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Gao Z, Janakiraman H, Xiao Y, Kang SW, Dong J, Choi J, Ogretmen B, Lee HS, Camp ER. Sphingosine-1-Phosphate Inhibition Increases Endoplasmic Reticulum Stress to Enhance Oxaliplatin Sensitivity in Pancreatic Cancer. World J Oncol 2024; 15:169-180. [PMID: 38545484 PMCID: PMC10965266 DOI: 10.14740/wjon1768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/19/2024] [Indexed: 05/02/2024] Open
Abstract
Background Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer resistant to current therapies, including oxaliplatin (Oxa). Growing evidence supports the ability of cancers to harness sphingolipid metabolism for survival. Sphingosine-1-phosphate (S1P) is an anti-apoptotic, pro-survival mediator that can influence cellular functions such as endoplasmic reticulum (ER) stress. We hypothesize that PDAC drives dysregulated sphingolipid metabolism and that S1P inhibition can enhance ER stress to improve therapeutic response to Oxa in PDAC. Methods RNA sequencing data of sphingolipid mediators from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression Project (GTEx) datasets were analyzed. Murine and human PDAC cell lines were treated with small interfering RNA (siRNA) against sphingosine kinase-2 (SPHK2) or ABC294640 (ABC) and incubated with combinations of vehicle control or Oxa. In an orthotopic syngeneic KPC PDAC model, tumors were treated with either vehicle control, Oxa, ABC, or combination therapy. Results RNA sequencing analysis revealed multiple significantly differentially expressed sphingolipid mediators (P < 0.05). In vitro, both siRNA knockdown of SPHK2 and ABC sensitized cells to Oxa therapy (P < 0.05), and induced eukaryotic initiation factor 2α (eIF2α) and protein kinase RNA-like endoplasmic reticulum kinase (PERK) phosphorylation, hallmarks of ER stress. In vitro therapy also increased extracellular high mobility group box 1 (HMGB1) release (P < 0.05), necessary for immunogenic cell death (ICD). In vivo combination therapy increased apoptotic markers as well as the intensity of HMGB1 staining compared to control (P < 0.05). Conclusions Our evidence suggests that sphingolipid metabolism is dysregulated in PDAC. Furthermore, S1P inhibition can sensitize PDAC to Oxa therapy through increasing ER stress and can potentiate ICD induction. This highlights a potential therapeutic target for chemosensitizing PDAC as well as an adjunct for future chemoimmunotherapy strategies.
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Affiliation(s)
- Zachary Gao
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Yang Xiao
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sung Wook Kang
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Houston, TX 77030, USA
- Systems Onco-Immunology Laboratory, David J. Sugarbaker Division of Thoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jiangling Dong
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jasmine Choi
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Hyun-Sung Lee
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Houston, TX 77030, USA
- Systems Onco-Immunology Laboratory, David J. Sugarbaker Division of Thoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ernest Ramsay Camp
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Houston, TX 77030, USA
- Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
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Janakiraman H, Becker SA, Bradshaw A, Rubinstein MP, Camp ER. Critical evaluation of an autologous peripheral blood mononuclear cell-based humanized cancer model. PLoS One 2022; 17:e0273076. [PMID: 36095023 PMCID: PMC9467357 DOI: 10.1371/journal.pone.0273076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 07/26/2022] [Indexed: 11/29/2022] Open
Abstract
The use of humanized mouse models for oncology is rapidly expanding. Autologous patient-derived systems are particularly attractive as they can model the human cancer's heterogeneity and immune microenvironment. In this study, we developed an autologous humanized mouse cancer model by engrafting NSG mice with patient-derived xenografts and infused matched peripheral blood mononuclear cells (PBMCs). We first defined the time course of xenogeneic graft-versus-host-disease (xGVHD) and determined that only minimal xGVHD was observed for up to 8 weeks. Next, colorectal and pancreatic cancer patient-derived xenograft bearing NSG mice were infused with 5x106 human PBMCS for development of the humanized cancer models (iPDX). Early after infusion of human PBMCs, iPDX mice demonstrated engraftment of human CD4+ and CD8+ T cells in the blood of both colorectal and pancreatic cancer patient-derived models that persisted for up to 8 weeks. At the end of the experiment, iPDX xenografts maintained the features of the primary human tumor including tumor grade and cell type. The iPDX tumors demonstrated infiltration of human CD3+ cells with high PD-1 expression although we observed significant intra and inter- model variability. In summary, the iPDX models reproduced key features of the corresponding human tumor. The observed variability and high PD-1 expression are important considerations that need to be addressed in order to develop a reproducible model system.
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Affiliation(s)
- Harinarayanan Janakiraman
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Scott A. Becker
- Molecular and Systems Pharmacology, Emory University, Atlanta, GA, United States of America
| | - Alexandra Bradshaw
- Department of Surgery, Medical University Of South Carolina, Charleston, SC, United States of America
| | - Mark P. Rubinstein
- The Pelotonia Institute for Immuno-Oncology, Ohio State University Comprehensive Cancer Center–James, Columbus, OH, United States of America
| | - Ernest Ramsay Camp
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas, United States of America
- Dan L. Duncan Comprehensive Cancer Center, Houston, Texas, United States of America
- Michael E. DeBakey VA Medical Center, Houston, Texas, United States of America
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Khan I, Koide A, Zuberi M, Ketavarapu G, Denbaum E, Teng KW, Rhett JM, Spencer-Smith R, Hobbs GA, Camp ER, Koide S, O'Bryan JP. Identification of the nucleotide-free state as a therapeutic vulnerability for inhibition of selected oncogenic RAS mutants. Cell Rep 2022; 38:110322. [PMID: 35139380 PMCID: PMC8936000 DOI: 10.1016/j.celrep.2022.110322] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/12/2021] [Accepted: 01/10/2022] [Indexed: 11/16/2022] Open
Abstract
RAS guanosine triphosphatases (GTPases) are mutated in nearly 20% of human tumors, making them an attractive therapeutic target. Following our discovery that nucleotide-free RAS (apo RAS) regulates cell signaling, we selectively target this state as an approach to inhibit RAS function. Here, we describe the R15 monobody that exclusively binds the apo state of all three RAS isoforms in vitro, regardless of the mutation status, and captures RAS in the apo state in cells. R15 inhibits the signaling and transforming activity of a subset of RAS mutants with elevated intrinsic nucleotide exchange rates (i.e., fast exchange mutants). Intracellular expression of R15 reduces the tumor-forming capacity of cancer cell lines driven by select RAS mutants and KRAS(G12D)-mutant patient-derived xenografts (PDXs). Thus, our approach establishes an opportunity to selectively inhibit a subset of RAS mutants by targeting the apo state with drug-like molecules. Khan et al. develop a high-affinity monobody to nucleotide-free RAS that, when expressed intracellularly, inhibits oncogenic RAS-mediated signaling and tumorigenesis. This study reveals the feasibility of targeting the nucleotide-free state to inhibit tumors driven by oncogenic RAS mutants that possess elevated nucleotide exchange activity.
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Affiliation(s)
- Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Akiko Koide
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA; Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Mariyam Zuberi
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Gayatri Ketavarapu
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - Eric Denbaum
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - Kai Wen Teng
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Russell Spencer-Smith
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - G Aaron Hobbs
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Ernest Ramsay Camp
- Department of Surgery, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA
| | - Shohei Koide
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA.
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Ramsay Camp E, Gerry B, Chung D, Findlay V, Ford M, Curran T. Differences in Immune Gene Expression Profiles of Colorectal Cancer Between African-American and European-American Patients. J Am Coll Surg 2020. [DOI: 10.1016/j.jamcollsurg.2020.07.581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Anderson BJ, Hill EG, Sweeney RE, Wahlquist AE, Marshall DT, O'Carroll KFS, Cole DJ, Camp ER. The Impact of Surgical Diversion Before Neoadjuvant Therapy for Rectal Cancer. Am Surg 2015. [DOI: 10.1177/000313481508100522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Up-front fecal diversion can palliate emergent symptoms related to locally advanced rectal cancer (LARC) allowing patients to receive neoadjuvant chemoradiation therapy (nCRT). We analyzed outcomes of pretreatment-diverted LARC patients relative to nondiverted patients to define the impact of this management strategy. We retrospectively collected data on 103 LARC patients treated with nCRTand surgery. Medical records were reviewed for patient characteristics, staging, treatment plan, and outcomes. Thirteen LARC patients underwent pretreatment diversion for urgent symptoms and 90 LARC patients proceeded directly to nCRT. In all, 50 per cent of diverted patients presented with T4 tumor compared with 14 per cent in the nondiverted patients ( P = 0.003). Diverted patients experienced a delay in time-to-treatment initiation of 12 days, although this difference was not statistically significant. Similar rates of chemoradiation and surgical toxicities were observed. Even though diverted patients demonstrated less pathologic response to nCRT compared with nondiverted patients ( P = 0.04), there was no significant difference in overall survival. In conclusion, our study demonstrates the effectiveness of up-front fecal diversion at managing emergent obstructive symptoms related to advanced rectal cancer without additional complications, allowing patients to proceed with nCRT followed by radical surgery.
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Affiliation(s)
| | - Elizabeth G. Hill
- Department of Public Health Sciences, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - Robert E. Sweeney
- Department of Surgery, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Amy E. Wahlquist
- Department of Public Health Sciences, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - David T. Marshall
- Department of Radiation Oncology, Medical University of South Carolina
| | - Kevin F. Staveley O'Carroll
- Department of Surgery, Medical University of South Carolina
- Department of Public Health Sciences, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - David J. Cole
- Department of Surgery, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - Ernest Ramsay Camp
- Department of Surgery, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
- the Ralph H. Johnson VA Medical Center, Charleston, South Carolina
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Anderson BJ, Hill EG, Sweeney RE, Wahlquist AE, Marshall DT, O’Carroll KFS, Cole DJ, Camp ER. The impact of surgical diversion before neoadjuvant therapy for rectal cancer. Am Surg 2015; 81:444-449. [PMID: 25975325 PMCID: PMC5929168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Up-front fecal diversion can palliate emergent symptoms related to locally advanced rectal cancer (LARC) allowing patients to receive neoadjuvant chemoradiation therapy (nCRT). We analyzed outcomes of pretreatment-diverted LARC patients relative to nondiverted patients to define the impact of this management strategy. We retrospectively collected data on 103 LARC patients treated with nCRT and surgery. Medical records were reviewed for patient characteristics, staging, treatment plan, and outcomes. Thirteen LARC patients underwent pretreatment diversion for urgent symptoms and 90 LARC patients proceeded directly to nCRT. In all, 50 per cent of diverted patients presented with T4 tumor compared with 14 per cent in the nondiverted patients (P = 0.003). Diverted patients experienced a delay in time-to-treatment initiation of 12 days, although this difference was not statistically significant. Similar rates of chemoradiation and surgical toxicities were observed. Even though diverted patients demonstrated less pathologic response to nCRT compared with nondiverted patients (P = 0.04), there was no significant difference in overall survival. In conclusion, our study demonstrates the effectiveness of up-front fecal diversion at managing emergent obstructive symptoms related to advanced rectal cancer without additional complications, allowing patients to proceed with nCRT followed by radical surgery.
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Affiliation(s)
| | - Elizabeth G. Hill
- Department of Public Health Sciences, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - Robert E. Sweeney
- Department of Surgery, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Amy E. Wahlquist
- Department of Public Health Sciences, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - David T. Marshall
- Department of Radiation Oncology, Medical University of South Carolina
| | - Kevin F. Staveley O’Carroll
- Department of Surgery, Medical University of South Carolina
- Department of Public Health Sciences, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - David J. Cole
- Department of Surgery, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
| | - Ernest Ramsay Camp
- Department of Surgery, Medical University of South Carolina
- Hollings Cancer Center, Medical University of South Carolina
- Ralph H. Johnson VA Medical Center, Charleston, South Carolina
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Camp ER, Wang C, Little EC, Watson PM, Pirollo KF, Rait A, Cole DJ, Chang EH, Watson DK. Transferrin receptor targeting nanomedicine delivering wild-type p53 gene sensitizes pancreatic cancer to gemcitabine therapy. Cancer Gene Ther 2013; 20:222-8. [PMID: 23470564 DOI: 10.1038/cgt.2013.9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To overcome gene therapy barriers such as low transfection efficiency and nonspecific delivery, liposomal nanoparticles targeted by a single-chain antibody fragment to the transferrin receptor (TfRscFv) delivering wild-type (wt) human p53 (SGT-53) were developed for tumor-specific targeting. We hypothesize that SGT-53 in combination with gemcitabine will demonstrate enhanced therapeutic benefit in an in vivo metastatic pancreatic cancer model. Intrasplenic injection of 1 × 10(6) Panc02 murine pancreatic cancer cells was used to generate in vivo hepatic metastatic tumors. Nanoparticle localization was assessed by tail vein injection of TfRscFv with fluorescently labeled oligonucleotides (6-carboxyfluorescein phosphoramidite (6FAM) ODN) imaged by Xenogen IVIS 200 scan. SGT-53 (equivalent to 30 μg of p53 intravenously) and gemcitabine (20 mg/kg intraperitoneally) alone and in combination were administered biweekly and compared with untreated mice. Survival was determined by blinded daily assessment of morbidity. Human wtp53 expression and transferrin levels in the tumors were assessed by western blot analysis. Tumor burden was quantified by liver weight. Xenogen imaging demonstrated tumor-specific uptake of TfRscFv-6FAM ODN. Exogenous human wtp53 protein was detected in the SGT-53-treated tumors compared with control. Compared with untreated mice with metastatic tumors demonstrating median survival of 20 days, SGT-53, gemcitabine and the combination demonstrated improved median survival of 29, 30 and 37 days, respectively. The combination treatment prolonged median survival when compared with single drug treatment and decreased tumor burden. The tumor targeting liposomal-based SGT-53 nanoparticle is capable of sensitizing pancreatic cancer to conventional chemotherapy in pancreatic cancer models. This approach has the potential to be translated into a new, more effective therapy for pancreatic cancer. Further optimization is ongoing, moving towards a Phase 1B/2 clinical trial.
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Affiliation(s)
- E R Camp
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA.
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Badgwell BD, Camp ER, Feig B, Wolff RA, Eng C, Ellis LM, Cormier JN. Management of bevacizumab-associated bowel perforation: a case series and review of the literature. Ann Oncol 2007; 19:577-82. [PMID: 18024857 DOI: 10.1093/annonc/mdm508] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND This study examined the various approaches to the management of perforation and the associated outcomes in patients with bevacizumab-associated bowel perforation at a tertiary cancer center. PATIENTS AND METHODS Our institutional pharmacy database was searched to identify all patients who had received bevacizumab over a 2-year period (January 2004 to October 2006). Medical records of these patients were examined for reports of confirmed bowel perforation or fistula, associated clinicopathological factors, treatment, and outcomes. RESULTS We identified 1442 patients who had been treated with bevacizumab over the study period with perforation occurring in 24 (1.7%). The breakdown of these 24 patients by disease site was as follows: ovarian (3 of 50, 6%), gastroesophageal (2 of 38, 5.3%), pancreatic (7 of 141, 5%), unknown primary (1 of 60, 1.7%), lung (1 of 67, 1.5%), colorectal (6 of 478, 1.3%), and renal cell (4 of 269, 1.5%). The majority of patients (n = 19, 79%) were initially managed nonoperatively. Only five (21%) patients ultimately underwent surgical exploration, with a subsequent anastomotic leak developing in one patient. The overall 30-day mortality rate was 12.5%. CONCLUSIONS Bevacizumab-associated bowel perforation occurs in patients with various malignancies, with an incidence of 1.7%. Nonoperative treatment is a viable approach to management in selected patients.
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Affiliation(s)
- B D Badgwell
- Department of Surgical Oncology, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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Camp ER, Cendan JC, Feezor R, Lind DS, Wilkinson E, Copeland EM. The hottest sentinel lymph node is not always the positive node. Am Surg 2004; 70:475-8; discussion 478. [PMID: 15212397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The technique of identifying the sentinel lymph node (SLN) varies from each individual institution. Generally, the highest isotope count in a lymph node is considered the SLN, whereas other radioactive nodes might also be removed. The purpose of our study was to determine if the hottest node was always the tumor-containing node. Two hundred forty-seven breast cancer patients underwent SLN biopsy from April 1998 to April 2002. Lymphatic mapping involved a radiocolloid injection and lymphoscintigraphy followed by intraoperative assessment with a hand-held gamma probe. All SLN(s) with radioactive counts 10 per cent or more of the ex vivo counts of the most radioactive SLN were removed. The SLN were sliced at 2-mm intervals with 4-microm step-sections (92-microm spacing) and evaluated by microscopy and immunohistochemistry. One hundred twenty (49%) of the 247 patients had 2 or more nodes resected. Of these 120 patients, 33 (28%) had a tumor-bearing node. In 25 (74%) cases, the tumor-bearing node was the most radioactive; however, in 8 (26%) cases, the positive node was a lesser reactive node. Although the most radioactive node in a draining basin is considered the SLN, this is often not the metastatic node. Therefore, all nodes with significant radioactive counts must be removed to ensure accurate staging.
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Affiliation(s)
- E R Camp
- Department of Surgery, University of Florida, College of Medicine, Gainesville, Florida 32610, USA
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