Evaluation of breast cancer screening results of women who applied to the cancer screening center in İlkadım district of Samsun province between 2018 and 2023

Aim: This study aims to retrospectively analyze the screening results, pathological findings, diagnoses, and treatment methods of women who applied to the Cancer Early Diagnosis, Screening, and Training Center (KETEM) in İlkadım district of Samsun for breast cancer screening between January 2018 and March 2023. Material and Method: This study is a cross-sectional and retrospective study, including all 26,413 women in the population; therefore, no sample size calculation was performed. Mammographic breast cancer screening was evaluated using the BIRADS classification, and the data were analyzed using IBM SPSS 26.0. The relationships between categorical variables were examined using the Pearson ChiSquare Test. Based on screening and diagnostic data, the true positive rate, false positive rate, positive predictive values (PPV1, PPV2, PPV3), minimal cancer detection rate were calculated. Results: Distribution of Screenings: 34.9% of the screenings were conducted in 2018, 32.0% in 2019, 8.5% in 2020, 2.9% in 2021, 17.2% in 2022, and 4.5% in the first three months of 2023. A significant decline in screening rates was observed during the pandemic years (2020-2021). Age Distribution: Among the screened women, 45.0% were aged 40-49, 36.8% were aged 50-59, and 18.2% were aged 60-69. The mean age was calculated as 51.6 years. Breast Density Distribution: 43.6% of the women had B-type breast density, 41.1% had C-type, 8.8% had A-type, and 6.4% had D-type breast density. BIRADS Distribution in Screening Results: 92.4% were categorized as BIRADS 1-2, 6.8% were classified as BIRADS 0 and referred for further evaluation, while 0.5% were reported as BIRADS 4 and 0.3% as BIRADS 5. Ultrasound (USG) Findings: Among women categorized as BIRADS 4 and 5, malignancy was detected in 69.3% of cases. Lymphoma was identified in 0.1% of cases. Biopsy and Pathology Results: Among 176 biopsies, 69.3% were diagnosed as malignant breast lesions, while 30.7% were benign. The most common malignancy type was invasive ductal carcinoma (84.4%). The overall cancer detection rate was 4.6 per 1000 women. Cancer Staging: 67.2% of detected cancers were in the early stage, 23.8% were locally advanced, and 9.0% were metastatic. Cancer Subtypes: 57.4% of ix cases were classified as Luminal A, 36.1% as Luminal B, 4.1% as Basal-like, and 2.5% as HER2+. Tumor Size and Surgical Approaches: 60.7% of cancers were detected at ≤2 cm, with a minimal cancer detection rate of 11.5%. Breast-conserving surgery was performed in 62.3% of cases, while 26.2% underwent modified radical mastectomy. Treatment Modalities: 95.9% of patients received radiotherapy, and 62.3% underwent chemotherapy. Mortality Rate: During the treatment process, 5.7% of the patients succumbed to the disease. Positive Predictive Values (PPV): PPV1: 6.1%, PPV2: 69.3%, PPV3: 69.3% Conclusion: This study evaluated the effectiveness of breast cancer screening programs, the impact of the pandemic on screenings, and the distribution of results. The findings indicate that screenings conducted at KETEMs are effective in increasing early-stage diagnosis rates. It has been observed that interruptions in screening during the pandemic period may lead to an increase in advanced-stage cases. The high recall rates in individuals with dense breast tissue and in younger age groups suggest the need for additional imaging methods such as ultrasound alongside mammography. Furthermore, it has been confirmed that BIRADS 4 and 5 categories are associated with a high risk of cancer.In conclusion, ensuring the continuity of screening programs and increasing public awareness are critical to strengthening early diagnosis success. Keywords: KETEM, Breast Cancer, Mammography, Screening Program