May Lab

Colorectal Cancer Prevention and Control

Two fellows in front of poster for Colon Cancer Prevention
Fellows in front of DDW Sign

Colorectal cancer is the third-most common malignancy in the United States and the second-leading cause of cancer-related mortality.

Although screening is universally recommended in the United States, screening rates are low nationally and among racial and ethnic minorities.

The May Laboratory works with collaborators in public health, informatics, general internal medicine, and biostatistics to design and implement interventions to increase uptake of colorectal cancer screening and to improve completion of diagnostic follow-up when screening is abnormal.
 
Research in this area also includes analyses utilizing publicly available national- and state-level databases to evaluate screening rates and cancer outcomes.

The portfolio of work encompass both health disparities research and health systems quality improvement research, but goes beyond.

Collaborations

  • Roshan Bastani, PhD, Professor, Health Policy and Management
  • Beth Glenn, PhD, Associate Professor, Health Policy and Management
  • Allison Hermann, PhD, Associate Director, Center for Health Equity, Health Equity

Grants

  1. NIH/NCI R01: Multilevel health system intervention to increase surveillance colonoscopy for high-risk colorectal polyps (PI)
  2. Veterans Health Administration; Merit Award: Surveillance Colonoscopy in Older Adults: The SurvOlderAdults Study (Co-PI with Samir Gupta, UCSD)
  3. NIH/NRG FORTE Study: Five or Ten Year Colonoscopy for 1-2 Non-Advanced Adenomatous Polyps (Site PI)
  4. Stand Up to Cancer Colorectal Cancer Health Equity Dream Team: Community Collaboration to Advance Racial/Ethnic Equity in CRC Screening (CARES) (Co-PI with Jennifer Haas, MGH)
  5. Exact Sciences; “A Longitudinal Study of CologuardTM in an Average Risk Population Assessing a Three Year Test Interval” (site PI)
  6. UCLA Jonsson Cancer Center Foundation Seed Grant; “A Community-Academic Partnership to Improve Colorectal Cancer Screening in South Los Angeles” (PI)
  7. Charles Drew University-UCLA Cancer Center Partnership to Eliminate Cancer Health Disparities Seed Grant; “A Community Partnership to Improve Follow-up After Positive Colorectal Cancer Screening” (PI)
  8. National Cancer Institute: “Follow-up of Abnormal Findings on Colorectal Cancer Screening in a Federally Qualified Health Center: The Role of System-Level Clinical Care Processes"

Selected publications

View full list of May Lab publications

  1. Gupta S, Liu L, Demb J, Qin J, Earles A, Lamm M, Huang X, Shah SC, Chawla N, Le Y, Burns Loeb T, Dominitz JA, Robertson DJ, Schoenborn NL, Calderwood AH, Levin TR, Seligman BJ, May FP. Colorectal cancer and mortality risk among older adults with vs without adenoma on prior colonoscopy. JAMA. April 9, 2026
  2. Galoosian A, Dai H, Croymans D, Saccardo S, Fox CR, Goshgarian G, De Silva S, Han MA, Vangala S, May FP. Population health colorectal cancer screening strategies in adults aged 45 to 49 years. JAMA. August 4, 2025
  3. Zaki TA, Zhang NJ, Forbes SP, Raymond VM, Das AK, May FP. Colonoscopic follow-up after abnormal blood-based colorectal cancer screenings. Gastroenterology. July 29, 2025
  4. May FP, Mehtsun WT, Jemal A & Gupta S. Black-White disparities across the colorectal care continuum in the USA. Nature Reviews Gastroenterology & Hepatology. 21 July 2025
  5. Alagoz O, May FP, Doubeni CA, Fendrick AM, Vahdat V, Estes C, Ellis T, Limburg PJ, Brooks D. Impact of racial disparities in follow-up and quality of colonoscopy on colorectal cancer outcomes. JNCI. 24 July 2024
  6. Rutter CM, Nascimento de Lima P, Maerzluft CE, May FP, Murphy CC. Black-White disparities in colorectal cancer outcomes: A simulation study of screening benefit. JNCI Monographs. November 2023
  7. Uche-Anya E, Anyane-Yeboa A, Berzin TM, Ghassemi M, May FP. Artificial intelligence in gastroenterology and hepatology: how to advance clinical practice while ensuring health equity. Gut. 2022 Sep;71(9):1909-1915. doi: 10.1136/gutjnl-2021-326271. Epub 2022 Jun 10. PMID: 35688612
  8. Peterson E, May FP, Kachikian O, Soroudi C, Naini B, Kang Y, Myint A, Guyant G, Elmore J, Bastani R, Maehara C, Hsu W. Automated identification and assignment of colonoscopy surveillance recommendations for individuals with colorectal polyps. Gastrointest Endosc. 2021 Nov;94(5):978-987. doi: 10.1016/j.gie.2021.05.036. Epub 2021 Jun 1. PMID: 34087201
  9. Ng K, May FP, Schrag D. US Preventive Services Task Force Recommendations for Colorectal Cancer Screening: Forty-Five Is the New Fifty. JAMA. 2021 May 18;325(19):1943-1945. doi: 10.1001/jama.2021.4133. PMID: 34003238
  10. San Miguel Y, Demb J, Martinez ME, Gupta S, May FP. Time to Colonoscopy After Abnormal Stool-Based Screening and Risk for Colorectal Cancer Incidence and Mortality. Gastroenterology. 2021 May;160(6):1997-2005.e3. doi: 10.1053/j.gastro.2021.01.219. Epub 2021 Feb 2. PMID: 33545140; PMCID: PMC8096663
  11. Bui A, Yang L, Myint A, May FP. Race, Ethnicity, and Socioeconomic Status Are Associated With Prolonged Time to Treatment After a Diagnosis of Colorectal Cancer: A Large Population-Based Study. Gastroenterology. 2021 Mar;160(4):1394-1396.e3. doi: 10.1053/j.gastro.2020.10.010. Epub 2020 Oct 12. PMID: 33058864; PMCID: PMC7956146
  12. May FP, Yang L, Corona E, Glenn BA, Bastani R. Disparities in Colorectal Cancer Screening in the United States Before and After Implementation of the Affordable Care Act. Clin Gastroenterol Hepatol. 2019 Sep 13;. doi: 10.1016/j.cgh.2019.09.008. [Epub ahead of print] PubMed PMID: 31525514
  13. Bharti B, May FFP, Nodora J, Martinez ME, Moyano K, Davis SL, Ramers CB, Garcia-Bigley F, O'Connell S, Ronan K, Barajas M, Gordon S, Diaz G, Ceja E, Powers M, Arredondo EM, Gupta S. Diagnostic colonoscopy completion after abnormal fecal immunochemical testing and quality of tests used at 8 Federally Qualified Health Centers in Southern California: Opportunities for improving screening outcomes.Cancer. 2019 Sep 3;. doi: 10.1002/cncr.32440. [Epub ahead of print] PubMed PMID: 31479529
  14. May FP, Yano EM, Provenzale D, Brunner J, Yu C, Phan J, Bharath P, Aby E, Dinh D, Ehrlich DS, Storage T, Lin LD, Jamaluddin NN, Washington DL. Barriers to Follow-up Colonoscopies for Patients with Positive Results from Fecal Immunochemical Tests During Colorectal Cancer Screening. Clin Gastroenterol Hepatol. 2018 May 29 pii: S1542-3565(18)30554-8. doi: 10.1016/j.cgh.2018.05.022. PMID: 29857147
  15. May FP, Yano EM, Provenzale D, Neil Steers W, Washington DL. The Association Between Primary Source of Healthcare Coverage and Colorectal Cancer Screening Among US Veterans. Dig Dis Sci. 2017 Aug;62(8):1923-1932
  16. May FP, Glen B, Crespi C, Spiegel B, Ponce N, Bastani R. Decreasing black-white disparities in colorectal cancer incidence and stage at presentation in the United States. Cancer Epidemiol Biomarkers Prev. 2016 Dec. 2017 May;26(5):762-768. PMID: 28035021
  17. May FP, Almario C, Ponce N, Spiegel BM. Racial minorities are more likely than whites to report lack of provider recommendation for colon cancer screening. Am J Gastroenterol. 2015 Oct;110(10):1388-94. doi: 10.1038/ajg.2015.138. Epub 2015 May 12
  18. May FP, Bromley EG, Baek M, Yoon J, Cohen E, Lee A, Reid MW, van Oijen MG, Spiegel BM. Low uptake of colorectal cancer screening among African-Americans in an integrated Veterans Affairs health care network. Gastrointest Endosc. 2014 Aug; 80(2):291-8. doi: 10.1016/j.gie.2014.01.045. Epub 2014 Mar 25. PMID: 24674351