Key Points PCNSLs and PTLs have a defining genetic signature that differs from other LBCLs and suggests rational targeted therapies. PCNSLs and PTLs frequently exhibit 9p24.1/PD-L1/PD-L2 copy number alterations and translocations, likely genetic bases of immune evasion.

Sirolimus is an effective agent used in graft-versus-host disease (GVHD) prophylaxis after allogeneic transplantation. It also has antiproliferative effects on vascular endothelium when used to coat coronary artery stents. We noted an excess of veno-occlusive disease (VOD) in a clinical trial, and retrospectively reviewed the records of 488 patients to determine the association between sirolimus and VOD. When used with cyclophosphamide/total body irradiation (Cy/TBI) conditioning, sirolimus is associated with an increased incidence of VOD (OR 2.35, P ‫؍‬ .005). The concomitant use of methotrexate further increased this rate (OR 3.23, P < .001), while sirolimus without methotrexate was not associated with an increased risk of VOD (OR 1.55, P ‫؍‬ .33). Mortality after VOD diagnosis was unaffected, and overall treatment-related mortality was lowest when sirolimus was used without methotrexate. Similar findings were noted in matched, related, and unrelated as well as mismatched donor subgroups. When used with busulfan-based conditioning, sirolimus use was associated with an even higher rate of VOD (OR 8.8, P ‫؍‬ .008). Our findings suggest that sirolimus use is associated with VOD after TBI-based transplantation when used with methotrexate after transplantation. Sirolimusbased GVHD prophylaxis without methotrexate is associated with the greatest overall survival. Myeloablative doses of busulfan should not be used with sirolimus-based immunosuppression.

IMPORTANCE Chemotherapy-related hospitalizations in patients with advanced cancer are common, distressing, and costly. Methods to identify patients at high risk of chemotherapy toxic effects will permit development of targeted strategies to prevent chemotherapy-related hospitalizations. OBJECTIVE To demonstrate the feasibility of using readily available clinical data to assess patient-specific risk of chemotherapy-related hospitalization. DESIGN, SETTING, AND PARTICIPANTS Nested case-control study conducted from January 2003 through December 2011 at the Mass General/North Shore Cancer Center, a community-based cancer center in north eastern Massachusetts. The parent cohort included 1579 consecutive patients with advanced solid-tumor cancer receiving palliative-intent chemotherapy. Case patients (n = 146) included all patients from the parent cohort who experienced a chemotherapy-related hospitalization. Controls (n = 292) were randomly selected from 1433 patients who did not experience a chemotherapy-related hospitalization. EXPOSURES Putative risk factors for chemotherapy-related hospitalization—including patient characteristics, treatment characteristics, and pretreatment laboratory values—were abstracted from medical records. Multivariable logistic regression was used to model the patient-specific risk of chemotherapy-related hospitalization. MAIN OUTCOMES AND MEASURES Chemotherapy-related hospitalization, as adjudicated by the oncology clinical care team within a systematic quality-assessment program. RESULTS A total of 146 (9.2%) of 1579 patients from the parent cohort experienced a chemotherapy-related hospitalization. In multivariate regression, 7 variables were significantly associated with chemotherapy-related hospitalization: age, Charlson comorbidity score, creatinine clearance, calcium level, below-normal white blood cell and/or platelet count, polychemotherapy (vs monotherapy), and receipt of camptothecin chemotherapy. The median predicted risk of chemotherapy-related hospitalization was 6.0% (interquartile range [IQR], 3.6%–11.4%) in control patients and 14.7% (IQR, 6.8%–22.5%) in case patients. The bootstrap-adjusted C statistic was 0.71 (95% CI, 0.66–0.75). At a risk threshold of 15%, the model exhibited a sensitivity of 49% (95% CI, 41%–57%) and a specificity of 85% (95% CI, 81%–89%) for predicting chemotherapy-related hospitalization. CONCLUSIONS AND RELEVANCE In patients initiating palliative chemotherapy for cancer, readily available clinical data were associated with the patient-specific risk of chemotherapy-related hospitalization. External validation and evaluation in the context of a clinical decision support tool are warranted.