OCOliver Clark

Oliver Clark

*This is an algorithmically generated author record based on publicly available information.

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Oliver Clark has a total of 40 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Cross-Ancestry and Phenome-Wide Associations of Cancer-Specific Polygenic Risk Scores

    by Louise Wang, Heena Desai, Craig Teerlink, Oliver Clark, Kathryn M. Pridgen, Jennifer Lee, Kyong-Mi Chang, Rachel L. Kember, Marijana Vujkovic, Julie A. Lynch, et al.

    Purpose: Genome-wide association studies have identified many common variants associated at low effect sizes with various cancers. Summing the effects of these variants into polygenic risk scores (PRS) can improve cancer risk prediction. However, cross-cancer and cross-phenotype pleiotropic associations of cancer-specific PRS are limited. Methods: Using logistic regression models, we tested the association of 13 cancer-specific PRS with curated phenotypes representing the same 13 cancers and 340 cancer and cardiometabolic phecodes in 560,287 individuals (114,255 African ancestry [AFR] and 446,032 European ancestry [EUR]) from the Million Veteran Program. Models were stratified by ancestry and used age, principal components, and cancer-specific PRS per standard deviation as independent variables, and correction was applied for multiple comparisons. Results: All 13 cancer-specific PRS were significantly associated with their respective cancers among EUR individuals with odds ratios per standard deviation of PRS (odds ratio [OR]) 1.05-1.70. Among AFR individuals, the effect sizes of the cancer PRS were lower, with OR 1.01-1.48, and cancer-specific PRS were significantly associated with their respective cancers for five of 13 cancers (bladder, breast in female patients, colorectal, prostate, and thyroid). In cancer-cancer pleiotropy studies, only the renal cancer-specific PRS was significantly associated with skin cancer (OR = 1.04, P = 4.5 × 10 –06 ) among EUR individuals. PheWAS demonstrated five positive pleotropic associations with cardiometabolic conditions (thyroid cancer PRS with thyroid goiter, oral cancer PRS with diabetes phenotypes, and hypothyroidism) and two negative associations (oral and lung cancer PRS separately with coronary artery disease). Conclusion: Cancer PRS have stronger associations per cancer among EUR versus AFR individuals. In contrast to PRS of other chronic diseases, the majority of cancer-related PRS are highly specific and pleiotropic associations with other cancers and cardiometabolic traits are uncommon.

  • Non-invasive neuromodulation in the acute treatment of migraine: a systematic review and meta-analysis of randomized controlled trials

    by Oliver Clark, Areej Mahjoub, Nily Osman, Ann-Marie Surmava, Saber Jan, Ana Marissa Lagman-Bartolome

    Objective A systematic review and meta-analysis was performed to determine the efficacy of non-invasive neuromodulation modalities for the treatment of acute migraine. Background Although pharmacological treatments are the gold standard for the management of acute migraine, some patients may require non-pharmacological treatment options. Non-invasive neuromodulation may provide an alternative, and techniques include transcranial magnetic stimulation (TMS), non-invasive vagal nerve stimulation (nVNS), non-painful remote electrical stimulation (NRES), and external trigeminal nerve stimulation (e-TNS). Methods This systematic review and meta-analysis was performed following PRISMA guidelines. We searched PUBMED, EMBASE, ClinicalTrials.gov, Cochrane Center Register of Controlled Trials, and LILACS databases. We included randomized controlled clinical trials studying patients with migraine treated with any form of non-invasive neuromodulation. Primary outcome was pain freedom within 2 h post-treatment. Secondary outcomes were pain relief within 2-h post-treatment and sustained pain freedom and sustained pain relief 48 h post-treatment. Results Pooled analysis demonstrated a significant effect of non-invasive neuromodulation on pain-free rates within 2 h (RR, 1.66; 95% CI, 1.35 to 2.05; P < 0.00001) and pain relief rates within 2 h (RR, 1.52; 95% CI, 1.13 to 2.05; P = 0.005) post-treatment. Non-invasive neuromodulation had no significant effect on sustained pain freedom at 48 h (RR, 1.56; 95% CI, 0.68 to 3.59; P = 0.29) or sustained pain relief at 48 h (RR, 1.47; 95% CI, 0.57 to 3.77; P = 0.43) after administration. Conclusion Neuromodulation has demonstrated some efficacy in acute migraine management and may be considered in the treatment paradigm of acute migraine in patients with contraindications to pharmacological therapies.