Brain Metastases in EGFR- and ALK-Positive NSCLC: Outcomes of Central Nervous System-Penetrant Tyrosine Kinase Inhibitors Alone Versus in Combination With Radiation.

INTRODUCTION: Management of central nervous system (CNS) metastases in patients with driver-mutated NSCLC has traditionally incorporated both tyrosine kinase inhibitors (TKIs) and intracranial radiation. Whether next generation, CNS-penetrant TKIs can be used alone without upfront radiation, however, remains unknown. This multi-institutional retrospective analysis aimed to compare outcomes in patients with EGFR- or ALK-positive NSCLC who received CNS-penetrant TKI therapy alone versus in combination with radiation for new or progressing intracranial metastases. METHODS: Data were retrospectively collected from three academic institutions. Two treatment groups (CNS-penetrant TKI alone versus TKI + CNS radiation therapy) were compared for both EGFR- and ALK-positive cohorts. Outcome variables included time to progression, time to intracranial progression, and time to treatment failure, measured from the date of initiation of CNS-penetrant TKI therapy. RESULTS: A total of 147 patients were included (EGFR n = 94, ALK n = 52, both n = 1). In patients receiving radiation, larger metastases, neurologic symptoms, and receipt of steroids were more common. There were no significant differences between TKI and CNS radiation therapy plus TKI groups for any of the study outcomes, including time to progression (8.5 versus 6.9 mo, p = 0.13 [EFGR] and 11.4 versus 13.4 mo, p = 0.98 [ALK]), time to intracranial progression (14.8 versus 20.5 mo, p = 0.51 [EGFR] and 18.1 versus 21.8 mo, p = 0.65 [ALK]), or time to treatment failure (13.8 versus 8.6 mo, p = 0.26 [EGFR] and 13.5 versus 23.2 mo, p = 0.95 [ALK]). CONCLUSIONS: These results provide preliminary evidence that intracranial activity of CNS-penetrant TKIs may enable local radiation to be deferred in appropriately selected patients without negatively affecting progression.

Capturing what matters: A retrospective observational study of advance care planning documentation at an academic medical center during the COVID-19 pandemic.

BACKGROUND: Advance care planning allows patients to share their preferences for medical care with the aim of ensuring goal-concordant care in times of serious illness. The morbidity and mortality of the COVID-19 pandemic has increased the importance and public visibility of advance care planning. However, little is known about the frequency and quality of advance care planning documentation during the pandemic. AIM: This study examined the frequency, quality, and predictors of advance care planning documentation among hospitalized medical patients with and without COVID-19. DESIGN: This retrospective cohort analysis used multivariate logistic regression to identify factors associated with advance care planning documentation. SETTING/PARTICIPANTS: This study included all adult patients tested for COVID-19 and admitted to a tertiary medical center in San Francisco, CA during March 2020. RESULTS: Among 262 patients, 31 (11.8%) tested positive and 231 (88.2%) tested negative for SARS-CoV-2. The rate of advance care planning documentation was 38.7% in patients with COVID-19 and 46.8% in patients without COVID-19 (p = 0.45). Documentation consistently addressed code status (100% and 94.4% for COVID-positive and COVID-negative, respectively), but less often named a surrogate decision maker, discussed prognosis, or elaborated on other wishes for care. Palliative care consultation was associated with increased advance care planning documentation (OR: 6.93, p = 0.004). CONCLUSION: This study found low rates of advance care planning documentation for patients both with and without COVID-19 during an evolving global pandemic. Advance care planning documentation was associated with palliative care consultation, highlighting the importance of such consultation to ensure timely, patient-centered advance care planning.

Therapeutic Advances in the Management of Patients with Advanced RET Fusion-Positive Non-Small Cell Lung Cancer.

OPINION STATEMENT: Screening for activating driver gene alterations at the time of diagnosis is the standard of care for advanced non-small cell lung cancer (NSCLC). Activating RET fusions are identified in approximately 1-2% of NSCLCs and have emerged as a targetable driver alteration. Selpercatinib and pralsetinib are RET-selective tyrosine kinase inhibitors (TKIs) with encouraging efficacy, intracranial activity, and tolerability that we recommend as first-line therapy. As with use of TKIs in other oncogene-addicted NSCLCs, development of acquired resistance is pervasive and should be specifically delineated through use of repeat tissue biopsy with genetic profiling at the time of disease progression. If an actionable resistance mechanism emerges for which there is a candidate targeted therapy, combination inhibition should be considered. Alternatively, or in the absence of such findings, platinum doublet chemotherapy or particularly platinum-pemetrexed therapy with or without bevacizumab demonstrates a moderate effect.We would not recommend the routine use of nonselective multi-targeted TKIs such as cabozantinib and vandetanib, which have modest activity but limited tolerability due to predictable off-target effects. Single-agent immunotherapy has minimal activity in RET fusion-positive NSCLC. The role of combination chemotherapy and immunotherapy requires further study but may be considered, particularly in the presence of an activating KRAS alteration. While further development of novel RET-selective TKIs may address common RET-specific resistance mutations, they will not have activity against off-target, RET-independent resistance mechanisms. This again highlights the importance of serial biopsy and next-generation sequencing for the rational choice of sequential therapy in RET fusion-positive NSCLC.

Incidence of peripheral edema in patients receiving PI3K/mTOR/CDK4/6 inhibitors for metastatic breast cancer.

PURPOSE: This study evaluated development of edema in patients receiving PI3K/mTOR/CDK4/6 targeted therapy for metastatic breast cancer (MBC). METHODS: We reviewed medical records of 160 patients receiving targeted therapy with PI3K/mTOR/CDK4/6 inhibitors to treat MBC (n = 160; 185 treatment occurrences). Clinicopathologic data, treatment details, and edema incidence were recorded. RESULTS: Edema incidence was 43.1% (69/160) overall and 25.6% (41/160) in the upper extremity ipsilateral to the treated breast. In 185 therapy regimens administered, 6.8% of patients on a PI3K inhibitor, 8.8% of patients on an mTOR inhibitor, and 9.2% of patients on a CDK4/6 inhibitor experienced new onset or worsened preexisting upper extremity edema. Further, 9.1% of patients on a PI3K inhibitor, 18.8% of patients on an mTOR inhibitor, and 10.5% of patients on a CDK4/6 inhibitor experienced new onset or worsened preexisting edema elsewhere in the body. Multivariate logistic regression showed that, beyond the established breast cancer-related lymphedema (BCRL) risk factors [axillary lymph node dissection (Odds Ratio (OR) 2.69, p = 0.020), regional lymph node irradiation (OR 6.47, p < 0.001), and body-mass index ≥ 30 kg/m2 (OR 3.46, p = 0.006)], a relative decrease in serum albumin after 3 months of treatment increased risk of developing edema (OR 2.07, p = 0.062). Neither duration nor type of therapy were significant risk factors for edema. CONCLUSION: PI3K/mTOR/CDK4/6 inhibitors may influence the development of edema, which may cause or exacerbate progression of BCRL in patients with MBC. The varied incidence of edema between therapeutic regimens warrants vigilant monitoring of patients treated with these therapies, especially those at high risk of developing BCRL.

Perometry versus simulated circumferential tape measurement for the detection of breast cancer-related lymphedema.

PURPOSE: Despite increasing emphasis on screening and early intervention for breast cancer-related lymphedema (BCRL), there is marked heterogeneity in diagnostic methodology, including for volumetric measures. This retrospective study compared two volumetric modalities, perometry and simulated circumferential tape measurement (anatomic- and interval-based), for BCRL detection. METHODS: Between 2005 and 2017, 287 female patients with unilateral breast cancer were prospectively screened for BCRL by perometry and the relative volume change (RVC) formula. Circumferential measurement was performed by sampling at five anatomic landmark-based points or 4-cm intervals from pairs of perometer arm diameter measurements. Volumetric conversion was by a frustum model. The Bland-Altman method was used to compare segmental volume differences. Confusion matrix analysis was performed for each circumferential measurement technique against perometry. RESULTS: Median follow-up was 34.7 months over 4 postoperative visits. There was no difference in total arm volume comparing any of the circumferential measurement techniques to perometry. Landmark-based methods significantly underestimated upper arm volume (mean difference - 207 mL [- 336, - 78 mL]) and overestimated forearm volume (mean difference + 170 mL [+ 105, + 237 mL]). Landmark-based methods had greater sensitivity and specificity compared to 4-cm interval methods for detection of both RVC ≥ 10 and 5-10%. Landmark-based methods were comparable to perometry for detection of RVC ≥ 10%, but sensitivity was only 63.2-66.7% for RVC 5-10%. CONCLUSIONS: This hypothesis-generating study suggested the superiority of anatomic landmark-based circumferential tape measurement compared to interval-based methods, while generating questions about the underestimation of upper arm volume and overestimation of forearm volume of circumferential tape measurement compared to perometry.

Amino Acid Uptake Measured by [18F]AFETP Increases in Response to Arginine Starvation in ASS1-Deficient Sarcomas.

Rational: In a subset of cancers, arginine auxotrophy occurs due to the loss of expression of argininosuccinate synthetase 1 (ASS1). This loss of ASS1 expression makes cancers sensitive to arginine starvation that is induced by PEGylated arginine deiminase (ADI-PEG20). Although ADI-PEG20 treatment is effective, it does have important limitations. Arginine starvation is only beneficial in patients with cancers that are ASS1-deficient. Also, these tumors may metabolically reprogram to express ASS1, transforming them from an auxotrophic phenotype to a prototrophic phenotype and thus rendering ADI-PEG20 ineffective. Due to these limitations of ADI-PEG20 treatment and the potential for developing resistance, non-invasive tools to monitor sensitivity to arginine starvation are needed. Methods: Within this study, we assess the utility of a novel positron emission tomography (PET) tracer to determine sarcomas reliant on extracellular arginine for survival by measuring changes in amino acid transport in arginine auxotrophic sarcoma cells treated with ADI-PEG20. The uptake of the 18F-labeled histidine analogue, (S)-2-amino-3-[1-(2-[18F]fluoroethyl)-1H-[1,2,3]triazol-4-yl]propanoic acid (AFETP), was assessed in vitro and in vivo using human-derived sarcoma cell lines. In addition, we examined the expression and localization of cationic amino acid transporters in response to arginine starvation with ADI-PEG20. Results: In vitro studies revealed that in response to ADI-PEG20 treatment, arginine auxotrophs increase the uptake of L-[3H]arginine and [18F]AFETP due to an increase in the expression and localization to the plasma membrane of the cationic amino acid transporter CAT-1. Furthermore, in vivo PET imaging studies in mice with arginine-dependent osteosarcoma xenografts showed increased [18F]AFETP uptake in tumors 4 days after ADI-PEG20 treatment compared to baseline. Conclusion: CAT-1 transporters localizes to the plasma membrane as a result of arginine starvation with ADI-PEG20 in ASS1-deficient tumor cells and provides a mechanism for using cationic amino acid transport substrates such as [18F]AFETP for identifying tumors susceptible to ADI-PEG20 treatment though non-invasive PET imaging techniques. These findings indicate that [18F]AFETP-PET may be suitable for the early detection of tumor response to arginine depletion due to ADI-PEG20 treatment.

Cytosolic delivery of siRNA by ultra-high affinity dsRNA binding proteins.

Protein-based methods of siRNA delivery are capable of uniquely specific targeting, but are limited by technical challenges such as low potency or poor biophysical properties. Here, we engineered a series of ultra-high affinity siRNA binders based on the viral protein p19 and developed them into siRNA carriers targeted to the epidermal growth factor receptor (EGFR). Combined in trans with a previously described endosome-disrupting agent composed of the pore-forming protein Perfringolysin O (PFO), potent silencing was achieved in vitro with no detectable cytotoxicity. Despite concerns that excessively strong siRNA binding could prevent the discharge of siRNA from its carrier, higher affinity continually led to stronger silencing. We found that this improvement was due to both increased uptake of siRNA into the cell and improved pharmacodynamics inside the cell. Mathematical modeling predicted the existence of an affinity optimum that maximizes silencing, after which siRNA sequestration decreases potency. Our study characterizing the affinity dependence of silencing suggests that siRNA-carrier affinity can significantly affect the intracellular fate of siRNA and may serve as a handle for improving the efficiency of delivery. The two-agent delivery system presented here possesses notable biophysical properties and potency, and provide a platform for the cytosolic delivery of nucleic acids.

The need for preoperative baseline arm measurement to accurately quantify breast cancer-related lymphedema.

Breast cancer-related lymphedema (BCRL) is a feared outcome of breast cancer treatment, yet the push for early screening is hampered by a lack of standardized quantification. We sought to determine the necessity of preoperative baseline in accounting for temporal changes of upper extremity volume. 1028 women with unilateral breast cancer were prospectively screened for lymphedema by perometry. Thresholds were defined: relative volume change (RVC) ≥10 % for clinically significant lymphedema and ≥5 % including subclinical lymphedema. The first postoperative measurement (pseudo-baseline) simulated the case of no baseline. McNemar's test and binomial logistic regression models were used to analyze BCRL misdiagnoses. Preoperatively, 28.3 and 2.9 % of patients had arm asymmetry of ≥5 and 10 %, respectively. Without baseline, 41.6 % of patients were underdiagnosed and 40.1 % overdiagnosed at RVC ≥ 5 %, increasing to 50.0 and 54.8 % at RVC ≥ 10 %. Increased pseudo-baseline asymmetry, increased weight change between baselines, hormonal therapy, dominant use of contralateral arm, and not receiving axillary lymph node dissection (ALND) were associated with increased risk of underdiagnosis at RVC ≥ 5 %; not receiving regional lymph node radiation was significant at RVC ≥ 10 %. Increased pseudo-baseline asymmetry, not receiving ALND, and dominant use of ipsilateral arm were associated with overdiagnosis at RVC ≥ 5 %; increased pseudo-baseline asymmetry and not receiving ALND were significant at RVC ≥ 10 %. The use of a postoperative proxy even early after treatment results in poor sensitivity for identifying BCRL. Providers with access to patients before surgery should consider the consequent need for proper baseline, with specific strategy tailored by institution.