Cell membrane microfragments called microvesicles (MV) originating from different cells are circulating in the blood of healthy subjects and their elevated numbers are found in different diseases, including cancer. This study was designed to characterise MV present in plasma of gastric cancer patients. Since majority of MV in blood are platelets-derived (PMV), plasma samples deprived of PMV were used. In comparison to control, the number of MV in patients was significantly elevated in all stages, higher in more advanced disease. Patients' MV showed an increased membrane expression of CCR6 and HER-2/neu. The proportion of MV carrying some leucocyte determinants was low and similar in patients and control. Transmission electron microscopy showed their substantial heterogeneity in size and shape. The size determined by dynamic light scattering analysis confirmed this heterogeneity. The MV size distribution in patients was broader within the range of 10-800 nm, while in control MV showed 3-mode distribution within the range of 10-400 nm. Atomic force microscopy confirmed MV size heterogeneity with implication that larger objects represented aggregates of smaller microparticles. Patients' MV exhibited increased absolute values of zeta potential, indicating a higher surface charge. Tumour markers HER-2/neu, MAGE-1, c-MET and EMMPRIN were detected both in control and patients' samples with stronger expression in the latter. Significantly higher expression of MAGE-1 and HER-2/neu mRNA was observed in individual patients. All together, it suggests that at least some MV in plasma of gastric cancer patients are tumour-derived. However, their role in cancer requires further studies.

BackgroundDespite progress in surgical techniques and perioperative care, gastrectomy remains a procedure of significant morbidity. Several scoring systems and clinical measures have been adopted to predict postoperative complications in gastric cancer patients. The aim of this study was to investigate whether high serum levels of interleukin 6 (IL-6) in the early postoperative period may be a prognostic factor of postoperative morbidity.MethodsA group of 99 consecutive patients with resectable gastric cancer were enrolled. The mean age was 62.9 years and the male/female ratio was 72:27. Subtotal gastric resection was performed in 22 patients and total gastric resection in 77. The IL-6 serum level was measured on the 1st postoperative day (POD).ResultsComplications were recorded in 28 patients (28.3%). The observed case-fatality rate was 3.03%. An IL-6 serum level of >288.7 pg/ml on the 1st POD in univariate and multivariate Cox proportional hazard models was an independent prognostic factor for overall complications and infective complications.ConclusionOur study showed an association between perioperative IL-6 serum levels and postoperative morbidity in gastric cancer patients. The IL-6 serum level on the 1st POD was shown to be an independent prognostic factor for both overall complications and infective complications.

This study, based on a limited number of patients, indicates that adjuvant immunochemotherapy (BCG + FAM) may prolong the survival of gastric cancer patients after curative gastrectomy; in particular, in patients with pT2/T3 tumors and intestinal-type primary tumors. There was no survival benefit from FAM adjuvant chemotherapy.

Human peripheral blood monocytes cocultured with tumour cells were used as an in vitro model of in situ interactions between tumour-infiltrating macrophages and the tumour. Tumour cells stimulated de novo expression of the human tumour necrosis factor alpha (TNF) gene in monocytes and caused the release of TNF into the culture supernatant. A group of 14 patients with stage IVA gastric cancer receiving adjuvant chemotherapy (5-FU, Adriamycin, mitomycin C: FAM) or immunochemotherapy (BCG+FAM) was investigated for the ability of monocytes to produce TNF in vitro upon stimulation with tumour cells or purified protein derivative of tuberculin (PPD). Patients were followed at biweekly intervals, i.e. before each instillation of BCG epicutaneously over a period of 10 weeks. It was found that monocytes of some patients receiving BCG at the end of the observation period had an enhanced ability to produce TNF following stimulation with tumour cells. In contrast, such production was not substantially altered during the study period in patients on chemotherapy. PPD-induced TNF production was much weaker and was not significantly changed during this observation time. We infer that BCG immunotherapy may induce the subtle changes in some cancer patients that lead to an increased interaction between monocytes and tumour cells and result in enhanced production of cytokine(s) with antitumour properties.

The absolute number of Tregs in peripheral blood of gastric cancer but not colorectal cancer patients was significantly decreased in comparison with that in healthy controls.