title: Basal subtype of invasive breast cancer is associated with a higher risk of true recurrence after conventional breast-conserving therapy.
abstract: OBJECTIVE
  To determine whether breast cancer subtype is associated with patterns of ipsilateral breast tumor recurrence (IBTR), either true recurrence (TR) or elsewhere local recurrence (ELR), among women with pT1-T2 invasive breast cancer (IBC) who receive breast-conserving therapy (BCT).
  
  
  METHODS
  From Jan 1998 to Dec 2003, 1,223 women with pT1-T2N0-3 IBC were treated with BCT (lumpectomy plus whole-breast radiation). Ninety percent of patients received adjuvant systemic therapy, but none received trastuzumab. Biologic cancer subtypes were approximated by determining estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), and human epidermal growth factor receptor-2-positive (HER-2+) expression, classified as luminal A (ER+ or PR+ and HER-2 negative [HER-2-]), luminal B (ER+ or PR+ and HER-2+), HER-2 (ER- and PR- and HER-2+), and basal (ER- and PR- and HER-2- ) subtypes. Imaging, pathology, and operative reports were reviewed by two physicians independently, including an attending breast radiologist. Readers were blinded to subtype and outcome. TR was defined as IBTR within the same quadrant and within 3 cm of the primary tumor. All others were defined as ELR.
  
  
  RESULTS
  At a median follow-up of 70 months, 24 patients developed IBTR (5-year cumulative incidence of 1.6%), including 15 TR and 9 ELR patients. At 5 years, basal (4.4%) and HER-2 (9%) subtypes had a significantly higher incidence of TR than luminal B (1.2%) and luminal A (0.2%) subtypes (p < 0.0001). On multivariate analysis, basal subtype (hazard ratio [HR], 4.8, p = 0.01), younger age at diagnosis (HR, 0.97; p = 0.05), and increasing tumor size (HR, 2.1; p = 0.04) were independent predictors of TR. Only younger age (HR, 0.95; p = 0.01) significantly predicted for ELR.
  
  
  CONCLUSIONS
  Basal and HER-2 subtypes are significantly associated with higher rates of TR among women with pT1-T2 IBC after BCT. Younger age predicts for both TR and ELR. Strategies to reduce TR in basal breast cancers, such as increased boost doses, concomitant radiation and chemotherapy, or targeted therapy agents, should be explored.
authors: Harvard Radiation Oncology Program, Boston, Massachusetts, USA.
authors: Jona A
authors: JA
authors: Hattangadi-Gluth
authors: Jennifer Y
authors: JY
authors: Wo
authors: Paul L
authors: PL
authors: Nguyen
authors: Rita F
authors: RF
authors: Abi Raad
authors: Meera
authors: M
authors: Sreedhara
authors: Andrzej
authors: A
authors: Niemierko
authors: Phoebe E
authors: PE
authors: Freer
authors: Dianne
authors: D
authors: Georgian-Smith
authors: Jennifer R
authors: JR
authors: Bellon
authors: Julia S
authors: JS
authors: Wong
authors: Barbara L
authors: BL
authors: Smith
authors: Jay R
authors: JR
authors: Harris
authors: Alphonse G
authors: AG
authors: Taghian
references: Cancer. 2004 Sep 15;101(6):1264-74
references: 15316900
references: Lancet. 2002 Apr 27;359(9316):1471-7
references: 11988246
references: J Clin Oncol. 1998 May;16(5):1642-9
references: 9586873
references: Int J Radiat Oncol Biol Phys. 1985 Jul;11(7):1271-6
references: 4008287
references: Nature. 2000 Aug 17;406(6797):747-52
references: 10963602
references: N Engl J Med. 2002 Oct 17;347(16):1233-41
references: 12393820
references: N Engl J Med. 1995 Apr 6;332(14):907-11
references: 7877647
references: J Clin Oncol. 2002 Oct 15;20(20):4141-9
references: 12377957
references: J Natl Cancer Inst. 1995 Jan 4;87(1):19-27
references: 7666458
references: Int J Radiat Oncol Biol Phys. 1988 Aug;15(2):255-61
references: 2841261
references: Int J Radiat Oncol Biol Phys. 1995 Sep 30;33(2):245-51
references: 7673011
references: Int J Radiat Oncol Biol Phys. 2011 Jan 1;79(1):19-25
references: 20471183
references: J Clin Oncol. 2009 May 20;27(15):2466-73
references: 19349544
references: Int J Radiat Oncol Biol Phys. 2003 Nov 1;57(3):724-31
references: 14529777
references: J Clin Oncol. 2008 Mar 20;26(9):1419-26
references: 18285604
references: Int J Radiat Oncol Biol Phys. 1990 Oct;19(4):833-42
references: 2170305
references: Cancer. 2002 Nov 15;95(10):2059-67
references: 12412158
references: J Clin Oncol. 2009 Oct 1;27(28):4701-8
references: 19720911
references: J Clin Oncol. 2007 Aug 1;25(22):3259-65
references: 17577015
references: Int J Radiat Oncol Biol Phys. 2009 Jul 15;74(4):987-1001
references: 19545784
references: Eur J Cancer. 2009 Sep;45 Suppl 1:27-40
references: 19775602
references: Ann Oncol. 2009 Dec;20(12):1913-27
references: 19901010
references: J Clin Oncol. 2001 Mar 15;19(6):1688-97
references: 11250998
references: Int J Radiat Oncol Biol Phys. 2010 Aug 1;77(5):1296-302
references: 20472353
references: J Clin Oncol. 2010 Apr 1;28(10):1684-91
references: 20194857
references: J Clin Oncol. 2008 May 10;26(14):2373-8
references: 18413639
references: Int J Radiat Oncol Biol Phys. 2000 Dec 1;48(5):1281-9
references: 11121624
references: Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10869-74
references: 11553815
references: J Clin Oncol. 2004 May 15;22(10):1830-8
references: 15143075
references: Int J Radiat Oncol Biol Phys. 2010 May 1;77(1):188-96
references: 20171798
references: Ann Oncol. 2001 Jul;12(7):997-1003
references: 11521809
references: Int J Radiat Oncol Biol Phys. 2005 Apr 1;61(5):1328-36
references: 15817334
references: N Engl J Med. 2005 Oct 20;353(16):1659-72
references: 16236737
references: J Clin Oncol. 2005 Oct 10;23(29):7350-60
references: 16145060
references: Cancer. 1989 May 15;63(10):1912-7
references: 2702564
references: N Engl J Med. 2005 Oct 20;353(16):1673-84
references: 16236738
references: JAMA. 2006 Jun 7;295(21):2492-502
references: 16757721
references: N Engl J Med. 2002 Oct 17;347(16):1227-32
references: 12393819
references: J Clin Pathol. 2006 Jul;59(7):729-35
references: 16556664
references: Cancer. 1996 Mar 15;77(6):1094-100
references: 8635129
references: Int J Radiat Oncol Biol Phys. 2008 Nov 15;72(4):1056-63
references: 18676094
references: Breast Cancer. 2005;12(2):104-11
references: 15858440