What cervical cancer screening method would you recommend in a low resource setting?

Source: National Cancer Institute \ Winship Cancer Institute of Emory University
Creator: Scott Wilkinson, Adam Marcus

We will be discussing Accuracy of combinations of visual inspection using acetic acid or Iugol Iodine to detect cervical precancer: A meta-analysis.  Catarino et al. BJOG 2017 on Wednesday 27 September, 8pm BST.

Scenario

You have been asked to develop a screening system for cervical cancer in a low income country.    What method do you recommend?

 Description of research

 

Participants 101,273 women participating in 23 studies in India (11 studies), Africa (9 studies), Oceania (one study) and Latin America (two studies)
Interventions Four strategies of cervical screening:

(1) visual inspection of the cervix with acetic acid (VIA);

(2) visual inspection with Iugol’s iodine (VILI);

(3) cotesting;

(4) VILI as a triage test of a positive VIA result.

Comparison Histology if a cervical biopsy was performed; colposcopy when no sample was taken
Outcomes Sensitivity and specificity of testing strategy
Study Design Diagnostic test accuracy meta-analysis

 

Discussion Points:

  • What are the described screening strategies? Do they differ from what you do in clinical practice?
  • What are the properties of an ideal screening test?
  • What is the relationship between sensitivity and specificity, and positive predictive value?
  • Most of the studies included were cross-sectional and prone to bias. What kinds of bias are discussed in this meta-analysis? Are there others you can think of? (1)
  • What other information would you like in order to answer the question in the scenario?
  • Imagine that a funder, hearing of the need for cancer screening in this country and the paucity of evidence, offers research funding for a trial to evaluate different methods. How would you design such a trial?

Suggested reading

Leeflang MMG, Deeks JJ, Gatsonis C, Bossuyt PMM, Cochrane Diagnostic Test Accuracy Working Group. Systematic reviews of diagnostic test accuracy. Ann Intern Med. NIH Public Access; 2008 Dec 16;149(12):889–97.