing, beyond cancer risk assessment, for the goal of treatment selection or clinical trial eligibility determination. Genetic testing for treatment selection should ensure patients receive appropriate pretest education and consent and occur under auspices of a research study whenever feasible. Providers offering genetic testing should be able to interpret results and recommend post-test genetic counseling for patients. When performing tumor (somatic) genomic profiling, providers should discuss the potential for uncovering germline mutations and recommend appropriate genetic counseling. In addition, family members may benefit from cascade testing and early cancer screening and prevention strategies.

Conclusion

As germline genetic testing is incorporated into practice, further development is needed in establishing prompt testing for time-sensitive treatment decisions, integrating cascade testing for family, ensuring equitable access to testing, and elucidating the role of less-characterized germline DNA damage repair genes, individual gene-level biologic consequences, and treatment response prediction in advanced disease.

SUBMITTER: Carlo MI

PROVIDER: S-EPMC6370313 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:A previous linkage study provided evidence for a prostate cancer-susceptibility locus at 1q24-25. Subsequent reports in additional collections of families have yielded conflicting results. In addition, evidence for locus heterogeneity has been provided by the identification of other putative hereditary prostate cancer loci on Xq27-28, 1q42-43, and 1p36. The present study describes a combined analysis for six markers in the 1q24-25 region in 772 families affected by hereditary prostate cancer and ascertained by the members of the International Consortium for Prostate Cancer Genetics (ICPCG) from North America, Australia, Finland, Norway, Sweden, and the United Kingdom. Overall, there was some evidence for linkage, with a peak parametric multipoint LOD score assuming heterogeneity (HLOD) of 1.40 (P=.01) at D1S212. The estimated proportion of families (alpha) linked to the locus was.06 (1-LOD support interval.01-.12). This evidence was not observed by a nonparametric approach, presumably because of the extensive heterogeneity. Further parametric analysis revealed a significant effect of the presence of male-to-male disease transmission within the families. In the subset of 491 such families, the peak HLOD was 2.56 (P=.0006) and alpha =.11 (1-LOD support interval.04-.19), compared with HLODs of 0 in the remaining 281 families. Within the families with male-to-male disease transmission, alpha increased with the early mean age at diagnosis (<65 years, alpha =.19, with 1-LOD support interval.06-.34) and the number of affected family members (five or more family members, alpha =.15, with 1-LOD support interval.04-.28). The highest value of alpha was observed for the 48 families that met all three criteria (peak HLOD = 2.25, P=.001, alpha=.29, with 1-LOD support interval.08-.53). These results support the finding of a prostate cancer-susceptibility gene linked to 1q24-25, albeit in a defined subset of prostate cancer families. Although HPC1 accounts for only a small proportion of all families affected by hereditary prostate cancer, it appears to play a more prominent role in the subset of families with several members affected at an early age and with male-to-male disease transmission.

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