Bahia Public Health System Recorded 9,355 Precursor Lesions
- Severe cervical intraepithelial neoplasia accounted for nearly half of all histologically confirmed precursor lesions recorded in Bahia's public health system between 2014 and 2023.
- The study extracted data from the Department of Informatics of the Brazilian Unified Health System to track histopathological examinations for women aged 15 to 74 years.
- Annual counts remained low between 2014 and 2016, ranging from 40 to 104 examinations per year during the implementation phase of the database module.
Severe cervical intraepithelial neoplasia accounted for nearly half of all histologically confirmed precursor lesions recorded in Bahia’s public health system between 2014 and 2023. Researchers analyzing data from the Cancer Information System found that CIN 3 represented 45.9% of the 9,355 total diagnoses recorded during the period, highlighting patterns of disease severity across the Brazilian state.
Distribution of Precursor Lesions in Bahia Public Health Data
The study extracted data from the Department of Informatics of the Brazilian Unified Health System to track histopathological examinations for women aged 15 to 74 years. Out of the 9,355 total examinations evaluated in the public health network, CIN 1 accounted for 2,990 cases, or 32.0%, while CIN 2 represented 2,072 cases, or 22.1%. CIN 3 comprised the largest share at 4,293 cases.
Annual counts remained low between 2014 and 2016, ranging from 40 to 104 examinations per year during the implementation phase of the database module. Volumes exceeded 1,000 examinations annually starting in 2017, reaching a peak of 1,664 examinations in 2019 before dropping 38.3% to 1,026 examinations in 2020. Counts subsequently recovered to 1,676 examinations by 2023.
Shifts in Proportions and Screening Volumes
Following the full implementation of the screening registry, the proportion of CIN 3 diagnoses shifted upward. The proportion was 40.6% from 2017 through 2019, climbing to 50.3% for the 2020–2023 period with an odds ratio of 1.48.
Researchers determined that this proportional increase was driven largely by a drop in recorded CIN 1 examinations. Rates for CIN 1 fell from 9.5 to 6.7 per 10,000 cytology examinations, while CIN 3 rates moved from 10.5 to 12.1 per 10,000 cytology examinations.
Age Distribution and Vaccination Timeline Factors
Women aged 25 to 44 years formed the majority of severe diagnoses, accounting for 71.6% of all CIN 3 examinations in the public network. Younger women aged 15 to 24 years experienced a measurable decline in their share of CIN 1 and CIN 2 examinations.
That drop among younger cohorts mirrored a broader reduction in overall screening volume for women under 25, whose share of total cytology examinations fell from 16.0% to 11.7%. Researchers noted that while the trend could potentially reflect early population-level impacts from the national human papillomavirus vaccination program launched in 2014, reduced screening participation among younger women remains an equally plausible explanation.