Cancer-associated Macrophage-like Cells in Patients with Non-metastatic Adenocarcinoma of the Esophagus – Cytomorphological Heterogeneity
Introduction: Esophageal adenocarcinoma (EAC) often recurs systemically despite therapy with a curative aim. New diagnostic and therapeutic approaches are urgently needed. A promising field is liquid biopsy, meaning the investigation of tumor-associated cells in the peripheral blood, for example cancer-associated macrophage-like cells (CAML). The aim of this multicentric study was to investigate the presence and cytomorphological appearance of CAML in patients with non-metastatic and operable esophageal cancer.
Methods: Blood samples from 252 patients with locally advanced EAC were obtained before starting curative treatment including surgery, and then processed using ScreenCell® filtration devices. Cytological analysis was performed via May-Grünwald-Giemsa staining. CAML were defined by their morphological characteristics. We also performed immunofluorescence staining with the mesenchymal marker vimentin on a subset of our study cohort.
Results: We detected cytomorphologically heterogeneous CAML in 31.8% (n=80) patients. Their presence and cell count did not correlate significantly with pretherapeutic cTNM. Even in patients with small tumors and no lymph-node infiltration, cell counts were high. CAML showed heterogenous staining patterns for vimentin.
Conclusion: This is one of the first studies demonstrating the presence and phenotype of CAML in a uniquely broad cohort of EAC patients. As they are believed to be representatives of the inflammatory tumor microenvironment shed into the bloodstream, their presence in non-metastatic EAC is a promising finding.
Cytopathological Heterogeneity of Circulating Tumor Cells in Non-metastatic Esophageal Adenocarcinoma
Background/Aim: The presence of circulating tumor cells (CTC) has been reported to have an impact on prognosis in different tumor entities. Little is known about CTC morphology and heterogeneity. Patients and Methods: In a multicenter setting, pre-therapeutic peripheral blood specimens were drawn from patients with non-metastatic esophageal adenocarcinoma (EAC). CTCs were captured by size-based filtration (ScreenCell®), subsequently Giemsa-stained and evaluated by two trained readers. The isolated cells were categorized in groups based on morphologic criteria. Results: Small and large single CTCs, as well as CTC-clusters, were observed in 69.2% (n=81) of the 117 specimens; small CTCs were observed most frequently (59%; n=69), followed by large CTCs (40%; n=47) and circulating cancer-associated macrophage-like cells (CAMLs; 34.2%, n=40). Clusters were rather rare (12%; n=14). CTC/CAML were heterogeneous in the cohort, but also within one specimen. Neither the presence of the CTC subtypes/CAMLs nor the exact cell count were associated with the primary clinical TNM stage. Conclusion: Morphologically heterogenic CTCs and CAMLs are present in patients with non-metastatic, non-pretreated EAC.
Non-Metastatic Esophageal Adenocarcinoma: Circulating Tumor Cells in the Course of Multimodal Tumor Treatment
Background: Isolation of circulating tumor cells (CTC) holds the promise to improve response-prediction and personalization of cancer treatment. In this study, we test a filtration device for CTC isolation in patients with non-metastatic esophageal adenocarcinoma (EAC) within recent multimodal treatment protocols. Methods: Peripheral blood specimens were drawn from EAC patients before and after neoadjuvant chemotherapy (FLOT)/chemoradiation (CROSS) as well as after surgery. Filtration using ScreenCell® devices captured CTC for cytologic analysis. Giemsa-stained specimens were evaluated by a cytopathologist; the cut-off was 1 CTC/specimen (6 mL). Immunohistochemistry with epithelial (pan-CK) and mesenchymal markers (vimentin) was performed. Results: Morphologically diverse malignant CTCs were found in 12/20 patients in at least one blood specimen. CTCs were positive for both vimentin and pan-CK. More patients were CTC positive after neoadjuvant therapy (6/20 vs. 9/15) and CTCs per/ml increased in most of the CTC-positive patients. After surgery, 8/13 patients with available blood specimens were still CTC positive. In clinical follow-up, 5/9 patients who died were CTC-positive. Conclusions: Detection of CTC by filtration within multimodal treatment protocols of non-metastatic EAC is feasible. The rate of CTC positive findings and the quantity of CTCs changes in the course of multimodal neoadjuvant chemoradiation/chemotherapy and surgery.