Chest?regional recurrence and metastasis are the main modes of treatment failure after surgery for patients with esophageal cancer. As one of the primary approaches for local therapy, radiotherapy has a satisfactory efficacy in the reduction of postoperative chest?regional recurrence in patients with esophageal cancer. Right now, the value of postoperative adjuvant therapy for patients with positive lymph nodes has been widely recognized by clinicians. Postoperative adjuvant chemoradiotherapy has become a standard treatment mode. However, there is no consensus on whether adjuvant radiotherapy should be performed in patients with negative lymph nodes. To determine whether patients with stage pN0 esophageal cancer should receive postoperative adjuvant therapy, this paper reviews the current research advances in possible evidence for the necessity of postoperative adjuvant radiotherapy for patients with stage pN0 esophageal cancer, current related reports, and the effects of different surgical methods on treatment outcomes of postoperative adjuvant therapy.

From 1970 to 1984,100 patients with esophageal cancer survived over 10 years after radiotherapy alone. In theis group 58 male, 42 female; section of upper thoracic 53, section of middle thoracic 47; medullary type 82, fungoid type 14; tumor length ≤5cm 49, 5.1～7.0cm 34, 7.1～9.0cm 17. They were teated by three or four intersecting radiation, total doses were 50～70Gy. 9 patients received second radiotherapy for local relapse. In 100 patients, 58 patients still survived , 42 patients died of local relapse 18, bleeding 6 and fistula 4. 5 patients suffered from radiation myelitis and 3 patients fracture of rib in 58 living patients. Conclusion: the result of treatment is better in group of young people. Patients with supraclavicular metastasis have received seccond radiotherapy after first raditherapy could still survive for a long time. Local relapse is the important factor for death yet. We think total dose is adapted between 50～70Gy. The spinal received dose

Purpose: At present ,the local control of esophageal carcinoma have been improved by using intra-cavitary irradiation, but the complications a much more than before. It is necessary to study the real condition of these complications.Materials and Methods: From August 1993 to May 1994,38 patients with esophageal carcinoma were treated with external beam combined with intra-cavitary radiotherapy in our hospital. Conventional radiotherapy was used 200cGy/F,5F/W.When the dose of external beam reached 3800cGy/19F,intra-cavitary radiotherapy was added with the dose of 500cGy/F/W(patient did not receive the external beam at the same day). The total dose of external and intra-cavitary radiotherapy were 5000cGy/25F/5W and 1500cGy/3F/3W at end of the course respectively.Results: ① 68.4%(26/38) patients had esophagitis.②25 patients suffered from the non-carcinoma esophagostenosis, which was related to the length of tumor before treatment, the shade of soft tissue around lesion, the esophagitis, the diameter of esophagus cavitary and stiff of esophagus wall before intracavitary radiotherapy.③10 of 38 cases had non-carcimoma ulcer. All patients had received 1500cGy/3F/3W intracavitary radiotherapy and occured serious esophagitis, 7 of 10 suffered from the non-carcinoma stricture and ulcer before or later.④ 6 of 38 cases had the fistula and 5 patients had been exposed 1500cGy/3F/3W intracavitary radiotherapy.Conclusion: Esophageal carcinoma treated by afterloading techniques may improve the serious obstruction immediately, but it is not sure the long-term survial yet. We also find the increasing serious complications and the decreasing life quality by using this treatment.We suggests that this method only can be used as an auxilliary way with the external beam radiotherapy.

Objective To study the dose distribution of intra-cavitary NiTi metal-stent for correction in radiotherapy of esophageal carcinoma.Methods Thermoluminescence Dosimeter(TLD) with LiF dose units was used to simulate the dose variation in wax phantom with or without Chinese and Japanese metal stents in esophageal lumen on 60Co, 4 MV X-ray and 6 MV X-ray machines. The dose distribution on the stent fringe (i.e.,on the esophageal mucosa) was compared with that at the center of esophagus without metal stent.Results When a single anterior field was used to irradiate the esophageal carcinoma, the dose enhancement on the anterior and posterior point of the Chinese metal stent was 16.2% and 7.8% by 60Co,15.4% and 6.8% by 4 MV X-ray and 12.8% and 5.8% by 6 MV X-ray. With the same set-up, the dose enhancement of Japanese stent was 13.0% by 6 MV X-ray. When anterioposterior and posterioanterior (AP/PA) opposing fields were used ,the dose enhancement ratio was 11.7%～24.0%. When three fields from three different directions were used ,the dose were increased by 3.2～16.2%.Conclusions When irradiating esophageal carcinoma with intra-cavitary metal stent,we suggest the fraction dose be below 1.7 Gy when one field is used and not exceed 1.5 Gy when AP/PA fields are used. It is advisable to use the three field technique with the diameter of the stent limited to 1.5 cm.

Objective To study the correlation between dose-volummetrics and changes of pulmona- ry function tests(PFTs), and to study the ability of standard dose-volummetrics to predict these changes after radiotherapy. Methods Pulmonary function was measured in 39 patients with inoperable lung cancer one week before and 2-4 months after radiotherapy. The pulmonary function parameters were the forced vital ca- pacity(FVC), forced expiratory volume in ls (FEV 1.0) and diffusion capacity of carbon monoxide(DL- CO). Dose-volumrnetrics were V_(10), V_(15), V_(20), V_(25), V_(30), V_(35), V_(40), CTV_(100), CTV_(95), CTV_(90), CTV_(80), lung D_(mean), V_(eff) and NTCP. Pearson and line regression analysis was performed to determine whether the correlation exis- ted between the metrics and the changes of PFTs. Results No correlation was found between the dose- volummetrics and the changes in PFTs. Excluding patients(n=15) with pretreatment atelectasis, signifi- cant correlation was found between the dose-volummetrics (V_(20), V_(25), V_(30), V_(35), V_(40), GTV, V_(eff) and D_(mean)) and the PFTs changes(r=0.469-0.695, P≤0.05). Therefore, the re-expansion may have jesperdized the proper data to the present record. Multivariate analysis showed that V_(30) was the risk factor to affect the chan- ges of FEV 1.0 and DLCO(P=0.046、0.041). The pulmonary function of patients with V_(30)≥18% was worse than patients with V_(30)

Objective To evaluate the possibility of using preoperative conventional lung function tests and impulse oscilloresistometry system (IOS) to predict the development of postoperative respiratory failure after radical lung cancer surgery in patients with poor pulmonary function. Methods Fifty-two male patients with lung cancer between 51-63 yrs undergoing radical lung cancer surgery were included in this study. Preoperative pulmonary function was assessed by conventional lung function tests ( FEV1.0 , VC, MVV) and impulse oscilloresistometry system (IOS) (peripheral airway resistance R5-R20; elastic resistance ( X5 ) and Fres. Postoperative respiratory failure was defined as short of breath (SOB) , cyanosis, SpO2 45 mm Hg.Results Nine patients developed postoperative respiratory failure (17.3%). There was significant difference in FEV1.0 , R5-R20, X5 and Fres between patients who developed postoperative respiratory failure and those who did not. Logistic regression analysis showed that Fres is an independent factor predicting respiratory failure. Conclusion Fres is an important parameter of impulse oscilloresistometry system (IOS) for prediction of postoperative respiratory failure after lung cancer surgery in patients with poor pulmonary function.

Objective To investigate the effect of antisense VEGF on radiation sensitivity of esophageal cancer cells in vivo.Methods Sixteen male BLBA/C/nu nude mice were randomly divided into 4 groups and prepared cells were injected subcutaneously on paw pat of mice(2?106/100 ?L/mice): The size of the subcutaneous tumors was measured before and after irradiation and transfection.The effect of treatment was evaluated by speed of tumor growth. The expression level of VEGF was examined in different groups by RT-PCR,western blotting respectively.Results The absolute growth delay (AGD)for antisene group, irradiation group and antisene plus irradiation group was 3.0?2.6, 10.1?5.4 and 27.4?3.1 days,and nominal growth delay (NGD) was 24.4?3.1 days. The enhancement factor of antisense VEGF for radiotherapy was 2.41. A decreased expression level of endogenous VEGF mRNA and protein were found in antisene group by RT-PCR and western blotting analysis.Conclusion Antisense VEGF and radiotherapy may enhance radiotherapic effect for esophageal cancer xenografts.

Objective To study the expression of proliferating cell nuclear antigen (PCNA), metastasis-related gene nm23-H1 in supratentorial astrocytomas, and analyze the prognostic factors and the relationship between PCNA expression, nm23-H1 expression and clinical, MRI features.Methods From November 1994 to December 1998, 52 pathologically proved astrocytoma patients with complete clinical data were analyzed. The expressions of PCNA and nm23-H1 were detected by streptabitin peroxidase (SP) immunohistochemical method. Clinical and MRI data were collected and analyzed by Cox proportional hazard model .Results There was a significant difference in the expressions of PCNA and nm23-H1 in the lesion and their adjacent tissues (P

Objective To investigate the effects of inhibition of MDC1 protein expression on xenografted tumors in nude mice,and to observe the histopathological and cellular changes in nude mice.Methods Three pairs of effective and control short hairpin RNA targeting MDC1 mRNA were designed and cloned into the pSIH1-H1-copGFP vector.Real-time PCR and Western blot were used to determine the mRNA and protein expression of MDC1.After selection by copGFP reporter gene,cells were divided into negative transfection group (ECA109-N) and MDC1 transfection group (ECA109-M).The transfected cells were injected into nude mice.The mice were divided into ECA109 group,ECA109-N group,and ECA109-M group.Each group was divided into irradiation subgroup and non-irradiation subgroup.The changes in tumor size after irradiation were evaluated in each group.Western blot was used to measure the expression of CHK1,CHK2,and CHK2T68 in xenografted tumors.Flow cytometry was used to analyze the cell cycle distribution and apoptosis of tumor cells in nude mice.The variance analysis was used to compare the mean of multiple groups,and the SNK-q test was used in the two two groups.Results The pMDC1-shRNA plasmid was successfully constructed and used to transfect ECA109 cells.ECA109-M cells were obtained by stable transfection with the recombinant plasmid.All inoculated nude mice survived with visible xenografted tumors at the underside of the paw in about one week.There was no swelling and wound in inoculation sites.There was no significant difference in tumor size between different groups (P＞0.05).The tumor growth in the ECA109 group and the ECA109-N group significantly slowed down after irradiation with a dose of 15 Gy (P＜0.05).Compared with the other two groups,the ECA109-M group had a significant smaller tumor size,significantly slower relative tumor growth,and significantly higher growth inhibition (all P＜0.05).The q value of the ECA109-M group was 1.36.In the ECA109-M group,there were no significant changes in the protein expression of CHK1 and CHK2 after irradiation (P＞ 0.05);however,the phosphorylation of CHK2T68 protein was significantly reduced after irradiation (P＜0.05).There were no significant differences in cell cycle distribution or the proportion of apoptotic cells in tumor tissue between the three groups (P＞0.05).Conclusions Inhibition of MDC1 protein expression by RNA interference can effectively inhibit the growth of xenografted tumors after irradiation in the nude mice by increasing their radiosensitivity.

Objective To apply RNA interference technique for reducing the expression of MDC1 gene in esophageal carcinoma cell line ECA109, observe the changes in cell cycle and radiosensitivity after radiation, and discuss related mechanisms. Methods Three pairs of effective interference sequences and negative control sequences were synthesized for MDC1 mRNA sequence, and a recombinant plasmid was constructed with the vector pSIH1?H1?copGFP. RT?PCR and Western blot were used to determine the expression levels of MDC1 mRNA and protein. Colony?forming assay was applied to measure radiosensitivity, flow cytometry to determine cell cycle, Western blot to determine the expression of CHK1 and CHK2 proteins, and laser scanning confocal microscope to observe the number of MDC1 blotches inside the nucleus. One?way analysis of variance was used to analyze the differences between groups. Results The pSIH1?H1?copGFP plasmid was constructed successfully and ECA109 cells were infected to obtain ECA109M cells with stable transfection. The expression levels of MDC1 mRNA and protein in ECA109M cells were lower than those in ECA109N and ECA109 cells ( P= 0. 032 and 0. 041, respectively ) . After 5?Gy radiation, ECA109M cells had a lower proportion of G2+M cells than ECA109N and ECA109 cells ( P=0. 026) . After 5?Gy radiation, ECA109, ECA109N, and ECA109M cells had similar expression levels of CHK1 and CHK2 proteins ( P= 0. 345 and 0. 451, respectively ) , and ECA109M cells had a lower expression level of CHK2 T68 protein than ECA109 and ECA109N cells ( P=0. 012) . ECA109 cells had a D0 value of 3. 06 Gy and an SF2 value of 0. 91;the D0 values for ECA109N and ECA109M cells were 2. 90 Gy and 1. 88 Gy, respectively, and the SF2 values for them were 0. 89 and 0. 84, respectively ( P=0. 021 and 0. 037, respectively ) . Conclusions RNA interference can reduce the expression levels of MDC1 protein and cell cycle?related proteins, release cell cycle arrest, and enhance radiosensitivity in esophageal carcinoma ECA109 cells.