1654P - Circulating tumor cells (CTCs) as prognostic factor for pancreatic cancer: Updated of a prospective study

Background

CTCs have been extensively studied in different neoplasms. There are several techniques for their identification, however, it is not clear which is the most effective. In pancreatic cancer (PC) their significance in different stages of the disease and correlation with tumor markers are poorly understood.

Methods

Prospective, observational, cohort study in two Spanish centers. We analyzed CTCs at day 0 (before chemotherapy). Isolation was carried out with Isoflux technology, combining cell separation by immunomagnetic particles (positive selection) with a microfluidic system. Four different markers were used, including two mesenchymal markers, EpCAM and EGFR. The count of CTCs was done in a confocal microscope using the iMSRC (intelligent Matrix Screen Remote Control). Primary endpoint was the correlation of CTCs with overall survival (OS). Secondary endpoints: correlation between CTCs with Ca19.9/CEA values and the difference in the median value of CTCs in metastatic compared to locally advanced disease were secondary endpoints.

Results

Sixty-three patients were analyzed. Clinical characteristics: (Table) Median follow up was 11.6 months. Median value of CTC-0 was 343 (range 33 - 6259) for metastatic patients while it was 436 (81 - 1082) for locally advanced patients (p = 0.380). Correlation coefficient for Ca 19.9 was 0.03 (p = 0.824); CEA correlation coefficient was 0.121 (p = 0.366). Kaplan-Meier analysis showed an estimated median OS of 9.9 months for > 500 CTCs (95% confident interval [95% CI] 8.1 – 11.6) vs 14.7 (95% confident interval [95% CI] 6.7 – 22.6) for < 500 CTCs (p = 0.021).

Table: 1654P

Conclusions

With an increased number of patients there is still absence of differences of CTC-0 between metastatic and non-metastatic patients as well as no correlation of CTCs with tumor markers at diagnosis. 500 CTCs continues to be a significant cutoff for overall survival.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Instituto de Investigación Sanitaria Gregorio Marañón.

Funding

SEOM.

Disclosure

L. Ortega Morán: Financial Interests, Advisory Role: Sanofi; Financial Interests, Speaker’s Bureau: Leo Pharma, Sanofi. G. Torres Perez-Solero: Financial Interests, Personal, Advisory Board: Adacap; Financial Interests, Personal, Invited Speaker: Adacap, Ipsen, Amgen, Roche, Merck, Servier; Financial Interests, Personal, Writing Engagement: Sanofi. P. García Alfonso: Financial Interests, Personal, Advisory Board: Amgen. M. Martin Jimenez: Financial Interests, Personal, Advisory Board: AstraZeneca, Lilly, Roche/Genentech, Daiichi Sankyo, Menarini-Stemline; Financial Interests, Personal, Invited Speaker: Pfizer, AstraZeneca, Lilly, Novartis, Roche/Genentech; Financial Interests, Institutional, Research Grant: Novartis, Roche, Puma; Non-Financial Interests, Member of Board of Directors: TRIO; Non-Financial Interests, Leadership Role: Geicam; Non-Financial Interests, Member: ASCO; Non-Financial Interests, Advisory Board: Seom. A.J. Munoz Martin: Financial Interests, Advisory Board: Sanofi, Pfizer, Leo Pharma, Bayer; Financial Interests, Speaker’s Bureau: Rovi. All other authors have declared no conflicts of interest.