Occurrence of Distal Colorectal Neoplasia Among Whites and Blacks Following Negative Flexible Sigmoidoscopy: An Analysis of PLCO Trial

Adeyinka O. Laiyemo, Chyke Doubeni, Paul F. Pinsky, V. Paul Doria-Rose, Robert Bresalier, Thomas Hickey, Thomas Riley, Tim R. Church, Joel Weissfeld, Robert E. Schoen, Pamela M. Marcus, Philip C. Prorok

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


BACKGROUND: It is unclear whether the higher rate of colorectal cancer (CRC) among non-Hispanic blacks (blacks) is due to lower rates of CRC screening or greater biologic risk. OBJECTIVE: We aimed to evaluate whether blacks are more likely than non-Hispanic whites (whites) to develop distal colon neoplasia (adenoma and/or cancer) after negative flexible sigmoidoscopy (FSG). DESIGN: We analyzed data of participants with negative FSGs at baseline in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial who underwent repeat FSGs 3 or 5 years later. Subjects with polyps or masses were referred to their physicians for diagnostic colonoscopy. We collected and reviewed the records of diagnostic evaluations. PARTICIPANTS: Our analytic cohort consisted of 21,550 whites and 975 blacks. MAIN MEASURES: We did a comparison by race (whites vs. blacks) in the findings of polyps or masses at repeat FSG, the follow-up of abnormal test results and the detection of colorectal neoplasia at diagnostic colonoscopy. KEY RESULTS: At the follow-up FSG examination, 304 blacks (31.2 %) and 4183 whites (19.4 %) had abnormal FSG, [adjusted relative risk (RR) = 1.00; 95 % confidence interval (CI), 0.90–1.10]. However, blacks were less likely to undergo diagnostic colonoscopy (76.6 % vs. 83.1 %; RR = 0.90; 95 % CI, 0.84–0.96). Among all included patients, blacks had similar risk of any distal adenoma (RR = 0.86; 95 % CI, 0.65–1.14) and distal advanced adenoma (RR = 1.01; 95 % CI, 0.60–1.68). Similar results were obtained when we restricted our analysis to compliant subjects who underwent diagnostic colonoscopy (RR = 1.01; 95 % CI, 0.80–1.29) for any distal adenoma and (RR = 1.18; 95 % CI, 0.73–1.92) for distal advanced adenoma. CONCLUSIONS: We did not find any differences between blacks and whites in the risk of distal colorectal adenoma 3–5 years after negative FSG. However, follow-up evaluations were lower among blacks.

Original languageEnglish (US)
Pages (from-to)1447-1453
Number of pages7
JournalJournal of general internal medicine
Issue number10
StatePublished - Oct 29 2015

Bibliographical note

Publisher Copyright:
© 2015, Society of General Internal Medicine.


  • PLCO
  • adenomatous polyps
  • colorectal cancer disparities
  • flexible sigmoidoscopy
  • screening


Dive into the research topics of 'Occurrence of Distal Colorectal Neoplasia Among Whites and Blacks Following Negative Flexible Sigmoidoscopy: An Analysis of PLCO Trial'. Together they form a unique fingerprint.

Cite this