Recent advances in photodynamic diagnosis of gastriccancer using 5-aminolevulinic acid

Photodynamic diagnosis based on 5-aminolevulinic acidinduced protoporphyrin IX has been clinically applied in many fields based upon its evidenced efficacy and adequate safety. In order to establish a personalized medicine approach for treating gastric cancer patients, rapid intraoperative detection of malignant lesions has become important. Feasibility of photodynamic diagnosis using 5-aminolevulinic acid for gastric cancer patients has been investigated, especially for the detection of peritoneal dissemination and lymph node metastasis. This method enables intraoperative realtime fluorescence detection of peritoneal dissemination, exhibiting higher sensitivity than white light observation without histopathological examination. The method also enables detection of metastatic foci within excised lymph nodes, exhibiting a diagnostic accuracy comparable to that of a current molecular diagnostics technique. Although several complicating issues still need to be resolved, such as the effect of tissue autofluorescence and the insufficient depth penetration of excitation light, this simple and rapid method has the potential to become a useful diagnostic tool for gastric cancer, as well as urinary bladder cancer and glioma.

Feasible endoscopic therapy for early gastric cancer

AIM: To analyze the relationship between lymph node metastasis and clinical pathology of early gastric cancer(EGC) in order to provide criteria for a feasible endoscopic therapy.METHODS: Clinical data of the 525 EGC patients who underwent surgical operations between January 2009 and March 2014 in the West China Hospital of Sichuan University were analyzed retrospectively. Clinical pathological features were compared between different EGC patients with or without lymph node metastasis, and investigated by univariate and multivariate analyses for possible relationships with lymph node metastasis.RESULTS: Of the 2913 patients who underwent gastrectomy with lymph node dissection, 529 cases were pathologically proven to be EGC and 525 cases were enrolled in this study, excluding 4 cases of gastric stump carcinoma. Among 233 patients with mucosal carcinoma, 43(18.5%) had lymph node metastasis. Among 292 patients with submucosal carcinoma, 118(40.4%) had lymph nodemetastasis. Univariate analysis showed that gender, tumor size, invasion depth, differentiation type and lymphatic involvement correlated with a high risk of lymph node metastasis. Multivariate analysis revealed that gender(OR = 1.649, 95%CI: 1.091-2.492, P = 0.018), tumor size(OR = 1.803, 95%CI: 1.201-2.706, P = 0.004), invasion depth(OR = 2.566, 95%CI: 1.671-3.941, P = 0.000), histological differentiation(OR = 2.621, 95%CI: 1.624-4.230, P = 0.000) and lymphatic involvement(OR = 3.505, 95%CI: 1.590-7.725, P = 0.002) wereindependent risk factors for lymph node metastasis. Comprehensive analysis showed that lymph node metastasis was absent in patients with tumor that was limited to the mucosa, size ≤ 2 cm, differentiated and without lymphatic involvement.CONCLUSION: We propose an endoscopic therapy for EGC that is limited to the mucosa, size ≤ 2 cm, differentiated and without lymphatic involvement.

The potential of carcinoembryonic antigen,p53,Ki-67 and glutathion Stransferase-π as clinico-histopathological markers for colorectal cancer

Objective： Colorectal cancer is one of the major contributors to cancer death worldwide. Lack of reliable colorectal cancer markers has hampered the management of these cancer patients. Our main purpose was to study the correlation between histopathological variables of colorectal adenocarcinomas and identify histopathological markers that are of prognostic value in patients with colorectal cancer. Methods： In the present study, we examined the expression of carcinoembryonic antigen （CEA）, p53, Ki-67 and glutathion Stransferase （GST） -n by using immunohistochemical staining methods in 126 colorectal carcinoma patients and evaluated the lymph node metastasis status in these patients by histopathological examination. Results： The positive rates of CEA, p53, Ki-67 and GST-π expression in the colorectal cancer tissue specimens examined were 95.23%, 55.56%, 53.38% and 82.30%, respectively. Expression of p53 and Ki-67 was significantly correlated with the Dukes stages of the tumor, with higher levels of these proteins in Dukes＇ C and D tumors than those in Dukes＇ A and B tumors. Furthermore, the expression of p53, GST-π and Ki-67 correlated with prognosis of patients with colorectal cancer. Additionally, the expression of p53 in colorectal cancer was closely related to the expression of Ki-67 and the expression of GST-π was directly correlated with that of p53. Conclusion： The expression of CEA, p53, Ki-67 and GST-π was correlated with various clinical features of patients with colorectal cancer. The combined use of these histopathological markers appeared to be a promising tool in predicting the prognosis of patients with this type of cancer.