Fibrosis and postoperative fistula of the pancreas: correlation with MR imaging findings--preliminary results

PURPOSE

To assess the potential value of magnetic resonance (MR) imaging in evaluating pancreatic fibrosis and predicting the development of postoperative pancreatic fistula.

MATERIALS AND METHODS

This retrospective study had institutional review board approval, and the requirement for informed consent was waived. MR images obtained in 29 consecutive patients (15 men, 14 women; mean age, 64.9 years; age range, 21-80 years) who underwent pancreatectomy were evaluated. The pancreas-to-muscle signal intensity (SI) ratio on unenhanced T1- and T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted images and the apparent diffusion coefficient (ADC) of the pancreas were measured. MR imaging parameters were correlated with the degrees of pancreatic fibrosis and expression of activated pancreatic stellate cells (PSCs) by using univariate and multivariate regression analyses and receiver operating characteristic curve analysis. The relationships between the development of postoperative pancreatic fistula and the MR imaging measurements were examined by using logistic regression analysis and the Mann-Whitney U test.

RESULTS

Multiple regression analysis showed that pancreas-to-muscle SI ratios on T1-weighted images and ADC values were independently associated with pancreatic fibrosis (r(2) = 0.66, P < .001) and with activated PSC expression (r(2) = 0.67, P < .001). The mean pancreas-to-muscle SI ratio (± standard deviation) on T1-weighted images was higher (P = .0029) for patients with postoperative pancreatic fistula (1.6 ± 0.2) than for those without (1.2 ± 0.2), and the odds ratio for postoperative pancreatic fistula was 21.3 in patients with an SI ratio of 1.41 and higher.

CONCLUSION

The pancreas-to-muscle SI ratio on T1-weighted MR images of the pancreas may be a potential biomarker for assessment of pancreatic fibrosis and prediction of postoperative pancreatic fistula.

Long-term outcomes of treatment of gastric gastrointestinal stromal tumor by laparoscopic surgery: review of the literature and our experience

BACKGROUND/AIMS

Although the feasibility of laparoscopic resection of gastric gastrointestinal stromal tumors (GISTs) has been established, various aspects are debated. This paper describes the problems of minimally invasive resection of gastric GISTs and compares this experience with an extensive literature review.

METHODOLOGY

Between October 2003 and June 2012, 24 consecutive patients undergoing laparoscopic resection of gastric GISTs were enrolled in a prospective study. A comparison with authors' experience with laparoscopic wedge-segmental resection of GISTs was also carried out.

RESULTS

Twenty-four patients, mean age 64.0 +/- 11.2 years, were submitted to laparoscopic wedge-segmental gastric resections. Mean tumor size was 3.1 +/- 1.2 cm, mean operative time was 118.0 +/- 57.3 min, mean blood loss was 21.6 +/- 47.7 mL, and mean hospital stay was 7.1 +/- 1.9 days. There were no major operative complications or mortalities. All lesions had negative resection margins. Postoperative complications were detected in 2 patients. The rate of complication of grade 2 was 8.3%. At a mean follow-up of 23.9 months, all patients were disease-free. Morbidity, mortality, length of stay, and oncologic outcomes were comparable to experience with an extensive literature review. The stomach was divided into 3 areas (U, M, L area). When operation time and blood loss were examined, a significant difference was not indicated. However, both operation time and blood loss of M area tended to be low compared with U area. According to the mitotic index, 21 (87.5%) tumors were evaluated as low risk, 2 (7.3%) tumors as medium risk, and 1 (4.2%) tumor as high risk.

CONCLUSIONS

Laparoscopic resection is safe and effective in treating gastric GISTs. Therefore, a minimally invasive approach should be the preferred surgical treatment in patients with small- and medium-sized gastric GISTs.

Cutaneous vasculitis and glomerulonephritis associated with C4 deficiency

Complete deficiency of the fourth component of complement (C4) is an extremely rare condition. However, it has been reported that partial C4 deficiency can occur in normal subjects, and is associated with several immune diseases. We report a 44-year-old woman who developed slight oedema and punctate purpura on her lower legs after a common cold. She was noted to have persistent microscopic haematuria and proteinuria, and her C4 level was undetectable. On histological examination of a skin biopsy specimen, leucocytoclastic vasculitis was seen, with granular deposition of IgG, IgM, C3 and C1q on the vessel walls in the upper dermis. A renal biopsy showed mild mesangial proliferative glomerulonephritis with slight damage to the capillary loops, and granular deposits of IgM and C4 mainly in the mesangium. The patient was systemically well and needed no medication. The C4 level remained low during the observation period, but neither genotyping nor allotyping analysis identified a C4 deficiency.

Determining timing of hepatectomy for colorectal cancer with distant metastasis according to imaging-based tumor shrinkage ratio

BACKGROUND

The optimal timing of surgical resection of liver metastasis remains controversial, and guidelines regarding the upper limits of operative indications have not yet been defined. Surgical indication for metastasis from colorectal cancer (CLM) based on results of preoperative chemotherapy and RNF8 was investigated.

METHODS

Differences in CLM size on CT were evaluated as shrinkage rate/day by dividing tumor shrinkage rates by the interval in days between CT. Levels of RNF8 of resected colorectal cancer and CLM frozen specimen were detected.

RESULTS

When the cut line for shrinkage rate at 12 weeks was set at 0.35%, disease-free survival was significantly better in patients with a shrinkage rate >0.35% vs. ≤0.35% (p=0.003). RNF8 expression was significantly higher in Tis (p=0.001). In liver metastasis, RNF8 expression level was significantly lower in patients with partial response to FOLFOX than with stable disease, (p=0.017).

CONCLUSIONS

A strategy of FOLFOX administration for 12 weeks to patients with low RNF8 expression and hepatectomy planned after 4 weeks rest may be accepted as the best therapeutic option for treating CLM.

Two rare cases of a solid pseudopapillary neoplasm of the pancreas

A solid pseudopapillary neoplasm (SPN) of the pancreas has distinct histopathological features. A solid pattern of growth with pseudopapillary structures that result from degeneration is observed. On rare occasions, the tumor may vary from being entirely solid to completely cystic. The present study describes two unique cases of SPN. A 25-year-old male presented with a pancreatic tumor showing a predominantly solid pattern with no degenerative change, although the pre-operative cytological specimens that were obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) revealed pseudopapillary structures. The second case was of an 11-year-old female who presented with a pancreatic tumor with prominent degeneration. Nests and cords of the remaining neoplastic cells were located only at the periphery, with perineural invasion. An immunohistochemical analysis revealed that the tumor cells in the two cases were positive for CD10 and β-catenin and negative for trypsin. An awareness of the broad morphological variability of SPN and an immunohistochemical panel that includes CD10, β-catenin and trypsin are useful for establishing an accurate diagnosis.

Laparoscopic technique and safety experience with barbed suture closure for pelvic cavity after abdominoperineal resection

BACKGROUND

Between April 2005 and December 2012, we performed laparoscopic colorectal resection with regional lymph node dissection on 273 cases of colorectal cancer patients. However, Laparoscopic rectal cancer surgery requires a high degree of skill. Any surgeon who is going to embark on these difficult resections should have at a minimum laparoscopic suturing skills in order to be able to close the peritoneal defect.

METHODS

In laparoscopic surgery for rectal cancer, the intracorporeal suture technique required to close the pelvic cavity is very difficult. Barbed sutures have recently been proposed to facilitate laparoscopic suturing. Two patients with rectal cancer who underwent laparoscopic abdominoperineal resection (APR) with intracorporeal closure of the pelvic cavity from September to October 2012 were enrolled in this study.

RESULTS

We present our initial experience of two consecutive cases of intracorporeal closure of the pelvic cavity by totally laparoscopic APR. After clinical follow-up, the two patients have no complaints and have shown no signs of recurrence.

CONCLUSIONS

We hypothesized that barbed sutures could potentially improve the efficiency of intracorporeal closure of the pelvic cavity after laparoscopic APR. Further, we expect that use of the V-Loc™ will reduce intra-operative stress on the endoscopic surgeon.

Predictive value of orotate phosphoribosyltransferase in colorectal cancer patients receiving 5-FU-based chemotherapy

Pretreatment knowledge of chemosensitivity and side-effects of chemotherapy for colorectal cancer (CRC) patients are likely to ensure the best chemotherapeutic outcome. The aim of this study was to identify additional predictive factors of chemosensitivity to the key CRC treatment drug 5-fluorouracil (5-FU). Surgically obtained specimens from 106 patients treated for CRC were immunohistochemically assessed to investigate the correlation between the protein expression of the 5-FU metabolic enzymes orotate phosphoribosyltransferase (OPRT), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD), and clinicopathological characteristics as well as the correlation between the protein expression and outcomes of 5-FU-based chemotherapy. A correlation was detected between the high expression of the 5-FU metabolic enzyme OPRT and negative lymph node metastasis (P=0.0496), as well as between DPD and advanced Tumor-Node-Metastasis (TNM) grade cases (IIIA-IVB) and positive lymph node metastases (P=0.0414, respectively). In all 106 patients and in 79 patients undergoing 5-FU-based chemotherapy, survival was improved in those patients with a positive OPRT expression (P=0.0144 and 0.0167, respectively). OPRT expression was higher in the 79 patients with no recurrence (P=0.0179) as well as in patients treated with R0 surgery and 5-FU-based chemotherapy without side-effects (P=0.0126). Disease-free survival (DFS) rate was higher in patients without side-effects, and in patients with a positive OPRT expression without side-effects (P=0.0021 and 0.0031, respectively). Findings of this study demonstrated that OPRT expression positively correlated with fewer side-effects of 5-FU-based chemotherapy and longer patient survival.

Extracellular signal-regulated kinase and Akt activation play a critical role in the process of hepatocyte growth factor-induced epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) has recently been studied to elucidate mechanisms of the liver metastatic process. We investigated EMT in the process of liver metastasis and the effects of chemotherapy on EMT cells as therapeutic strategy for colorectal liver metastasis. We used the CT26 murine colorectal carcinoma cell line to create an in vivo mouse liver metastasis model. Liver tumors were stained immuno-histochemically. Expression of proteins associated with TGF-β/Smad and hepatocyte growth factor (HGF)/c-Met pathways were investigated by western blotting. Cells with c-Met mRNA knockdown by siRNA techniques showed clearly reduced liver metastases compared with regular cells at 21 days. TGF-β and HGF induced EMT expression, but signal transduction was quite different. TGF-β induced ERK, but not Akt phosphory-lation. HGF mediated both ERK and Akt phosphorylation. Akt inhibitor blocked Akt phosphorylation but did not affect TGF-β-induced activation of ERK, Snail and Slug. U-0126 did not reduce Snail activity by TGF-β at a concentration to block ERK phosphorylation. However, Akt inhibitor and U-0126 completely inhibited HGF-induced Slug activation. 5-FU mediated cell death in the EMT process induced by TGF-β more effectively than HGF. ERK/Akt signaling, but not the Smad pathway, may be one of the main processes in HGF-induced EMT, despite the Smad pathway, but not ERK/Akt, being critical for TGF-β-induced EMT. The MAPK/Akt pathway is indispensable in HGF/c-Met signaling. The ERK/Akt pathway particularly may be critical in the HGF-induced EMT process. However, long-term use of chemotherapeutic agents may induce drug resistance and distant metastases through EMT-related signaling pathway activation.

Human gastric cancer organizes neighboring lymphatic vessels via recruitment of bone marrow-derived lymphatic endothelial progenitor cells

BACKGROUND

Lymphatic metastasis is a critical determinant of prognosis in human gastrointestinal cancers. Studies suggest that lymphatic metastasis has been linked to lymphangiogenesis, the growth of lymphatic vessels, while the mechanisms of tumor lymphangiogenesis remain poorly characterized.

METHODS

Human gastric cancer cells, MKN45, were implanted under the gastric submucosa of nude mice receiving green fluorescent protein-positive bone marrow (BM) transplants. In addition, MKN45 cells were subcutaneously injected into the back of each mouse as a model of human tumor xenografts. The tumor tissue was analyzed 3 weeks after implantation.

RESULTS

The mice with MKN45 cells represent recruitment and incorporation of BM-derived lymphatic endothelial progenitor cells (LEPC) into gastric lymphatics. Moreover, in a xenograft model, MKN45 cells induced lymphangiogenesis as well as recruitment of BM-derived LEPC in tumor lymphatics in a xenograft model.

CONCLUSIONS

These findings of this study suggest that human gastric adenocarcinoma induces tumor lymphangiogenesis via recruitment of LEPC from BM.

Therapeutic strategies for synchronous and multiple liver metastases from colorectal cancer

Metastasis in the liver is one of the most critical factors in the prognosis of patients with colorectal cancer. The incidence of synchronous liver metastasis has been found to be approximately 20-25%, but the optimal timing of surgical resection remains controversial. Neoadjuvant chemotherapy has also been found to be beneficial not only for initially unresectable but also resectable synchronous metastases and traditional surgical strategies of hepatic resection with past chemotherapeutic regimens have been used less and less over the past several years. This review will discuss treatments in association with the recently developed chemotherapeutic regimens.

Strategy for synchronous and multiple liver metastasis

BACKGROUND/AIMS

Surgical indications for resection of synchronous metastasis from colorectal cancer (CRC) and the optimal timing of hepatectomy are still controversial and widely debated.

METHODOLOGY

Synchronous and multiple metastatic liver tumors were detected in 57 patients since May 2005. Our treatment policy was to perform hepatectomy if the resection could be done with no limit on size and number of tumors. However, if curative resection could not be done, chemotherapy was begun and timing for the possibility of a radical operation was planned immediately.

RESULTS

In 37 patients whose tumors were located only in the liver, primary tumor resection was performed in 16 patients and after tumor-decreasing by chemotherapy, in 7 patients. In 20 patients in whom chemotherapy was performed first, after controlling the distant metastasis, hepatectomy was performed in 3 patients and staged hepatectomy was performed in 10. Recurrence was detected after hepatectomy in 75.0% of simultaneous resection cases and in 70.0% of staged cases. In the recurrence cases, early detection after tumor resection occurred in 58.3% of the simultaneous and 14.2% of the staged.

CONCLUSIONS

The present data show that neoadjuvant chemotherapy does not increase the risk of postoperative complications or the surgical difficulties of hepatectomy for colorectal metastases.

Therapeutic strategies for synchronous and multiple liver metastases from colorectal cancer

Metastasis in the liver is one of the most critical factors in the prognosis of patients with colorectal cancer. The incidence of synchronous liver metastasis has been found to be approximately 20–25%, but the optimal timing of surgical resection remains controversial. Neoadjuvant chemotherapy has also been found to be beneficial not only for initially unresectable but also resectable synchronous metastases and traditional surgical strategies of hepatic resection with past chemotherapeutic regimens have been used less and less over the past several years. This review will discuss treatments in association with the recently developed chemotherapeutic regimens.

Reconstruction method after pancreaticoduodenectomy. Idea to prevent serious complications

Pancreatic fistula after pancreaticoduodenectomy represents a critical trigger of potentially life-threatening complications and is also associated with markedly prolonged hospitalization. Many arguments have been proposed for the method to anastomosis the pancreatic stump with the gastrointestinal tract, such as invagination vs. duct-to-mucosa, Billroth I (Imanaga) vs. Billroth II (Whipple and/or Child) or pancreaticogastrostomy vs. pancreaticojejunostomy. Although the best method for dealing with the pancreatic stump after pancreaticoduodenectomy remains in question, recent reports described the invagination method to decrease the rate of pancreatic fistula significantly compared to the duct-to-mucosa anastomosis. In Billroth I reconstruction, more frequent anastomotic failure has been reported, and disadvantages of pancreaticogastrostomy have been identified, including an increased incidence of delayed gastric emptying and of pancreatic duct obstruction due to overgrowth by the gastric mucosa. We review recent several safety trials and methods of treating the pancreatic stump after pancreaticoduodenectomy, and demonstrate an operative procedure with its advantage of the novel reconstruction method due to our experiences.

[Treatment of advanced gastric cancer in the elderly]

Because the aging process varies among individuals, elderly people of the same age, especially those over 80 years, do not necessarily have similar organ function. After consideration of lower organ function and concomitant disease, less invasive treatment should be selected for elderly patients. Therefore, it is important to limit preventive lymph node dissection, and when determining the dose of anticancer drugs, major organ function should be taken into consideration.

Growth effect of neutrophil elastase on breast cancer: favorable action of sivelestat and application to anti-HER2 therapy

AIM

To investigate the relation between neutrophil elastase (NE) and proliferation of breast cancer cells and whether the NE inhibitor sivelestat could both contribute and be applied to therapy for anti-epithelial growth factor receptor 2 (HER2)-positive breast cancers.

MATERIALS AND METHODS

The proliferation or inhibition of breast cancer cell line SKBR-3 by each agent was evaluated by methylthiazole tetrazolium (MTT) assay. Signal transduction and expression of signaling molecules were evaluated by Western blot analysis.

RESULTS

The auto tumor progression mechanism initiated by NE through tumor growth factor-α (TGF-α) was present in breast cancer cells, and this mechanism was intensively suppressed by sivelestat. The effect of trastuzumab was suppressed, and trastuzumab-induced HER2 down-regulation was impaired by TGF-α. TGF-α not only promoted cell proliferation as a ligand but also enhanced resistance to trastuzumab by impairing HER2 down-regulation. Furthermore, combined use of trastuzumab and sivelestat suppressed cell proliferation more intensively than either drug alone and did not provoke impairment by TGF-α of HER2-induced down-regulation.

CONCLUSION

Combinatorial use of sivelestat and trastuzumab might be a novel therapeutic strategy for HER2-positive breast cancer.

Docetaxel, nedaplatin, and S-1 (DGS) chemotherapy for advanced esophageal carcinoma: a phase I dose-escalation study

AIM

More effective regimens are urgently needed for treatment of esophageal carcinoma; therefore, we conducted a phase I trial of a combination of docetaxel, nedaplatin, and S-1 (DGS) to determine the optimal dose in patients with advanced esophageal carcinoma.

PATIENTS AND METHODS

We studied 14 patients with previously untreated advanced cervical esophageal carcinoma with T3-4 tumors and/or M1 staging and esophageal carcinoma with cervical lymph node metastasis. The patients received an infusion of docetaxel at different dose levels (levels 1, 2, 3, 4: 25, 30, 35, 40 mg/m(2), respectively) and an infusion of nedaplatin (40 mg/m(2)) on day 8 plus oral administration of S1 (80 mg/m(2)/day) for two consecutive weeks at two-week intervals.

RESULTS

Dose-limiting toxicities (DLTs) included febrile neutropenia and leukopenia. DLTs occurred in 2 out of 5 patients at level 4. The response rate was 78.6 (11/14)%, including a complete response rate of 35.7(5/14)%.

CONCLUSION

The DGS regimen reported here was well tolerated and toxicities were manageable. The maximum tolerated dose was level 4, and the recommended dose was determined to be docetaxel at 35 mg/m(2) with nedaplatin at 40 mg/m(2) plus S1 at 80 mg/m(2). We found that our regimen, administered on an outpatient basis, showed high activity and tolerance. A phase II study has been started.

The roles of surgical oncologists in the new era: minimally invasive surgery for early gastric cancer and adjuvant surgery for metastatic gastric cancer

In the new era of technical development in surgery, operative devices, molecular targeting and chemotherapeutic agents, surgical oncologists have two main roles in the treatment of gastric cancer. One is to provide patients with minimally invasive surgery, including laparoscopy- or robot-assisted surgery in early gastric cancer patients, and the new concept of surgical intervention toward advanced and metastatic disease. Since recently, laparoscopy-assisted distal gastrectomy has become prevalent in Japan as a surgery which is minimally invasive for the patients and provides them with a good quality of life afterwards. However, the provision of advanced surgical techniques, including lymph node dissection and reconstruction, is more important for patient survival. The second role of surgical oncologists is to evaluate the significant values of the aggressive treatment which we term 'adjuvant surgery' for stage IV gastric cancer patients who have successfully responded to initial chemotherapy for curative intent. Stage IV gastric cancer patients are now being informed about the possibility of longer survival with the new chemotherapeutic and surgical strategic approach.

Mucinous cystic neoplasm of the pancreas in a male patient

Mucinous cystic neoplasms (MCNs) make up a morphologic family of similar appearing tumors arising in the ovary and various extraovarian organs such as pancreas, hepatobiliary tract and mesentery. MCNs of the pancreas occur almost exclusively in women. Here, we report a rare case of MCN in a male patient. A 39-year-old man was admitted to our hospital with the chief complaint of back pain. Abdominal computed tomography revealed a multilocular cyctic mass 6.3 cm in diameter in the pancreatic tail. In addition, the outer wall and septae with calcification were demonstrated in the cystic lesion. On magnetic resonance imaging , the cystic fluid had low intensity on T1-weighted imaging and high intensity on T2-weighted imaging. Endoscopic retrograde cholangio-pancreatography (ERCP) showed neither communication between the cystic lesion and the main pancreatic duct nor encasement of the main pancreatic duct. Endoscopic ultrasonography revealed neither solid component nor thickness of the septae in the cystic lesion. Consequently, we performed distal pancreatectomy with splenectomy under the diagnosis of cystic neoplasia of the pancreas. Histopathologically, the cystic lesion showed two distinct component: an inner epithelial layer and an outer densely cellular ovarian-type stromal layer. Based on these findings, the cystic lesion was diagnosed as MCN.

Signal transduction of vitamin K3 for pancreas cancer therapy

We characterized molecular mechanisms of vitamin K3 (VK3)-induced inhibition of proliferation to evaluate VK3 effectiveness in treating advanced pancreatic cancer. A novel endoscopic drug delivery system, ultrasound injection technique, was used to study local effects of VK3. VK3 inhibited pancreas cancer cell growth by rapid phosphorylation of growth factor receptor and cellular signal factors such as extracellular signal-regulated kinase. VK3 also activated apoptosis, and apoptosis inhibitor antagonized the apoptosis pathway without inhibiting cell growth. Thiol antioxidant treatment completely abrogated VK3-induced ERK but not JNK phosphorylation or inhibition of proliferation. Non-thiol antioxidant did not affect ERK phosphorylation or growth inhibitory actions. Arylation was considered the main mechanism of VK3-induced growth inhibition through ERK activation. VK3 may lead to favorable outcomes in the treatment of pancreatic tumors. Detection of ERK phosphorylation in tissue is important to predict VK3 effect. Endoscopic ultrasound-guided fine-needle injection may be beneficial for treating pancreatic cancer with VK3.