Biomedical subjects

G B Dores

Publications and source records attributed to G B Dores.

3 recordsLinked to original sources

PubMed2006

Primary screening for cervical cancer through self sampling.

OBJECTIVE: To evaluate the use of community health agents (CHAs) to instruct women living in poor rural areas in obtaining self-collected cervical samples and compare the high-risk HPV (hrHPV) hybrid capture (HC) results obtained to those for gynecologist-collected samples. METHODS: After a one-day training, CHAs visited sexually active women, instructing each in the use of collection brush and the Universal Collection Medium tube. One week thereafter, a gynecologist collected cervical samples from, and performed colposcopies on, the same women. A single reference lab performed all HCs. RESULTS: 878 women (Age: 15-69 years) participated. Among self-collected samples, hrHPV prevalence was 33.9% (95% CI: 30.8%-37%), compared with 28.6% (95% CI: 27%-30%) among gynecologist-collected samples. However, 9.3% of the patients were HPV HC II-positive in the self-collected sample and HPV HC II-negative in the gynecologist-collected samples (95% CI: 7.38%-11.22%), whereas 4% tested positive in gynecologist-collected samples and negative in self-collected samples (95% CI: 2.7%-5.3%) (P<0.01; kappa=0.7). Of 9 cases of histologically-confirmed, high-grade squamous intraepithelial lesion, self-collected and provider-collected samples missed one each. CONCLUSION: Self-collected vaginal sampling could be made an additional CHA function under existing program conditions, improving access to cervical cancer screening in poor rural settings.

Adolescent↗

PubMed2005

Evaluation of visual inspection with acetic acid (VIA), Lugol's iodine (VILI), cervical cytology and HPV testing as cervical screening tools in Latin America. This report refers to partial results from the LAMS (Latin AMerican Screening) study.

OBJECTIVES: To assess the performance indicators of visual inspection with acetic acid (VIA) and visual inspection with Lugol's iodine (VILI) in four Latin American centres participating in the ongoing Latin AMerican Screening (LAMS) study, in settings with moderate incidence of cervical disease and with poorly to moderately well-organized cervical cancer screening. SETTING: Three Brazilian centres (São Paulo, Campinas and Porto Alegre) and one Argentine centre (Buenos Aires) recruited a total of 11,834 healthy women to undergo VIA, VILI, conventional Pap smear and Hybrid Capture II (HCII). METHODS: Women who had a positive result from any of these tests were subjected to colposcopy and biopsies (if necessary), and women with high-grade cervical intraepithelial neoplasia (CIN) were properly treated. To control for verification bias, 5% of women with normal tests were referred for colposcopy, as were 20% of HCII-negative women. RESULTS: Data on VIA (n=11,834), VILI (n=2994), conventional Pap smear (n=10,138) and HCII (n=4195) were available for test comparisons, calculating sensitivity, specificity, and positive and negative predictive values. Overall test positivity was 11.6% for VIA, 23.0% for VILI, 2.2% for Pap smear (LSIL threshold), 1.1% for Pap smear (HSIL threshold) and 17.1% for HCII. VIA was positive in 61.8% of the women with CIN 1, 57.0% of those with CIN 2, 35.0% of women with CIN 3 and in 21 of 28 (75%) of women with cancer. Approximately 10% of women with no detectable disease had an abnormal VIA. Regarding VILI, 83.3% of women diagnosed with CIN 1 and 62.5% of those with CIN 3 had an abnormal test. VILI failed to detect one of three cases of cancer. Both the sensitivity, specificity and positive predictive value of VIA and VILI in detecting CIN 2 or CIN 3 could be significantly improved depending on the combination with Pap smear or HCII (sensitivity up to 100.0% and specificity up to 99.8%). CONCLUSIONS: The LAMS study failed to reproduce the performance figures obtained with VIA and VILI (as stand-alone tests) in some other settings, where the prevalence of cervical disease was higher. However, a combined use of VIA or VILI with the Pap test or HCII allowed specific detection of cervical abnormalities.

Acetic Acid↗

PubMedDate not supplied

Comparing PAP smear cytology, aided visual inspection, screening colposcopy, cervicography and HPV testing as optional screening tools in Latin America. Study design and baseline data of the LAMS study.

OBJECTIVES: This is a European Commission (EC)-funded ongoing study known as the LAMS (Latin American Screening) study, where PAP smear/liquid-based cytology and screening colposcopy were compared with i) three optional screening tools [visual inspection with acetic acid (VIA), or Lugol's iodine (VILI), cervicography] and with ii) Hybrid Capture II from a) conventional samples and from b) self-samples, in women at different risk for cervical cancer in Brazil and Argentina. STUDY DESIGN: During 2002-2003, a cohort of 12,107 women attending four clinics: Campinas (CA), Sao Paulo (SP), Porto Alegre (PA) and Buenos Aires (BA), were interviewed for risk factors, and examined using the 8 diagnostic arms. Colposcopy was performed for women positive in any test and for 5% of women with baseline PAP-negative and 20% of HCII-negatives. All high-grade lesions (CIN2/3) were treated, and low-grade CIN are prospectively followed-up. RESULTS: Of the 12,107 women, the following baseline data are available: epidemiological data (n=11,996), conventional PAP smears (n=10,363), LBC, SurePATH (n=320), LBC, DNA-Citoliq (n=1,346), VIA (n=12.067), VILI (n=3,061), cervicography (n=279), screening colposcopy (n=3,437), HCII conventional (n=4,710), HCII self-sampling (n=246) and cervical biopsies (n=1,524). The four sub-cohorts differ significantly in all their baseline data on the implicated risk factors of cervical cancer, consonant with their origin from regions with different cancer incidence. Around 95% of all PAP smears were negative, with slight variations in the prevalence of LSIL and HSIL between the four centers. Significant differences were found in the detection rates of abnormal findings in VIA, VILI and colposcopy between the four centers (p=0.0001). The prevalence of HPV was practically identical (16.5-18.8%) in all four cohorts (p=0.486), with no differences in the relative viral loads. Biopsy results were different depending on whether the women underwent screening colposcopy (BA) or elective colposcopy (others). CONCLUSION: Four cohorts with significantly different baseline data are available, and prospective follow-up of these women permits analysis of whether variations in cervical cancer incidence in these regions is due to i) different natural history of the precursor lesions, or ii) due to different levels of exposure to the known risk factors.

Adult↗