Surgery (St Vincent's) - Research Publications

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    The role of F-18-FDG PET/CT in retroperitoneal sarcomas-A multicenter retrospective study
    Subramaniam, S ; Callahan, J ; Bressel, M ; Hofman, MS ; Mitchell, C ; Hendry, S ; Vissers, FL ; Van Der Hiel, B ; Patel, D ; Van Houdt, WJ ; Tseng, WW ; Gyorki, DE (WILEY, 2021-01-14)
    BACKGROUND: The role of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG PET/CT) in the evaluation of retroperitoneal sarcomas is poorly defined. We evaluated the correlation of maximum standardized uptake value (SUVmax) with pathologic tumor grade in the surgical specimen of primary retroperitoneal dedifferentiated liposarcoma (DDLPS) and leiomyosarcoma (LMS). METHODS: Patients with the above histological subtypes in three participating institutions with preoperative 18 F-FDG PET/CT scan and histopathological specimen available for review were included. The association between SUVmax and pathological grade was assessed. Correlation between SUVmax and relapse-free survival (RFS) and overall survival (OS) were also studied. RESULTS: Of the total 58 patients, final pathological subtype was DDLPS in 44 (75.9%) patients and LMS in 14 (24.1%) patients. The mean SUVmax was 8.7 with a median 7.1 (range, 2.2-33.9). The tumors were graded I, II, III in 6 (10.3%), 35 (60.3%), and 17 (29.3%) patients, respectively. There was an association of higher histological grade with higher SUVmax (rs  = 0.40, p = .002). Increasing SUVmax was associated with worse RFS (p = .003) and OS (p = .003). CONCLUSION: There is a correlation between SUVmax and pathologic tumor grade; increasing SUVmax was associated with worse OS and RFS, providing a preoperative noninvasive surrogate marker of tumor grade and biological behavior.
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    Arthroplasty information on the internet: quality or quantity?
    Davaris, MT ; Dowsey, MM ; Bunzli, S ; Choong, PF (Elsevier, 2021-04-01)
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    Abstract 2671: SMAD4 as a potential gatekeeper for genomic instability and mTOR-mediated tumorigenesis in esophageal adenocarcinoma
    Milne, JV ; Gotovac, JR ; Fujihara, KM ; Duong, CP ; Phillips, WA ; Clemons, NJ (American Association for Cancer Research (AACR), 2021-07-01)
    Abstract Esophageal cancer is the 8th most common cancer worldwide and has the 6th highest mortality rate of all cancers. The 5-year survival rate following esophageal adenocarcinoma (EAC) diagnosis is dismal at less than 15 percent, indicating a dire need for improved therapeutic strategies and early detection. EAC develops stepwise following exposure to chronic gastric reflux: From pre-malignant Barrett's metaplasia, through stages of low- and high-grade dysplasia until developing into invasive cancer. Mutation or loss of common tumor suppressor genes TP53 and SMAD4 act as markers for cancer progression, occurring in high-grade dysplastic tissue and invasive EAC, respectively. Our novel in vivo tumorigenesis model demonstrates progression of Barrett's metaplasia to EAC, in which SMAD4-deficient Barrett's metaplasia cells form tumors in immunodeficient mice after a period of latency and in a dose-dependent manner. This delayed tumor growth onset suggests further drivers are required for oncogenesis, and these SMAD4-deficient cells and tumors display a greater degree of genomic instability than wildtype-SMAD4 controls. A genome-wide CRISPR-Cas9 knockout screen unveiled a synthetic lethal relationship between SMAD4-deficiency and cell cycle checkpoint inhibition, suggesting a role for SMAD4 in maintaining genomic stability and a potential novel therapeutic avenue for SMAD4-deficient EAC. Additionally, a concurrent in vivo CRISPR-Cas9 tumorigenesis screen produced tumors 4-fold faster than the previous model and identified regulators of mTOR signaling as co-operative drivers of tumorigenesis in EAC. Wildtype-SMAD4 cells failed to generate tumors despite undergoing the same genetic perturbations, indicating a potential gatekeeping effect of SMAD4 in mTOR-mediated EAC tumorigenesis. In sum, loss of SMAD4 acts as a double-edged sword, increasing genomic instability and thereby rendering EAC cells sensitive to cell cycle checkpoint inhibition, whilst simultaneously co-operating with modulated mTOR signaling to promote tumorigenesis in EAC xenograft models. Citation Format: Julia V. Milne, Jovana R. Gotovac, Kenji M. Fujihara, Cuong P. Duong, Wayne A. Phillips, Nicholas J. Clemons. SMAD4 as a potential gatekeeper for genomic instability and mTOR-mediated tumorigenesis in esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2671.