title: Breast cancer-specific mortality in small-sized tumor with node-positive breast cancer: a nation-wide study in Korean breast cancer society.
abstract: Tumor size and number of lymph node (LN) metastases are well known as the most important prognostic factors of breast cancer. We hypothesized that very small breast cancers with LN metastasis represent a progressive biologic behavior and evaluated tumor size stratified by LN metastasis. Data between 1990 and 2010 were obtained retrospectively from the Korean Breast Cancer Society Registry with inclusion criteria of female, non-metastatic, unilateral, and T1/2 breast cancer. We collected the following variables: age at surgery, tumor size, number of LN metastases, nuclear grade (NG), lymphovascular invasion (LVI), estrogen receptor status, progesterone receptor status, and epidermal growth factor receptor-2 status. Patient characteristics were compared by means of independent t-tests for continuous variables and the Chi-square or Fisher's exact test for categorical variables. Kaplan-Meier curves, with corresponding results of log-rank tests, were constructed for breast cancer-specific survival (BCSS). Five- and eight-year breast cancer-specific mortality (BCSM) was obtained in groups of 300 patients, followed by smoothing according to the confidence interval using the lowess method. We identified 39,826 breast cancer patients who met the inclusion criteria. Among them, 1433 (3.6 %) patients died due to breast cancer. The median follow-up duration was 63.4 (3-255) months. In the multivariate analysis, age at surgery, NG, LVI, subtype, and tumor size-nodal interactions were independently associated with BCSM. The N1 group had lower BCSS for T1a than T1b. The N2+ group also had lower BCSS for T1b than T1c or T2. In the N1 group of tumors smaller than 10 mm, 5- and 8-year BCSM decreased with larger tumor size. Patients with very small tumors with LN metastasis have decreased BCSM according to increase tumor size. Small tumors with LN metastasis could have aggressive biological behavior.
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea.
authors: Jai Min
authors: JM
authors: Ryu
authors: Department of Surgery, Saegyaero Hospital, Busan, South Korea.
authors: Hyouk Jin
authors: HJ
authors: Lee
authors: Division of Breast and Endocrine Surgery, Department of Surgery, University of Ulsan, College of Medicine, Asan Medical Center, Seoul, South Korea.
authors: Tae In
authors: TI
authors: Yoon
authors: Center for Breast Cancer, National Cancer Center, Goyang, South Korea.
authors: Eun Sook
authors: ES
authors: Lee
authors: Department of Surgery, Yeungnam University Hospital, Daegu, South Korea.
authors: Soo Jung
authors: SJ
authors: Lee
authors: Department of Surgery, Kyungpook National University School of Medicine, Daegu, South Korea.
authors: Jin Hyang
authors: JH
authors: Jung
authors: Department of Surgery, Seoul St. Mary's Hospital and Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors: Byung Joo
authors: BJ
authors: Chae
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea.
authors: Seok Jin
authors: SJ
authors: Nam
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea.
authors: Jeong Eon
authors: JE
authors: Lee
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea.
authors: Se Kyung
authors: SK
authors: Lee
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea.
authors: Soo Youn
authors: SY
authors: Bae
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea.
authors: Jonghan
authors: J
authors: Yu
authors: Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center Hospital, Sungkyunkwan University School of Medicine, 5th Floor Breast-Endocrine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea. seokwon.kim@samsung.com.
authors: Seok Won
authors: SW
authors: Kim
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D012042:Registries; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D047368:Tumor Burden
keywords: Breast neoplasm; Lymph node; Mortality