P-36 Characteristics and Trends of Breast Biopsy Methods in Guyana: A Retrospective Cross-Sectional Study.

Methods: A retrospective cross-sectional quantitative study was done using a selected histopathology laboratory. The study participants consisted of all females (≥13 years) who underwent a breast biopsy in Guyana between January 1st, 2016, and May 31st, 2023. Data were collected via a standardized form and analyzed using SPSS v26. Descriptive statistics were used to summarize prevalence, temporal and regional trends of biopsy methods; 2x2 contingency tables for associations between biopsy method and histopathological outcome. A p-value of <0.05 was considered statistically significant.

Results: Electronic Medical Records (n=2863) were analyzed. Most breast biopsies were done in the 50+ age group (n=938, 32.8%), particularly in Region 4 (n=2309, 80.6%). Open breast biopsy (OBB) rates (57.3%) far exceeded that of Fine needle aspiration biopsy (FNAB, 30.0%) and Core needle biopsy (CNB, 12.7%). Temporal trends revealed a rise in CNB usage but decline in FNAB and OBB usage over the study period. Most breast biopsies were benign (n=1804, 63%). The odds ratio for an inconclusive outcome with FNAB compared to non-FNAB methods (CNB and OBB) was 7.1 (95% CI: 5.3 9.4, p<0.001), indicating a significantly higher likelihood. Similarly, CNB was associated with a higher likelihood of malignant outcomes, with an odds ratio of 1.4 (95% CI: 1.1–1.8, p=0.007) compared to non-CNB methods (FNAB and OBB).

Conclusion: Overwhelming OBB rates were mitigated by positive temporal trends with a rise in CNB, potentially aligning with international standards. The majority of benign outcomes and FNA’s link to inconclusive results emphasize the need for minimally invasive techniques, particularly CNB. Ongoing education and upgraded diagnostic resources are necessary to optimize breast biopsy practices in Guyana.