title: Differences in Prognostic Factors and Failure Patterns Between Invasive Micropapillary Carcinoma and Carcinoma With Micropapillary Component Versus Invasive Ductal Carcinoma of the Breast: Retrospective Multicenter Case-Control Study (KROG 13-06).
abstract: OBJECTIVE
  We designed the present study to investigate differences in prognostic factors and failure patterns between patients with invasive micropapillary carcinoma or carcinoma with micropapillary component (IMPC) and randomly matched patients with invasive ductal carcinoma (IDC) of the breast at multiple institutions of the Korean Radiation Oncology Group (KROG).
  
  
  METHODS
  This retrospective multicenter study was performed using subjects treated from January 1999 to November 2011. Female patients who had undergone curative resection for breast cancer without neoadjuvant chemotherapy were considered for this study. Exact matches were made for age (± 3 years), pathologic tumor and node stage, treatment method (surgery with or without radiotherapy), and period when surgery was performed (within 1 year) at the same institution.
  
  
  RESULTS
  A total of 534 patients were analyzed. The median follow-up period was 59 months in both groups. In the comparison of clinicopathologic characteristics, rates of lymphovascular invasion (LVI) and nuclear grade III were both significantly higher in IMPC than in IDC (P < .001, P = .01, respectively). During the follow-up period, recurrences developed in 40 patients with IMPC (15.0%) and 21 with IDC (7.9%). Locoregional recurrence (LRR) developed in 22 patients with IMPC (8.2%) and 10 with IDC (3.7%). The rate of distant metastasis did not differ between the 2 groups (P = .52). LRR-free survival (P = .03) and recurrence-free survival (P = .007) were significantly different between the 2 groups, but overall survival was not (P = .67).
  
  
  CONCLUSIONS
  IMPC is associated with a higher rate of LVI, high nuclear grade, and a propensity for LRR compared to IDC. Modification of the locoregional treatment modality might be needed in this pathologic subtype of breast cancer.
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jeong Il
authors.initials: JI
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: doho.choi@samsung.com.
authors.forename: Doo Ho
authors.initials: DH
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Huh
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun Yoon
authors.initials: EY
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eui Kyu
authors.initials: EK
authors.lastname: Chie
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sung W
authors.initials: SW
authors.lastname: Ha
authors.affiliation: Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: In Ae
authors.initials: IA
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Sung Ja
authors.initials: SJ
authors.lastname: Ahn
authors.affiliation: Department of Pathology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Ji Shin
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Center of Breast Cancer, National Cancer Center, Goyang, Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Center of Breast Cancer, National Cancer Center, Goyang, Korea.
authors.forename: Youngmee
authors.initials: Y
authors.lastname: Kwon
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chang-Ok
authors.initials: CO
authors.lastname: Suh
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ja Seung
authors.initials: JS
authors.lastname: Koo
authors.affiliation: Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Gyeongsang Institute of Health Sciences, Jinju, Korea.
authors.forename: Bae Gwon
authors.initials: BG
authors.lastname: Jeong
authors.affiliation: Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: In Ah
authors.initials: IA
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, St. Vincent's Hospital, The Catholic University of Korea College of Medicine, Suwon, Korea.
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Park
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D018270:Carcinoma, Ductal, Breast / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D002291:Carcinoma, Papillary / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor
keywords: Breast cancer; Case–control study; Invasive micropapillary carcinoma; Locoregional recurrence; Pattern of failure