Model for end-stage liver disease dynamic stratification of survival benefit

Only patients with Model for End-stage Liver Disease (MELD) scores ≥18 or ≥17 experience a survival benefit (SB) at 12 and 36 months after liver transplantation (OLT). The SB calculation estimates the difference after stratification for risk categories between the survival rate of transplanted versus waiting list patients. The aim of this study was to perform a short- and long-term (60 months) SB analyses of a Italian OLT program. One-hundred seventy-one patients were stratified into four MELD classes (6-14, 15-18, 19-25, 26-40), and two groups: namely, waiting list (WL) and transplanted groups (TX). The median waiting time for transplanted patients was 4.4 months (range, 0-35). SB was expressed as mortality hazard ratio (MHR) as obtained through a Cox regression analysis using as a covariate the status of each patient in the waiting list (WL = 0, reference group) or the TX group (TX = 1). Values over 1 indicated the MHR in favor of the WL with the values below 1 indicating MHR in favor of Tx. In the MELD class 6 to 14, the MHR was above 1 at 3 and 6 months, indicating an SB in favor of WL; subsequently, the MHR dropped below 1, indicating an SB in favor of TX (P < .05). In the MELD class 15 to 18 the MHR was above 1 at 3 months, but below 1 subsequently (P < .05). For MELD classes 19 to 25 and 26 to 40, the MHR was always below 1 (P < .01). According to the SB approach, patients in the MELD class 6 to 14 could safely wait for at least 36 months; patients in the MELD class 15 to 18 should likely remain no longer than 12 months on the waiting list, and all the remaining patients with MELD > 18 should be transplanted as soon as possible. OLT should not be precluded but only postponed for MELD < 19 patients.

Hepatic resection for giant haemangioma in a patient with a contemporaneous adult polycystic liver disease

Hepatic resection for giant haemangioma in a patient with a contemporaneous adult polycystic liver disease. According to Gigot classification, and to the characteristics of haemangioma surgery in these patients can be considered safe. We report the case of a 55 year-old man affected by an adult polycystic liver disease (PCLD) and a contemporaneous symptomatic haemangioma of the III segment. At the preoperative imaging scans, APCLD was classified in a type II grading according to Gigot classification. The patient underwent surgery: a wedge resection of the III segment with the exportation of the haemangioma and a fenestration of a large cyst placed in the VIII segment were performed. Post-operative course was regular and the patient was discharged uneventfully in post-operative 9th day, with a total regress of the initial symptoms. APCLD and haemangioma are two benign conditions that do not require surgery except if they cause important symptoms, such as pain. The good clinical conditions of the patient, the moderate gravity of the APCLD and the particular exofitic localisation of the cavernous haemangioma gave us the possibility to make a safe surgery for the patient. To the best of our knowledge, this is the first case reported in literature in which a liver resection for haemangioma in patient with APCLD was performed. In conclusion, liver resection for haemangioma is not contraindicated, mainly if it is symptomatic, even in the contemporaneous presence of an APCLD.

Later diagnosed with a neuroendocrine tumor, case report of a 60-year-old

Neuroendocrine tumours of the colon and rectum are infrequent. Clinical manifestations are not different from standard adenocarcinoma. Symptoms are non specific; the most common are abdominal pain, nausea and vomiting, weight loss and gastrointestinal blood loss. We report an advanced case of transverse colon neuroendocrine carcinoma with multiple metastasis. When these tumours are diagnosed, they have distance disease related to a poor prognosis for the patient. Surgery is the treatment that can offer a greater chance of survival to these patients.

P5-21-01: A Renewable Tissue Resource of Phenotypically Stable Human Breast Cancer Xenografts for Preclinical Studies

Introduction Translational breast cancer research is hampered severely by difficulties in obtaining and studying primary human breast tissue, and by the lack of in vivo preclinical models that accurately reflect patient tumor biology. These limitations are due, in part, to the fact that traditional immunocompromised mouse models are not generally permissive for growth. We sought to circumvent some of these limitations by transplanting and growing human mammary tumors in the mammary fat pad of SCID/Beige immunocompromised mice in the absence of exogenous human fibroblasts.

Aims and Methods To establish a set of stable human breast cancer xenografts for preclinical studies. Human breast cancer biopsies were received, minced into small fragments and then transplanted directly into “cleared” fat pads of recipient SCID/Beige immunocompromised mice. Transplanted fat pads were checked weekly. After initial tumor was palpated and harvested, tumor fragments were transplanted into new SCID/Beige hosts for subsequent transplant generations. Serial immunohistochemical evaluations were performed to confirm human origin and biomarker status. Analytical flow cytometry for evaluating expression of proposed “cancer stem cell” markers, and gene and protein expression analysis were carried out on all stable lines.

Results and Conclusions Xenograft lines were established directly from breast cancer patient samples, without intervening culture in vitro, using the epithelium-free mammary fat pad as the transplantation site. Of the conditions tested, xenograft take rate was highest in the presence of a low-dose estradiol pellet without exogenous human fibroblasts. Thirty six stably transplantable xenograft lines representing 27 patients were established, using pre-treatment, mid-treatment, and/or post-treatment samples. Most patients yielding xenografts were “triple-negative” (ER-PR-HER2−) (n=21), we were able to establish lines from three ER-PR-HER2+ patients, one ER+PR+HER2−, one ER+PR-HER2−and one “triple-positive” (ER+PR+HER2+) patients. Serially passaged xenografts show phenotypic consistency with the tumor of origin at the histopathology level, and remarkable stability across multiple transplant generations at both the genomic, transcriptomic, and proteomic levels. Of 27 lines evaluated fully, thirteen xenografts showed metastasis to the mouse lung. These models thus serve as a renewable, quality-controlled tissue resource, and should prove useful for preclinical evaluation of experimental therapeutics.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-21-01.

P1-03-02: The Norton-Simon Hypothesis and Cancer Stem Cells: How Cancer Stem Cells May Explain the Effectiveness of Dose-Dense Chemotherapy

Background: Systemic therapies are effective initially in controlling and reversing tumor growth; however, residual cancers will invariably re-grow despite this initial response. We have published data from paired human breast cancer samples that standard therapy every three weeks kills dividing daughter cells but not tumor-initiating cells (TICs), so that samples obtained after therapy are enriched for CD44+/CD24−/low putative “tumor-initiating” or “cancer stem” cells, indicating that standard treatment regimens are missing the critical targets, TICs. Interestingly, we have recent data in human breast tumors that indicate that TICs may in fact be chemosensitive initially, with a decrease in TICs observed within two days of chemotherapy, but shortly thereafter, TICS are actually induced by chemotherapy.

Materials and Methods: To evaluate TICs response to chemotherapy, mice with human breast tumor xenograft lines BCM-2665a and BCM-2147 were treated with vehicle, 10-, or 33-mg/kg docetaxel, and then tumors were collected for TIC assays and molecular analysis at both 48 and 72h after treatment. Using Affymetrix gene expression microarrays and reverse phase protein array (RPPA) analysis with 119 different validated antibodies, we identified pathways involved in regulation of TICs. Results: According to flow cytometric analysis for TIC markers and mammosphere (MS) formation efficiency, BCM-2665 TICs were reduced by docetaxel treatment compared to vehicle-treated at 48h post 10 mg/kg docetaxel (4-fold decrease) and 48 and 72h post 33 mg/kg docetaxel compared to control (14- and 2-fold decrease, respectively). Although the BCM-2147 TICs did not significantly decrease at any time points or doses tested, they were clearly induced at 72h post-treatment compared to control. Additionally, BCM-2665 TICs were increased within 72h post 10 mg/kg docetaxel, indicating that these time points are ideal for defining the mechanisms responsible for induction of TICs. Ingenuity Pathway Analysis of Affymetrix microarray data for both BCM-2665 and BCM-2147 revealed induction of inflammatory pathways, suggesting leukocyte infiltration associated with induction of TICs. Furthermore, RPPA analysis confirmed gene expression changes from the microarray data, and implicated apoptosis and inflammatory pathways. Sixteen of 28 proteins significantly changed with activation of CSC are involved in development of leukocytes. Discussion: These findings are consistent with the Norton-Simon Hypothesis in that chemotherapy regimens given more frequently may in fact eliminate TICs, thereby explaining the proven increased effectiveness of dose-dense chemotherapy. Based on when TICs became chemoresistant, we are comparing dose-dense treatment (4 mg/kg docetaxel every 3 days) to a traditional single dose of 32 mg/kg, in an effort to eliminate the tumor cells that cause tumor recurrence. Furthermore, our analysis of gene expression at both the RNA and protein level implicated the immune cells as TICs inducers. Since our immunocompromised mice lack T- and B- cells but have active macrophages, macrophages are indicated as inducers of TICs. We are focusing our current efforts at identifying how immune cells activate TICs and thus enhance tumorigenesis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-03-02.

Does caval reconstruction technique affect early graft function after liver transplantation? A preliminary analysis

BACKGROUND

In the past decades, the inferior vena cava (IVC) reconstruction technique has undergone several evolutions, such as biopump, piggyback technique (PB), and laterolateral approach (LLPB). Several advantages are reported comparing the PB technique to biopump use. However, comparison between PB and LLPB has not been as well investigated. The aim of this study was to compare the results in terms of immediate graft function and intermediate graft survival among 3 subgroups characterized by distinct caval reconstruction techniques.

METHODS

We retrospectively analyzed a cohort of 200 consecutive adult patients who underwent liver transplantation from January 2001 to December 2009. The patients were stratified according to 3 caval reconstructive techniques: biopump (n=135), PB (n=32) and LLPB (n=33).

RESULTS

The LLPB group showed the shortest cold and warm ischemia times and the best immediate postoperative graft function. Survival analysis revealed LLPB patients to present the best 1-year graft survival rates: namely, 90.9% versus 75.0% and 74.1% among the PB and biopump groups, respectively (log-rank tests: LLPB vs biopump: P=.03; LLPB vs PB: P=.05). In our experience, LLPB showed the best graft survivals with an evident reduction in both cold and warm ischemia times. However, it is hard to obtain an irrefutable conclusion owing to the retrospective nature of this study, the small sample, and the different periods in which the groups were transplanted.

CONCLUSIONS

LLPB technique was a safe procedure that minimized the sequelal of ischemia-reperfusion damage. This technique yielded results superior to venovenous bypass. No definitive conclusions can to be obtained in this study comparing classic PB or LLPB.

Tacrolimus trough levels and level-to-dose ratio in stable renal transplant patients converted to a once-daily regimen

Numerous evidence has been reported to support a safe 1:1 conversion from the twice-daily tacrolimus (Tac-T) to the once-daily tacrolimus regimen (Tac-O), but frequently there is a reduction in drug trough levels, which has been estimated by some authors to be about 20%. The relationship between Tac-O dosage and trough levels after conversion is not clear. The tacrolimus trough levels-to-dose ratio has been applied to better define the wide variability in doses and blood levels of tacrolimus. The aim of this study was to evaluate tacrolimus trough levels, tacrolimus daily dosage, and tacrolimus level-to-dose ratio during 1 year pre-postconversion follow-up in 31 stable kidney transplant patients who had received Tac-T therapy for over 6 months with stable renal function. They were converted to the same dosage of Tac-O. Patients before and after conversion were their own controls. The trough levels of tacrolimus showed a slight albeit significant reduction after conversion, remaining in the therapeutic range. Nineteen percent underwent an adjustment in total daily dosage after conversion versus 39% before conversion with no significant difference. No significant differences were detected in the total daily dose administered either by tacrolimus level-to-dose ratio before or after conversion. Kidney transplant recipients under Tac-O therapy were safely maintained using the same therapeutic monitoring as when receiving Tac-T.

Clinical and virological characteristics of chronic hepatitis B with concurrent hepatitis B E antigen and antibody detection

The concurrent detection of hepatitis B e antigen (HBeAg) and its corresponding antibody (anti-HBe) in patients with chronic hepatitis B virus (HBV) infection is well established but the clinical features remain poorly understood. Demographic information, clinical and laboratory data were collected from 1624 consecutive inpatient records of patients with chronic hepatitis B. Viral genotype, basic core promoter and precore mutations were determined by direct sequencing. In vitro HBeAg and anti-HBe binding experiments were conducted with three pairs of HBeAg-positive and anti-HBe-positive serum samples, which were mixed at variable ratios and incubated at 37°C for 3-24h. Of the 1624 chronic patients, 169 (10.4%) had concurrent HBeAg and anti-HBe positivity, and this was associated with intermediate age and HBV-DNA load, higher alanine aminotransferase level and more pronounced liver damage compared with HBeAg-positive or anti-HBe-positive patients alone. HBeAg and anti-HBe titres (median and interquartile range, S/CO) in the concurrent positive group were 4.2 (1.8-9.6) and 0.54 (0.27-0.72), which were closer to their respective cut-off values than those of HBeAg-positive or anti-HBe-positive groups alone. For the cases successfully sequenced, 110/134 (82.1%) harboured T1762/A1764 or/and A1896 mutants. The binding experiments showed that HBeAg and anti-HBe could be concurrently observed provided an optimal ratio (HBeAg to anti-HBe) was chosen. In antiviral treatment-naive patients, concurrence of HBeAg and anti-HBe was not uncommon, and such patients had profound liver disease. An optimal ratio between HBeAg and anti-HBe led to their concurrent detection when sera were tested by sensitive assays.

An unusual case of hepatic carcinosarcoma

We report a rare case of a hepatic carcinosarcoma with rabdomyosarcomatous differentiation in its sarcomatous component. A 71-year old Caucasian female patient underwent a liver resection for a 4-cm lesion developed on an underlying HCV-related cirrhosis. Post-operative course was uneventful and the patient was discharged 5 days after surgery. At pathology, the tumor presented the features of hepatocellular carcinoma and rhabdomyosarcoma Three months later the patient experienced a liver recurrence, dying 2 months later for systemic disease. The reported case presents several peculiarities, i.e. the female gender, the HCV-related cirrhotic status, and the European origin of the patient. However, the outcome of our case confirms that this neoplasm pursues a highly aggressive course with poor prognosis.

Impact of anti-hepatitis B core-positive donors in liver transplantation: a survival analysis

INTRODUCTION

The current shortage of organs for liver transplantation (OLT) requires expansion of the donor pools. A possible approach to this problem may be the use of donors positive for antibody against hepatitis B core antigen (anti-HBc). However, it is not clear whether recipients who receive anti-HBc-positive livers show worse survival. The aim of this study was to retrospectively analyze the patient and graft survivals of two groups of OLT recipients according to the anti-HBc status of their respective donors.

METHODS

We stratified 133 patients into group 1 (n = 120; anti-core-negative donors) versus group 2 (n = 13; anti-core-positive donors).

RESULTS

Comparing the two groups by univariate analysis, there was no significant differences with regard to recipient, donor, or transplant characteristics. Group 2 showed worse 5-year patient (46.2% vs 72.0%; P = .006) and graft survivals (38.5% vs 68.4%; P = .003). After adjustment for several risk factors for post-OLT death and graft failure, there was no significant difference between patients who received anti-core-positive versus anti-core-negative donors, in terms of patient and graft survivals, particularly only after adjustment for Model for End-stage Liver Disease (MELD) degree of severity.

CONCLUSION

The use of anti-HBc-positive donors resulted in worse post-OLT patient and graft survival rates. Unlike the results obtained in the United States, we did not find possible confounders in our results, excluding MELD ≥ 20. However, due to the small size of our cohort, future prospective multicenter studies are required to clarify the safety of anti-core-positive grafts.

Predictive parameters after molecular absorbent recirculating system treatment integrated with model for end stage liver disease model in patients with acute-on-chronic liver failure

AIM

The aim of study was to highlight parameters that in association with Model for End-stage Liver Disease (MELD) provide predictive criteria for long-term survival after treatment with the Molecular Adsorbent Recirculating System (MARS). Two homogenous groups were studied: one treated with standard medical therapy (SMT) and the other, with MARS.

MATERIALS AND METHODS

Twenty acute-on-chronic liver failure patients on the waiting list for liver transplantation and affected by alcoholic cirrhosis with similar MELD scores (20-29) were evaluated for 7 days from inclusion and for 6-month survival. Ten patients (seven males and three females) were treated with MARS. Their mean age was 48.5 years (range = 35-61). The number of MARS applications was six for 6 consecutive days, and the length of the applications was 8 hours. Ten other patients (seven males and three females) were treated with SMT, including prophylaxis against bacterial infections and judicious use of diuretics. The precipitating factors were also treated appropriately. The mean age of the patients was 51 years (range = 37-64). All the variables that were significant upon univariate analysis were enrolled in a receiver operating characteristic analysis, with the intention to detect predictive parameters for patient death at 6 months. We considered a significant area under curve (AUC) value to be greater than 0.5.

RESULTS

Among 11 patients who died within 6 months there were in the MARS group and eight in the SMT group: the 3- and 6-month patient survival rates were 90% and 70% versus 30% and 20% in the two groups, respectively. Nine measures resulted in an AUC > 0.5: DeltaMELD; interleukin (IL)-8; IL-6; tumor necrosis factor- alpha, MELD score; creatinine, bilirubin international normalized ratio (INR) and cardiac index. DeltaMELD and postoperative IL-8 concentrations showed better results (AUC = 0.899), followed by postoperative creatinine (AUC = 0.879), postoperative cardiac index (AUC = 0.833), and postoperative INR (AUC = 0.818). Postoperative creatinine showed the best sensitivity (100%), while IL-8, the best specificity (88.9%).

CONCLUSION

A combination of biochemical and clinical variables probably represent the best way to predict the survival of patients, allowing physicians to select the best therapies for each patient.

Novel Stably Transplantable Xenograft Models of Human Breast Cancer for Evaluation of Experimental Therapeutics

In translational breast cancer research, our ability to evaluate clinical responses of human tumors to new therapeutic agents is severely limited experimentally. For example, it is not possible to evaluate the response of a single tumor to multiple candidate therapeutic agents. Conversely, the limited number of well-characterized in vivo preclinical human tumor models currently available precludes evaluation of multiple clinically relevant tumors with candidate therapeutic agents. These limitations severely impinge on our ability to develop and test novel therapeutic agents, particularly those that may target tumor-initiating “cancer stem cells”, which are relatively resistant to chemotherapy and radiation and may be responsible for disease recurrence and metastases.Historically, in vivo experimental therapeutic research has relied on either genetically engineered animal models, or “xenograft” transplantation models in which established human cancer cell lines are transplanted into immunocompromised host mice. However, each type of model has significant limitations. We sought to circumvent some of these limitations by propagating a cohort of human tumors as stably transplantable xenograft tissue lines grown in the absence of engineered or immortalized fibroblasts by transplanting clinical biopsies directly into the mammary fat pad of SCID/Beige immunocompromised mice (lacking B-cell, T-cell, and NK cell function) without intervening culture in vitro.Thus far, we have established 13 independent stably transplantable xenograft lines representing nine “triple-negative” (ER-PR-HER2-), two HER2+, and two ER+ breast cancers. Established xenograft lines show phenotypic similarity to the primary tumor with respect to histology and gene expression. Xenografts are being characterized genetically by whole genome sequencing as well as for the diversity of tumor-initiating cell types present. These models are proving useful for the evaluation of experimental therapeutics for their ability to inhibit tumor growth, and for their ability to target the subset cancer cells capable of regenerating tumors upon transplantation, with the goals of overcoming chemoresistance, preventing disease recurrence, and eliminating metastases.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1159.