The BARCODE1 Pilot: a feasibility study of using germline single nucleotide polymorphisms to target prostate cancer screening

OBJECTIVES

To assess the feasibility and uptake of a community-based prostate cancer (PCa) screening programme selecting men according to their genetic risk of PCa. To assess the uptake of PCa screening investigations by men invited for screening. The uptake of the pilot study would guide the opening of the larger BARCODE1 study recruiting 5000 men.

SUBJECTS AND METHODS

Healthy males aged 55-69 years were invited to participate via their general practitioners (GPs). Saliva samples were collected via mailed collection kits. After DNA extraction, genotyping was conducted using a study specific assay. Genetic risk was based on genotyping 130 germline PCa risk single nucleotide polymorphisms (SNPs). A polygenic risk score (PRS) was calculated for each participant using the sum of weighted alleles for 130 SNPs. Study participants with a PRS lying above the 90th centile value were invited for PCa screening by prostate magnetic resonance imaging (MRI) and biopsy.

RESULTS

Invitation letters were sent to 1434 men. The overall study uptake was 26% (375/1436) and 87% of responders were eligible for study entry. DNA genotyping data were available for 297 men and 25 were invited for screening. After exclusions due to medical comorbidity/invitations declined, 18 of 25 men (72%) underwent MRI and biopsy of the prostate. There were seven diagnoses of PCa (38.9%). All cancers were low-risk and were managed with active surveillance.

CONCLUSION

The BARCODE1 Pilot has shown this community study in the UK to be feasible, with an overall uptake of 26%. The main BARCODE1 study is now open and will recruit 5000 men. The results of BARCODE1 will be important in defining the role of genetic profiling in targeted PCa population screening. Patient Summary What is the paper about? Very few prostate cancer screening programmes currently exist anywhere in the world. Our pilot study investigated if men in the UK would find it acceptable to have a genetic test based on a saliva sample to examine their risk of prostate cancer development. This test would guide whether men are offered prostate cancer screening tests. What does it mean for patients? We found that the study design was acceptable: 26% of men invited to take part agreed to have the test. The majority of men who were found to have an increased genetic risk of prostate cancer underwent further tests offered (prostate MRI scan and biopsy). We have now expanded the study to enrol 5000 men. The BARCODE1 study will be important in examining whether this approach could be used for large-scale population prostate cancer screening.

The relative activity of cisplatin, oxaliplatin and satraplatin in testicular germ cell tumour sensitive and resistant cell lines

BACKGROUND

Germ cell tumours (GCT) can become resistant to cisplatin, which is associated with a relatively poor prognosis. Oxaliplatin and satraplatin have been developed to overcome cisplatin resistance in other cancers, but their effect in cisplatin resistant (cisR) GCTs is unclear. In this work we address this issue by comparing their efficacy in three paired sensitive and cisR GCT cell lines.

METHODS

Three established cisplatin sensitive (cisS) and resistant cell line pairs were used (GCT27, GCT27r: SUSA, SUSAr: 833k, 833kr). Viability was assessed using a luciferase based ATP assay and EC(50) and EC(80) concentrations were calculated. Western blot analysis and flow cytometry was used for further assessment.

RESULTS

Sensitivity to the three platinum compounds was broadly similar in the three cisS lines GCT cell lines (EC(50) = 0.27-0.51 microM for cisplatin, 0.52-0.79 microM for oxaliplatin, 0.31-1.26 microM for satraplatin). EC(50) values for cisplatin in the three cisR sub lines were 1.8- to 3.8-fold higher than in the sensitive parental lines. Cross resistance to satraplatin and oxaliplatin occurred in all three cisR cell lines (resistance factor 1.9-4.4), with the exception of oxaliplatin in the 833Kr (resistance factor 0.9). Differences in the effect of specific drugs on cell cycle distribution, p53, p21 and MDM2 were observed.

CONCLUSIONS

These data suggest that satraplatin and oxaliplatin could theoretically be used in chemo-naive GCTs and support the further clinical evaluation of these agents in this setting. The mechanism of cross resistance to these drugs appears multifactorial.

How can we recruit more men of African or African-Caribbean ancestry into our research? Co-creating a video to raise awareness of prostate cancer risk and the PROFILE study

BACKGROUND

Men of African ancestry are at increased risk of developing prostate cancer (PrCa) compared to men from other backgrounds. The PROFILE study aims to understand whether genetic information can better target who needs PrCa screening. PROFILE has so far had difficulty reaching men of African or African -Caribbean ancestry to take part. In this involvement project we worked in partnership with a group of such men to co-create a video to raise awareness of PrCa risk amongst this community and promote participation in the study.

METHODS

We recruited seven men of African or African-Caribbean ancestry who completed an initial survey on the Cancer Patients' Voice platform. We then held an online discussion panel and maintained contact to encourage dialogue and planning of the video. Utilising a participatory approach, the ideas for the video were decided in collaboration with the panel who held expert knowledge of various communities and understood the messages that would best resonate and engage with other men of the same origins. Once the video had been edited and finalised, two members of the group expressed interest in writing up the project and are listed as co-authors.

RESULTS

The video in its entirety was driven by the panel's ideas. The choice of a barber shop setting; leading with a positive case study and highlighting the importance of men's family members rather than a focus on scientific language, statistics or researchers were all features that were discussed and agreed upon by the panel. The men shared the video within their networks. It was placed on websites and promoted as part of a social media campaign during Black History Month.

CONCLUSIONS

Groups with the greater healthcare needs and the most to gain from advances in care and treatment can often be the most excluded from research participation. This is pertinent in PrCa research where men of African or African-Caribbean ancestry are at greater risk. The project gave equal power and decision making to the men and provides an example of successful inclusive involvement. The result was a unique approach to making a study video.

The profile study: Prostate cancer screening in men of Black African and African Caribbean ancestry—Early results

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Background: Heritable risk factors account for a significant proportion of prostate cancer (PrCa) risk, of which only a minority are high risk Mendelian traits. Men of Black African and African Caribbean ancestry are at higher risk of developing PrCa in their lifetime (1 in 4) compared with the general population in the United Kingdom (1 in 8). PROFILE is a multi-cohort study of targeted screening for groups of men at higher risk of developing PrCa: 1) men of European ancestry with family history of PrCa, 2) men of black African and African Caribbean ancestry regardless of family history and 3) men with known rarer higher risk gene mutations for PrCa. This abstract concentrates on group 2. The aim is to investigate the role of targeted PrCa screening in men at higher genetic risk and its association with specific genetic profiles and biomarkers. Methods: Healthy men aged 40-69 are invited to participate. Inclusion Criteria: Both parents and all four grandparents must be of either black African or African Caribbean ancestry. Arm 1: PSA only – once PSA is below an age-related threshold (aged 40-49 and PSA ≥0ng/ml, aged 50-69 PSA >/= 2ng/ml) they continue on the study with annual PSA, only triggering a prostate MRI and Biopsy if the PSA is above the threshold. Arm 2: Regardless of PSA men opt for prostate mpMRI and biopsy. Polygenic risk score (PRS) calculated based on 230 SNPs including latest AA specific variants. Results: Arm 1: 121 enrolled PSA only (this has triggered 8 biopsies with 3 cancers). Arm 2: 58 enrolled MRI and biopsy, 58 MRIs and 36 biopsies carried out, PrCa detected in 15 men (42%). 22% are Gleason score ≥7. Association between PRS and MRI/Biopsy results will be presented. Conclusions: We will continue to perform MRI and biopsies on men, we will also carry out polygenic risk scores on these men to verify whether a genetic PRS can help guide enhanced screening for certain men in the population. Although data are early, a significant proportion of biopsies are positive for PrCa that needs radical treatment. Clinical trial information: NCT02543905 .

Germline sequencing in men with metastatic castration-resistant prostate cancer from the BARCODE2 study reveals a wide range of pathogenic variants in DNA repair genes

BACKGROUND

The presence of germline mutations plays an increasingly important role in risk assessment and treatment of prostate cancer (PrCa). Screening for high-risk mutations in subsets of patients is becoming routine. We explore the prevalence of germline genetic mutations in men with metastatic castration-resistant prostate cancer (mCRPC) recruited to the BARCODE2 trial.

METHODS

The BARCODE2 trial is a two-part study investigating the response to carboplatin chemotherapy in mCRPC patients carrying a germline variant in a DNA repair gene (DRG). We report interim data from Part 1, in which participants are recruited for germline genetic testing using a customised next-generation sequencing panel consisting of 115 genes.

RESULTS

These interim results (N = 220) demonstrate a similar frequency of germline DRG variants in mCRPC patients compared with previously published data (15% detection rate). No significant clinical differences were identified between all carriers and non-carriers, though BRCA2/ATM carriers were found to have a shorter time to mCRPC diagnosis.

CONCLUSIONS

Germline pathogenic/likely pathogenic (P/LP) variants in BRCA2 and ATM genes are associated with a shorter time to progression and rarer P/LP variants in other DRG genes may play a role in mCRPC. This justifies the use of routine screening of men with advanced PrCa for germline variants and supports the need for an expanded panel test.