Targeting BCRP/ABCG2 by RNA interference enhances the chemotherapy sensitivity of human colon cancer side population cells.

Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics. This study isolated side population (SP) cells from a colon cancer cell line (Colo-320) and examined their self-renewal and differentiation abilities. Compared to non-SP (NSP) cells, SP colon cancer cells were more tumorigenic in vivo and exhibited more invasive characteristics and a greater ability to form colonies. Additionally, more cells were in G0/G1 phase and more highly expressed the multidrug resistance protein BCRP/ABCG2. We achieved enhanced chemotherapy sensitivity by transfecting SP cells with a hairpin-like, small interfering RNA (siRNA) eukaryotic expression plasmid targeting BCRP/ABCG2.

[Determinants of long-term survival in 38 patients with carcinoma of ampulla of Vater treated by local resection].

OBJECTIVE: To investigate determinants of long-term survival for carcinoma of ampulla of Vater treated by local resection. METHODS: The clinical and pathological data of 38 such patients treated by local resection from 1983 to 2003 were retrospectively analyzed. According to UICC staging system, there were T1 30, T2 7 and T3 1. Lymph nodes were involved in 4 during operation which was present in primary lesions larger than 2 cm across. All patients were treated by local resection. At first, external palpation was carried out to ascertain accessibility. Then with the duodenum opened, direct exploration was carried out. On deciding for resection, the common bile duct was probe explored which guided the circumferential ring resection 1 cm, away from the tumor, including all layers of duodenum, ampula and partial bile and terminal pancreatic ducts and the posterial wall of duodenum was completed in steps. Meticulous care was taken not to suture the pancreatic duct and endotheliation was ensured at the mouth of common bile duct and duodenum. The basal tissue was frozen sectioned to ensure negative stumps. The gall bladder of 6 patients was also resected. SPSS 10.0 software was used in data processing, log-rank test used in univariate analysis and Cox equation for multivariate analysis and Kaplan-Meirer method for the survival rates. RESULTS: Thirty-eight patients received local resection giving an operative mortality of 0% and morbidity of 13.2%. The 1-, 5- and 10-year survival rate was 83.5%, 51.4%, and 38.9%, respectively, with a median survival of 3.35 years. Up to now, 13 patients have survived for more than five years and 2 patients beyond ten years. The tumour size, tumour grading, lymph node status and UICC stage were significant prognostic factors in univariate analysis. However, only lymph node status was a statistically independent predictor of prognosis in multivariate analysis. CONCLUSION: Local excision is safe giving low morbidity and good survival in carefully selected cases. Preferably it is indicated only in high risk patients with a pT1 and well differentiated ampullary cancer smaller than 1 cm in diameter.

[Malignant fibrous histiocytoma of the retroperitoneum: an analysis of 31 cases].

OBJECTIVE: To investigate the diagnosis and treatment of malignant fibrous histiocytoma of the retroperitoneum (MFHR). METHODS: The clinicopathological features, treatment and prognosis of 31 patients with MFHR were retrospectively analyzed. RESULTS: The mean age of the patients was 52.7 +/- 14.1 years. Male:Female = 22:9. The primary symptoms were abdominal mass and pain. The average diameter of tumor was 15 cm. The histopathologic types of the tumor were inflammatory, storiform-pleomorphic, myxoid and giant cell in 16, 10, 4 and 1 cases. The overall survival rate of 1-, 3- and 5-year was 61.3% +/- 9.8%, 31.6% +/- 11.3% and 21.1% +/- 11.4% with a median survival time of 17.0 +/- 6.3 months. Complete resection of the tumor was the major prognostic factor. Postoperative radiotherapy of 20 - 45 Gy was able to prolong the median survival from 12.1 +/- 11.6 months of surgery alone to 26.4 +/- 22.0 months of surgery plus postoperative radiotherapy though without statistical significance (P = 0.051). Postoperative CHOP chemotherapy was not shown to be beneficial. CONCLUSION: Chemotherapy remains the important method of cure. The survival in patients with MFHR might be improved by complete resection combined with chemotherapy or/and radiotherapy.

Management of nonfunctioning islet cell tumors.

AIM: To more clearly define the clinical and pathological characteristics and appropriate diagnosis and treatment of nonfunctioning (NFICTs) islet cell tumors, and to review our institutional experience over the last 30 years. METHODS: The records of 43 patients confirmed to have nonfunctioning islet cell tumors of pancreas were retrospectively reviewed. Survival was estimated by the Kaplan-Meier methods and potential risk factors for survival were compared with the log-rank tests. RESULTS: The mean age was 31.63 years (range, 8 to 67 years). There were 7 men and 36 women. Twenty-eight patients had a confirmed diagnosis of nonfunctioning islet cell carcinoma (NFICC) and benign islet cell tumors were found in 15 patients. The most common symptoms in patients with NFICTs were abdominal pain (55.8%), nausea and/or vomiting (32.6%), fatigue (25.6%) and abdominal mass (23.3%). Preoperative ultrasonic and computed tomography localized the tumors in all patients. Forty-three NFICTs were distributed throughout the pancreas, with 21 located to the right of the superior mesenteric vessels, 10 in the body of the pancreas, 6 in the tail of the pancreas, and multiple tumors were found in one patient. Thirty-nine of 43 patients (91%) underwent surgical resection. Surgical treatment was curative in 30 patients (70%) and palliative in 9(21%). The resectability and curative resection rate in patients with NFICC of pancreas were 89% and 61%, respectively. The overall cumulative 5- and 10-year survival rates for patients with NFICC were 58.05% and 29.03%, respectively. Radical operation and diameter of cancer small than 10 cm were positive prognostic factors in females younger than 30 years old. Multivariate Cox regression analysis indicated that radical operation was the only independent prognostic factor, P=0.007. CONCLUSION: Nonfunctioning islet cell tumors of pancreas are found mainly in young women. The long-term results for patients undergone surgery, especially curative resection are good.

[Analysis of prognostic factors of rectal cancer in the elderly].

BACKGROUND & OBJECTIVE: The relation between patient age and outcomes from colorectal cancer surgery is complex. It is generally believed that age should not be a determinant in consideration of prognosis for colorectal cancer patient. But there were few studies on the prognostic factors of rectal cancer in the elderly. We therefore performed a retrospective analysis of clinicopathologic characteristics of rectal cancer in 343 old patients with rectal cancer by univariate and multivariate analysis. METHODS: A total of 343 patients (older than 60 years) with rectal cancer were treated surgically during a period of 10 years. R0, R1, and R2 operations were carried out in 261 patients (76.09%), 29 patients (8.45%), and 53 patients (15.45%), respectively. Low anterior resection was performed in 116 patients; 169 patients underwent Miles operation; 58 patients underwent the other operations. RESULTS: The operation mortality was 0.87%; 149 patients died of occurrence or metastases of the tumor within 108 months postoperatively. Liver, lung, and bone metastases were occurred in 17, 18, and 1 patients, respectively. The mean survival time for all patients was 72.12+/-2.60 months and the overall 3-, 5-, and 10-year survival rates were 69.62%, 55.73%, and 34.23%, respectively. Univariate analysis showed that the predictors of survival were type of operations, radical resection, histological type, diameter of the tumors, depth of tumor invasion, lymphatic invasion, distance metastases, liver and lung metastases. Multivariate analysis showed that only radical resection, lymphatic invasion, liver and lung metastases were independent factors. CONCLUSION: The follow prognostic factors can influence the survival of rectal cancer in the elderly: type of operations, nature of operation, histological type, diameter of the tumors, depth of tumor invasion, lymphatic invasion, distance metastases, liver and lung metastases. The independent factors were nature of operation, lymphatic invasion, liver and lung metastases.

[Multivariate Cox analysis on prognostic factors after surgery for rectal carcinoma].

OBJECTIVE: To analyze a large cohort of patients with rectal cancer within a cancer center to determine the prognostic factors by univariate and multivariate analyses. METHODS: A total of 952 patients with rectal cancer were treated surgically during a period of 10 years. R0, R1 and R2 operations were carried out in 741 patients (77.8%), 75 patients (7.9%) and 136 patients (14.3%), respectively. There were more Miles operation (53.5%) than lower abdominal resection (LAR, 33.7%). RESULTS: The operation mortality was 0.3%, 418 patients were dead within 108 months postoperatively due to recurrence or metastases to liver, lung and bone in 53, 39 and 12 patients. The overall mean survival time for all patients was 73.52 +/- 1.70 months and the overall 3-, 5-and 10-year survival rates were 67.6%, 55.4% and 38.2%. The overall 3-, 5- and 10-year survival rates for patients treated by radical operation were 81.4%, 70.3%, 48.8%, respectively. Kaplan-Meier estimate showed that patient gender, age, radicality of resection, histological type, liver and pulmonary metastasis and TNM stage were the predictors of survival. Multivariate analysis showed statistically significant correlation with radicality of operation, histological type, depth of tumor invasion, lymphatic invasion, TNM stage, liver and pulmonary metastasis. CONCLUSION: For survival, statistically significant differences among prognostic factors in relation to radicality of resection, lymphatic invasion, TNM stage, depth of tumor invasion, histological type, liver and pulmonary metastasis are found.

[Prospective randomized trial of prophylaxis of postoperative peritoneal carcinomatosis of advanced gastric cancer: intraperitoneal chemotherapy with mitomycin C bound to activated carbon particles].

OBJECTIVE: To evaluate the beneficial effect of intraperitoneally applied mitomycin bound to activated carbon particles (MMC-CH) in the prevention and treatment of intraabdominal recurrence after curative surgery for gastric cancer. METHODS: One hundred and twenty-four patients with radically resected gastric cancer infiltrating the serosal surface were randomly divided into group receiving 50 mg mitomycin bound to a solution of 375 mg carbon adsorbent intraperitoneally before closure of the abdominal wound (n = 62) and a control group (n = 62). The patients with MMC-CH and the control group were received systemic chemotherapy 3 months or 3 weeks after operation respectively. The postoperative recurrence-free survival was evaluated to analyze the benefits of this treatment. RESULTS: After observation for 8 months (range, 2 - 65). The 3-, 5-year postoperative recurrence-free survival rates were significantly higher in the MMC-CH group (70.16%, 44.51%) than in the control group (27.09%, 14.45%), P < 0.01. CONCLUSION: Adjuvant intraperitoneal chemotherapy of gastric cancer by mitomycin bound to activated carbon particles is effected by an increased postoperative recurrence-free survival rate.