Metastatic Myxofibrosarcoma with Durable Response to Temozolomide Followed by Atezolizumab: A Case Report.

Myxofibrosarcoma (MFS) is a well-recognized histotype of soft tissue sarcomas that generally presents with localized disease. Herein, we describe the case of a patient with metastatic MFS who experienced durable response to sixth-line therapy with temozolomide. Upon further progression, his tumor was notable for a high tumor mutational burden, and he was subsequently treated with seventh-line immunotherapy, atezolizumab, achieving a second durable response. This case highlights the role of immunotherapy after administration of alkylating agents. Review of the literature indicates that recurrent tumors treated with alkylating agents often experience hypermutation as a means of developing resistance and that checkpoint inhibitors are subsequently effective in these tumors. KEY POINTS: To the authors' knowledge, this is the first report of a patient with myxofibrosarcoma with high tumor mutational burden after administration of temozolomide monotherapy. Hypermutation may be a resistance mechanism for patients with soft tissue sarcoma who develop resistance to alkylating agents. Checkpoint inhibition may be effective therapy in patients with soft tissue sarcoma with high tumor mutational burden as a consequence of alternate systemic therapy resistance.

Surgical Site Infection, Readmission, and Reoperation After Posterior Long Segment Fusion.

STUDY DESIGN: Retrospective case series. OBJECTIVE: We sought to identify risk factors associated with surgical site infection (SSI) after posterior long segment spinal fusion (PLSF). SUMMARY OF BACKGROUND DATA: Patients who undergo PLSF may be at elevated risk of SSI. Identifying factors associated with SSI in these operations can help risk stratify patients and tailor management. METHODS: We analyzed PLSFs-seven or more levels-at our institution from 2000 to 2015. Data on patients' clinical characteristics, procedural factors, and antimicrobial management were collected. Multivariable analysis identified factors independently associated with outcomes of interest. RESULTS: In 628 cases, SSI was associated with steroid use (P = 0.024, odds ratio [OR] = 2.54) and using cefazolin (P < 0.001, OR = 4.37) or bacitracin (P = 0.010, OR 3.49) irrigation, as opposed to gentamicin or other irrigation. Gram-positive infections were more likely with staged procedures (P = 0.021, OR 4.91) and bacitracin irrigation (P < 0.001, OR = 17.98), and less likely with vancomycin powder (P = 0.050, OR 0.20). Gram-negative infections were more likely with a history of peripheral arterial disease (P = 0.034, OR = 3.21) or cefazolin irrigation (P < 0.001, OR 25.47). Readmission was more likely after staged procedures (P = 0.003, OR = 3.31), cervical spine surgery (P = 0.023, OR = 2.28), or cefazolin irrigation (P = 0.039, OR = 1.85). Reoperation was more common with more comorbidities (P = 0.022, OR 1.09), staged procedures (P < 0.001, OR = 4.72), cervical surgeries (P = 0.013, OR = 2.36), more participants in the surgery (P = 0.011, OR = 1.06), using cefazolin (P < 0.001, OR = 3.12) or bacitracin (P = 0.009, OR = 3.15) irrigation, and higher erythrocyte sedimentation rate at readmission (P = 0.009, OR = 1.04). Washouts were more likely among patients with more comorbidities (P = 0.013, OR = 1.16), or who used steroids (P = 0.022, OR = 2.92), and less likely after cervical surgery (P = 0.028, OR = 0.24). Instrumentation removal was more common with bacitracin irrigation (p = 0.013, OR = 31.76). CONCLUSION: Patient factors, whether a procedure is staged, and choice of antibiotic irrigation affect the risk of SSI and ensuing management required.Level of Evidence: 4.