Mesothelin is Commonly Expressed in Pancreatic Adenocarcinoma but Unrelated to Cancer Aggressiveness.

Data on Mesothelin (MSLN) expression in human normal and cancerous tissues is controversial. We employed immunohistochemistry (IHC) on a tissue microarray (TMA) from 599 pancreatic cancers and 12 large tissue sections of pancreatitis. MSLN expression was highest in pancreatic adenocarcinomas (89%) and adenocarcinomas of the ampulla Vateri (79%), infrequent in pancreatitis and absent in 6 acinus cell carcinomas and normal pancreas. MSLN expression was unrelated to pathological tumor stage, grade, metastasis, and tumor-infiltrating CD8+ lymphocytes. In conclusion, pancreatic cancer may be ideally suited for putative anti- MSLN therapies, and MSLN may represent a suitable biomarker for pancreatic cancer diagnosis, especially on small biopsies.

High density of cytotoxic T-lymphocytes is linked to tumoral PD-L1 expression regardless of the mismatch repair status in colorectal cancer.

BACKGROUND: Immune checkpoint-inhibitors targeting the PD-1/PD-L1 system are FDA approved in microsatellite instable (MSI) or mismatch repair deficient (dMMR) colorectal cancer (CRC). PD-L1 expression is tightly linked to features connected to immune checkpoint inhibitor response, but studies on large subsets of cancers analyzing the correlation between different status of MSI/dMMR, tumor infiltrating lymphocytes and PD-L1 expression are still lacking. METHODS: More than 1800 CRC were analyzed for PD-L1 by immunohistochemistry in a tissue microarray format. Data were compared to MMR, the number of intratumoral CD8+ cytotoxic T-cells, and adverse clinico-pathological parameters. Different cutoff levels for defining PD-L1 positivity in tumor cells (1%, 5%, 10%, and 50%) yielded comparable results. RESULTS: At a cutoff level of 5%, PD-L1 positivity was seen in 5.1% of tumors. PD-L1 was more often positive in dMMR (18.6%) than in MMR proficient (pMMR) cancers (4.1%; p < 0.0001). The number of intratumoral CD8+ lymphocytes was strikingly higher in PD-L1 positive (939.5 ± 118.2) than in PD-L1 negative cancers (310.5 ± 24.8). A higher number of intratumoral CD8+ lymphocytes was found in dMMR CRC (PD-L1 positive: 1999.7 ± 322.0; PD-L1 negative: 398.6 ± 128.0; p < 0.0001) compared to pMMR CRC (PD-L1 positive: 793.2 ± 124.8; PD-L1 negative: 297.2 ± 24.2; p < 0.0001). In dMMR and pMMR CRC, PD-L1 expression in tumor cells was unrelated to tumor stage, lymph node status or lymphatic/venous invasion. PD-L1 positivity in tumor associated immune cells was seen in 47.5% of cases and was significantly linked to high numbers of tumor infiltrating CD8+, low tumor stage, and absence of lymph node metastasis and lymphatic/venous invasion (p < 0.0001 each). CONCLUSION: The data support the previously suggested fact that PD-L1 expression in tumor cells is driven by extensive cytotoxic T-cell infiltration in highly immunogenic dMMR and pMMR CRC. Frequent and intense PD-L1 expression in tumor cells of dMMR CRC may contribute to the high response rates of dMMR CRC to immune checkpoint-inhibitors.

Elevated MUC5AC expression is associated with mismatch repair deficiency and proximal tumor location but not with cancer progression in colon cancer.

Mucin 5AC (MUC5AC) is a secreted gel-forming mucin expressed by several epithelia. In the colon, MUC5AC is expressed in scattered normal epithelial cells but can be abundant in colorectal cancers. To clarify the relationship of MUC5AC expression with parameters of tumor aggressiveness and mismatch repair deficiency (dMMR) in colorectal cancer, a tissue microarray containing 1812 colorectal cancers was analyzed by immunohistochemistry. MUC5AC expression was found in 261 (15.7%) of 1,667 analyzable colorectal cancers. MUC5AC expression strongly depended on the tumor location and gradually decreased from proximal (27.4% of cecum cancers) to distal (10.6% of rectal cancers; p < 0.0001). MUC5AC expression was also strongly linked to dMMR. dMMR was found in 21.3% of 169 cancers with MUC5AC positivity but in only 4.6% of 1051 cancers without detectable MUC5AC expression (p < 0.0001). A multivariate analysis showed that dMMR status and tumor localization predicted MUC5AC expression independently (p < 0.0001 each). MUC5AC expression was unrelated to pT and pN status. This also applied to the subgroups of 1136 proficient MMR (pMMR) and of 84 dMMR cancers. The results of our study show a strong association of MUC5AC expression with proximal and dMMR colorectal cancers. However, MUC5AC expression is unrelated to colon cancer aggressiveness.

MMR Deficiency is Homogeneous in Pancreatic Carcinoma and Associated with High Density of Cd8-Positive Lymphocytes.

BACKGROUND: Microsatellite instability (MSI) has emerged as a predictive biomarker for immune checkpoint inhibitor therapy. Cancer heterogeneity represents a potential obstacle for the analysis of predicitive biomarkers. MSI has been reported in pancreatic cancer, but data on the possible extent of intratumoral heterogeneity are lacking. METHODS: To study MSI heterogeneity in pancreatic cancer, a tissue microarray (TMA) comprising 597 tumors was screened by immunohistochemistry with antibodies for the mismatch repair (MMR) proteins MLH1, PMS2, MSH2, and MSH6. RESULTS: In six suspicious cases, large section immunohistochemistry and microsatellite analysis (Bethesda panel) resulted in the identification of 4 (0.8%) validated MSI cases out of 480 interpretable pancreatic ductal adenocarcinomas. MSI was absent in 55 adenocarcinomas of the ampulla of Vater and 7 acinar cell carcinomas. MMR deficiency always involved MSH6 loss, in three cases with additional loss of MSH2 expression. Three cancers were MSI-high and one case with isolated MSH6 loss was MSS in PCR analysis. The analysis of 44 cancer-containing tumor blocks revealed that the loss of MMR protein expression was always homogeneous in affected tumors. Automated digital image analysis of CD8 immunostaining demonstrated markedly higher CD8 + tumor infiltrating lymphocytes in tumors with (mean = 685, median = 626) than without (mean = 227; median = 124) MMR deficiency (p < 0.0001), suggesting a role of MSI for immune response. CONCLUSIONS: Our data suggest that MSI occurs early in a small subset of ductal adenocarcinomas of the pancreas and that immunohistochemical MMR analysis on limited biopsy or cytology material may be sufficient to estimate MMR status of the entire cancer mass.

DOG1 overexpression is associated with mismatch repair deficiency and BRAF mutations but unrelated to cancer progression in colorectal cancer.

INTRODUCTION: The transmembrane channel protein DOG1 (Discovered on GIST1) is normally expressed in the gastrointestinal interstitial cells of Cajal and also in gastrointestinal stroma tumors arising from these cells. However, there is also evidence for a relevant role of DOG1 expression in colorectal cancers. This study was undertaken to search for associations between DOG1 expression and colon cancer phenotype and key molecular alterations. METHODS: A tissue microarray containing samples from more than 1,800 colorectal cancer patients was analyzed by immunohistochemistry. RESULTS: DOG1 immunostaining was detected in 503 (30.2%) of 1,666 analyzable colorectal cancers and considered weak in 360 (21.6%), moderate in 78 (4.7%), and strong in 65 (3.9%). Strong DOG1 immunostaining was associated with advanced pT stage (p=0.0367) and nodal metastases (p=0.0145) but these associations were not retained in subgroups of 1,135 mismatch repair proficient and 86 mismatch repair deficient tumors. DOG1 positivity was significantly linked to several molecular tumor features including mismatch repair deficiency (p=0.0034), BRAF mutations (p<0.0001), nuclear p53 accumulation (p=0.0157), and PD-L1 expression (p=0.0199) but unrelated to KRAS mutations and the density of tumor infiltrating CD8 positive lymphocytes. CONCLUSION: Elevated DOG1 expression is frequent in colorectal cancer and significantly linked to important molecular alterations. However, DOG1 overexpression is largely unrelated to histopathological parameters of cancer aggressiveness and may thus not serve as a prognostic parameter for this tumor entity.

Mucin 5AC expression is common but unrelated to tumor progression in pancreatic adenocarcinoma.

Introduction: Mucin 5AC (MUC5AC) belongs to the family of secreted gel-forming mucins. It is physiologically expressed in some normal mucin producing epithelial cells but also in pancreatic, ovarian, and colon cancer cells. The role of MUC5AC expression in cancer is not fully understood. This study was designed to explore the role of MUC5AC for pancreatic cancer progression, its association to microsatellite instability, and its diagnostic utility. Methods: Mucin 5AC expression was studied immunohistochemically in a tissue microarray (TMA) from 532 pancreatic cancers, 61 cancers of the ampulla Vateri, six acinar cell carcinomas and 12 large sections of pancreatitis. Results: Mucin 5AC staining was interpretable in 476 of 599 (79%) arrayed cancers. Staining was completely absent in normal pancreas and pancreatitis, but frequent in pancreatic cancer. Membranous and cytoplasmic MUC5AC expression was most common in pancreatic adenocarcinomas (71% of 423), followed by carcinomas of the ampulla Vateri (43% of 47), and absent in six acinar cell carcinomas. Mucin 5AC expression was unrelated to tumor phenotype (tumor stage, tumor grade, lymph node, and distant metastasis), and microsatellite instability in ductal adenocarcinomas and carcinomas of the ampulla Vateri. Conclusion: Our study indicates that MUC5AC is an excellent biomarker for pancreatic cancer diagnosis, especially to support the sometimes-difficult diagnosis on small biopsies. Mucin 5AC expression is unrelated to pancreatic cancer aggressiveness.

DOG1 is commonly expressed in pancreatic adenocarcinoma but unrelated to cancer aggressiveness.

BACKGROUND: DOG1 (ANO1; TMEM16A) is a voltage-gated calcium-activated chloride and bicarbonate channel. DOG1 is physiologically expressed in Cajal cells, where it plays an important role in regulating intestinal motility and its expression is a diagnostic hallmark of gastrointestinal stromal tumors (GIST). Data on a possible role of DOG1 in pancreatic cancer are rare and controversial. The aim of our study was to clarify the prevalence of DOG1 expression in pancreatic cancer and to study its association with parameters of cancer aggressiveness. METHODS: DOG1 expression was analyzed by immunohistochemistry in 599 pancreatic cancers in a tissue microarray format and in 12 cases of pancreatitis on large tissue sections. RESULTS: DOG1 expression was always absent in normal pancreas but a focal weak expression was seen in four of 12 cases of pancreatitis. DOG1 expression was, however, common in pancreatic cancer. Membranous and cytoplasmic DOG1 expression in tumor cells was highest in pancreatic ductal adenocarcinomas (61% of 444 interpretable cases), followed by cancers of the ampulla Vateri (43% of 51 interpretable cases), and absent in 6 acinus cell carcinomas. DOG1 expression in tumor associated stroma cells was seen in 76 of 444 (17%) pancreatic ductal adenocarcinomas and in seven of 51 (14%) cancers of the ampulla Vateri. Both tumoral and stromal DOG1 expression were unrelated to tumor stage, grade, lymph node and distant metastasis, mismatch repair protein deficiency and the density of CD8 positive cytotoxic T-lymphocytes in the subgroups of ductal adenocarcinomas and cancers of ampulla Vateri. Overall, the results of our study indicate that DOG1 may represent a potential biomarker for pancreatic cancer diagnosis and a putative therapeutic target in pancreatic cancer. However, DOG1 expression is unrelated to pancreatic cancer aggressiveness.

Management of major postsurgical gastroesophageal intrathoracic leaks with an endoscopic vacuum-assisted closure system.

BACKGROUND: Endoscopic treatment options for postsurgical intrathoracic leaks include injection of fibrin glue, clip application, and stent placement. Endoscopic vacuum-assisted closure (E-VAC) may be an effective treatment option. OBJECTIVE: To demonstrate that E-VAC is an effective endoscopic treatment option for closure of major intrathoracic postsurgical leaks. DESIGN AND SETTING: A prospective, single-center study at an academic medical center. PATIENTS: Eight consecutive patients with major intrathoracic postsurgical leaks. INTERVENTIONS: Endoscopic placement of transnasal draining tubes, armed with a size-adjusted sponge at their distal end, in the necrotic anastomotic cavities, followed by continuous suction. Sponge and drainage were changed twice weekly. Patients were followed-up for 193 +/- 137 days. MAIN OUTCOME MEASUREMENT: Successful leak closure. RESULTS: Successful closure of leaks was achieved in 7 of 8 patients (88%) after a mean of 23 +/- 8 days. A median of 7 endoscopic interventions was necessary. No major treatment-associated short-term or long-term (follow-up, 193 +/- 137 days) complications were noted. LIMITATIONS: Small sample size, single-center study, and lack of randomization. CONCLUSION: E-VAC is an effective endoscopic treatment modality for major postsurgical intrathoracic leaks. (This study is registered at Clinicaltrials.gov, identifier NCT00876551.).

Renal transplantation today.

BACKGROUND: The first successful renal transplant was carried out more than five decades ago between identical twins. At these early days, acute rejection was the limiting factor. DISCUSSION: Due to tremendous progress in immunosuppressive therapy and surgical technique, today, renal transplantation is the gold standard therapy for patients with end-stage renal disease. In fact, in comparison with chronic hemodialysis, renal transplantation offers an increase in quality of life while reducing comorbidities associated with dialysis treatment. RESULTS: Despite numerous beneficial achievements, no further improvement regarding patient outcome can be observed over the last two decades. Graft survival rates remain unchanged. The leading causes for graft loss are chronic allograft nephropathy and death with functioning graft. This might be related to a constant increase of the proportion of donors presenting extended donor criteria as well as a more liberal acceptance of candidates for a renal transplant. CONCLUSION: In the near future, one has to focus more closely on the posttransplant patient care to minimize factors associated with chronic allograft damage. These include post-transplant diabetes, hyperlipidemia, high blood pressure, cytomegalovirus infection, etc.

Indications for and outcomes after combined lung and liver transplantation: a single-center experience on 13 consecutive cases.

BACKGROUND: Combined lung and liver transplantation (Lu-LTx) is a therapeutic option for selected patients with coexisting lung and liver disease. For several reasons, Lu-LTx is performed in few centers and information about the technical issues, posttransplant management and long-term outcomes associated with this procedure is limited. METHODS: We analyzed data from 13 consecutive patients who underwent combined Lu-LTx at Hannover Medical School (Hannover, Germany) between April 1999 and December 2003. The main indications were cystic fibrosis, alpha1-proteinase inhibitor deficiency and portopulmonary hypertension. All patients had advanced cirrhosis and severe pulmonary disease manifestation. RESULTS: Ten patients received a sequential double Lu-LTx, one patient received a single Lu-LTx, one received a double lung and split liver transplantation, and one received an en-bloc heart-lung and liver transplantation. Immunosuppression was based on cyclosporine in a triple/quadruple regimen. Postoperative surgical complications occurred in eight patients. There were two perioperative deaths; two patients died during the first year on day 67 and 354, respectively, and one patient died at month 53. The overall patient survival rates at 1, 3, and 5 years were 69%, 62%, and 49%, respectively. CONCLUSION: Combined Lu-LTx is a therapeutic option for highly selected patients with end-stage lung and liver disease with acceptable long-term outcome.

Pancreas transplantation with histidine-tryptophan-ketoglutarate (HTK) solution and University of Wisconsin (UW) solution: is there a difference?

CONTEXT: In clinical pancreas transplantation the choice of preservation solution may have an impact on graft pancreatitis. Experience with histidine-tryptophan-ketoglutarate (HTK) is still limited whereas University of Wisconsin (UW) solution is currently the preferred perfusate worldwide. OBJECTIVE: The aim of this study was to analyze our experience with HTK in pancreas transplantation. PARTICIPANTS: In a retrospective analysis, data from 95 primary simultaneous pancreas-kidney transplantations were reviewed. The use of HTK (n=48) and UW (n=47) solution was stratified into two groups. MAIN OUTCOME MEASURES: Patient/graft survival and early graft function were compared. RESULTS: No significant differences between 1, 3 and 12 month patient survival (HTK: 97.9%, 97.9%, and 95.7% vs. UW: 95.7%, 89.4%, and 89.4%, respectively), and pancreas graft survival (HTK: 87.5%, 87.5%, and 85.4% vs. UW: 87.0%, 82.6%, and 82.6%, respectively) were detected. Higher values for peak lipase were observed on day 1 in the HTK group (not reaching significance: P=0.131) whereas no differences were noted for amylase and C-reactive protein. CONCLUSIONS: HTK is clinically comparable to UW. Both solutions have been shown to be safe for pancreas preservation. Successful pancreas transplantation depends on many factors such as donor and recipient factors, but skilled organ procurement techniques, organ preservation, and transplant experience in this field is mandatory. The choice of organ preservation solution is only one point in this context.

Quality of life in adult transplant recipients more than 15 years after kidney transplantation.

BACKGROUND: With continuously rising survival rates following renal transplantation, health-related quality of life (HQOL) of long-term transplant survivors becomes increasingly important. METHODS: Recipients more than 15 years after successful renal transplantation were studied retrospectively. HQOL in 139 long-term transplant recipients was assessed using the SF-36 and the disease-specific kidney transplant questionnaire (KTQ-25). RESULTS: Long-term transplant recipients revealed satisfactory HQOL that was comparable to the healthy population in four of eight SF-36 categories (role physical, social functioning, role emotional and mental health). Other SF-36 categories such as physical functioning, physical pain, general health, and vitality were reduced. Among the study population, disease-specific HQOL was comparable or even improved to that of patients awaiting transplantation. In contrast to retired or unemployed patients, employed recipients revealed a highly significant improved HQOL in numerous SF-36 categories such as physical functioning (P<0.001), physical pain (P<0.001), general health (P<0.001), vitality (P<0.001), social functioning (P<0.005), and mental health (P<0.001), as well as for the KTQ-dimensions physical symptoms (P<0.001), fatigue (P>0.001), uncertainty/fear (P<0.01), and emotions (P<0.05). Other factors positively correlating with improved HQOL in certain dimensions were living situation, systolic blood pressure, and recipient age. CONCLUSIONS: More than 15 years after renal transplantation, recipients present satisfactory HQOL comparable to the general healthy population or at least to pretransplant patients. Vocational rehabilitation following renal transplantation is of highest importance among long-term survivors and is associated with improved HQOL.

Sinusoidal obstruction syndrome of the liver after hematopoietic stem cell transplantation: decision making for orthotopic liver transplantation.

Sinusoidal obstruction syndrome (SOS) is a specific complication of hematopoietic stem cell transplantation (HSCT) that can lead to substantial morbidity and treatment-related mortality. Heparin is frequently used as prophylaxis of and defibrotide as therapy for mild to moderate SOS. In severe cases of SOS these therapies are often ineffective, and orthotopic liver trans-plantation (OLT) may be the only option. Reports in the literature about the outcome of liver transplantation for SOS are contradictory. We describe our second case of OLT after HSCT. The patient died of intracranial hemorrhage 2 weeks after liver transplantation with good initial organ function. In the first case at our center, however, the patient survived more then 8 years. The reported short- to medium-range survival rate for OLT following HSCT is approximately 50%. On the basis of the experience at our center and the findings in a review of the literature, we developed a rational approach to the selection for liver transplantation of patients with life-threatening liver dysfunction after marrow transplantation.

Surgical experience in splitting donor liver into left lateral and right extended lobes.

AIM: To outline the surgical experience with donor liver splitting in split liver transplantation. METHODS: From March 1 to September 1 in 2004, 10 donor livers were split ex situ into a left lateral lobe (segments II and III) and a right extended lobe (segments I, IV-VIII) in Medical School of Hannover, and thereafter split liver transplantation was performed successfully in 19 cases. The average age, weight and ICU staying period of the donors were 32.7 years (15-51 years), 64.5 kg (45-75 kg) and 2.4 d (1-8 d) respectively. RESULTS: The average weight of the whole graft and the left lateral lobe was 1,322.6 g (956-1,665 g) and 281.8 g (198-373 g) respectively, and the average ratio of left lateral lobe to the whole graft was 0.215 (0.178-0.274). The average graft to recipient weight ratio (GRWR) of the left lateral lobe and the right extended lobe reached 2.44% (1.22-5.41%) and 1.73% (1.31-2.30%) respectively. On average it took approximately 105 min (85-135 min) to split the donor liver. Five donor organs showed anatomic variation including the left hepatic vein variation in two cases, the left hepatic artery variation in two cases and the bile duct variation in one case. CONCLUSION: Split liver transplantation has become a mature surgical technique to expand the donor pool with promising results. In the process of graft splitting, close attention needs to be paid to potential anatomic variations, especially to variations of the left hepatic vein, the left hepatic artery, and the bile duct.

Living donor nephrectomy: flank incision versus anterior vertical mini-incision.

BACKGROUND: Currently, many centers perform laparoscopic donor nephrectomy (DN). We studied the outcome of donors and recipients following open DN using either flank incision (ODN) or mini-incision (MIDN). METHODS: Data of 196 living kidney donors were recorded prospectively. In 127 cases ODN and 69 cases MIDN were performed. RESULTS: Demographic details of donors were comparable for both groups. The left kidney was procured in 58% for ODN and in 64% for MIDN. Multiple arteries were more frequently present when MIDN (11% vs. 28%) was performed. The mean operating time was 129 min for ODN and 133 min for MIDN. Early complications occurred in 7% following ODN and in 4% following MIDN. Late complications were observed in 21% after ODN and 1% after MIDN. The mean hospital stay was significantly longer following ODN compared with MIDN (7.5 vs. 6.4 days). The primary graft function rate was 97% in both groups. One-year graft survival was 97% after ODN and 100% after MIDN. CONCLUSIONS: Results following MIDN are superior to those following ODN. Even in case of multiple renal vessels MIDN can be safely applied. In comparison with laparoscopic DN advantages of MIDN may be reduced costs, shorter operating time, and comparable cosmetic results.

Kidney transplant in children weighing less than 15 kg: donor selection and technical considerations.

BACKGROUND: Small children represent a challenging patient group in kidney transplantation (KTx). The aim of this study was to analyze patient and donor data influencing outcome in children that weighed <15 kg. METHODS: Sixty-eight kidneys were transplanted in 64 children that weighed <15 kg. In 44 cases, kidneys came from cadaveric donors (CAD) and in 24 cases from living-related donors (LRD). Grafts were placed transperitoneally via midline incision (n=16) or extraperitoneally to the iliac fossa (n=52). Vascular anastomoses were routinely performed to the aorta and vena cava even when the extraperitoneal approach was used. RESULTS: Vascular thrombosis was observed in two (3%), urinary leaks in five (7%), and stenosis in four (6%) patients. In six children receiving organs from adults to the iliac fossa, wound closure was performed using an absorbable mesh to avoid organ compression. Initial graft function occurred in 60 cases (88%). Frequency of initial graft function was significantly higher after KTx from LRD (100%) compared with CAD (82%). The 1-, 5-, and 10-year patient survival was 93%, 91%, and 91%, respectively, and the 1-, 5-, and 10-year graft survival was 92%, 85%, and 85%, respectively. There was no significant difference in patient and graft survival when KTx from LRD and CAD were compared. Within the CAD group, graft survival was improved using kidneys from donors >12 years compared with younger donors. CONCLUSION: Despite size discrepancy between recipients and grafts, KTx is feasible in children that weigh <15 kg by using an improved surgical technique even when adult organs are placed to the iliac fossa.

Delayed low-level calcineurin inhibition promotes allospecific tolerance induction by posttransplantation donor leukocyte infusion.

BACKGROUND: Donor lymphocytes infused after organ transplantation can have strong immunoregulatory effects. Application of such protocols for transplant tolerance induction in a clinical setting will, however, require combination of specific immunomodulatory strategies with nonspecific immunosuppressive medication for safety reasons. The aim of this study was to analyze the effects of immunosuppressive treatment on tolerance induction protocols by posttransplantation donor lymphocyte infusion. METHODS: The interaction of postoperative donor leukocyte infusion with different types, dosage, and timing of immunosuppressive drugs were studied in a rat model of heart transplantation. RESULTS: Tolerance could be achieved if donor cell infusion was combined with delayed, but not immediate, low-dose cyclosporine treatment, and this was associated with activation and apoptosis of host lymphocytes. In contrast, combinations with an antibody against the interleukin 2 receptor led to long-term graft survival but severe chronic rejection, and combinations with high-dose cyclosporine or sirolimus led to acute rejection. CONCLUSIONS: Postoperative donor leukocyte infusion is a potential way for tolerance induction, but the type, dose, and timing of medication are highly critical for its efficacy.