title: Factors associated with late recurrence after completion of 5-year adjuvant tamoxifen in estrogen receptor positive breast cancer.
abstract: Recent large trials have shown the survival benefits of 10-year use of tamoxifen by reducing late recurrence compared with 5-year therapy in estrogen receptor(ER)-positive breast cancer. We tried to identify clinical factors associated with the late recurrence.
  
  
  
  We reviewed our database of ER-positive patients who had received operations between 1996 and 2006 in two institutions. We selected 444 who had completed 5-year tamoxifen and were disease-free up to 10 years after the operation. Patients who had received aromatase inhibitors with any regimens were excluded. As a late recurrence group, 139 patients were identified who had completed 5-year tamoxifen, but had recurrence afterwards. Among them, 61 had local/contralateral breast recurrence and 78 had distant metastasis. The median follow-up was 9.7 years. Clinicopathological factors at the time of initial operation, such as age, menopausal status, progesterone receptor expression, HER2 status, tumor grade and Ki-67, were compared between the disease-free group and the late recurrence group.
  
  
  
  In a univariate analysis, tumor size (>2 cm), lymph node metastasis and high histologic grade were significantly associated with late recurrences (p < 0.05). In a multivariate analysis, only axillary lymph node metastasis was significant (p < 0.001). Late distant metastasis was significantly associated with tumor size and axillary lymph node metastasis (p = 0.038, p < 0.001,respectively). Late local/contralateral breast recurrence was associated with axillary lymph node metastasis (p = 0.042).
  
  
  
  Our data showed axillary lymph node metastasis at initial operation was the only risk factor of late recurrence after completion of tamoxifen for 5 years. Our results can be helpful in making decisions to use extended tamoxifen beyond 5 years.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eun-Shin
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea. hanw@snu.ac.kr.|Department of Surgery, Seoul National University Hospital, National University College of Medicine, Cancer Research Institute, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-744, Korea. hanw@snu.ac.kr.
authors.forename: Wonshik
authors.initials: W
authors.lastname: Han
authors.affiliation: Department of Surgery, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Min Kyoon
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Surgery, SMG - SNU Boramae Medical Center, Seoul, Korea.
authors.forename: Jongjin
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Tae-Kyung
authors.initials: TK
authors.lastname: Yoo
authors.affiliation: Department of Surgery, Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Moo Hyun
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung Hun
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyeong-Gon
authors.initials: HG
authors.lastname: Moon
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Noh
authors.affiliation: Department of Surgery, Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D011960:Receptors, Estrogen / Q000378:metabolism*; D012307:Risk Factors; D016019:Survival Analysis; D013629:Tamoxifen / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D011960:Receptors, Estrogen; D013629:Tamoxifen
keywords: Estrogen receptor (ER)-positive breast cancer; Extended tamoxifen; Late recurrence