Kaplan, Jamie L.

While breast cancer is a common disease with many available treatment options, many patients still have limited responses, especially those with metastatic breast cancer. Surgery of the primary tumor or metastatic sites is often not part of the treatment regimen for patients with metastatic breast cancer. Cryoablation is a relatively non-invasive procedure that is being investigated for patients with breast cancer. Patients with metastatic breast cancer who are not surgical candidates may derive benefit from cryoablation through the abscopal effect. In this case report, we present a patient with stage IV breast cancer who was treated with cryoablation of the primary breast tumor and showed evidence of an abscopal effect in regional and distant metastases.

Abstract INTRODUCTION: HER2/neu is a potent biomarker for which anti-HER2/neu antibodies offer significant responses. However, many cancers, such as melanoma, have less than 5% expression of HER2/neu. The purpose of this study was to determine whether induced expression of erbb2 (mouse HER2/neu analogue) could function as a neoantigen target for anti-erbb2 antibody. METHODS: RT-PCR was used to construct a rat erbb2-encoding vector using the live, non-replicating lentivirus pLenti6.3. erbb2-encoding pLenti6.3 was transfected in vitro into the B16 mouse melanoma cell line, which has less than 5% endogenous expression of erbb2. The generated erbb2+ B16 cell line was designated B16/neu. Anti-erbb2 antibody (7.16.4) was used to treat C57Bl/6 male and female mice bearing B16/neu (200 ug intraperitoneally three times per week for 3 weeks). To confirm activity of 7.16.4, this antibody (100 ug per T75 flask) was co-cultured with B16/neu in vitro, and cell growth/confluence was measured. RESULTS: The novel B16/neu cell line expressed approximately 50% erbb2 in vitro on flow cytometry analysis, compared to 2% errb2 expression in naïve B16. Erbb2/neu expression was confirmed on fluorescent Western blot. Anti-erbb2 antibody (7.16.4) slowed the growth of B16/neu in vitro, confirming the suppressive effects of 7.16.4. In B16/neu-bearing mice, 7.16.4 resulted in effective control of tumor growth and a complete tumor response rate of 35.7%, (5/14 mice) compared to placebo controls (p < 0.01). Interestingly, B16/neu tumors demonstrated slower growth kinetics compared to naïve B16 tumors (p = 0.013), suggesting immune recognition of erbb2 in naïve C57Bl/6 mice as a neoantigen target. No adverse reactions were observed with 7.16.4. In vivo inoculation of erbb2-encoding pLenti6.3 in naïve B16 tumors and treatment of in vivo transfected B16/neu tumors with 7.16.4 comprise ongoing experiments. CONCLUSIONS: erbb2 expression on B16 melanoma was successfully achieved using a novel erbb2-encoding lentivirus. Induced erbb2 served as a neoantigen target for anti-erbb2 antibody. This preclinical study provides translational evidence that induced HER2/neu expression may be utilized to repurpose anti-HER2 antibodies for human malignancies that do not normally express high levels of HER2/neu. Citation Format: Emmanuel M. Gabriel, Brian Necela, Deborah Bahr, Jamie Kaplan, Kristopher Attwood, Keith Knutson. Repurposing erbb2 (HER2/neu) as a neoantigen target for neu-negative tumors using a novel erbb2-encoding lentivirus [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5371.

Abstract INTRODUCTION: Intratumoral phenylephrine (α1 vasoconstrictor) combined with chemotherapy has been used for cutaneous malignancies with modest local response. The purpose of this study was to improve the efficacy of intratumoral melphalan using sustained-release, liposomal nanoparticles containing phenylephrine in a mouse model of melanoma. METHODS: A modified ethanol injection method was used to develop the liposomal phenylephrine nanoparticles. These were injected peri-tumorally to generate a local vasoconstrictive effect intended to “entrap” intratumorally injected melphalan. Drug exposure/dwell time was measured with fluorescent imaging. Mice bearing B16 (subclone F10) melanoma tumors were treated with intratumoral melphalan (20 ug/50 ul) with or without peri-tumoral liposomal phenylephrine (10 ug/50-100 ul x 4-5 injections around the tumor periphery) twice weekly x 3 weeks. RESULTS: UV-Absorbance spectroscopy confirmed encapsulation of phenylephrine within the liposomal nanoparticles with an expected absorbance of 275 nm. The modified ethanol injection method produced liposomal phenylephrine encapsulation of approximately 25%. Peri-tumoral, liposomal phenylephrine caused vasoconstriction of normal surrounding vessels with an approximate 10% decrease in vessel diameter. Our liposomal phenylephrine nanoparticles also led to increased retention of intratumorally injected fluorescently-labeled (FITC) liposomes 24-48 hours after inoculation, using both melanoma (B16) and breast (TUBO/4T1) cell lines orthotopically grown within mice (C57Bl/6 and BALB/c, respectively). The combination of intratumoral melphalan with peri-tumoral phenylephrine resulted in more effective control of tumor growth and a complete tumor response rate of 44.4%, compared to phenylephrine/melphalan only controls (p < 0.01, n=18 per group). However, there was significant adverse reaction with the combination therapy, resulting in ulceration of the injection/tumor site. Ulcers healed about 14 days after completion of treatment. Immunohistochemistry demonstrated increased infiltration of CD11b+ cells into the tumors, suggesting an immune-mediated response in addition to direct chemotoxicity. CONCLUSIONS: Liposomal nanoparticles containing phenylephrine increased retention/dwell time of intratumorally administered melphalan and resulted in superior anti-tumor response. Our preclinical model holds innovative, translational promise for the clinical advancement of intralesional therapies in cutaneous/subcutaneous malignancies. Citation Format: Emmanuel M. Gabriel, Vijay Madamsetty, Deborah Bahr, Jamie Kaplan, Kristopher Attwood, Sanjay Bagaria, Keith Knutson, Debabrata Mukhopadhyay. Novel approach to intra- and peri-tumoral delivery of sustained-release chemotherapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5071.

AbstractBackgroundDue to duty hour regulations, patient safety and inadequate operative time simulation have become a necessary part of surgical education and training in residency. Currently, there is no formal adoption of simulators for the use of surgical education or assessment in hand surgery. This literature review analyzes that the simulation techniques established thus far in hand surgery.MethodsA comprehensive literature search was performed on PubMed. Search results were filtered by title and abstract to isolate articles that were relevant to simulation in hand surgery. Articles that were nonspecific to the hand, non‐English and cadaveric were excluded. Additional articles were identified through references from the initial search.ResultsA total of 1192 articles were yielded from the initial query. After the application of the inclusion criteria, this was narrowed down to 28 articles. Another 8 additional articles were excluded as they did not pertain to the hand although the simulators could be adapted for hand surgery. A total of 20 articles were included in this study.ConclusionsSurgical simulation is a growing and essential field of surgical education. Simulators in hand surgery are limited and require further research and validation. Like other surgical subspecialties, hand surgery may benefit from the adoption of an official simulation curriculum for the assessment of residents and enhancement of technical skills.