Value of high resolution magnetic resonance imaging for preoperative evaluation of Denonvilliers fascia in patients with rectal cancer / 中华胃肠外科杂志

Objective: Total mesorectal excision (TME) is the gold standard for surgical treatment of mid-low rectal cancer, but the postoperative incidence of urination and sexual dysfunction is relatively high. Preserving the Denonvilliers fascia (DF) during TME can reduce the postoperative incidence of urination and sexual dysfunction. In this study, high resolution magnetic resonance imaging (MRI) was used to observe the imaging performance and display of DF, so as to determine the value of this technique in preoperative evaluation of the preservation of DF. Methods: A descriptive cohort study was carried out. Clinical data of patients with rectal cancer who underwent TME and received preoperative high-resolution MRI at department of Gastrointestinal Surgery, the Third Affiliated Hospital of Sun Yat-sen University from August 2015 to June 2017 were retrospectively analyzed. The characteristics of DF were examined, and the shortest distance (d) between the anterior edge of tumor and DF was measured on high-resolution MRI. The distance d was compared between patients with stage T1-T2 and those with stage T3. Receiver operating characteristic (ROC) analysis was used to determine the predictive value of d for stage T1-T2 disease. Results: Thirty-two patients were enrolled in the study, including 27 males and 5 females with mean age of (62.9±8.9) years. DF was visualized in 96.9% (31/32) of cases on the T2WI sequence. The mean distance d in patients with stage T1-T2 disease (n=23) was (6.73±2.65) mm, and in those with stage T3 disease (n=9) was (1.30±1.15) mm (t=5.893, P<0.001). A cutoff of d >3 mm yielded specificity and positive predictive value for diagnosing stage T1-T2 disease of both 100%, sensitivity of 95.7% and negative predictive value of 90%. The optimum threshold of d was >3.05 mm, and Youden index was 0.957. Conclusions: High-resolution MRI can show the DF and accurately evaluate the relationship of DF with tumor in rectal cancer patients. Analysis on d value can provide an objective basis for the safe preservation of DF.

Mechanical properties and cytocompatibility of a new-type nano-bionic anti-adhesion hernia mesh / 中国组织工程研究

BACKGROUND:A new-type nano-bionic anti-adhesion hernia mesh was developed in our previous research.OBJECTIVE:To investigate the mechanical properties and cytocompatibility of the new-type nano-bionic anti-adhesion hernia mesh.METHODS:The tensile strength of the compound hernia mesh was detected using a textile detector.Mouse fibroblasts (L929) were cultured with the compound hernia mesh,and cell structures on the mesh surface were observed under electron microscope at 1,3,5 days after culture.In addition,L929 cells were co-cultured with compound hernia mesh,polypropylene patch,and polyester patch,respectively.Cells cultured alone were used as negative controls.After 1,3,5 days of culture,MTS array was used to detect cell proliferation and evaluate cytotoxicity;after 3 days of culture,western blot was used to detect the content of type Ⅰ and Ⅲ collagens.RESULTS AND CONCLUSION:The average tensile strength of the compound hernia mesh was 31.2 N The number of fibroblasts on the nanofibrous layer of the compound hernia mesh increased as long as cultured.The cells spread along the nanofibers and pseudopodia extended from the cells formed polygon and fusiform structures,with a good cross-linking with the mesh.A complete cell layer covered all pores of the nanofibers at 5 days.The cytotoxicity of the nanofibrous layer of the compound hernia mesh was graded 0,and the cytotoxicity was graded 1 of polypropylene and polyester patches.All the three kinds of patches fulfilled the implantation requirements,and the compound hernia mesh had better biological properties.No significant differences were found among groups in the contents of type Ⅰ and Ⅲ collagens at 3 days of culture.To conclude,the new-type nano-bionic anti-adhesion hernia mesh has good mechanical properties and cytocompatibility.

Predictive models of adjuvant chemotherapy for patients with stage ii colorectal cancer: A retrospective study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>It remains controversial whether patients with Stage II colorectal cancer would benefit from adjuvant chemotherapy after radical resection. The aim of this study was to establish two mathematical models to identify the suitable patients for adjuvant chemotherapy.</p><p><b>METHODS</b>The current study comprised of two steps. In the first step, 353 patients with Stage II colorectal cancer who underwent surgical procedures at the Third Affiliated Hospital of Sun Yat-sen University between June 2006 and December 2015 were entered and followed up for 6-120 months. Their clinical data were collected and enrolled into the database. We established two mathematical models by univariate and multivariate Cox regression analysis to identify the target patients; in the second step, 230 patients under the same standard between January 2012 and December 2016 were entered and followed up for 3-62 months to verify the two models' validation.</p><p><b>RESULTS</b>In the first step, totally 340 surgical patients with Stage II colorectal cancer were finally enrolled in this study. Statistical analysis showed that tumor differentiation (TD) (P < 0.001), lymphovascular invasion (LVI) (P < 0.001), uncertain or positive margins (UPM) (P < 0.001), and fewer lymph nodes (LNs) (<12) retrieved (P < 0.001) were correlated with the overall survival (OS) and disease free survival (DFS). We obtained two models: (1) OS risk score = 1.116 × TD + 2.202 × LVI + 3.676 × UPM + 1.438 × LN - 0.493; (2) DFS risk score = 0.789 × TD + 2.074 × LVI + 3.183 × UPM + 1.329 × LN - 0.432. According to the models and cutoff points [(0.07, 1.33) and (-0.04, 1.30), respectively], patients can be divided into three groups: low-risk, moderate-risk, and high-risk. Moreover, the high-risk group patients could benefit from adjuvant chemotherapy. In the second step, totally 221 patients were finally used to verify the models' validation. The results proved that the models were accurate and feasible (P< 0.05).</p><p><b>CONCLUSIONS</b>According to the predictive models, patients with Stage II colorectal cancer in the high-risk group are strongly recommended for adjuvant chemotherapy, thus facilitating the individualized and precise treatment.</p>

Laparoscopy-assisted combined radical resection for synchronous rectal and gastric cancer in elderly patients: report of two cases / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the safety and feasibility of laparoscopy-assisted combined radical resection for synchronous rectal and gastric cancer in elderly patients.</p><p><b>METHODS</b>Clinical data of two elderly patients undergoing laparoscopy-assisted combined radical resection for synchronous rectal and gastric cancer were analyzed retrospectively.</p><p><b>RESULTS</b>The two cases were 78 and 75 years old respectively. Both were complicated with many medical conditions. One case suffered from stage II cancer in the gastric body and stage IB rectal cancer, and the other suffered from stage IIIA gastric cancer and stage IB rectal cancer. Both cases had received laparoscopy-assisted combined radical resection for synchronous rectal and gastric cancer, with 5 cm of incision. The operative time was 260 and 255 min and the intraoperative bleeding was 60 and 80 ml respectively. No complication occurred intraoperatively. Time to resume oral intake was 4 and 5 days and length of postoperative hospital stay was 13 and 14 days respectively. No postoperative complication occurred. The patients were followed up for 13 and 12 months and no postoperative recurrence or metastasis was noticed.</p><p><b>CONCLUSION</b>Laparoscopy-assisted combined radical resection for elderly synchronous rectal and gastric cancer is safe and feasible when performed by surgeons with plentiful experience in laparoscopic technology, and associated with less injury and faster recovery.</p>

Comparison of laparoscopy-assisted distal gastrectomy with open gastrectomy for advanced gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility, safety and short-term outcomes of laparoscopy-assisted distal gastrectomy for advanced gastric cancer.</p><p><b>METHODS</b>From January 2007 to June 2008, 135 patients with advanced gastric cancer in the lower or middle stomach were operated, of whom 66 underwent laparoscopy-assisted distal gastrectomy(LADG) with D2 dissection of lymph nodes and 69 received conventional open D2 distal gastrectomy(ODG). Clinical data were recorded and compared between the two groups.</p><p><b>RESULTS</b>There were no significant differences in age, gender, and TNM staging between LADG and ODG(all P>0.05). All the patients in the LADG group underwent gastrectomy and lymph nodes dissection successfully without conversion to open surgery and no operative deaths occurred. The operative time was significantly longer for the LADG group than for the ODG group[(266.1±55.1) min vs. (223.8±26.8) min)]. The patients in the laparoscopic surgery group had less blood loss[(131.9±88.7) ml vs.(342.3±178.7) ml], earlier recovery of bowel activity[(3.18±1.22) d vs.(4.50±1.59) d], and shorter hospitalization time[(9.20±3.39) d vs. (11.35±4.61) d]. No significant differences were found in the total number of retrieved lymph nodes(25.81±12.53 vs. 27.47±10.28). The morbidity of complications was comparable between two groups(6.1% vs. 15.94%). No mortality and recurrence were observed during a follow-up period of 1-19 months.</p><p><b>CONCLUSIONS</b>LADG with D2 lymph node dissection is a safe and feasible procedure with adequate lymphadenectomy for advanced gastric cancer.</p>

Expression and its significance of retinoic acid receptor-beta in colorectal cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the expression and its significance of retinoic acid receptor-beta (RAR-beta) in colorectal cancer.</p><p><b>METHODS</b>RAR-beta was detected by immunohistochemistry methods and carcino-embryonic antigen (CEA) was tested by chemiluminescence immunoassay methods in normal tissues, paracancerous tissues and colorectal cancer tissues of 60 patients with colorectal cancer treated from January 2006 to January 2007. Above-mentioned data, together with the clinicopathological data of these 60 patients, were analyzed to figure out the expression and its significance of RAR-beta in colorectal cancer.</p><p><b>RESULTS</b>The expression rate of RAR-beta in tumor tissues (48%) was significantly lower than those in both normal tissues (87%) and paracancerous tissues (87%) (P < 0.05). And its expression was also significant lower in patients with lymph node metastasis (32%) and patients with advanced cancer (TNM stage III and IV) (29%) than in those without lymph nodes metastasis (60%) and those with early stage cancer (stage I and II) (69%). There was no significant differences among well, mildly and poorly differentiated cancer tissues. The CEA level rose in 20 patients, and its rising rate was remarkably higher in patients with lymph node metastasis (48%) and in patients with advanced cancer (52%) than those without lymph node metastasis (23%) and in early stage(14%).</p><p><b>CONCLUSIONS</b>The expression of RAR-beta decreases significantly in cancer tissues in patients with colorectal cancer, which may be related to the carcinogenesis of colorectal cancer; and its decreasing degree is correlated negatively with the lymph node metastasis and advanced clinicopathological stage. The expression level of RAR-beta may be a new prognostic indication of patients with colorectal cancer.</p>

Gene expression profile difference between colorectal cancer tissue and pericancerous mucosa by DNA microarray / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the difference of gene expression profile among colorectal cancer tissue, pericancerous mucosa and normal mucosa, and to screen associated novel genes in colorectal carcinogenesis by DNA microarray.</p><p><b>METHODS</b>cDNA chip containing approximate 8000 genes was used to detect differentially expressed genes in colorectal cancer tissues, pericancerous mucosa and normal mucosa, and to screen associated novel genes in colorectal carcinogenesis by DNA microarray.</p><p><b>RESULTS</b>As compared with normal mucosa, 769 genes differentially expressed in cancerous tissue were identified, which included 363 up-regulated and 406 down-regulated genes. In pericancerous mucosa 3 cm away from cancerous tissues, 155 genes differentially expressed were identified, of whom 52 genes were up-regulated and 103 were down-regulated. In pericancerous mucosa 5 cm away from cancerous tissues, 230 genes differentially expressed were identified, of whom 46 genes were up-regulated and 184 genes were down-regulated. The genes expressed differentially were associated with several functional types. According to the primary results, the differentially expressed genes with prominent functions included tumor-related genes, genes regulating cell proliferation and apoptosis, transcriptional control genes, and construction and degradation of extracellular matrix-associated genes. The cancerous mucosa was obviously different from the normal mucosa(about 20%, 769/3944). The differences between the normal mucosa and pericancerous mucosa were relatively small (3.9%,5.8%).</p><p><b>CONCLUSIONS</b>Different tissues have their own biological property. Several genes play roles in the development of colorectal carcinogenesis. Genes in adjacent non-cancerous tissues are also expressed differentially, leading to a malignant change.</p>

Effect of all-trans retinoic acid on drug sensitivity and expression of survivin in LoVo cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>All-trans retinoic acid (ATRA) can influence the tumor cell proliferation cycle, and some chemotherapeutic drugs are cycle specific. In this study, we hypothesize that ATRA can enhance chemotherapeutic drug sensitivity by affecting the cell cycle of tumor cells.</p><p><b>METHODS</b>The cell cycle of LoVo cells was evaluated using flow cytometry (FCM). Cell viability was analyzed using the MTT assay. The morphologic changes in the treated LoVo cells were measured with acridine orange (AO)/ethidium bromide (EB) staining. Expression of survivin in LoVo cells was analyzed by immunofluorescence assay.</p><p><b>RESULTS</b>After LoVo cells were treated with ATRA, the G0/G1 ratio of the tumor cells increased and the cell ratio of S- and G2/M-phase decreased. Viability of the cells decreased significantly after combined treatment with ATRA and 5-fluorouracil (5-FU) or mitomycin c (MMC) and was evaluated by fluorescence microscopy. Expression level of survivin in the tumor cells decreased after ATRA combination treatment.</p><p><b>CONCLUSIONS</b>ATRA enhances drug sensitivity of the LoVo cell line to cell cycle-specific agents and inhibits the expression of survivin in LoVo cells. The combination of ATRA and 5-FU or MMC promoted cell apoptosis, and the mechanism involved in apoptosis may be related to inhibition of survivin gene expression.</p>