ObjectiveTo detect methylation status of the 5'CpG island locating in the promoter region of p27 gene in gastric carcinoma and to analyze the relationship between the aberrant methylaion of p27 gene and the bionomics of gastric carcinoma.MethodsMethylation-specific PCR were used to detect the methylation status of p27 in gastric carcinoma( n =49), adjacent tissue of carcinoma ( n =20) and normal tissue(n =10), respectively.ResultsThe mathylation rate is 49％ (24/49) for gastria cancer, 25％(5/20) for tumor-sideward mucosa and 0 (0/10)for normal mucosa.There was a significant positive correlation between gastric carcinoma specimens and normal mucosa specimens ( P ＜ 0. 05 ). There was no significant diference between normal gastric group and tumor-sideward mucosa group ( P ＞ 0. 05 ) and no significant diference between tumor-sideward mucosa group and tumor group ( P ＞ 0. 05 ). The mathylation rate of p27 gene with lymph node metastases (61％) are higher than those without metastasis (28％) (P ＜ 0. 05). And there is no relation on patients' age, sex, tumor size and location.Conclusionp27 gene methylation of the p27 gene is correlated to oncogenesis and metastasis of gastric carcinoma and could lead to the loss of p27mRNA transcription.

Objective To investigate the expression of EphrinB2 and microvessel density(MVD) in colorectal carcinoma and to analyze the relationship between the expression of EphrinB2 and the biological characteristics of colorectal carcinoma. Methods EphrinB2 and MVD of 63 colorectal carcinoma diagnosed by pathology were examined by immunohistochemistry, and 25 specimens from normal colorectal tissue were examined as controls. Results The expression of EphrinB2 protein was 82.0 % (51/63) in colorectal carcinoma and 32.0 % (8/25) in the normal colorectal tissues, the difference was significant (P <0.05). Meanwhile, MVD was significantly higher in EphrinB2 positive group (39.39±8.97) than that in negative group (33.00 ±10.19) (P<0.05). The expression of EphrinB2 protein had significant positive correlation with differentiation grade, infiltration, lymph node metastases and clinical stage (P <0.05), and had no relation to age, sex, tumor size and location(P >0.05). Conclusion The EphrinB2 protein expression increase may be involved in development of colorectal carcinoma and play important roles in the tumorigenesis and progression of colorectal carcinoma.

Objective To explore the relationship between the abnormal expression of anti-oncogene PTEN in gastric carcinoma and the clinicopathological characteristics. Methods Mythylation specific PCR was applied to detect the expression of PTEN methylation in gastric carcinoma and their normal tissues from 45 patients. Results The methylation took place in 40.0 percent in gastric carcinoma and 2.2 percent in their normal tissues, and the difference was significant(P<0.05). The methylation rate in poorly differentiated adenocarcinoma was 60.0 percent ,while 15.0 percent in highly-moderately differentiated group, the difference was significant (P<0.05). In the 24 cases with lymph node metastasis, mythylation was observed in 13 cases, and the difference was significant (P<0.05). Conclusion The methylation of PTEN gene was associated with gastric carcinoma, it may play an important role in the development of the disease.

Objective To examine the frequency and mode of distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Methods Thirty-four specimens from low and middle rectal cancer were collected between August 2004 and December 2005 in Cancer Center of Sun Yat-sen University. Twenty-eight specimens of low and middle rectal cancer were collected between October 2006 and October 2007 in Shandong Provincial Hospital of Shandong University. All 62 specimens were studied using large slices stained with CK20. Logistic regression was used to analyze clinicopathologic factors related to distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Results Two types of distal spread of the tumor were observed in rectal wall: submucosa invasion and muscularis propria invasion. Distal spread in rectal wall was observed in 16% (10/62) of the patients. The length of distal spread in rectal wall was found from O. 5 cm to 1.0 cm. Four types of distal spread of the tumor were observed in mesorectum: lymph node invasion, blood and lymphatic vessel invasion, perineural invasion, isolated neoplastic microfoci. Distal spread in mesorectum was observed in 24% (15/62) of the patients. The length of distal spread in mesorectum was found from 0. 5 cm to 4. 0 cm. Three more cases with microcapillary invasion in distal mesorectum was observed by immunohistochemical technique, which was difficult to identify by conventional HE staining. Univariate analysis showed that serum CEA , lymph node invasion, CMI and TNM stage were correlated with distal spread of low and middle rectal cancer in the mesorectum and rectal wall. TNM stage was shown to be independent impact factor by multivariate analysis( Wald = 9. 567, P =0. 002). Conclusion TNM stage is an independent impact factor for distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Resection of 1.5 cm for distal rectal wall is necessary for a curative intention, but it must be emphasized that the clearance for distal mesorectum should be 5 cm at least.

Objective:To evaluate the impact of bladder volume on dosimetric parameters of clinical target volume (CTV) and organs at risk (OAR) of intensity modulated proton therapy (IMPT) for localized prostate cancer during the treatment planning and daily treatment.Methods:Clinical data of 25 patients with localized prostate cancer admitted to Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine from November 2021 to June 2022 and enrolled in the "Proton Therapy System" (SAPT-PS-01) registered clinical trial were retrospectively analyzed. All patients were male and the median age was 72 years old. A total of 30 sets of IMPT plans were obtained. Based on the planning CT (30 sets) and weekly verification CT during treatment (172 sets), bladder volume, CTV and OAR dose parameters were collected. Spearman correlation analysis was used to evaluate the correlation between bladder volume in CT and the dosimetric parameters of CTV and OAR during IMPT plans, and Wilcoxon-Mann-Whitney test was adopted to compare the dosimetric parameters of CTV and OAR among different bladder volume change groups.Results:The V 95% of CTV1 and CTV2 were both 100.0%±0.0% in IMPT plans. Bladder volume was significantly negatively correlated with D mean, V 70 Gy(RBE), V 60 Gy(RBE), V 50 Gy(RBE), V 40 Gy(RBE) of the bladder ( P<0.001, 0.003, <0.001, <0.001,<0.001), and D mean, V 50 Gy(RBE) of the small intestine (both P<0.001). During treatment, bladder D mean, V 70 Gy(RBE), V 60 Gy(RBE), V 50 Gy(RBE), V 40 Gy(RBE)( P<0.001, 0.001, <0.001, <0.001, <0.001), rectal D mean, V 50 Gy(RBE), V 40 Gy(RBE) (all P<0.001), small intestine D mean, V 50 Gy (RBE) (both P<0.001) of patients with bladder volume increase >20% compared to baseline were significantly decreased compared to those in IMPT plans. But CTV1 V 100%, and CTV2 V 95% were significantly decreased too( P=0.029, 0.020). In the bladder volume decreased>20% patients, the D mean, V 70 Gy(RBE), V 60 Gy(RBE), V 50 Gy(RBE), V 40 Gy(RBE) of the bladder were significantly increased compared to those in IMPT plans (all P<0.001). However, a bladder volume reduction of ≤20% and increase of ≤20% from baseline had no significant impact on CTV and OAR dosimetric parameters during treatment. Conclusions:For patients with localized prostate cancer undergoing proton therapy, a certain bladder volume should be ensured during planning CT scans. During the daily treatment, the bladder volume should be maintained between 80%-120% of the baseline level to ensure CTV coverage and good dose sparing to OAR.