Interaction analysis of high-risk pathological features on adjuvant chemotherapy survival benefit in stage II colon cancer patients: a multi-center, retrospective study.

BACKGROUND: We aimed to analyze the benefit of adjuvant chemotherapy in high-risk stage II colon cancer patients and the impact of high-risk factors on the prognostic effect of adjuvant chemotherapy. METHODS: This study is a multi-center, retrospective study, A total of 931 patients with stage II colon cancer who underwent curative surgery in 8 tertiary hospitals in China between 2016 and 2017 were enrolled in the study. Cox proportional hazard model was used to assess the risk factors of disease-free survival (DFS) and overall survival (OS) and to test the multiplicative interaction of pathological factors and adjuvant chemotherapy (ACT). The additive interaction was presented using the relative excess risk due to interaction (RERI). The Subpopulation Treatment Effect Pattern Plot (STEPP) was utilized to assess the interaction of continuous variables on the ACT effect. RESULTS: A total of 931 stage II colon cancer patients were enrolled in this study, the median age was 63 years old (interquartile range: 54-72 years) and 565 (60.7%) patients were male. Younger patients (median age, 58 years vs 65 years; P < 0.001) and patients with the following high-risk features, such as T4 tumors (30.8% vs 7.8%; P < 0.001), grade 3 lesions (36.0% vs 22.7%; P < 0.001), lymphovascular invasion (22.1% vs 6.8%; P < 0.001) and perineural invasion (19.4% vs 13.6%; P = 0.031) were more likely to receive ACT. Patients with perineural invasion showed a worse OS and marginally worse DFS (hazardous ratio [HR] 2.166, 95% confidence interval [CI] 1.282-3.660, P = 0.004; HR 1.583, 95% CI 0.985-2.545, P = 0.058, respectively). Computing the interaction on a multiplicative and additive scale revealed that there was a significant interaction between PNI and ACT in terms of DFS (HR for multiplicative interaction 0.196, p = 0.038; RERI, -1.996; 95%CI, -3.600 to -0.392) and OS (HR for multiplicative interaction 0.112, p = 0.042; RERI, -2.842; 95%CI, -4.959 to -0.725). CONCLUSIONS: Perineural invasion had prognostic value, and it could also influence the effect of ACT after curative surgery. However, other high-risk features showed no implication of efficacy for ACT in our study. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov, NCT03794193 (04/01/2019).

Laparoscopic resection of large retrorectal developmental cysts in adults: Single-centre experiences of 20 cases.

Context: Retrorectal tumours are rare with developmental cysts being the most common type. Conventionally, large retrorectal developmental cysts (RRDCs) require the combined transabdomino-sacrococcygeal approach. Aims: This study aims to investigate the surgical outcomes of the laparoscopic approach for large RRDCs. Settings and Design: A retrospective case series analysis. Subjects and Methods: Data of patients with RRDCs of 10 cm or larger in diameter who underwent the laparoscopic surgery between 2012 and 2017 at our tertiary centre were retrospectively analyzed. Statistical Analysis Used: Results are presented as median values or mean ± standard deviation for continuous variables and numbers (percentages) for categorical variables. Results: Twenty consecutive cases were identified (19 females; median age, 36 years). Average tumour size was 10.9 ± 1.1 cm. Cephalic ends of lesions ranged from S1/2 junction to S4 level. Caudally, 18 cysts extended to the sacrococcygeal hypodermis. Seventeen patients underwent the pure laparoscopy; three patients received a combined laparoscopic-posterior approach. The operating time was 167.1 ± 57.3 min for the pure laparoscopic group and 212.0 ± 24.5 min for the combined group. The intraoperative haemorrhage was 68.2 ± 49.7 and 66.7 ± 28.9 (mL), respectively. Post-operative complications included one trocar site hernia, one wound infection and one delayed rectal wall perforation. The median post-operative hospital stay was 7 days. With a median follow-up period of 36 months, 1 lesions recurred. Conclusions: The laparoscopic approach can provide a feasible and effective alternative for large RRDCs, with advantages of the minimally invasive surgery. For lesions with ultra-low caudal ends, especially those closely clinging to the rectum, a combined posterior approach is still necessary.

Prognostic Superiority of Log Odds of Positive Lymph Nodes in Stage 3 Colorectal Cancer.

Objective To evaluate the prognostic value of the log odds of positive lymph nodes (LODDS) in stage 3 colorectal cancer (CRC) patients who have undergone curative resection. Methods We performed a retrospective review of 175 stage 3 CRC patients who underwent curative resection in Peking Union Medical College Hospital from 2005 to 2012. Patients were categorized respectively according to the AJCC/UICC N grade,the metastatic lymph node ratio (LNR),and the ratio of their LODDS. The relationship between the N grade,LNR,LODDS,and overall survival (OS) rates were assessed.Results The five-year disease-free survival (DFS) was significantly different among stage 3 CRC patients in different N grade (Χ(2)=33.1,P=0.000),LNR (Χ(2)=14.3,P=0.001),and LODDS (Χ(2)=14.9,P=0.001). Univariate analysis showed that TNM stage (Χ(2)=27.0,P=0.000),cancerous node(Χ(2)=3.6,P=0.040),N grade (Χ(2)=33.1,P=0.000),LNR (Χ(2)=14.3,P=0.001),and LODDS (Χ(2)=30.4,P=0.000) were related to OS. Multivariate analysis indicated that TNM stage (HR:1.84,95%CI:1.59～6.29,P=0.001) and LODDS classification (HR:1.34,95%CI:1.01～1.80,P=0.047) were independent prognostic factors for OS in stage 3 CRC patients. Conclusion LODDS is a good prognostic indicator in stage 3 CRC patients who have undergone curative resection.

[Outcome of laparoscopic radical right hemicolectomy with complete mesocolic resection and D3 lymphadenectomy].

OBJECTIVE: To investigate the feasibility of laparoscopic approach for totally mesocolic resection and D3 lymphadenectomy in right colectomy. METHODS: A retrospective study was conducted to analyze the operating time, blood loss, lymph node retrieval, postoperative complications and converting rate. The relationships of 3-year disease-free survival (DFS), 3-year overall survival (OS) to gender, age, American Society of Anesthesiologists (ASA) score, body mass index (BMI), T-staging, N-staging and TNM classification were also analyzed by Kaplan-Meier surviving curve and Log-rank test. RESULTS: A total of 111 patients were enrolled in present study. There were 50 male and 61 female patients. The average operating time was (168 ± 42) minutes, blood loss was (81 ± 63) ml, lymph node retrieval was (30 ± 12). The converting rate to open surgery was 1.8%. There was no death within 30 days after operation. The 3-year DFS and 3-year OS was 86.5% and 93.7% respectively. The short-term complications occurred in 17.1% of the patients, including diarrhea (7 cases), ileus (3 cases), urinary infection (3 cases), wound dehiscence (2 cases) and so on. With the T staging progress, DFS and OS in patients showed a gradual decline, but the difference did not reach statistical significance (P > 0.05). TNM classification had relation to DFS (χ(2) = 6.985, P = 0.030), while N-staging showed significant relations both to DFS and OS (χ(2) = 14.397, P = 0.001; χ(2) = 16.699, P = 0.000). CONCLUSION: Laparascopic approach to right hemicolectomy with complete mesocolic resection and D3 lymphadenectomy is safe and has satisfied oncological outcome.

Laparoscopic excision for intrapelvic schwannoma of the sciatic nerve: A case report.

Schwannoma is a benign tumor of the nerve sheath originating from Schwann cells. The tumor rarely occurs in the sciatic nerve. The patient in the present case report was a 58-year-old woman presenting with pain in the right hip and leg, as well as numbness of the right lower limb. Magnetic resonance imaging revealed a solid tumor of 2.9 cm in diameter in the right pelvic space. The mass was considered to be a neurogenic tumor originating from the right sciatic nerve. Total laparoscopic surgery was performed to safely separate the tumor from the surrounding tissues, with preservation of the right sciatic nerve. The pathological result suggested a schwannoma. The patient recovered well with a transient numbness in the right heel. The laparoscopic approach used for this intrapelvic schwannoma of the sciatic nerve was safe and feasible, with the advantages of a magnified surgical field and small skin incision. However, the specific surgical approach should be based on the detailed condition of each patient and the experience of the surgeon with regard to laparoscopic surgery on benign presacral tumors and rectal tumors.

Comparison of safety of loop ileostomy and loop transverse colostomy for low-lying rectal cancer patients undergoing anterior resection: A retrospective, single institution, propensity score-matched study.

INTRODUCTION: This study was to compare the prevalence of stoma-related complications and stoma reversal perioperative complications of patients with low-lying rectal cancer who received preventative loop ileostomy and those who underwent loop transverse colostomy. METHODS: This retrospective single-center study analyzed the clinicopathologic and surgical data of 288 patients with pathologically proven primary rectal cancer who underwent anterior resection with either preventative loop ileostomy (n = 82) or loop transverse colostomy. To achieve comparability of a propensity score matching method was used to match patients from each group in a 1:2 ratio. Determinants of stoma-related complications were analyzed by multivariate logistic regression analysis. RESULTS: Forty-nine (74.3%) patients in the loop ileostomy group experienced stoma-related complications versus 48.7% in the loop transverse colostomy group (P < 0.01). Irritant dermatitis was the most frequent complication in both groups. The loop ileostomy group had a significantly higher rate (24.24%) of stoma reversal perioperative complications than the loop transverse colostomy group. Multivariate logistic regression analysis showed that ileostomy versus loop transverse colostomy was a significant independent risk for stoma-related complications and stoma reversal perioperative complications. Furthermore, by Clavien-Dindo classification, patients receiving loop ileostomy had an overall higher rate of complications and stoma reversal perioperative complications versus those undergoing loop transverse colostomy (P < 0.01). The rate of grade II complications was significantly higher in the loop ileostomy group (43.9%) than that of loop transverse colostomy group (13.5%, P < 0.01), whereas the rate of grade I, and grade IIIa and IIIb complications and stoma reversal perioperative complications was comparable between the two groups. CONCLUSION: The study has demonstrated that loop transverse colostomy is associated with significantly lower rates of stoma-related complications and stoma reversal perioperative complications compared to loop transverse colostomy.

[A comparative study upon two surgical procedures of local resection of early rectal cancer].

OBJECTIVE: To compare the application of transanal endoscopic microsurgery (TEM) technique with Mason's operation in the treatment of early rectal cancer. METHODS: Patients with early rectal cancer were divided into two groups according to different surgical procedures they underwent during different period. Patients in Mason Group underwent Mason's operations during the period from January 2000 to March 2006; and in TEM Group were managed with TEM procedures from April 2006 to July 2011. There were 21 patients in TEM Group and 26 patients in Mason Group. No statistically significant difference was found between the two groups in terms of patient's age, gender, preoperative TNM staging, and tumor diameter. In comparison with Mason Group, TEM Group had a longer distance of the tumor from the anal verge. The safety, postoperative complications, patients' postoperative recovery, and the oncological outcomes of 2 groups were compared with each other. RESULTS: No perioperative death occurred in the two groups. The TEM Group had notably shorter operating time ((67 ± 24) minutes) and lesser intra-operative blood loss ((9 ± 6) ml) than Mason Group (t = 3.526 and 7.078, P < 0.05). The time of the postoperative bed rest, the urinary drainage, the recovery of oral intake, and the hospital stay in TEM Group were (1.3 ± 0.5) days, (1.2 ± 0.4) days, (1.5 ± 0.5) days, and (4.3 ± 1.6) days, respectively, and all were prominently shorter than those of Mason group (t = 4.925 - 14.640, P < 0.05). Patients in TEM group were followed up for an average of 36.5 months with one patient being lost, while patients in Mason group were followed up for an average of 81.6 months. The difference between the two groups in terms of short-term accumulated survival (94.8% vs. 96.3%) showed no statistical significance (P > 0.05). CONCLUSION: TEM technique is a favorable minimally invasive procedure associated with satisfactory oncological outcomes in the treatment of early rectal cancer.

[Acquiring laparoscopic skill for colorectal surgery: based on the experience of a colorectal surgeon].

OBJECTIVE: Laparoscopic colorectal surgery is a skill-dependent procedure. The present study aims to analyze the learning curve of a properly trained surgeon, with basic laparoscopic techniques, to become skillful in performing laparoscopic colorectal operations. METHODS: A series of non-selective, consecutive 189 cases of laparoscopic colorectal surgery were accomplished, from December 2009 to February 2012, by one surgeon with years of skilled technique in laparoscopic cholecystectomy, rich experience in assisting laparoscopic colorectal surgery, and experience of approximately 180 procedures of gastric and colorectal surgery annually. 170 out of 189 procedures were radical operations for colorectal neoplasma, including right colectomies in 28 cases, left colectomies in 5 cases, sigmoidectomies in 28 cases, high Dixon procedures in 45 cases, low Dixon (total mesorectal excision, TME) procedures in 41 cases and Miles procedure in 23 cases. 19 other patients underwent combined procedures for multi-primary tumors or inflammatory enteritis. All these procedures were analyzed according to time span (the earlier half and later half) in respect to length of surgery, intraoperative blood loss, number of lymph nodes retrieved, intraoperative events and postoperative complications. RESULTS: For radical right colectomy, the D2 dissection conducted in the earlier phase (n = 8) had the similar length of surgery, more blood loss and less LN retrieval, compared with the D3 dissection conducted in recent phase (n = 20). The earlier performed high Dixon procedures (n = 22) consumed longer time than the later procedures (n = 23) consumed, but with similar blood loss and LN retrieval. Low Dixon (TME) procedures showed significant differences in length of surgery and blood loss relative to time span. Recently performed simoidectomy and Miles procedures showed a trend of shorter time consumed compared with earlier performed procedures. Conversion ratio to open surgery was 1.05%. Adverse effects occurred in 8 cases of surgeries, including intestinal injury (3/189), insufficient distal margin (2/189), intraoperative bleeding (2/189) and vaginal injury (1/76). There was no operative death. Chief complications included urinary retention 5.82%, ileus 4.76%, anastomotic leak 4.24%, perineal infection 23.08% (6/26), wound dehiscence 2.65%, gastrointestinal bleeding 1.59%, peritoneal infection 1.06%. Surgery for distal rectum tended to have more complications, such as urinary retention, anastomotic leak and perineal infection. The later performed low Dixon procedures produced insignificantly fewer anastomotic leaks than those in the earlier phase. CONCLUSIONS: For a trained surgeon with basic laparoscopic techniques, there are at least 15 - 25 cases of different procedures needed for him/her to become skilled to perform laparoscopic surgery. The learning curve should also depend on the annual number of colorectal surgeries.

Comparing the techniques and outcomes of laparoscopic transverse colectomy to laparoscopic hemicolectomy in mid-transverse colon cancer resection.

Introduction: The mid-transverse colon cancer is relatively uncommon in all colon cancers and the optimal surgical approach of mid-transverse colon cancer remains debatable. Aim and Objectives: Our study aimed to depict the techniques and outcomes of laparoscopic transverse colectomy in one single clinical center and compare this surgical approach to traditional laparoscopic right hemicolectomy and laparoscopic left hemicolectomy. Method: This was a retrospective cohort study of patients with mid-transverse colon cancer in one single clinical center from February 2012 to October 2020. The enrolled patients were divided into two groups undergoing laparoscopic transverse colectomy and laparoscopic right/left hemicolectomy, respectively. The intraoperative, postoperative complications, oncological outcomes and functional outcomes were compared between the two groups. The primary endpoint was disease free survival (DFS). Results: The study enrolled 70 patients with 40 patients undergoing laparoscopic transverse colectomy and 30 patients undergoing laparoscopic hemicolectomy. The intraoperative accidental hemorrhage and multiple organ resection occurred similarly in the two groups. In transverse colectomy, caudal-to-cephalic approach was likely to harvest more lymph nodes although require more operation time than cephalic-to-caudal approach (23.1 ± 14.3 vs. 13.4 ± 5.4 lymph nodes, P = 0.004; 184.3 ± 37.1 min vs. 146.3 ± 44.4 min, P = 0.012). The laparoscopic transverse colectomy was marginally associated with lower incidence of overall postoperative complications and shorter postoperative hospital stay although without statistical significance (8(20.0%) vs. 12(40.0%), P = 0.067; 7(5-12) vs. 7(5-18), P = 0.060). The 3-year DFS showed no significant difference (3-year DFS 89.7% in transverse colectomy vs. 89.9% in hemicolectomy, P = 0.688) between the two groups. The alternating consistency of defecation occurred significantly less after laparoscopic transverse colectomy than laparoscopic hemicolectomy (15(51.7%) vs. 20(80.0%), P = 0.030). Conclusion: The laparoscopic transverse colectomy is technically feasible with satisfactory oncological and functional outcomes for mid-transverse colon cancer. Performing the caudal-to-cephalic approach might be more advantageous in lymphadenectomy.

Serial Circulating Tumor DNA in Predicting and Monitoring the Effect of Neoadjuvant Chemoradiotherapy in Patients with Rectal Cancer: A Prospective Multicenter Study.

PURPOSE: We investigated the value of circulating tumor DNA (ctDNA) in predicting tumor response to neoadjuvant chemoradiotherapy (nCRT), monitoring tumor burden, and prognosing survival in patients with locally advanced rectal cancer (LARC). EXPERIMENTAL DESIGN: This prospective multicenter trial recruited 106 patients with LARC for treatment with nCRT followed by surgery. Serial ctDNAs were analyzed by next-generation sequencing at four timepoints: at baseline, during nCRT, presurgery, and postsurgery. RESULTS: In total, 1,098 mutations were identified in tumor tissues of the 104 patients being analyzed (median, seven mutations/patient). ctDNA was detected in 75%, 15.6%, 10.5%, and 6.7% of cases at the four timepoints, respectively. None of the 29 patients with pathologic complete response (ypCR) had preoperative ctDNA detected. The preoperative ctDNA-positive rate was significantly lower in the well-responded patients with pathologic tumor regression grade of ypCAP 0-1 than ypCAP 2-3 group (P < 0.001), lower in ypCR than non-ypCR group (P = 0.02), and lower in pathologic T stage (ypT) 0-2 than ypT 3-4 group (P = 0.002). With a median follow-up of 18.8 months, 13 patients (12.5%) experienced distant metastasis. ctDNA positivity at all four timepoints was associated with a shorter metastasis-free survival (MFS; P < 0.05). Multivariate analyses showed that the median variant allele frequency (VAF) of mutations in baseline ctDNA was a strong independent predictor of MFS (HR, 1.27; P < 0.001). CONCLUSIONS: We show that ctDNA is a real-time monitoring indicator that can accurately reflect the tumor burden. The median VAF of baseline ctDNA is a strong independent predictor of MFS.

An unusual case of acute lower gastrointestinal bleeding due to fungal infection.

A 63-year-old woman was admitted to our hospital with herpes zoster viral infection and intermittent disorder of consciousness. On day 13 of hospitalization for glucocorticoid treatment, the patient experienced seven episodes of hematochezia. She had a 2-year history of systemic lupus erythematosus and had undergone splenectomy at 40 years of age. Computed tomography and electronic endoscopy revealed bleeding and contrast agent leakage into the splenic flexure of the colon. The patient underwent an emergency exploratory laparotomy and left hemicolectomy for suspected active hemorrhaging into the digestive tract. Pathological examination revealed that the bleeding had been caused by a fungal infection. No further hemorrhaging occurred after the surgery, suggesting that intestinal fungal infection might be a potential differential diagnosis for gastrointestinal bleeding in compromised hosts.

Comparison of safety of loop ileostomy and loop transverse colostomy for low-lying rectal cancer patients undergoing anterior resection: A retrospective, single institute, propensity score-matched study.

PURPOSE: To compare the prevalence of stoma-related complications and stoma reversal perioperative complications of patients with low-lying rectal cancer who received preventative loop ileostomy and those who underwent loop transverse colostomy. METHODS: This retrospective single-center study analyzed the clinicopathologic and surgical data of 288 patients with pathologically proven primary rectal cancer who underwent anterior resection of rectal cancer with preventative loop ileostomy or loop transverse colostomy between January 2012 and July 2017 at the Department of General Surgery, Peking Union College Hospital. The patients were allocated to the ileostomy group (n=82) and the loop transverse colostomy group (n=206). To achieve comparability of the ileostomy group and the loop transverse colostomy group with regard to potential confounding variables, a propensity score-matching method was used to match patients from each group in a 1:2 ratio. Determinants of stoma-related complications were analyzed by multivariate logistic regression analysis. RESULTS: The propensity score-matched loop ileostomy group (n=66) and the loop transverse colostomy group (n=111) were comparable in patient demographic and baseline characteristics. Forty-nine (74.3%) patients in the loop ileostomy group experienced stoma-related complications vs 48.7% in the loop transverse colostomy group (p<0.001). Irritant dermatitis was the most frequent complication in both groups. The loop ileostomy group had a significantly higher rate (24.24%) of stoma reversal perioperative complications than the loop transverse colostomy group (9.01%, p=0.008). Multivariate logistic regression analysis showed that ileostomy vs loop transverse colostomy was a significant independent risk for stoma-related complications (Odds ratio/OR 3.495; 95%CI 1.741, 7.018; p<0.001) and stoma reversal perioperative complications (OR 2.124; 95%CI 1.010, 4.512; p< 0.05). CONCLUSION: This study has demonstrated that loop transverse colostomy is associated with significantly lower rates of stoma-related complications and stoma reversal perioperative complications compared to loop transverse colostomy. Prospective controlled studies with a larger patient population are warranted to examine the efficacy and safety of loop ileostomy and loop transverse colostomy.

[Laparoscopic segmental gastrectomy for early gastric cancer].

OBJECTIVE: To investigate the feasibility of segmental pylorus-reservation gastrectomy in patients with early gastric cancer. METHOD: A retrospective cohort study on clinical data of 6 patients strictly met the criteria of early gastric cancer locating in the middle of the stomach undergoing laparoscopic segmental gastrectomy from January 2014 to April 2016 at Department of General Surgery, Peking Union Medical College Hospital was carried out. Preoperative clinical staging revealed T1N0M0 for all the cases. One case received endoscopic mucosa resection(EMR) first, and postoperative pathology showed moderate differentiated adenocarcinoma invading substratum of mucosa, so a complementary laparoscopic segmental gastrectomy was performed. Surgical procedure was laparoscopic segmental gastrectomy with D1 or D2 lymph node dissection. Vagus nerve was not reserved during lymph node dissection in lesser curvature side. Number of resected lymph node, postoperative complication and long-term gastric function were observed. RESULT: Of 6 cases, 3 were male and 3 were female with age ranging from 55 to 59 years old. The distal resection margin was (4.6±0.5) cm away from pylorus. The average number of resected lymph node was 18.3±7.5 without metastasis. Follow-up time was 1 to 29 months for all the 6 cases and no relapse or metastasis was found during the follow-up. In 4 cases with follow-up beyond 1 year, 3 cases had slight distension in superior belly after meal and dyspepsia; another one case had vomiting nocturnal occasionally. Gastroscope examination one year after operation found food residue in all the cases. Images indicated the decrease of stomach size in all the cases. Two cases had esophagogastric reflux. All the patients had delayed gastric emptying symptoms after operations and were relieved within one year. CONCLUSIONS: It is technically feasible to perform laparoscopic segmental gastrectomy in patients with early gastric cancer. Whether vagus nerve should be reserved requires further investigation.

[A pilot study on the impact of the drug resistance on the radioresistance in human pancreatic cancer cell lines].

OBJECTIVE: To investigate the impact of the drug resistance on the radioresistance in human pancreatic cancer cell lines. METHODS: Three drug resistant pancreatic cancer cell sublines induced by fluorouracil (5-FU), adriamycin (ADM) and gemcitabine respectively, SW1990/FU, SW1990/ADM and SW1990/Gz, were tested for the cell cycle and radio-sensitivity with flow cytometry and clonogenic assay. RESULTS: Compared with SW1990, the cell cycle assay indicated higher G(0)/G(1) period percentage in SW1990/FU and SW1990/Gz, but the G(2)/M period percentage decreased; SW1990/FU had the same while SW1990/Gz had lower S period percentage. SW1990/ADM almost had a similar cell cycle with SW1990. Clonogenic assay showed both SW1990/FU and SW1990/Gz had greater survival fraction (SF(2)) than SW1990, but SW1990/ADM had seemingly similar SF(2) as SW1990. CONCLUSION: Drug resistant pancreatic cancer cell lines have reduced G(2)/M period percentage and increased radioresistance.

Laparoscopic restorative proctocolectomy with ileal pouch-anal anastomosis for Peutz-Jeghers syndrome with synchronous rectal cancer.

We report on a patient diagnosed with Peutz-Jeghers syndrome (PJS) with synchronous rectal cancer who was treated with laparoscopic restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). PJS is an autosomal dominant syndrome characterized by multiple hamartomatous polyps in the gastrointestinal tract, mucocutaneous pigmentation, and increased risks of gastrointestinal and nongastrointestinal cancer. This report presents a patient with a 20-year history of intermittent bloody stool, mucocutaneous pigmentation and a family history of PJS, which together led to a diagnosis of PJS. Moreover, colonoscopy and biopsy revealed the presence of multiple serried giant pedunculated polyps and rectal adenocarcinoma. Currently, few options exist for the therapeutic management of PJS with synchronous rectal cancer. For this case, we adopted an unconventional surgical strategy and ultimately performed laparoscopic restorative proctocolectomy with IPAA. This procedure is widely considered to be the first-line treatment option for patients with ulcerative colitis or familial adenomatous polyposis. However, there are no previous reports of treating PJS patients with laparoscopic IPAA. Since the operation, the patient has experienced no further episodes of gastrointestinal bleeding and has demonstrated satisfactory bowel control. Laparoscopic restorative proctocolectomy with IPAA may be a safe and effective treatment for patients with PJS with synchronous rectal cancer.

[Drug resistance and activity changes of thioredoxin reductase in pancreatic cancer cells strain SW1990 induced by gemcitabine].

OBJECTIVE: To establish gemcitabine-resistant pancreatic cancer cell strain and study the role of thioredoxin reductase (TrxR) in drug-resistant process. METHODS: Gemcitabine-resistant pancreatic cancer cell strain SW1990/GZ was induced by increasing drug dosage intermittently, then the changes of its biological features and the activity of TrxR were examined. RESULTS: Stable drug-resistant SW1990/GZ cell strain was established by culturing with gemcitabine for 9 months. The morphology and growth characteristics of the cell strain changed remarkably. The cells shrunk and became rounder; its endoplasm expanded; granular substances increased; and the doubling-time was prolonged. Resistance of the cell line to gemcitabine, fluorouracil, adriamycin, and mitomycin significantly increased. The TrxR activity of the drug-resistant cells was increased markedly. CONCLUSION: SW1990/GZ has certain multidrug resistance to some chemotherapy drugs, and TrxR plays a role in the drug-resistant process.

[Clinical application of anterior perineal plane for ultra-low anterior resection of the rectum].

OBJECTIVE: To summarize clinical experience in the treatment of low rectal cancer with anterior perineal plane for ultra-low anterior resection of the rectum(APPEAR). METHODS: Clinical and follow-up data of 26 patients with low rectal cancer undergoing the APPEAR operation in Department of General Surgery at Peking Union Medical College from September 2009 to August 2011 were retrospectively analyzed. RESULTS: The 26 cases consisted of 19 male and 7 female patients with an average age of (63.4 ± 9.5) years. The average tumor distance from the anal verge was (4.6 ± 0.7) cm according to preoperative examinations. Fourteen patients received neoadjuvant radiochemotherapy before the operation. All the 26 patients had successful sphincter-preserving operations. The average operative time was (170 ± 21) min and the average intra-operative blood loss (140 ± 69) ml. Complications included one case of intraoperative injury to the rectal wall and 4 cases of postoperative perineal wound infection. Postoperative pathological examination showed well to moderately differentiated adenocarcinomas(n=10), moderately differentiated adenocarcinomas with partial mucinous adenocarcinomas (n=7), poorly differentiated adenocarcinoma(n=1), villous adenoma with high-grade intraepithelial neoplasia (n=1), and rectal villous adenoma(n=1). In 6 cases no residual tumor cells were detected in the surgical specimens. All the patients were followed-up for an average period of(11.4 ± 5.6) months. No impaired urinary function or tumor recurrence was observed during the follow-up. Eighteen patients had the transverse colon stoma closure six months after the operation. The average Wexner continence score was 5.5 after colostomy reversal surgery. The anorectal manometry tests showed that maximum squeeze pressure of the anal sphincter was(224.0 ± 59.3) mm Hg. The maximum resting pressure was (42.5 ± 11.8) mm Hg, and the maximum tolerable volume of the rectum was (120.0 ± 27.4) ml. Anorectal reflexes were present in all these patients. CONCLUSION: The APPEAR technique can be applied in the sphincter-preserving operations for low rectal cancer patients with satisfactory anal function.

[Safety and efficacy of prophylactic single antibiotics administration in selective open colorectal surgery].

OBJECTIVE: To investigate the safety and efficacy of prophylactic single antibiotic administration in selective open colorectal surgery. METHODS: Two hundred and seventy-five patients undergoing selective open colorectal surgery in the Peking Union Medical College Hospital from October 2009 to October 2011 were retrospectively reviewed. Prophylatic single antibiotic administration was used by intravenous infusion 30-60 min before incision. No antibiotics would be given after operation if there was no surgical site infection(SSI). According to the incidence of postoperative SSI, unexplained use of antibiotics, anastomotic leakage and distant-site infection, the clinical outcome was assessed to be prophylactic success, prophylactic failure or distant-site infection, respectively. RESULTS: There was no intraoperative or postoperative antibiotics related drug anaphylaxis in all the 275 patients. By prophylactic single antibiotic administration, there were prophylactic success in 243 patients(88.4%,243/275), prophylactic failure in 23(8.4%,23/275), distant-site infection in 9(3.3%,9/275). In the 23 patients with failed prophylaxis, there were SSI in 13(4.7%,13/275) patients, postoperative use of broad-spectrum antibiotics for unexplained fever in 2(0.7%,2/275), postoperative anastomotic leakage in 8(3.6%,8/222). CONCLUSION: Prophylactic single antibiotic administration in selective open colorectal surgery is safe and effective.

[Hand-assisted laparoscopic versus laparoscopic-assisted right hemicolectomy: a clinical controlled study].

OBJECTIVE: To compare the outcomes of right hemicolectomy performed either by the hand-assisted laparoscopic(HALS) or conventional laparoscopic surgery(LAS). METHODS: Ninety-five patients undergoing HALS(n=47) from March 2002 to November 2006 or by LAS (n=48) from January 2007 to December 2009 were retrospectively studied. All the operations were performed by the same surgical team. Patient safety, postoperative recovery, complications, oncologic outcomes, medical expenses, and the follow-up results were compared between the two groups. RESULTS: No severe complications or perioperative deaths were oberved. There were significant differences between the two groups in terms of intraoperative bleeding, operative time, and length of incision(all P<0.05). However, the conversion rate, intraoperative injuries, time to first bowel movement, postoperative bed-rest time, hospital stay, time to first oral intake, and the number of patients requiring postoperative analgesia were comparable between the two groups(P>0.05). Length of surgical specimen was (25.6±9.9) cm in the HALS group and was (26.8±7.9) cm in the LAS group, the diffenence was not statistically significant(P<0.05). The mean number of lymph nodes retrieved in HALS group was 18.2±12.1, which was significantly lower than that in LAS group(24.1±9.3, P<0.05). The medical expense of the LAS group was (28 049.8±7576.1) RMB, which was significantly higher than that of the HALS group(21 132.7±5323.4) RMB(P<0.05). A follow-up rate of 93.7% was achieved in the HALS group with 3 patients lost to follow-up. The follow-up duration ranged from 45.4 to 101.9 months with a median of 66.7 months. In LAS group, the follow-up rate was 96% with 2 patients lost to follow-up and the follow-up duration ranged from 12.4 to 45.7 months with a median of 21.6 months. There was no significant difference in 3-year disease-free survival(91.3% vs. 87.9%, P>0.05) between the two groups. CONCLUSION: HALS and LAS can achieve similar minimal invasiveness efficacy and oncologic outcomes for right hemicolectomy.

[Efficacy comparison of neoadjuvant radiotherapy with or without chemotherapy for locally advanced rectal cancer].

OBJECTIVE: To evaluate the efficacy of neoadjuvant radiotherapy alone versus chemoradiotherapy in patients with mid-low locally advanced rectal cancer. METHODS: Data of 69 patients with advanced (stage T(3) or T(4)) rectal cancer, undergone neoadjuvant therapy in our hospital from October 1997 to October 2007, were analyzed retrospectively. Forty patients received preoperative radiotherapy (50 Gy in 25 fractions over 5 weeks) alone (RT group), and 29 patients received preoperative radiotherapy concomitant with 5-FU/leucovorin -based preoperative chemoradiotherapy (CRT group). Radical surgery was performed 4-6 weeks after radiation therapy by the rule of TME. RESULTS: All the patients underwent operations, including 26 abdominoperineal resections, 27 anterior resections, 10 Parks operations and 6 Hartmann's procedures. The sphincter preservation rate was 47.5%(19/40) in RT group, and 62.1%(18/29) in CRT group(P>0.05). In pathological findings, tumor and nodal downstaging were observed in 12 patients of RT group (30.0%), and 17 of CRT group (58.6%)(P<0.05). In RT group, 3 patients (7.5%) showed pathological complete regression (pCR), and the overall response rate (CR plus PR) was 60%(24/40). In CRT group, 4(13.8%) showed pCR and the overall response rate was 79.3%(23/29). There was significant difference of the overall response rate between two groups. Three-year disease-free survival for all patients was 77.3%. CONCLUSION: For patients with locally advanced rectal cancer, neoadjuvant chemoradiotherapy provides higher sphincter preservation rate, overall response rate and better down-staging as compared to radiotherapy alone.