Abstract P1-01-04: Nodal patterns of care in patients with invasive breast cancer treated with neoadjuvant systemic therapy: Results of a secondary analysis of TBCRC 017
Authors: McGuire KP , De Los Santos JF , Cantor A , Forero A , Golshan M , Meric-Bernstam F , Horton JK , Amos KD , Hudis CA , Hylton NM , Meszoely IM , Nanda R , Hwang S 
Published: August 2014

Background: Neoadjuvant chemotherapy (NCT) to downstage locally advanced tumors and potentially allow breast conservation has increased. In parallel, the use of sentinel lymph node biopsy (SNB) and axillary node dissection has evolved. This analysis reports patterns of care for axillary evaluation at 8 NCI Comprehensive Cancer Centers in women receiving NCT.

Methods: Between 2002 and 2010, 770 women were retrospectively identified as having received NCT, 758 of who had nodal imaging either before or after NCT. Clinical, pathologic, and treatment data were collected. Univariate and multivariate analyses of covariates associated with axillary management were performed using logistic regression (SAS 9.2, Proc Logistic).

Results: Between 2002 and 2010, the odds of receiving a post-NCT SNB increased by 8% per year (p&lt;0.001). Rates of post-NCT SNB were significantly different in only one of eight institutions (p&lt;0.001), where pre-NCT nodal evaluation was made by SNB. The remainder of institutions used SNB following NCT. Of those who underwent post-NCT SNB, regardless of nodal status pre-NCT, 55% (171/314) had axillary lymph node dissection (ALND). Prior to NCT, 74% (564/758) of patients exhibited at least one abnormal lymph node on pretreatment imaging.

Imaging modalities used pretreatment to assess axillary lymph nodes Suspicious Nodes N (%)Ultrasound24 (4.3)Ultrasound+MRI218 (38.7)Ultrasound +MRI+CT103 (18.3)Ultrasound+MRI+CT+PET39 (6.9)Ultrasound+MRI+PET9 (1.6)Ultrasound+CT12 (2.1)Ultrasound+CT+PET8 (1.4)Ultrasound+PET3 (0.5)MRI36 (6.4)MRI+CT58 (10.3)MRI+CT+PET21 (3.7)MRI+PET9 (1.6)CT18 (3.2)CT+PET3 (0.5)CT+PET3 (0.5)TOTAL564 (100)

Of those, 52% (291/564) of the lymph nodes were sampled using fine needle aspiration (FNA) and 27% (149/564) were sampled with CNB. Odds of undergoing a core needle biopsy (CNB) at presentation for radiographically or clinically suspicious lymph nodes increased by 27% per year (p&lt;0.001). 57% (322/564) of all sampled lymph nodes were positive for malignant cells by either FNA or CNB. Of those with confirmed positive nodes at diagnosis, 26% (83/322) had nodal sampling with SNB after NCT. Of the 462 patients with pretreatment MRI suggesting an abnormal lymph node, 155 (33.5%) had a complete imaging response in the lymph nodes by MRI. Of those patients 32% (49/155) had SNB as their initial axillary evaluation after NCT, of which 45% (22/49) of those exhibited persistently positive nodes and underwent completion axillary node dissection.

Conclusions: Among a contemporary cohort of women receiving NCT, a significant trend was observed towards increased use of needle biopsy for patients with abnormal pretreatment nodal imaging at presentation and sentinel lymph node biopsy after NCT nodal evaluation. A trend was also observed over time towards greater use of post-NCT SNB in patients with confirmed pathologic positive nodes at presentation. These data demonstrate a trend towards less invasive assessment of suspicious lymph nodes both before and after NCT.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-04.