Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Public Health

First Advisor's Name

Consuelo Beck-Sague M.D.

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Virginia McCoy Ph. D.

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Purnima Madhivanan M.D. M.P.H. Ph.D.

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Eric Fenkle R.N. Ph.D.

Fourth Advisor's Committee Title

Committee member

Keywords

"Cervical cancer", VIA, screening, Guatemala, low-resource

Date of Defense

6-28-2018

Abstract

Cervical cancer, caused by oncogenic (high risk [hr]) human papillomavirus (HPV) subtypes, is the most common cancer in women in Guatemala and the most common cause of cancer mortality in women aged 15-44 years. Visual inspection with acetic acid (VIA) with onsite cryotherapy “test-and-treat” is recommended for underserved Guatemalan indigenous rural women. This research assessed: 1) hrHPV infection prevalence in women screened by VIA; 2) Sensitivity and specificity of VIA in detecting hrHPV infection and cytologically identified precancerous and cancerous lesions; and 3) Factors associated with hrHPV infection. Analysis of anonymous data collected during VIA clinics in 2013 (N = 205) and 2017 (N = 234) for indigenous women aged 21-65 years in six villages showed 22.6% (95% confidence interval [CI]=18.7%-27.2%) had hrHPV cervical infection. VIA results were abnormal in 5.9% (95%CI=3.8%-8.8%). Only nine VIA exams in 89 women with hrHPV were abnormal (Sensitivity=10.1%, 95%CI=4.7%-18.3%), although abnormal VIA was associated with hrHPV (Prevalence Ratio [PR])=1.8; 95%CI=1.1-3.1; P=.05). Of 221 women who had VIA, hrHPV nucleic acid testing and liquid preparation cytology (equivalent to Papanicolaou or “Pap”) testing, 10 (4.7% [95%CI=2.3%-8.5%]) had abnormal cytological results, including one cancer, four high- and five low-grade squamous intraepithelial lesions. VIA sensitivity and specificity for detection of precancerous cytological abnormalities and cancerous lesions were 20.0% (95%CI=2.5%-55.6%) and 96.0% (95%CI=92.3%-98.3%) respectively. In contrast, hrHPV sensitivity and specificity were 100% (95%CI=71.7%-100%) and 88.7% (95%CI: 83.9%-92.7%). In both years combined, women aged fewer than 29 years or reporting fewer than four pregnancies were more likely to have hrHPV cervical infection (36.8%, 27.3%, respectively) than those who were older or reported more pregnancies (18.7; P=.025, respectively); 60.0% reported some form of modern contraception. Progesterone injections or implant users were more likely to have hrHPV infection (31.9%) than women using other or no contraceptives (19.5%); PR=1.6; 95%CI=1.1-2.4; P=.01). These data suggest that VIA may not be sufficiently sensitive for use in cervical cancer screening. “Test-and-treat” screening using hrHPV real-time testing, as recommended by the World Health Organization may be preferable to VIA, and may be acceptable using self-collected specimens.

Identifier

FIDC006881

Available for download on Friday, July 19, 2019

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