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“Background Gastric cancer is the second leading cause of cancer-related death worldwide [1]. Substantial geographic variations exist in the incidence of gastric cancer and it represents the most common cancer in China [2]. More and more gastric cancer patients have been diagnosed in recent years with changing diet and lifestyle as well as developing diagnostic

procedures. Although surgical treatment has shown to be effective for some early gastric cancers, including total gastrectomy and extended radical gastrectomy, the prognosis of these patients is poor due to the recurrence after surgery, in the form of lymphatic spread, blood-borne metastasis, or peritoneal dissemination [3]. The prognosis of patient check details with gastric cancer has been shown to be influenced by several established surgical-pathological features, such as the pathological stage, the location of the tumor and the histological type and grade of the tumor [4]. While Aurello et al. [5] have indicated that the number of nodes necessary to conclude N0 may vary according to the depth of tumor invasion (T), the TNM classification requires the retrieval and analysis of at least 15 lymph nodes for accurate staging. However, in most cases, the number of nodes

dissected is smaller and only 20 to 30% of the patients mTOR inhibitor have the recommended minimum dissection of 15 nodes. Accessorial indicators which can provide further information of the prognosis of gastric cancer patients are needed. Cancer-associated fibroblast (CAF), one of the important stromal cells comprising solid tumors, has been found to play prominent role in promoting tumor growth and progression [6]. In contrast to resting fibroblasts, CAFs possess an activated phenotype and can be identified by their expression of fibroblast-specific MycoClean Mycoplasma Removal Kit protein 1 (FSP1), vimentin, desmin, and α-smooth-muscle actin [7]. CAFs communicate among themselves as well as with cancer cells and inflammatory and immune cells directly through cell contact and indirectly

through paracrine/exocrine signaling, proteases, and modulation of the extracellular Ion Channel Ligand Library matrix (ECM). This complex communications network is pivotal to providing the appropriate microenvironment to support tumorigenesis, angiogenesis, and metastasis [8, 9]. Additionally, compared to transformed tumor cells, CAFs are more genetically homogeneous [10] and it has been demonstrated by Gastavo et al that reactive stroma can act as a predictor of recurrence in prostate cancer [11], thus represent an attractive predictor and therapeutic target for tumor patients. In this study, we collected 100 cases of surgical resection specimens of primary gastric cancer as well as normal gastric tissues (more than 5 cm far from tumor tissue) from January 2007 to June 2007 in the Second Military Medical University affiliated Changhai hospital (Shanghai, China).