Identification of miRNAs Present in Cell- and Plasma-Derived Extracellular Vesicles-Possible Biomarkers of Colorectal Cancer.

Globally, an increasing prevalence of colorectal cancer (CRC) prompts a need for the development of new methods for early tumor detection. MicroRNAs (also referred to as miRNAs) are short non-coding RNA molecules that play a pivotal role in the regulation of gene expression. MiRNAs are effectively transferred to extracellular vesicle (EVs) membrane sacs commonly released by cells. Our study aimed to examine the expression of miRNAs in four CRC cell lines and EVs derived from them (tumor EVs) in comparison to the normal colon epithelium cell line and its EVs. EVs were isolated by ultracentrifugation from the culture supernatant of SW480, SW620, SW1116, HCT116 and normal CCD841CoN cell lines and characterized according to the MISEV2023 guidelines. MiRNAs were analyzed by small RNA sequencing and validated by quantitative PCR. The performed analysis revealed 22 common miRNAs highly expressed in CRC cell lines and effectively transferred to tumor EVs, including miR-9-5p, miR-182-5p, miR-196b-5p, miR-200b-5p, miR-200c-3p, miR-425-5p and miR-429, which are associated with development, proliferation, invasion and migration of colorectal cancer cells, as well as in vesicle maturation and transport-associated pathways. In parallel, normal cells expressed miRNAs, such as miR-369 and miR-143, which play a role in proinflammatory response and tumor suppression. The analysis of selected miRNAs in plasma-derived EVs and tumor samples from CRC patients showed the similarity of miRNA expression profile between the patients' samples and CRC cell lines. Moreover, miR-182-5p, miR-196-5p, miR-425-5p and miR-429 were detected in several EV samples isolated from patients' plasma. Our results suggest that miR-182-5p, miR-196b-5p and miR-429 are differentially expressed between EVs from CRC patients and healthy donors, which might have clinical implications.

The impact of oncological package implementation on the treatment of rectal cancer in years 2013-2019 in Poland - multicenter study.

<b><br>Introduction:</b> In 2015, in Poland, the oncological package (OP) was established. This law constituted a fast track of oncological diagnosis and treatment and obligatory multidisciplinary team meetings (MDT).</br> <b><br>Aim:</b> The aim of this study was to analyze the impact of OP on rectal cancer treatment.</br> <b><br>Methods:</b> The study was a multicenter, retrospective analysis of data collected from five centers. It included clinical data of patients operated on due to rectal cancer between 2013 and 2019. For most analyses, patients were categorized into three groups: 2013-2014 - before OP (A), 2015-2016 - early development of OP (B), 2017-2019 - further OP functioning (C).</br> <b><br>Results:</b> A total of 1418 patients were included. In all time intervals, the majority of operations performed were anterior resections. There was a significantly lower local tumor stage (T) observed in subsequent time intervals, while there were no significant differences for N and M. In period C, the median of resected nodes was significantly higher than in previous periods. Four of the centers showed an increasing tendency in the use of preoperative radiotherapy. The study indicated a significant increase in the use of short-course radiotherapy (SCRT) and a decrease in the number of patients who did not receive any form of preoperative therapy in subsequent periods. In the group that should receive radiotherapy (T3/4 or N+ and M0), the use of SCRT was also significantly increasing.</br> <b><br>Conclusions:</b> In the whole cohort, there was a significant increase in the use of preoperative radiotherapy and a decrease in the T stage, changing with the development of OP. Nevertheless, this relation is indirect and more data should be gathered for further conclusions.</br>.

What determines complications and prognosis among patients subject to multivisceral resections for locally advanced gastric cancer?

BACKGROUND: Locally advanced gastric cancer (GC) extending to the surrounding tissues may require a multivisceral resection (MVR) to provide the best chance of cure. However, little is known about how the extent of organ resection affects the risks and benefits of surgery. METHODS: An electronic database of patients treated between 1996 and 2020 in an academic surgical centre was reviewed. MVRs were defined as partial or total gastrectomy combined with splenectomy, distal pancreatectomy, or partial colectomy. RESULTS: Suspected intraoperative tumour invasion of perigastric organs (cT4b) was found in 298 of 1476 patients with non-metastatic GC, and 218 were subject to MVRs, including the spleen (n = 126), pancreas (n = 51), and colon (n = 41). MVRs were associated with higher proportions of surgical and general complications, but not mortality. A nomogram was developed to predict the risk of major postoperative morbidity (Clavien-Dindo's grade ≥ 3a), and the highest odds ratio for major morbidity identified by logistic regression modelling was found for distal pancreatectomy (2.53, 95% CI 1.23-5.19, P = 0.012) and colectomy (2.29, 95% CI 1.04-5.09, P = 0.035). Margin-positive resections were identified by the Cox proportional hazards model as the most important risk factor for patients' survival (hazard ratio 1.47, 95% CI 1.10-1.97). The extent of organ resection did not affect prognosis, but a MVR was the only factor reducing the risk of margin positivity (OR 0.44, 95% CI 0.21-0.87). CONCLUSIONS: The risk of multivisceral resections is associated with the organ being removed, but only MVRs increase the odds of complete tumour clearance for locally advanced gastric cancer.

The Association of Polish Surgeons (APS) clinical guidelines for the use of laparoscopy in the management of abdominal emergencies. Part I.

Introduction: Over the past three decades, almost every type of abdominal surgery has been performed and refined using the laparoscopic technique. Surgeons are applying it for more procedures, which not so long ago were performed only in the classical way. The position of laparoscopic surgery is therefore well established, and in many operations it is currently the recommended and dominant method. Aim: The aim of the preparation of these guidelines was to concisely summarize the current knowledge on laparoscopy in acute abdominal diseases for the purposes of the continuous training of surgeons and to create a reference for opinions. Material and methods: The development of these recommendations is based on a review of the available literature from the PubMed, Medline, EMBASE and Cochrane Library databases from 1985 to 2022, with particular emphasis on systematic reviews and clinical recommendations of recognized scientific societies. Recommendations were formulated in a directive form and evaluated by a group of experts using the Delphi method. Results and conclusions: There are 63 recommendations divided into 12 sections: diagnostic laparoscopy, perforated ulcer, acute pancreatitis, incarcerated hernia, acute cholecystitis, acute appendicitis, acute mesenteric ischemia, abdominal trauma, bowel obstruction, diverticulitis, laparoscopy in pregnancy, and postoperative complications requiring emergency surgery. Each recommendation was supported by scientific evidence and supplemented with expert comments. The guidelines were created on the initiative of the Videosurgery Chapter of the Association of Polish Surgeons and are recommended by the national consultant in the field of general surgery. The first part of the guidelines covers 5 sections and the following challenges for surgical practice: diagnostic laparoscopy, perforated ulcer, acute pancreatitis, incarcerated hernia and acute cholecystitis. Contraindications for laparoscopy and the ERAS program are discussed.

Recommendations for modern perioperative care for elective surgery: consensus of panel of exerts.

INTRODUCTION: Correct surgical technique and perioperative care are two factors that can reduce the number of complications, improve treatment outcomes and shorten the length of hospital stay. The introduction of enhanced recovery protocols has changed the approach to patient care in some centers. However, there are significant differences among centers, and in some the standard of care has remained unchanged. AIM: the goal of the panel was to develop recommendations for modern perioperative care in accordance with current medical knowledge in order to reduce the number of complications associated with surgical treatment. An additional goal was to optimize and standardize perioperative care among Polish centers. MATERIALS AND METHODS: the development of these recommendations was based on a review of the available literature from the PubMed, Medline and Cochrane Library databases from January 1, 1985 to March 31, 2022, with particular emphasis on systematic reviews and clinical recommendations of recognized scientific societies. Recommendations were formulated in a directive form and were assessed using the Delphi method. RESULTS AND CONCLUSIONS: 34 recommendations for perioperative care were presented. They cover aspects of pre-, intra- and post-operative care. Implementation of the presented rules allows to improve the results of surgical treatment.

Nomogram-Based Prognostic Evaluation of Gastric Cancer Patients with Low Counts of Examined Lymph Nodes Outperforms the Predictive Ability of the 7th and 8th Editions of the American Joint Committee on Cancer Staging System.

BACKGROUND: The American Joint Committee on Cancer (AJCC) staging system has limited accuracy in predicting survival of gastric cancer patients with inadequate counts of evaluated lymph nodes (LNs). We therefore aimed to develop a prognostic nomogram suitable for clinical applications in such cases. METHODS: A total of 1511 noncardia gastric cancer patients treated between 1990 and 2010 in the academic surgical center were reviewed to compare the 7th and 8th editions of the AJCC staging system. A nomogram was developed for the prediction of 5-year survival in patients with less than 16 LNs evaluated (n = 546). External validation was performed using datasets derived from the Polish Gastric Cancer Study Group (n = 668) and the SEER database (n = 11,225). RESULTS: The 8th edition of AJCC staging showed better overall discriminatory power compared to the previous version, but no improvement was found for patients with < 16 evaluated LNs. The developed nomogram had better concordance index (0.695) than the former (0.682) or latest (0.680) staging editions, including patients subject to neoadjuvant treatment, and calibration curves showed excellent agreement between the nomogram-predicted and actual survival. High discriminatory power was also demonstrated for both validation cohorts. Subsequently, the nomogram showed the best accuracy for the prediction of 5-year survival through the time-dependent ROC curve analysis in the training and validation cohorts. CONCLUSIONS: A clinically relevant nomogram was built for the prediction of 5-year survival in patients with inadequate numbers of LNs evaluated in surgical specimens. The predictive accuracy of the nomogram was validated in two Western populations.

Selected Body Composition Parameters Analysis Based on Bioelectrical Impedance in Patients Operated for Gastrointestinal Cancer.

BACKGROUND/AIM: Bioelectrical Impedance Analysis is a method that evaluates body composition, useful in assessing the nutritional status of cancer patients. The analysis of its indicators may be helpful in predicting clinical course. The aim of the study was to evaluate the following body composition parameters: fat mass (FM), fat-free mass (FFM), skeletal muscle mass (SMM), muscle mass index (MMI), visceral fat (VF) and body mass index (BMI) measured before and after surgery in patients with gastrointestinal cancer and to determine the relationship between body composition and the course of treatment. PATIENTS AND METHODS: The study included 125 patients, aged 65-68, operated on due to gastric, pancreatic or colorectal cancer. Body composition was assessed with electrical bioimpedance before and on the fifth postoperative day. The severity of complications was assessed with the Clavien-Dindo classification. RESULTS: In the whole group of patients, the percentage of FM, VF, and BMI levels measured before surgery were significantly higher in curative surgery patients in comparison to palliative surgery patients, p<0.001. The MMI value was also significantly higher, p=0.045. In patients after curative surgery, the values of BMI and FM significantly decreased (BMI - p<0.001; FM - p=0.003) after the surgery. There was no relation between body composition parameters and severity of postoperative complications. CONCLUSION: In the investigated group, body composition differed between radical and palliative surgery groups. Surgery with curative intent produced more changes in body composition parameters in the early postoperative period than palliative surgery. These observations may be helpful in prehabilitation planning for such patients.

Effect of High-Intensity Strength and Endurance Training in the Form of Small Circuits on Changes in Lipid Levels in Men Aged 35-40 Years.

BACKGROUND: Blood lipid profiles consist of total cholesterol (TC) and its fractions, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), non-high-density lipoprotein cholesterol (non-HDL), and triglycerides (TG). For several decades, studies have examined the effects of various factors on lipid status and its association with the risk of developing arteriosclerosis and cardiovascular disease. The beneficial effects of increased physical activity on cardiovascular health have been demonstrated by appropriate modulation of lipid profiles. For individuals with low physical activity, the literature recommends engaging in various forms of training that can improve physical fitness and resting lipid status. The aim of the study was to examine whether a specific original training program improves lipid profiles to the levels recommended for the male population. METHODS: The study involved two equal (n = 15) groups of men (experimental and control groups, aged 35-40 years). The experimental group performed 60-min training sessions for 8 weeks (3 times a week) including a set of strength and endurance exercises. Before and after the training program, blood was drawn from both groups for serum determination of TC, HDL, LDL non-HDL, and TG, and a battery of four field physical performance tests was administered. RESULTS: Statistically significant decreases (TC by 19.3%, TG by 23.7%, LDL by 15%), a non-significant decrease (10% for non-HDL), and no change for HDL were found in the experimental group. Control group showed a statistically significant decrease, by 7.4% for TC. The results confirm the effectiveness of the proposed training in improving health indices. CONCLUSIONS: The 8-week training program met the health-related fitness paradigm recommended for physical activity in men aged 35-40 years. After the completion of the program, all the participants expressed their satisfaction from participating in a health-promoting experiment.

Polish Consensus on Gastric Cancer Diagnosis and Treatment - Update 2022.

This document - "Polish Consensus on Gastric Cancer Diagnosis and Treatment - Update 2022" - represents an expert consensus following a year's worth of dedicated effort by a team of specialists throughout 2021, put forward in a conference in December 2021 in Krakow, and finalized below for publication in 2022. The effective date of this document is June 14th 2022. The work that went into updating this consensus was made under auspices of the Polish Society of Surgical Oncology and the Association of Polish Surgeons.

Vitamin D-The Nutritional Status of Post-Gastrectomy Gastric Cancer Patients-Systematic Review.

Gastric cancer is a malignant neoplasm of the gastrointestinal tract, with one of the standard treatment methods remaining gastrectomy. The authors conducted a systemic review of the Medline and Embase databases concerning the serum vitamin D level in post-gastrectomy gastric cancer patients, regarding all articles published until 22 May 2022 according to the PRISMA guidelines. 18 studies with a total number of 908 gastric cancer survivors were included in the analysis. The initial rate of vitamin D deficiency in gastric cancer patients undergoing gastrectomy appears to be similar to the global population deficiency. In post-gastrectomy survivors, the level of 25(OH)D may remain stable or decrease, while the level of 1, 25(OH)2D remains normal. Supplementation with vitamin D results in an improvement in its serum concentration and positively affects bone mineral density, which is gradually reduced in post-gastrectomy survivors. Combining vitamin D supplementation with calcium and bisphosphonates enables us to obtain better results than vitamin D and calcium only. The type of surgery influences the level of serum vitamin D and its metabolites, with total or partial gastrectomy and maintenance of the duodenal food passage remaining the most important factors. There is a strong need for randomized, controlled trials that would investigate this matter in the future.

Prognostic value of lymph node ratio in resectable rectal cancer after preoperative short-course radiotherapy-results from randomized clinical trial.

PURPOSE: The value of the lymph node ratio (LNR) in patients with rectal cancer has not yet been unequivocally established. This study aims to assess the effect of the lymph node ratio on the prognosis of rectal cancer in patients operated after short-course preoperative 25 Gy radiotherapy, at 10-year follow-up. METHODS: This is a substudy based on data from a prospective randomized clinical trial. A total of 141 patients with resectable rectal cancer were included. Lymph node yield was compared in patients with short and long time intervals between radiotherapy and surgery. Survival curves were compared between patients with different ypN and LNR categories. Univariate and multivariate analyses were performed to identify independent prognostic factors for overall survival and disease-free survival. RESULTS: Survival and recurrence data were available for a median follow-up of 11.6 years. The lymph node yield did not differ significantly between the patients in the short- and long-interval groups. A greater difference in 10-year survival was observed in patients with LNR ≤ 0.41 and > 0.41 when compared to the ypN categories. Separate prognostic factor analyses were performed for the entire population and for subgroups that had < 12 and 12 lymph nodes resected. LNR was identified as an independent prognostic factor for overall survival, in multivariate analyses, for all patients and those with less than 12 retrieved lymph nodes. CONCLUSION: The lymph node yield is comparable in patients with different time intervals between radiation therapy and surgery. LNR better discriminates patients in terms of overall survival than ypN categories. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT01444495, date of registration: September 30, 2011.

Mo-MDSCs are pivotal players in colorectal cancer and may be associated with tumor recurrence after surgery.

Colorectal cancer (CRC) is the third most common malignancy. Its development and progression is associated with natural immunosuppression related, among others, to myeloid derived suppressor cells (MDSCs). Overall, 54 patients in different stage of CRC, before any treatment were recruited into the study. The analysis included flow cytometry evaluation of blood MDSCs subsets, correlation their level with the tumor stage and T cell subsets. In the case of 11 patients, MDSCs level was evaluated before and 3 days after surgery, and these patients were monitored for cancer recurrence over 5 years. The results showed that frequency of circulating MDSCs subsets is increased significantly in CRC patients, with highest level detected in most advanced tumor stages. Moreover, only monocytic MDSCs (Mo-MDSCs) positively correlate with regulatory Treg, and negatively with tumor Her2/neu specific CD8+ T cells. Circulating MDSCs, in contrast to tumor resident (mostly Mo-MDSCs), are negative for PD-L1 expression. Additionally, after surgery the blood level of Mo-MDSCs increases significantly, and this is associated with tumor recurrence during a 5-year follow-up. In conclusion, Mo-MDSCs are pivotal players in CRC-related immunosuppression and may be associated with the risk of tumor recurrence after surgery.

Preoperative radiotherapy 5 × 5 Gy and short versus long interval between surgery for resectable rectal cancer: 10-Year follow-up of the randomised controlled trial.

BACKGROUND: Studies on short-course preoperative radiotherapy in combination with total mesorectal excision for rectal cancer reported improved local control without clear survival benefits. The optimal fractionation and interval between radiotherapy and surgery are still under debate. We, therefore, aimed to report 10-year results of a randomized clinical trial (RCT, NCT01444495) comparing different time intervals between irradiation and surgery for rectal cancer. MATERIAL AND METHODS: Data from the RCT conducted at a single academic centre were reviewed based on regular control visits with the median follow-up of 12 years. Patients with rectal cancer were randomly assigned to short-course preoperative radiotherapy (5 × 5 Gy) followed by surgery 7-10 days (short interval) or 4-5 weeks (long interval) after the end of irradiation. The primary endpoint was the local recurrence rate at 5 years. The secondary endpoints included overall survival, disease-free survival, systemic recurrence rate, and downstaging. RESULTS: A total of 154 patients were randomly assigned to short (n = 77) or long interval (n = 77) surgery. The cumulative incidence of local recurrence at 10 years was 1.3% and 11.7% in the short and long-interval groups, respectively (p = 0.031). Accordingly, the incidence of systemic relapse was 14.3% versus 9.1% (p = 0.0319). There were no differences in the overall 10-year survival between patients subject to short and long-interval surgery (58% vs 61%, p = 0.754). However, patients with downstaging after radiotherapy had significantly better 10-year survival rates than non-responders. CONCLUSIONS: Short-course preoperative radiotherapy with delayed surgery demonstrated an increased risk of local relapse over a 10-year follow-up.

Preoperative Short-Course Radiotherapy and Surgery versus Surgery Alone for Patients with Rectal Cancer: A Propensity Score-Matched Analysis at 18-Year Follow-Up.

A significant problem for long-term rectal cancer survivors may be the late toxicity of radiotherapy. It creates the possible risk of developing second primary malignancy and a theoretical decrease in overall survival. This study aimed to assess the influence of short-course preoperative radiotherapy in patients with locally advanced rectal cancer on overall survival, local recurrence rate, and second malignancy at 18-year follow-up. The rectal cancer trial was conducted in a single tertiary center between February 1992 and June 2006. A total of 389 patients with locally advanced rectal cancer (cT2-cT4, cN0/+, cM0) were included in the study. Preoperative radiotherapy was conducted in 148 patients and 241 patients underwent surgery alone. The propensity-matched group consisted of 105 patients operated on after radiotherapy and 105 controls. The number of local recurrences was 7 (6.7%) in the preoperative radiotherapy group and 22 (21%) in the surgery alone group (p = 0.016). The 18-year survival analysis showed no survival benefit in the preoperative radiotherapy group (38% versus 48%, p = 0.107) but improved recurrence-free survival (81% versus 58%, p = 0.001). The preoperative short-course radiotherapy significantly decreases the risk of local recurrence in locally advanced rectal cancer and may improve recurrence-free survival without an increased risk of second primary malignancy.

Impact of disseminated tumor cells in the bone marrow on survival and disease progression in patients with left-sided colorectal cancer.

INTRODUCTION: Disseminated tumor cells (DTCs) are a subset of circulating tumor cells that migrate to the bone marrow. Colorectal cancer is a heterogeneous disease depending on the site of the primary tumor. OBJECTIVES: We aimed to assess the association between the presence of DTCs in the bone marrow and tumor characteristics as well as long­term treatment outcomes in patients with left­sided colorectal cancer. PATIENTS AND METHODS: This prospective study included 91 patients with left­sided colorectal cancer (37 with colon cancer and 54 with rectal cancer) treated between 2007 and 2012 in a single tertiary center. Fifteen patients had stage I cancer; 26, stage II; 26, stage III; and 24, stage IV. Overall survival and cancer relapse rates were compared between patients with different cancer stages and DTC status. RESULTS: Bone marrow DTCs were identified in 42 patients (46.1%). The prevalence of DTCs was not related to tumor infiltration depth, nodal involvement, distant metastasis, tumor stage, or primary tumor site. The 5­year overall survival rates were 59.5% and 53% in the DTC­positive and DTC­negative groups, respectively (P = 0.19). There was a notable trend favoring survival in patients with DTCs with stage II and III disease (both separately and when combined). The number of metachronous distant metastases was significantly lower in DTC­positive patients. CONCLUSIONS: The presence of DTCs in the bone marrow is not associated with primary tumor characteristics and seems to reduce metastasis formation in left­sided colorectal cancer. There is also a trend for improved overall survival in DTC­positive patients. These results are intriguing and warrant further confirmation.

T Regulatory CD4+CD25+FoxP3+ Lymphocytes in the Peripheral Blood of Left-Sided Colorectal Cancer Patients.

Background and objectives: T regulatory lymphocytes (Treg) are one of the subsets of T-lymphocytes involved in the interaction of neoplastic tumors and the host immune system, and they may impair the immune reaction against cancer. It has been shown that Treg are increased in the peripheral blood of patients with various cancers. In colorectal cancer, the prognostic role of Treg remains controversial. Colorectal cancer is a heterogenous disease, with many variations stemming from its primary tumor location. The aim of this study is to analyse the relationship between the amount of Treg in the peripheral blood of patients with left-sided colorectal cancer in various stages of disease and long-term survival. Materials and Methods: A prospective analysis of 94 patients with left-sided colorectal cancer and a group of 21 healthy volunteers was carried out. Treg levels in peripheral blood were analysed using flow cytometry. Results: There was a statistically significant difference between the amount of Treg in the Ist and IInd TNM stages (p = 0.047). The number of Treg in the entire study group was significantly lower than in the control group (p = 0.008) and between patients in stages II and III and the control group (p = 0.003 and p = 0.018). The group of pT3+pT4 patients also had significantly lower Treg counts in their peripheral blood than the control group (p = 0.005). In the entire study group, the level of Treg cells in the peripheral blood had no influence on survival. The analysis of the TNM stage subgroups also showed no difference in survival between patients with "low" and "high" Treg counts. Conclusion: The absolute number of Treg in the peripheral blood of patients with left-sided colorectal cancer was significantly decreased in comparison to healthy controls, especially for patients with stage II+III disease. Treg presence in the peripheral blood had no impact on survival.

Nutritional Status of Elderly Patients after Coronary Artery Bypass Surgery.

Surgical trauma can result in immobilization of biological material, degradation of muscle proteins, synthesis of acute-phase proteins in the liver, occurrence of catabolism phase and anabolism simultaneously, and as a consequence weight loss and nutritional deficiencies. The aim of this study was to assess the nutritional status of patients with ischemic heart disease subjected to coronary artery bypass surgery and physical activity and postoperative complications. The analysis among 96 men included total number of lymphocytes (TNL), body mass index (BMI), case history of a patient and results of laboratory tests. The activities of daily living (ADL) and the mini nutritional assessment (MNA) questionnaires were used. According to TNL, before the procedure malnutrition occurred in 46% of patients. BMI revealed overweight in 62.5% and obesity in 26.0%. After the surgery, no changes were observed. According to MNA, 59% of patients before the surgery were at risk of malnutrition. After the operation, the number of people at risk of malnutrition increased by 50% (p < 0.0001). The correlation was noted between BMI and patients' efficiency in the fifth day after the surgery (p = 0.0031). Complications after the surgery occurred in 35.4% of patients. After the surgery, the risk of malnutrition increased, decreased activity and complications occurred more frequently in people with underweight, obesity, and overweight than in people with normal BMI.

CD44+ cytokeratin-positive tumor cells in blood and bone marrow are associated with poor prognosis of patients with gastric cancer.

BACKGROUND: The phenotypic heterogeneity of circulating tumor cells (CTC) in peripheral blood and disseminated tumor cells (DTC) in bone marrow is an important constraint for clinical decision making. Here, we investigated the implications of two different subpopulations of these cells in gastric cancer (GC). METHODS: GC patients (n = 228) who underwent elective gastric resections were prospectively examined for CTC/DTC. The cells obtained from peripheral blood and bone marrow aspirates were sorted by flow cytometry and CD45- cells expressing cytokeratins (8, 18, and 19) and CD44 were identified by immunofluorescent double staining. RESULTS: Ninety-three (41%) patients had cytokeratin-positive tumor cells in either blood or bone marrow, while cells expressing CD44 were found in 22 (10%) cases. CK+CD44+ cells were significantly more common among patients with distant metastases (50 vs 19%, P = 0.001), while no such correlations were demonstrated for CK+CD44- cells. Detection of CK+CD44+ cells, but not CK+CD44-, was associated with significantly shortened survival. Moreover, the Cox proportional hazards model identified CK+CD44+ cells as a negative prognostic factor with an odds ratio of 2.38 (95% CI 1.28-4.41, P = 0.006). CONCLUSION: CD44+ phenotype of cytokeratin-positive cells in blood and bone marrow is an independent prognostic factor in patients with gastric cancer.