Circulating tumor cells and response to neoadjuvant paclitaxel and HER2-targeted therapy: a sub-study from the NeoALTTO phase III trial.
BACKGROUND
The role of circulating tumor cells (CTCs) in HER2-positive breast cancer patients receiving neoadjuvant therapy is unclear.


METHODS
We describe the CTC detection rate, HER2 phenotyping and pathological complete response (pCR) in patients enrolled in the NeoALTTO phase III trial. Participation in the CTC sub-study was optional. CTC evaluation was performed centrally using CellSearch at baseline, week 2 and week 18 (prior to surgery) of neoadjuvant therapy.


RESULTS
Samples for CTC analysis were available for 51/455 patients randomized. At baseline, week 2 and week 18, we detected ≥1 CTC/22.5 ml in 5/46 (11%), 4/41 (10%), and 5/31 (16%) patients and ≥1 HER2-positive CTC/22.5 ml in 2/46 (4%), 2/41 (5%), and 3/31 (10%) patients with evaluable samples, respectively. 11/51 patients (21%) had ≥1 CTC/22.5 ml in at least one time point. pCR was observed in 3/11 (27.3%) versus 17/40 (42.5%) patients with detectable and no detectable CTCs, respectively (p = 0.36). No pCR was observed in the three patients with detectable HER2-positive CTCs prior to surgery.


CONCLUSIONS
Numerically lower pCR rates were observed in patients with detectable CTCs, yet the study remains underpowered. A meta-analysis of CTC studies in this setting is warranted.
Breast Cancer Translational Research Laboratory, J.C. Heuson, Université Libre de Bruxelles, Institut Jules Bordet, Brussels, Belgium; Department of Medicine, BrEAST Data Centre, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Hatem A
HA
Azim
Francoise
F
Rothé
Claudia Monica
CM
Aura
Malcolm
M
Bavington
Marion
M
Maetens
Ghizlaine
G
Rouas
Geraldine
G
Gebhart
Cristina
C
Gamez
Holger
H
Eidtmann
José
J
Baselga
Martine
M
Piccart-Gebhart
Catherine
C
Ellis
Peter
P
Vuylsteke
Hervé
H
Cure
Julien
J
Domont
Antonella
A
Ferro
Juan Carlos
JC
Toral-Peña
Evandro
E
de Azambuja
Christos
C
Sotiriou
Serena
S
Di Cosimo
Michail
M
Ignatiadis
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D000077341:Lapatinib; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D020360:Neoadjuvant Therapy; D009360:Neoplastic Cells, Circulating / Q000737:chemistry / Q000473:pathology*; D017239:Paclitaxel / Q000008:administration & dosage; D011799:Quinazolines / Q000008:administration & dosage; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000037:antagonists & inhibitors*; D000068878:Trastuzumab; D055815:Young Adult
D061067:Antibodies, Monoclonal, Humanized; D000077341:Lapatinib; D017239:Paclitaxel; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human
Circulating tumor cells; HER2-positive breast cancer; Lapatinib; Trastuzumab; pCR