Effectiveness Of Three Strategies For The Management Of ASC-US Cytology In Healthcare Services Of Medellin, Colombia: Study Design Of A Pragmatic Randomized Trial (ASCUS-COL Trial) And Partial Results

Baena ARMANDO, School of Medicine, Universidad de Antioquia, Colombia
AGUDELO M. 1 , POSADA G. 2 , BUITRAGO C. 3 , GOMEZ L. 2 , JUAN O. 3 , PETER S. 4 , MARIBEL A. 5 , ROLANDO H. 5 , GLORIA S. 1

1 Infection and Cancer Group, School of Medicine, Universidad de Antioquia, Medellin, Colombia
2 Dinamica IPS, Medellin, Colombia
3 Clinica SOMA, Medellin, Colombia
4 Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
5 Prevention and Implementation Group, International Agency for Research on Cancer. Lyon, France

Purpose. To compare, under routine clinical conditions, three triage strategies in women with ASC-US cytology to reduce untreated CIN2/3+ at 2-years (effectiveness) and minimize healthcare utilization (efficiency). The strategies are: immediate colposcopy (IC-arm), repeat conventional cytology at 6/12 months (RC-arm) and HPV testing (HPV-arm).

Methods. Between 2011 and 2014, 20-69 years-old women from three healthcare management organizations (HMOs) in Medellin, Colombia, were enrolled, randomized in equal proportions and referred for routine colposcopy (IC-arm: everyone, RC-arm: if >=ASC-US and HPV-arm: if hrHPV+). All procedures, except HC2-HPV (QIAGEN©), were performed by HMOs. Women were scheduled to attend visits at 12 and 24 months (exit visit). Healthcare utilization data (number of cytologies, colposcopies and histologies) were retrieved from HMOs. Proportion ratios were used to compare healthcare utilization (relative utilization, RU) and rates of CIN2/3+ (relative risks, RR) identified by HMOs. Partial results within 15 months since the ASC-US index are presented under intention-to-treat principle.

Results. 2,661 women were randomized (IC-arm=882, RC-arm=890, HPV-arm=889). Twenty-seven percent in RC-arm had >=ASC-US and 41% in HPV-arm were hrHPV+. Compared to RC-arm, cytology utilization was similar in the IC-arm (RU=0.77, 95%CI 0.53-1.13) and lower in the HPV-arm (RU=0.64, 95%CI 0.58-0.69). Compared to IC-arm, colposcopy and histology utilization was lower in RC-arm (RU-colposcopy=0.44, 95%CI 0.41-0.48 and RU-histology=0.50, 95%CI 0.44-0.56) and HPV-arm (RU-colposcopy=0.58, 95%CI 0.54-0.62 and RU-histology=0.60, 95%CI 0.54-0.67). Although non-significant, the RRs of having a CIN2/3+ diagnosis suggest that RC-arm and HPV-arm identified 60-70% more cases than IC-arm (RR=1.6, 95%CI 0.8-3.0 and RR=1.7, 95%CI 0.9-3.2, respectively).

Conclusions. In these routine conditions, the follow-up of women with ASC-US cytology with repeat cytology or hrHPV testing identified same number of CIN2/3+ cases but with less colposcopy and histology utilization than immediate colposcopy.

Funding source. Fundación Pedro Nel Cardona, Estrategia Sostenibilidad, 2013-2014 -Universidad de Antioquia (CPT-9889-1208), COLCIENCIAS (1115-459-21657).