The positive non-sentinel status is not the main decisional factor for chemotherapy assignment in breast cancer with micrometastatic disease in the sentinel lymph node.
BACKGROUND
Surgical and systemic treatment modalities for breast cancer (BC) patients with micrometastatic disease in the sentinel lymph node biopsy (SNB) are controversial. The aim of this study was to evaluate decisional factors associated with assignment of adjuvant chemotherapy (CT).


METHODS
In a retrospective multicentric European study we evaluated cases of primary BC patients who underwent SNB. Logistic regression (LR) and recursive partitioning analyses (RPA) were performed to determine factors associated with CT.


RESULTS
Of the 172 patients with micrometastatic disease, 39.5% received adjuvant CT. In the group treated with CT, patients tended to be younger (P = 0.001), with higher grade (P = 0.001) and HER2 positive tumors (P = 0.006) compared to patients without CT. In multivariate LR, age (P = 0.0027), high grading (P = 0.01) HER2 positivity (P = 0.03), and positive non-SN status (P = 0.03) were significantly associated with CT. RPA demonstrated that tumor grade, and not the non-SN status, was the first split in the partition tree followed by HER2 status, and non-SN status influencing the probability for CT administration.


CONCLUSIONS
High tumor grade is the main decisional factor followed by HER2 positivity and then by the positive non-SN status for CT in micrometastatic disease in the SN.
Department of Breast Medical and Surgical Oncology, Institut Gustave Roussy, Villejuif, France. chafika.mazouni@igr.fr
Chafika
C
Mazouni
Roland
R
Reitsamer
Françoise
F
Rimareix
Heidi
H
Stranzl
Catherine
C
Uzan
Jean-Rémi
JR
Garbay
Suzette
S
Delaloge
Florentia
F
Peintinger
D000368:Aged; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D061206:Neoplasm Micrometastasis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy
D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human