Current Research Projects

Our research focuses on the early detection and prevention of colorectal cancer through increased screening, especially among medically underserved populations. Our current projects include evaluations of novel interventions to increase adherence to colorectal cancer screening and follow-up of abnormal results.

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Promoting Follow-up of Abnormal Colorectal Cancer Screening Tests through Multilevel Interventions (PROACT): In 2025, Dr. Issaka received a highly competitive NIH MERIT R37 grant to test a multicomponent strategy—including centralized tracking, navigation, patient-facing video education, and rideshare transportation—to improve completion of colonoscopy after abnormal stool-based tests among safety-net patients. This project directly targets a critical point along the cancer care continuum where safety-net patients and those from marginalized communities disproportionately fall through the cracks, aiming to reduce diagnostic delays and prevent avoidable colorectal cancer deaths.

A Video Decision Aid Decreases Fear of Colonoscopy After an Abnormal Fecal Immunochemical Test Result: A Pilot Study

Interventions to Increase Follow-Up of Abnormal Stool-Based Colorectal Cancer Screening Tests in Safety Net Settings: A Systematic Review

Barriers associated with inadequate follow-up of abnormal fecal immunochemical test results in a safety-net system: A mixed-methods analysis

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Modeled Cost-Effectiveness of a Rideshare Program to Facilitate Colonoscopy Completion

Health System-Provided Rideshare Is Safe and Addresses Barriers to Colonoscopy Completion

Operationalizing a Rideshare Intervention for Colonoscopy Completion: Barriers, Facilitators, and Process Recommendations

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Patient Perspectives on Barriers and Facilitators to 1-year Surveillance Colonoscopy Completion in Survivors of Colorectal Cancer: A Multimethod Analysis

Clinician perceptions on barriers and facilitators to 1-year surveillance colonoscopy completion in survivors of colorectal cancer

Association Between Patient-Level, Clinic-Level, and Geographical-Level Factors and 1-Year Surveillance Colonoscopy Adherence

Recent Publications

Fecal Immunochemical Test Completion by Instruction Type: A Randomized Clinical Trial Comparing Quick Response Code-Linked Video to Pictorial Instructions

The American Journal of Gastroenterology

2026 | Neha Naidoo; Ari Bell-Brown; Amanda Kimura; Nkem Akinsoto; Victoria Fang; Amy Peck; Jerry Wood; Rachel Issaka

Navigation activities in an organized colorectal cancer screening program improve follow-up colonoscopy completion

Scientific Reports

2026 | Amanda Kimura; Amy Peck, Ari Bell-Brown; Kaitlin Todd; Nkem O. Akinsoto; Victoria Fang; Jerry Wood; Rachel B. Issaka

Colorectal Cancer Test Completion among Adults Aged 45 to 75 in an Integrated Healthcare System: A Retrospective Analysis

Cancer Epidemiol Biomarkers Prev

2026 | Marina Hanna; Qin Sun; Ari Bell-Brown; Rachel Issaka

A Cell-free DNA Blood-Based Test for Colorectal Cancer Screening

N Engl J Med

2024 | Daniel Chung; Darrell Gray; Harminder Singh; Rachel Issaka; Victoria Raymond; Craig Eagle; Sylvia Hu; Darya Chudova; AmirAli Talasaz; Joel Greenson; Frank Sinicrope; Samir Gupta; William Grady