An Exploratory Graphical Method for Identifying Associations in r x c Contingency Tables

On finding a significant association between rows and columns of an r x c contingency table, the next step is to study the nature of the association in more detail. The use of a scree plot to visualize the largest contributions to Χ2 among all cells in the table in order to determine the nature of the association in more detail is proposed

High-risk prostate cancer treated with a stereotactic body radiation therapy boost following pelvic nodal irradiation

Purpose Modern literature has demonstrated improvements in long-term biochemical outcomes with the use of prophylactic pelvic nodal irradiation followed by a brachytherapy boost in the management of high-risk prostate cancer. However, this comes at the cost of increased treatment-related toxicity. In this study, we explore the outcomes of the largest cohort to date, which uses a stereotactic body radiation therapy (SBRT) boost following pelvic nodal radiation for exclusively high-risk prostate cancer. Methods and materials A large institutional database was interrogated to identify all patients with high-risk clinical node-negative prostate cancer treated with conventionally fractionated radiotherapy to the pelvis followed by a robotic SBRT boost to the prostate and seminal vesicles. The boost was uniformly delivered over three fractions. Toxicity was measured using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Oncologic outcomes were assessed using the Kaplan–Meier method. Cox proportional hazard models were created to evaluate associations between pretreatment characteristics and clinical outcomes. Results A total of 440 patients with a median age of 71 years were treated, the majority of whom were diagnosed with a grade group 4 or 5 disease. Pelvic nodal irradiation was delivered at a total dose of 4,500 cGy in 25 fractions, followed by a three-fraction SBRT boost. With an early median follow-up of 2.5 years, the crude incidence of grade 2+ genitourinary (GU) and gastrointestinal (GI) toxicity was 13% and 11%, respectively. Multivariate analysis revealed grade 2+ GU toxicity was associated with older age and a higher American Joint Committee on Cancer (AJCC) stage. Multivariate analysis revealed overall survival was associated with patient age and posttreatment prostate-specific antigen (PSA) nadir. Conclusion Utilization of an SBRT boost following pelvic nodal irradiation in the treatment of high-risk prostate cancer is oncologically effective with early follow-up and yields minimal high-grade toxicity. We demonstrate a 5-year freedom from biochemical recurrence (FFBCR) of over 83% with correspondingly limited grade 3+ GU and GI toxicity measured at 3.6% and 1.6%, respectively. Long-term follow-up is required to evaluate oncologic outcomes and late toxicity

Time interval from diagnosis to treatment of brain metastases with stereotactic radiosurgery is not associated with radionecrosis or local failure

IntroductionBrain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear.MethodsThis single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher’s exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure.ResultsA total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure.DiscussionAn optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy

The Effect of BAFF Inhibition on Autoreactive B-Cell Selection in Murine Systemic Lupus Erythematosus

Abstract The goal of this study was to determine how B-cell-activating factor of the TNF family (BAFF) availability influences selection of the autoreactive B-cell repertoire in NZB/W and NZW/BXSB lupus-prone mice bearing the site-directed heavy-chain transgene 3H9 that encodes for anti-dsDNA and anti-cardiolipin (CL) autoantibodies. We used a bone marrow chimera system in which autoreactive 3H9 transgenic B cells were allowed to mature in competition with wild-type cells and could be identified by green fluorescent protein. The light-chain repertoire associated with the 3H9 heavy chain in naive and antigen-activated B-cell subsets was assessed using single-cell polymerase chain reaction. We found that deletion of autoreactive transgenic B cells occurred in the bone marrow of both strains regardless of BAFF availability, and there were only modest and physiologically non-relevant effects on the naive B-cell repertoire. BAFF inhibition had different effects on selection of the germinal center repertoire in the two strains. In the NZW/BXSB strain, BAFF inhibition phenocopied the loss of one TLR7 allele in that it influenced the selection of 3H9-encoded autoreactive B cells in the germinal center but did not prevent somatic mutation. In the NZB/W strain, BAFF inhibition did not alter the selection of 3H9-encoded B cells in the germinal center, but it influenced selection of a subset of germinal center cells into the plasma cell compartment. Our data underscore the complexity of regulation of the autoreactive B-cell repertoire by BAFF and may help to explain the heterogeneity of responses observed after BAFF inhibition in humans

Survival models to support shared decision-making about advance care planning for people with advanced stage cystic fibrosis

Background For people with advanced stage cystic fibrosis (CF), tailored survival estimates could facilitate preparation for decision-making in the event of acutely deteriorating respiratory function.Methods We used the US CF Foundation national database (2008–2013) to identify adult people with incident advanced stage CF (forced expiratory volume in 1 s (FEV1) ≤45% predicted). Using the lasso method for variable selection, we divided the dataset into training and validation samples (2:1), and developed two multivariable Cox proportional hazards models to calculate probabilities of survival from baseline (T0 model), and from 1 year after (T12 model). We also performed Kaplan-Meier survival analyses.Results 4752 people were included. For the T0 model, FEV1; insurance; non-invasive ventilation; supplemental oxygen; Burkholderia colonisation; cirrhosis; depression; dialysis; current smoking; unclassifiable mutation class and cumulative CF exacerbations predicted increased mortality. Baseline transplant evaluation status of ‘accepted, on waiting list’ predicted decreased mortality. For the T12 model, interim decrease in FEV1 >10%, and pulmonary exacerbations additionally increased predicted mortality. Lung transplantation was associated with lower mortality. Of the 4752, 93.5%, 86.4%, 79.7% and 73.9% survived to 1, 2, 3 and 4 years, respectively, without considering any confounding variables. The models had moderate predictive ability indicated by the area under the time-dependent receiver operating characteristic curve (0.787, 95% CI 0.769 to 0.794 for T0 model; and 0.779, 95% CI 0.767 to 0.797 for T12 model).Conclusion We have developed models predicting survival in people with incident advanced stage CF, which can be reapplied over time to support shared decision-making about end-of-life treatment choices and lung transplantation. These estimates must be updated as data become available regarding long-term outcomes for people treated with CF transmembrane conductance regulator modulators