Early changes in circulating tumor cells are associated with response and survival following treatment of metastatic neuroendocrine neoplasms
A partir d'échantillons sanguins prélevés au début du traitement et 14 semaines plus tard sur 138 patients atteints d'une tumeur neuroendocrinienne métastatique, cette étude met en évidence l'intérêt de mesurer le nombre de cellules tumorales circulantes pour suivre la réponse thérapeutique
Purpose:To investigate post-treatment circulating tumor cell counts in patients with neuroendocrine neoplasms (NEN) as a predictive biomarker for disease progression and overall survival.
Experimental Design:Patients with metastatic NENs commencing therapy were prospectively recruited (n=138). Blood samples were obtained for evaluation of circulating tumor cells (CTCs) using the CellSearch™ platform and for chromogranin A (CgA) at baseline, 3-5 (median 4.3) weeks and 10-15 (median 13.7) weeks after commencing therapy. Radiological response and overall survival (OS) data were collected.
Results:There was a significant association between first post-treatment CTC count and progressive disease (PD) (P<0.001). Only 8% of patients with a favorable 'CTC response' (0 CTCs at baseline and 0 at first post-treatment time-point; or ≥50% reduction from baseline) had PD compared with 60% in the unfavorable group (<50% reduction or increase). Changes in CTCs were strongly associated with OS (P<0.001), the best prognostic group being patients with 0 CTCs before and after therapy; followed by those with ≥50% reduction in CTCs (Hazard Ratio HR 3.31); with those with a <50% reduction or increase in CTCs (HR 5.07) having the worst outcome. In multivariate analysis, changes in CTCs had the strongest association with OS (HR 4.13, P=0.0002). Changes in CgA were not significantly associated with survival.
Conclusions:Changes in CTCs are associated with response to treatment and overall survival in metastatic NENs suggesting CTCs may be useful as surrogate markers to direct clinical decision-making.
Clinical Cancer Research , résumé, 2015