Quantitation of sentinel node metastatic burden and Her-2/neu over-expression accurately predicts residual axillary nodal involvement and extranodal disease in breast cancer.

BACKGROUND DATA: Recent literature has suggested that completion axillary lymph node dissection (ALND) in breast carcinoma patients with positive SLN may not be necessary. However, a method for determining the risk of non-SLN or extranodal disease remains to be established. AIMS: To determine if pathological variables from primary tumors and sentinel lymph node (SLN) metastases could predict the probability of non-sentinel lymph node (NSLN) metastases and extranodal disease in patients with breast carcinoma and SLN metastases. METHODS: 84 women with T1-3 breast cancer and clinically-negative axillae underwent completion ALND. Maximum diameter and width of SLN metastases were measured to calculate metastatic area. When multiple SLNs contained metastases, areas were summed to calculate the Total Metastatic Area (TMA). Multiple linear regression models were used to identify predictive factors. RESULTS: Her-2/neu over-expression increased the odds of NSLN metastases (OR 4.3, p = 0.01) and extranodal disease (OR 7.9, p < 0.001). Independent SLN predictors were ≥1 positive SLN (OR, 7.35), maximum diameter and area of SLN metastases (OR 2.26, 1.85 respectively) and TMA (OR, 2.12). Maximum metastatic diameter/SLN diameter (OR 3.71, p = 0.04) and the area of metastases/SLN area (OR 3.4, p = 0.04) were predictive. For every 1 mm increase in diameter of SLN metastases, the odds of NSLN extranodal disease increased by 8.5% (p = 0.02). TMA >0.40 cm(2) was an independent predictor for NSLN metastases and extranodal disease. CONCLUSION: Her-2/neu over-expression and parameters assessing metastatic burden in the SLN, particularly TMA, predicted the presence of NSLN involvement and extranodal disease in patients with breast carcinoma and SLN metastases.

Incidence, mechanism and prognostic value of activated AKT in pancreas cancer.

When activated, the serine/threonine kinase AKT mediates an antiapoptotic signal implicated in chemoresistance of various cancers. The mechanism(s) of AKT activation are unknown, though overexpression of HER-2/neu has been implicated in breast cancer. Therefore, we determined the incidence of activated AKT in human pancreatic cancer, whether HER-2/neu is involved in AKT activation, and if AKT activation is associated with biologic behaviour. HER-2/neu expression and AKT activation were examined in seven pancreatic cancer cell lines by Western blotting. The in vitro effect of HER-2/neu inhibition on AKT activation was similarly determined. Finally, 78 pancreatic cancer specimens were examined for AKT activation and HER-2/neu overexpression, and correlated with the clinical prognostic variable of histologic grade. HER-2/neu was overexpressed in two of seven cell lines; these two cell lines demonstrated the highest level of AKT activation. Inhibition of HER-2/neu reduced AKT activation in vitro. AKT was activated in 46 out of 78 (59%) of the pancreatic cancers; HER-2/neu overexpression correlated with AKT activation (P=0.015). Furthermore, AKT activation was correlated with higher histologic tumour grade (P=0.047). Thus, it is concluded that AKT is frequently activated in pancreatic cancer; this antiapoptotic signal may be mediated by HER-2/neu overexpression. AKT activation is associated with tumour grade, an important prognostic factor.

AKT inhibition is associated with chemosensitisation in the pancreatic cancer cell line MIA-PaCa-2.

Activation of the serine/threonine kinase AKT is common in pancreatic cancer; inhibition of which sensitises cells to the apoptotic effect of chemotherapy. Of the various downstream targets of AKT, we examined activation of the NF-kappaB transcription factor and subsequent transcriptional regulation of BCL-2 gene family in pancreatic cancer cells. Inhibition of either phosphatidylinositol-3 kinase or AKT led to a decreased protein level of the antiapoptotic gene BCL-2 and an increased protein level of the proapoptotic gene BAX. Furthermore, inhibition of AKT decreased the function of NF-kappaB, which is capable of transcriptional regulation of the BCL-2 gene. Inhibiting this pathway had little effect on the basal level of apoptosis in pancreatic cancer cells, but increased the apoptotic effect of chemotherapy. The antiapoptotic effect of AKT activation in pancreatic cancer cells may involve transcriptional induction of a profile of BCL-2 proteins that confer resistance to apoptosis; alteration of this balance allows sensitisation to the apoptotic effect of chemotherapy.

Cost-benefit analysis of biopsy methods for suspicious mammographic lesions; discussion 994-5.

HYPOTHESIS: Stereotactic core biopsy (SCB) is more cost-effective than needle-localized biopsy (NLB) for evaluation and treatment of mammographic lesions. DESIGN: A computer-generated mathematical model was developed based on clinical outcome modeling to estimate costs accrued during evaluation and treatment of suspicious mammographic lesions. Total costs were determined for evaluation and subsequent treatment of cancer when either SCB or NLB was used as the initial biopsy method. Cost was estimated by the cumulative work relative value units accrued. The risk of malignancy based on the Breast Imaging Reporting Data System (BIRADS) score and mammographic suspicion of ductal carcinoma in situ were varied to simulate common clinical scenarios. MAIN OUTCOME MEASURES: Total cost accumulated during evaluation and subsequent surgical therapy (if required). RESULTS: Evaluation of BIRADS 5 lesions (highly suggestive, risk of malignancy = 90%) resulted in equivalent relative value units for both techniques (SCB, 15.54; NLB, 15.47). Evaluation of lesions highly suspicious for ductal carcinoma in situ yielded similar total treatment relative value units (SCB, 11.49; NLB, 10.17). Only for evaluation of BIRADS 4 lesions (suspicious abnormality, risk of malignancy = 34%) was SCB more cost-effective than NLB (SCB, 7.65 vs. NLB, 15.66). CONCLUSIONS: No difference in cost-benefit was found when lesions highly suggestive of malignancy (BIRADS 5) or those suspicious for ductal carcinoma in situ were evaluated initially with SCB vs. NLB, thereby disproving the hypothesis. Only for intermediate-risk lesions (BIRADS 4) did initial evaluation with SCB yield a greater cost savings than with NLB.

BCL2 expression correlates with metastatic potential in pancreatic cancer cell lines.

BACKGROUND: Programmed cell death (termed apoptosis) regulates normal tissue homeostasis. Loss of local paracrine signals and intercellular adhesion molecules are potent inducers of apoptosis and thereby eliminate normal cells that may have escaped beyond the confines of the local organ environment. Dysregulation in the expression of the BCL2 gene family, the prototypic regulators of apoptosis, is a common occurrence in cancer and imparts resistance to standard triggers of apoptosis. Therefore, the authors sought to examine whether abnormal BCL2 gene family expression correlated with resistance to apoptosis and increased metastatic potential in pancreatic carcinoma. METHODS: The authors examined BCL2 expression and apoptotic sensitivity in three panels of human pancreatic cancer cell lines that possess varying metastatic potential. Stable transfectants were generated that overexpress BCL2. These transfectants were then analyzed for differences in metastasis formation in athymic mice. RESULTS: Among the isogenic panels of pancreatic cancer cell lines, BCL2 expression levels correlated with metastatic potential. Highly metastatic variants of each family of cell lines were more resistant to induction of apoptosis. Finally, using the BCL2 transfectant in a xenograft model, elevated BCL2 expression led to a higher incidence of metastases. CONCLUSIONS: The authors conclude that increased BCL2 expression correlates with apoptotic resistance and metastatic potential; dysregulation of BCL2 expression may be involved in the metastatic progression of pancreatic carcinoma.

Chemosensitization of pancreatic cancer by inhibition of the 26S proteasome.

BACKGROUND: Pancreatic cancer is extremely resistant to the induction of apoptosis by chemotherapies; agents that regulate sensitivity to apoptosis may lead to chemosensitization of pancreatic cancer. MATERIALS AND METHODS: MIA-PaCa-2 human pancreatic cancer cells were treated in vitro with the 26S-proteasome inhibitor PS-341. Levels of the apoptosis-regulating proteins (BCL-2, BAK, and BAX) were determined by Western blotting. The effect of PS-341 on BCL-2 gene transcription was examined using a BCL-2 promoter/luciferase reporter construct. The chemosensitizing effect of PS-341 was determined by measurement of the cytotoxic effect of gemcitabine in the presence of PS-341 (10-1000 nM) using the MTT assay. A corresponding in vivo experiment using tumor xenografts in athymic mice was also performed. RESULTS: PS-341 decreased BCL-2, without effect on BAX or BAK. The downregulation of BCL-2 by PS-341 appears to be transcriptionally mediated. PS-341 induced apoptosis at high does (1000 nM) and increased the cytotoxicity of gemcitabine at low doses (10-100 nM). Xenograft growth was inhibited 59% by gemcitabine; the addition of PS-341 increased growth inhibition to 75%. CONCLUSIONS: Inhibition of the 26S proteasome disrupts the cellular content of key regulators of cell cycle progression and apoptotic control leading to increased sensitivity to standard chemotherapeutic agents, such as gemcitabine, in pancreatic cancer. Combination therapy may lead to better response rates.

Resident experience and opinions about physician-assisted death for cancer patients.

HYPOTHESIS: Surgical residents and staff oncologists (surgical, medical, and radiation therapy) have similar opinions on participation in physician-assisted death for patients with terminal cancer. DESIGN: Prospective survey. SETTING: Tertiary care referral center. PARTICIPANTS: Residents undergoing surgical training (n = 56) and faculty oncologists (n = 24) of all specialties (surgical, medical, and radiation therapy). MAIN OUTCOME MEASURES: Subjects were queried regarding previous experience and willingness to participate (either directly or indirectly) in assisted death for terminal cancer patients. RESULTS: Response rates were 39% (22 of 56) for the residents and 87% (21 of 24) for the oncologists. Of those who responded, 86% (19 of 22) of the residents would aid any of the hypothetical patients with assisted death, whereas only 19% (4 of 21) of the staff oncologists expressed willingness to perform the same service. Furthermore, 32% (7 of 22) of the residents reported previous involvement in a case of assisted death from any disease, whereas only 19% (4 of 21) of the staff oncologists reported previous direct experience with assisted death in the terminal cancer patient. CONCLUSIONS: Surgical residents tend to have more experience with assisted death and are much more willing than staff oncologists to aid terminal cancer patients with this procedure. These opinions and practices are probably not the result of medical education but are developed from personal values.

Sentinel lymph node biopsy for breast cancer.

Sentinel lymph node biopsy (SLNB) is an emerging surgical technique to improve lymph node staging for breast cancer. Despite the rapid development of this technique, there remain aspects of SLNB that need to be further defined to provide a standardized approach. Variables, including patient selection, technical details for the performance of SLNB, extent of pathologic evaluation of the sentinel lymph node, and the impact of micrometastases, are areas of controversy. This paper reviews the controversies and discusses available data as well as personal experience and opinion.

Laparoscopic suturing evaluation among surgical residents.

BACKGROUND: Laparoscopic suturing is an integral part of advanced laparoscopic surgery training. The objective of this study was to evaluate the performance and preference of surgical residents performing intracorporeal and extracorporeal knot-tying techniques using conventional and Endo Stitch instruments. The residents were also evaluated on their suturing techniques using conventional instruments, the Endo Stitch, and the Suture Assistant. METHODS: Using an inanimate laparoscopic trainer model, 39 residents were evaluated as they performed laparoscopic knot tying exercises. Endpoints of the study were execution time and subjective preference of surgical residents with respect to the type of instrument used for knot tying. Forty-three residents were evaluated as they performed laparoscopic suturing exercises with three different types of suturing instruments using the same endpoints. RESULTS: The intracorporeal technique was the preferred (89%) method of knot tying among surgical residents. The time for completion of laparoscopic suturing was significantly (P < 0.05) shorter with the Endo Stitch (114 +/- 64 s) than with the conventional instrument (206 +/- 107 s) or the Suture Assistant (151 +/- 70 s). Residents preferred the use of the Endo Stitch in all three categories for suturing, knot tying, and handling. CONCLUSION: The Endo Stitch enhanced laparoscopic skills and was the preferred instrument for laparoscopic knot tying and suturing among surgical residents.

Major vascular resection as part of pancreaticoduodenectomy for cancer: radiologic, intraoperative, and pathologic analysis.

Intraoperative assessment is inaccurate in defining the relationship of a pancreatic head neoplasm to adjacent vascular structures. We evaluated the ability of preoperative contrast-enhanced CT to predict the need for vascular resection during pancreaticoduodenectomy and examined the resected vessels for histologic evidence of tumor invasion. During a 7-year period, 63 patients underwent pancreaticoduodenectomy with en bloc resection of adjacent vascular structures for a presumed pancreatic head malignancy. Clinical, radiologic, operative, and pathologic data were reviewed and analyzed. Fifty-six patients underwent resection of the superior mesenteric-portal vein confluence, three patients required inferior vena cava resection, and the hepatic artery was resected and reconstructed in eight patients. The operative mortality rate was 1.6%, and the overall complication rate was 22%. CT predicted the need for resection of the superior mesenteric or portal veins in 84% of patients. Pathologic analysis revealed tumor invasion of the vein wall in 71% of resected specimens. Tumor invasion of vascular structures adjacent to the pancreas can be predicted with preoperative CT and should alert the surgeon that vascular resection may be required. Histologic evidence of tumor cell infiltration of vessel walls was present in the majority of the resected specimens.

Prognostic factors in resectable pancreatic cancer: p53 and bcl-2.

The p53 tumor suppressor gene and the Bcl-2 proto-oncogene regulate cell cycle progression and apoptosis. We evaluated the expression of these molecular markers with standard pathologic prognostic variables in patients who received multimodality therapy for resectable adenocarcinoma of the pancreas to study the effect of p53 and Bcl-2 on survival duration. Immunohistochemical staining of archival material was performed to determine levels of expression of p53 and Bcl-2 proteins in 70 patients with adenocarcinoma of pancreatic origin. All patients underwent a potentially curative pancreaticoduodenectomy and standardized pathologic analysis of resected specimens. Potential pathologic and molecular prognostic variables were assessed for their effect on survival duration. Nuclear staining for p53 was observed in 33 (47%) of 70 specimens. Immunostaining for Bcl-2 was observed in 23 specimens (33%). A trend toward improved survival duration was seen in patients whose tumors stained positive for either p53 or Bcl-2. Negative staining for both markers predicted short survival (P = 0.01). By univariate and multivariate analyses, no single pathologic factor was associated with survival duration. Immunohistochemical staging using both p53 and Bcl-2 significantly predicted survival duration by univariate and multivariate analysis; patients whose tumors stained positively for p53 and/or overexpressed Bcl-2 had a significantly longer survival than those whose tumors stained negative for both proteins.

Gemcitabine-induced programmed cell death (apoptosis) of human pancreatic carcinoma is determined by Bcl-2 content.

BACKGROUND: Gemcitabine is a new nucleoside analogue that produces a clinical response in 30% of patients with unresectable pancreatic carcinoma. The cytotoxic effects of many chemotherapeutic agents occur through induction of programmed cell death (apoptosis), which is controlled by the bcl-2 gene family. We determined whether induction of apoptosis by gemcitabine in pancreatic carcinoma is associated with cellular Bcl-2 content. METHODS: Four pancreatic carcinoma cell lines (MIA-PaCa-2, AsPC-1, Panc-1, and Panc-48) were screened by Western blotting for Bcl-2 protein expression. Dose-response relationships for the cytotoxic effects of gemcitabine were determined using methylthiotetrazole assays, and induction of apoptosis was confirmed by fluorescence-activated cell sorting analysis. MIA-PaCa-2 cells transfected with human bcl-2 were also analyzed for gemcitabine-induced apoptosis. RESULTS: Pancreatic cancer cell lines expressed varying amounts of Bcl-2, and the 50% lethal dose for gemcitabine-induced apoptosis was correlated with Bcl-2 content. Furthermore, Bcl-2 overexpression was associated with a significant increase in the 50% lethal dose for gemcitabine-induced apoptosis. CONCLUSIONS: Cellular Bcl-2 content was directly correlated with the cytotoxicity of gemcitabine in pancreatic carcinoma. Therefore, routine immunohistochemical analyses may be useful in predicting gemcitabine efficacy, and patients who would likely not benefit could be spared gemcitabine administration. Furthermore, the effectiveness of gemcitabine and other chemotherapeutic agents may be increased by gene therapy-mediated alteration of bcl-2 gene family members.

Patterns of recurrence in extremity liposarcoma: implications for staging and follow-up.

BACKGROUND: Liposarcoma is one of the most common histologic types of soft tissue sarcoma and presents a wide spectrum of clinical behavior. The authors examined the correlation among histologic subtypes, outcomes, and patterns of recurrence among patients with extremity liposarcomas. METHODS. A retrospective review of all patients with intermediate and high grade extremity liposarcoma referred to the University of Texas M. D. Anderson Cancer Center from January 1, 1980, to December 31, 1992, was performed. Data on clinical presentation, treatment, patterns of treatment failure, and outcome were evaluated. RESULTS: During the 13-year study period, 122 patients with intermediate or high grade extremity liposarcoma were identified: 102 patients (84%) with myxoid subtype, 18 patients (15%) with pleomorphic subtype, and 2 patients (2%) with mixed histology. There were no differences between the myxoid and pleomorphic subtype groups in tumor size (T1 vs. T2), depth in relation to the muscular fascia, or anatomic site. The median follow-up was 70 months. The 5-year overall survival rate for all intermediate and high grade extremity liposarcoma patients presenting with primary disease (n=85) was 74%; the 5-year local recurrence free survival, distant recurrence free survival, and disease free survival rates were 93%, 78%, and 73%, respectively. Among the 102 patients with myxoid tumors, 33 had distant recurrences; 31 of these were to extrapulmonary soft tissue sites (e.g., the retroperitoneum, chest wall, pleura, pericardium, pelvic sidewall, and soft tissue of the back), and 2 were to the lung only. Among the 18 patients with pleomorphic tumors, 10 had distant recurrences; 3 occurred at extrapulmonary sites, and 7 occurred in the lung only (P < 0.05 for myxoid vs. pleomorphic subtypes). CONCLUSIONS: Myxoid liposarcomas often metastasized to extrapulmonary sites and did so significantly more frequently than pleomorphic tumors. Imaging of the abdomen, retroperitoneum, and extrapleural chest should be performed for accurate staging and posttreatment follow-up of patients with myxoid liposarcoma. Patients presenting with "primary" myxoid liposarcoma of the trunk should be carefully evaluated for an occult primary tumor in an extremity.

Adenovirus-mediated wild-type p53 tumor suppressor gene therapy induces apoptosis and suppresses growth of human pancreatic cancer [seecomments].

BACKGROUND: The p53 tumor suppressor gene is mutated in up to 70% of pancreatic adenocarcinomas. We determined the effect of reintroduction of the wild-type p53 gene on proliferation and apoptosis in human pancreatic cancer cells using an adenoviral vector containing the wild-type p53 tumor suppressor gene. METHODS: Transduction efficiencies of six p53-mutant pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, CFPAC-1, MIA PaCa-2, and PANC-1) were determined using the reporter gene construct Ad5/CMV/beta-gal. Cell proliferation was monitored using a 3H-thymidine incorporation assay, Western blot analysis for p53 expression was performed, and DNA laddering and fluorescence-activated cell sorter analysis were used to assess apoptosis. p53 gene therapy was tested in vivo in a subcutaneous tumor model. RESULTS: The cell lines varied in transduction efficiency. The MIA PaCa-2 cells had the highest transduction efficiency, with 65% of pancreatic tumor cells staining positive for beta-galactosidase (beta-gal) at a multiplicity of infection (MOI) of 50. At the same MOI, only 15% of the CFPAC-1 cells expressed the beta-gal gene. Adenovirus-mediated p53 gene transfer suppressed growth of all human pancreatic cancer cell lines in a dose-dependent manner. Western blot analysis confirmed the presence of the p53 protein product at 48 hours after infection. DNA ladders demonstrated increased chromatin degradation, and fluorescence-activated cell sorter analysis demonstrated a four-fold increase in apoptotic cells at 48 and 72 hours following infection with Ad5/CMV/p53 in the MIA PaCa-2 and PANC-1 cells. Suppression of tumor growth mediated by induction of apoptosis was observed in vivo in an established nude mouse subcutaneous tumor model following intratumoral injections of Ad5/CMV/p53. CONCLUSIONS: Introduction of the wild-type p53 gene using an adenoviral vector in pancreatic cancer with p53 mutations induces apoptosis and inhibits cell growth. These data provide preliminary support for adenoviral mediated p53 tumor suppressor gene therapy of human pancreatic cancer.

Prospective, randomized, double-blind study of prophylactic antibiotics in axillary lymph node dissection.

BACKGROUND: Antibiotic prophylaxis is controversial in patients undergoing axillary lymph node dissection (ALND). We determined whether preoperative antibiotics decreased incidence or treatment cost of infectious complications following ALND. METHODS: Two hundred patients entered this prospective, randomized, double-blind trial. Patients received either placebo or cefonicid preoperatively. Loco-regional signs of infection were monitored for 4 weeks postoperatively. RESULTS: There was a trend toward fewer infections in the prophylactic group (placebo 13% versus cefonicid 6%; P = 0.080). Cefonicid significantly decreased severe infections requiring hospitalization (placebo 8% versus cefonicid 1%; P = 0.033). Cefonicid also decreased the treatment cost of infection per patient ($49.80 versus $364.87). CONCLUSIONS: We demonstrated a trend toward fewer overall infections and significantly fewer severe infections in patients given prophylactic antibiotics, which translated into a decrease in the cost of treatment for infectious complications. These findings support antibiotic prophylaxis for patients undergoing ALND.

Prospective, randomized trial of Doppler-assisted subclavian vein catheterization.

OBJECTIVE: To examine the rate of success and complications of Doppler-guided subclavian vein catheter insertion compared with standard insertion in patients considered at high risk for failure. DESIGN: Prospective, randomized, crossover trial. SETTING: University-affiliated tertiary care medical center. PATIENTS: Two hundred forty patients were enrolled in the study. Patients were stratified for 3 known risk factors: (1) prior surgery in the subclavian vein region, (2) prior radiotherapy at the attempted catheterization site, and (3) an abnormal weight-height ratio. INTERVENTIONS: Subclavian vein catheterization was performed either in standard or Doppler-guided fashion using the Smart Needle (Peripheral Systems Group, Mountain View, Calif), which is a Doppler probe at the tip of a cannulating needle. If subclavian vein catheterization was unsuccessful after 2 attempts, patients were crossed over to the other technique. MAIN OUTCOME MEASURE: Successful cannulation of the subclavian vein. RESULTS: The success rate, either as an initial technique or as a salvage technique, and complication rate were not significantly different with use of the Smart Needle. A subgroup of physicians had a significantly lower success rate using the Smart Needle. CONCLUSIONS: Doppler guidance did not increase the success rate or decrease the complication rate of subclavian vein catheterization when compared with the standard technique in high-risk patients. Doppler guidance was not more useful than the standard technique as a salvage technique following a previous failure of catheterization. Furthermore, real-time Doppler guidance of subclavian vein catheterization is a technique that is highly operator dependent.

A human gastric cancer cell line possesses a functional receptor for gastrin-releasing peptide.

Bombesin (BBS) exhibits diverse biological functions including those of neurotransmitter, regulator of gastrointestinal hormone release, and mitogen. Gastrin-releasing peptide (GRP, the mammalian equivalent of BBS) is found in mucosal cells of the gastric fundus and antrum. We determined whether a human gastric cancer cell line (SIIA) expresses a functional GRP-receptor (GRP-R). BBS increased intracellular calcium ([Ca2+]i), and a specific GRP-R antagonist, ([D-Phe6, Des-Met14]-BBS (6-14)-ethylamide), blocked BBS-induced increase in [Ca2+]i. SIIA cells possess GRP-R mRNA by reverse transcriptase-PCR. Furthermore, these cells possess an 80-kDa cell surface protein that specifically binds BBS with two high-binding affinities (Kd1 = 0.6 nM, Kd2 = 6.7 nM). These findings indicate that SIIA cells possess a GRP-R that is capable of physiological signal transduction, though the cellular response remains unknown.