Abstract P2-13-20: Conditional survival of female breast cancer patients by treatment patterns: Evidence from the Korean nationwide registry
Authors: Eun Jin Song, So-Youn Jung, Young Ae Kim, Sun-Young Kong, Eun Sook Lee, Eun-Gyeong Lee, Heein Jo, Jae Hong Han, Seeyoun Lee, Han-Sung Kang
Journal: Cancer Research (2020)

Abstract Objective: With the development of breast cancer treatment, the prognosis of breast cancer patients is getting better over time. Breast cancer patients want to get accurate information about prognosis according to the treatment pattern. In this study, we investigated the 5-year Conditiona relative survival (CRS) of Korean female breast cancer patients. Materials and Methods: The data from this study was collected from the Korean Central Cancer Registry (KCCR) data, National Health Insurance Service (NHIS) data and Korean Statistical Information Service (KOSIS) data to certify relative survival and conditional relative survival for the female patients of breast cancer in the Korea. We identified 141,779 female breast cancer cases diagnosed between 2002 and 2013. The CRS was estimated for every year after diagnosis, according to age, stage at diagnosis, histologic type, year at diagnosis and treatment patterns within 1year after diagnosis. Results: The 5-year RS at diagnosis was 91.0% and the 10-year RS was 85.9%. The 5-year CRS was 91.1% and 94.3% at 1 year and 5 years after diagnosis, respectively. Very young and very old patients had worse 5-year CRS after 5 years of survival than those of other age groups (89.6% in the &amp;lt;40-year and 84.4% in the ≥70-year groups vs. 92.6% in 40-54-year, and 90.3% in 55-69-year groups). Patients who underwent surgery within one year after diagnosis of breast cancer showed better 5-year CRS than those who did not (94.0% vs 65.6%). The 5-year CRS was 91.8% and 89.9% according to whether systemic therapy (chemotherapy and targeted therapy) was performed after diagnosis of breast cancer. The 5-year CRS of the anti-hormone treatment group was 95.2%, which was higher than that of the non-hormone treatment group. In the group without antihormonal therapy, there was a different 5-year CRS according to the histological characteristics (89.8% in NST type, 83.5% in lobular type, 97.3% in mucinous type, 98.5% in medullary type and 86.3% in metaplastic type). Conclusions: This study shows that the improvement pattern of CRS may vary according to age group, treatment pattern, and histologic type. In the group without antihormone therapy, the histologic type seems to be a different aspect of CRS, which is useful information for clinicians and patients. Key words: conditional survival, breast cancer, histology, age, stage, treatment pattern Citation Format: Eun Jin Song, So-Youn Jung, Young Ae Kim, Sun-Young Kong, Eun Sook Lee, Eun-Gyeong Lee, Heein Jo, Jae Hong Han, Seeyoun Lee, Han-Sung Kang. Conditional survival of female breast cancer patients by treatment patterns: Evidence from the Korean nationwide registry [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-13-20.