Improved outcomes for triple negative breast cancer brain metastases patients after stereotactic radiosurgery and new systemic approaches.

PURPOSE: Although ongoing studies are assessing the efficacy of new systemic therapies for patients with triple negative breast cancer (TNBC), the overwhelming majority have excluded patients with brain metastases (BM). Therefore, we aim to characterize systemic therapies and outcomes in a cohort of patients with TNBC and BM managed with stereotactic radiosurgery (SRS) and delineate predictors of increased survival. METHODS: We used our prospective patient registry to evaluate data from 2012 to 2023. We included patients who received SRS for TNBC-BM. A competing risk analysis was conducted to assess local and distant control. RESULTS: Forty-three patients with 262 tumors were included. The median overall survival (OS) was 16 months (95% CI 13-19 months). Predictors of increased OS after initial SRS include Breast GPA score > 1 (p < 0.001) and use of immunotherapy such as pembrolizumab (p = 0.011). The median time on immunotherapy was 8 months (IQR 4.4, 11.2). The median time to new CNS lesions after the first SRS treatment was 17 months (95% CI 12-22). The cumulative rate for development of new CNS metastases after initial SRS at 6 months, 1 year, and 2 years was 23%, 40%, and 70%, respectively. Thirty patients (70%) underwent multiple SRS treatments, with a median time of 5 months (95% CI 0.59-9.4 months) for the appearance of new CNS metastases after second SRS treatment. CONCLUSIONS: TNBC patients with BM can achieve longer survival than might have been previously anticipated with median survival now surpassing one year. The use of immunotherapy is associated with increased median OS of 23 months.

Use and definitions of perioperative mortality rates in low-income and middle-income countries: a systematic review.

BACKGROUND: Aggregate and risk-stratified perioperative mortality rates (POMR) are well-documented in high-income countries where surgical databases are common. In many low-income and middle-income country (LMIC) settings, such data are unavailable, compromising efforts to understand and improve surgical outcomes. We undertook a systematic review to determine how POMR is used and defined in LMICs and to inform baseline rates. METHODS: We searched PubMed for all articles published between Jan 1, 2009, and Sept 1, 2014, reporting surgical mortality in LMICs. Search criteria, inclusion and exclusion criteria, and study assessment methodology are reported in the appendix. Titles and abstracts were screened independently by two reviewers. Full-text review and data extraction were completed by four trained clinician coders with regular validation for consistency. We extracted the definition of POMR used, clinical risk scores reported, and strategies for risk adjustment in addition to reported mortality rates. FINDINGS: We screened 2657 abstracts and included 373 full-text articles. 493 409 patients in 68 countries and 12 surgical specialties were represented. The most common definition for the numerator of POMR was in-hospital deaths following surgery (55·3%) and for the denominator it was the number of operative patients (96·2%). Few studies reported preoperative comorbidities (41·8%), ASA status (11·3%), and HIV status (7·8%), with a smaller proportion stratifying on or adjusting mortality for these factors. Studies reporting on planned procedures recorded a median mortality of 1·2% (n=121 [IQR 0·0-4·7]). Median mortality was 10·1% (n=182 [IQR 2·5-16·2) for emergent procedures. INTERPRETATION: POMR is frequently reported in LMICs, but a standardised approach for reporting and risk stratification is absent from the literature. There was wide variation in POMR across procedures and specialties. A quality assessment checklist for surgical mortality studies could improve mortality reporting and facilitate benchmarking across sites and countries. FUNDING: None.

Mutation of nonessential cysteines shows that the NF-κB essential modulator forms a constitutive noncovalent dimer that binds IκB kinase-ß with high affinity.

NEMO (NF-κB essential modulator) associates with catalytic subunits IKKα and IKKß to form the IκB kinase (IKK) complex and is a key regulator of NF-κB pathway signaling. Biochemical and structural characterization of NEMO has been challenging, however, leading to conflicting data about basic biochemical properties such as the oligomeric state of active NEMO and its binding affinity for IKKß. We show that up to seven of NEMO's 11 cysteine residues can be mutated to generate recombinant full-length NEMO that is highly soluble and active. Using a fluorescence anisotropy binding assay, we show that full-length NEMO binds a 44-mer peptide encompassing residues 701-745 of IKKß with a K(D) of 2.2 ± 0.8 nM. The IKKß binding affinities of mutants with five and seven Cys-to-Ala substitutions are indistinguishable from that of wild-type NEMO. Moreover, when expressed in NEMO -/- fibroblasts, the five-Ala and seven-Ala NEMO mutants can interact with cellular IKKß and restore NF-κB signaling to provide protection against tumor necrosis factor α-induced cell death. Treatment of the NEMO-reconstituted cells with H2O2 led to the formation of covalent dimers for wild-type NEMO and the five-Ala mutant, but not for the seven-Ala mutant, confirming that Cys54 and/or Cys347 can mediate interchain disulfide bonding. However, the IKKß binding affinity of NEMO is unaffected by the presence or absence of interchain disulfide bonding at Cys54, which lies within the IKKß binding domain of NEMO, or at Cys347, indicating that NEMO exists as a noncovalent dimer independent of the redox state of its cysteines. This conclusion was corroborated by the observation that the secondary structure content of NEMO and its thermal stability were independent of the presence or absence of interchain disulfide bonds.