title: Pathobiology of small invasive breast cancers without metastases (T1a/b, N0, M0): National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-21.
abstract: BACKGROUND
  Uncertainties continue to exist concerning the outcomes and management of small (T1a/b N0 M0) invasive breast cancers.
  
  
  METHODS
  A central pathology review was performed of 638 such lesions from National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trial B-21.
  
  
  RESULTS
  Univariate analysis revealed a high risk for ipsilateral breast tumor recurrence with tumors exhibiting a ductal carcinoma in situ component or poor nuclear grade. The converse (protective effect) was found with tumors arising in radial scars, those of tubular histologic type, and those with moderate/marked tumor stroma. The correlations were generally similar for disease-free survival. However, only nuclear grade was found to be independently significant for both of these outcomes. Only lymphatic tumor extension was univariately and multivariately significant for overall survival.
  
  
  CONCLUSIONS
  The long-term results of follow-up (median, 11.2 years) from the current trial continue to support the need for local breast irradiation and adjuvant therapy in the management of patients with these small cancers.
authors: National Surgical Adjuvant Breast and Bowel Project (NSABP), Pittsburgh, Pennsylvania, USA. cgriffit@wpahs.org
authors: Edwin R
authors: ER
authors: Fisher
authors: Joseph P
authors: JP
authors: Costantino
authors: Marino E
authors: ME
authors: Leon
authors: Hanna
authors: H
authors: Bandos
authors: Alka S
authors: AS
authors: Palekar
authors: Bernard
authors: B
authors: Fisher
authors: Norman
authors: N
authors: Wolmark
mesh_terms: D001941:Breast Diseases / Q000473:pathology; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D011878:Radiotherapy; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use; D013629:Tamoxifen / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen