Pathobiology of small invasive breast cancers without metastases (T1a/b, N0, M0): National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-21.
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.
Fisher
Edwin R
ER
National Surgical Adjuvant Breast and Bowel Project (NSABP), Pittsburgh, Pennsylvania, USA. cgriffit@wpahs.org
Costantino
Joseph P
JP
Leon
Marino E
ME
Bandos
Hanna
H
Palekar
Alka S
AS
Fisher
Bernard
B
Wolmark
Norman
N
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
D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen