FALSE POSITIVE RATE OF SCREENING MAMMOGRAM IN DETECTING BREAST CANCERAT A TERTIARY CARE HOSPITAL, OVER THE LAST 24 MONTHS

Abstract

BACKGROUND

Breast cancer is among the world's leading cause of morbidity and mortality in women, and thus early detection is crucial for improved outcomes. Mammography is the most widely used screening modality. But false positive results, which falsely indicate the presence of cancer, can result in unwarranted interventional procedures, psychological morbidity, and increased healthcare expenditure. The aim of this study is to evaluate the false positive rate (FPR) of mammograms done in the last 24 months at a tertiary care center.

OBJECTIVE

To find out the false positive rate of screening mammogram in diagnosing breast cancer in a tertiary care hospital for the past 24 months and to measure its impact on patient management and screening effectiveness.

METHODS

After obtaining permission from ethical review committee, Jinnah post graduate medical centre (JPMC). Retrospective cohort study was conducted, comparing the data of all women over 39 years old who underwent screening mammography in the hospital in the last 24 months, excluding patients with known or previous history of breast cancer.Data were extracted from the Radiology department-JPMC, Karachi.Positive initial mammography results (BI-RADS 4 or 5) followed by no diagnosis of cancer on further investigation like ultrasound or MRI breast and biopsy if conducted was defined as False positive mammogram. Statistical analysis of descriptive statistics was evaluated and Chi-square test was applied to compare FPR across subgroups, including family history, perimenopausal (40 – 45 years) and menopausal status keeping p-value less than 0.05 as significant.

RESULTS

Total 277 participants were included in the study,out of which 96.4% women underwent bilateral mammography and rest 3.6% unilateral mammography. The majority(62.8%) were postmenopausal, and 97.5% had no breast cancer in family. Diagnostic outcomes showed that most cases (48.7%) were classified as BI-RADS II (benign), and 68.2% were true negatives, with 17.3% false positives and 14.4% false negatives. Subgroup analysis revealed that individuals with a positive breast cancer family history had slightly higher false positive rate (28.6%) compared to those with a negative family history (17.0%), though the difference was not statistically significant. Similarly, there was no significant difference in false positive results between perimenopausal and postmenopausal age groups (P=0.223).

CONCLUSION

In conclusion, the study emphasizes the effectiveness of mammography in identifying breast abnormalities, with most results being benign or normal. While some false positives and false negatives occurred, these findings underscore the importance of further diagnostic evaluation. The study also suggests that family history and age have little impact on mammography outcomes, highlighting the need for continued improvements in screening practices to enhance accuracy and ensure better patient care.

KEY WORDS: Breast cancer, mammography, false positive rate, screening efficacy, patient management.