Kwon et al. BMC Cancer 2010, 10:557 http://www.biomedcentral.com/1471-2407/10/557 R E S E A R C H A R T I C L E Open Access Triple negativity and young age as prognostic factors in lymph node-negative invasive ductal carcinoma of 1 cm or less Ji Hyun Kwon1,2, Yu Jung Kim1, Keun-Wook Lee1, Do-Youn Oh2, So Yeon Park3, Jee Hyun Kim1*, Eui Kyu Chie4, Sung-Won Kim5, Seock-Ah Im2, In-Ah Kim6, Tae-You Kim2, In Ae Park7, Dong-Young Noh8, Yung-Jue Bang2, Sung Whan Ha4 Abstract Background: Whether a systemic adjuvant treatment is needed is an area of controversy in patients with node- negative early breast cancer with tumor size of ≤1 cm, including T1mic. Methods: We performed a retrospective analysis of clinical and pathology data of all consecutive patients with node-negative T1mic, T1a, and T1b invasive ductal carcinoma who received surgery between Jan 2000 and Dec 2006. The recurrence free survival (RFS) and risk factors for recurrence were identified. Results: Out of 3889 patients diagnosed with breast cancer, 375 patients were enrolled (T1mic:120, T1a:93, T1b:162). Median age at diagnosis was 49. After a median follow up of 60.8 months, 12 patients developed recurrences (T1mic:4 (3.3%), T1a:2 (2.2%), T1b:6 (3.7%)), with a five-year cumulative RFS rate of 97.2%. Distant recurrence was identified in three patients. Age younger than 35 years (HR 4.91; 95% CI 1.014-23.763, p = 0.048) and triple negative disease (HR 4.93; 95% CI 1.312-18.519, p = 0.018) were significantly associated with a higher rate of recurrence. HER2 overexpression, Ki-67, and p53 status did not affect RFS. Conclusions: Prognosis of node-negative breast cancer with T1mic, T1a and T1b is excellent, but patients under 35 years of age or with triple negative disease have a relatively high risk of recurrence. Background Owing to the increased use of screening mammogra- phy, the proportion of early stage breast cancer is increasing internationally [1-3]. In Korea, an increase in the percentage of stage 0 and I types of breast can- cer has also been reported. The proportion of stage 0 breast cancer was 7.5% in 2002 and increased to 11.3% in 2003. For stage I breast cancer, the proportion of patients increased from 29.5% to 36.5% over the same period [4,5]. Generally, it has been reported that the prognosis of small-sized, node-negative breast cancer is excellent with complete surgical resection of the primary tumor, even without systemic adjuvant therapy [6]. For patients * Correspondence: jhkimmd@snu.ac.kr 1Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea Full list of author information is available at the end of the article with microinvasive breast cancer, which is defined as tumor foci of 0.1 cm or less, a very small percentage of women relapse or die of breast cancer [7]. According to an analysis of the Surveillance Epidemiology and End Results (SEER) data from 1998 to 2001, the ten-year overall breast cancer specific mortality of patients with T1a, bN0M0 disease was 4% [8]. Nevertheless, certain subgroups of patients who were initially diagnosed with small, node-negative breast can- cer tumors have a risk of recurrence. Some authors have reported that young patients under 35 years old had poor prognosis [9]. The biological factors of a high grade of tumor [8,10,11] and high Ki-67 [12] were asso- ciated with a high relapse or high mortality rate. There have been few clinical studies with large numbers of patients over a long duration of observation sufficient for the evaluation of the prognosis of node-negative breast cancer of 1cm or less in size. In addition, few studies © 2010 Kwon et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.