Randomized controlled trials in lung cancer surgery: How are we doing?

Objective: Randomized control trials are considered the highest level of evidence, yet the scalability and practicality of implementing randomized control trials in the thoracic surgical oncology space are not well described. The aim of this study is to understand what types of randomized control trials have been conducted in thoracic surgical oncology and ascertain their success rate in completing them as originally planned. Methods: The ClinicalTrials.gov database was queried in April 2023 to identify registered randomized control trials performed in patients with lung cancer who underwent surgery (by any technique) as part of their treatment. Results: There were 68 eligible randomized control trials; 33 (48.5%) were intended to examine different perioperative patient management strategies (eg, analgesia, ventilation, drainage) or to examine different intraoperative technical aspects (eg, stapling, number of ports, port placement, ligation). The number of randomized control trials was relatively stable over time until a large increase in randomized control trials starting in 2016. Forty-four of the randomized control trials (64.7%) were open-label studies, 43 (63.2%) were conducted in a single facility, 66 (97.1%) had 2 arms, and the mean number of patients enrolled per randomized control trial was 236 (SD, 187). Of 21 completed randomized control trials (31%), the average time to complete accrual was 1605 days (4.4 years) and average time to complete primary/secondary outcomes and adverse events collection was 2125 days (5.82 years). Conclusions: Given the immense investment of resources that randomized control trials require, these findings suggest the need to scrutinize future randomized control trial proposals to assess the likelihood of successful completion. Future study is needed to understand the various contributing factors to randomized control trial success or failure.

Barriers to Completing Low Dose Computed Tomography Scan for Lung Cancer Screening.

INTRODUCTION: Annual low-dose computed tomography (LDCT) screening has been shown to reduce lung cancer mortality in high-risk individuals by detecting the disease at an earlier stage. This study aims to assess the barriers to completing LDCT in a cohort of patients who were determined eligible for lung cancer screening (LCS). METHODS: We performed a single institution, mixed methods, cross-sectional study of patients who had a LDCT ordered from July to December 2022. We then completed phone surveys with patients who did not complete LDCT to assess knowledge, attitude, and perceptions toward LCS. RESULTS: We identified 380 patients who met inclusion criteria, including 331 (87%) who completed LDCT and 49 (13%) who did not. Patients who completed a LDCT and those who did not were similar regarding age, sex, race, primary language, household income, body mass index, median pack years, and quit time. Positive predictors of LDCT completion were: meeting USPSTF guidelines (97.9% vs 81.6%), being married (58.3% vs 44.9%), former versus current smokers (55% vs 41.7%), personal history of emphysema (60.4% vs 42.9%), and family history of lung cancer (13.9% vs 4.1%) (all P < .05). Of the patients who participated in the phone survey, only 7% of respondents thought they were high risk for developing lung cancer despite attending a shared decision-making visit and only 10% wanted to re-schedule their LDCT. CONCLUSION: There exist barriers to completing LDCT even after patients are identified as eligible and complete a shared decision-making visit secondary to knowledge barriers, misperceptions, and patient disinterest.

What is an Adequate Margin During Sublobar Resection of ≤3cm N0 Subsolid Lung Adenocarcinomas?

BACKGROUND: Sublobar resection offers non-inferior survival vs. lobectomy for ≤2cm NSCLC and is commonly employed for subsolid tumors. While data exists for solid tumors, the minimum adequate margin of resection for subsolid adenocarcinomas remains unclear. METHODS: Retrospective review of 1101 adenocarcinoma resections at our institution, 2006-2022. INCLUSION CRITERIA: tumors≤3cm with ≥10% radiographic ground glass, excised by sublobar resection. EXCLUSIONS: positive nodes, positive or unreported margin. The primary outcome was rate of local recurrence(LR) at multiple thresholds of margin distance. Relationship between margin distance and solid-component size was also explored. RESULTS: 194 patients met inclusion criteria. Median(IQR) tumor diameter and margin distance were 12(9-17)mm and 10(5-17)mm, respectively. Median follow-up was 42.5 months. There was a progressive increase in LR with diminishing margin (0.1cm decrements) from 1.5cm to 0.5cm. The difference in the rate of LR between "over"(n=143) and "under"(n=51) was most significant at 0.5cm [8/51(15.7%) vs. 6/143(4.2%),p=0.01] but did not reach α adjusted for multiple comparisons. On Cox regression for LR-free survival (LRFS), margin ≤0.5cm(p=0.19) and %solid component (p=0.14) trended to significance. Combining these using margin-distance-to-solid-component-size ratio, a ratio≤1 did show a significantly higher rate of local recurrence [7(14.3%) vs. 2(2.0%),p=0.009]. Treatment of local recurrences provided at least intermediate-term survival in 87% of recurrences (median post-recurrence follow-up 44 months). CONCLUSIONS: During sublobar resection of subsolid lung adenocarcinomas, margin-to-solid-component-size ratio>1.0 appears to be a more reliable factor than margin distance alone to minimize local recurrence. Local recurrence, however, may not impact survival in patients with subsolid adenocarcinomas if timely treatment is administered.

genRCT: a statistical analysis framework for generalizing RCT findings to real-world population.

When evaluating the real-world treatment effect, the analysis based on randomized clinical trials (RCTs) often introduces generalizability bias due to the difference in risk factors between the trial participants and the real-world patient population. This problem of lack of generalizability associated with the RCT-only analysis can be addressed by leveraging observational studies with large sample sizes that are representative of the real-world population. A set of novel statistical methods, termed "genRCT", for improving the generalizability of the trial has been developed using calibration weighting, which enforces the covariates balance between the RCT and observational study. This paper aims to review statistical methods for generalizing the RCT findings by harnessing information from large observational studies that represent real-world patients. Specifically, we discuss the choices of data sources and variables to meet key theoretical assumptions and principles. We introduce and compare estimation methods for continuous, binary, and survival endpoints. We showcase the use of the R package genRCT through a case study that estimates the average treatment effect of adjuvant chemotherapy for the stage 1B non-small cell lung patients represented by a large cancer registry.

Lepidic-Type Lung Adenocarcinomas: Is It Safe to Observe for Growth Before Treating?

BACKGROUND: Lepidic-type adenocarcinomas (LPAs) can be multifocal, and treatment is often deferred until growth is observed. This study investigated the potential downside of that strategy by evaluating the relationship of nodal involvement with tumor size and survival. METHODS: The impact of tumor size on lymph node involvement and survival was evaluated for National Cancer Database patients who underwent surgery without induction therapy as primary treatment for cT1-3 N0 M0 histologically confirmed LPA from 2006 to 2019 by using logistic regression, Kaplan-Meier, and Cox analyses. RESULTS: Positive nodes occurred in 442 of 8286 patients (5.3%). The incidence of having positive nodes approximately doubled with each 1-cm increment increase in size. Patients with positive nodes were more likely to have larger tumors (27 mm vs 20 mm, P < .001) and clinical ≥T2 disease (40.7% vs 26.8%, P < .001) compared with node-negative patients. However, tumor size was the only significant independent predictor of having positive nodal disease in logistic regression analysis, and this association grew stronger with each incremental centimeter increase in size. Patients with positive nodes were more likely to undergo adjuvant radiotherapy (23.5% vs 1.1%, P < .001) and chemotherapy (72.9% vs 7.9%, P < .001), and expectedly, had worse survival compared with the node-negative group in univariate (5-year overall survival, 50.9% vs 81.1%, P < .001) and multivariable (hazard ratio, 2.56; 95% CI, 2.14-3.05; P < .001) analyses. CONCLUSIONS: Nodal involvement is relatively uncommon in early-stage LPAs but steadily increases with tumor size and is associated with dramatically worse survival. These data can be used to inform treatment decisions when evaluating LPA patients.

Complications of Outpatient Chest Tube Management for Prolonged Air Leaks After Pulmonary Surgery.

PURPOSE: Air leaks are common after pulmonary surgery. Prolonged air leaks (PALs) may persist through discharge and often are managed with one-way valve devices (OWD). We sought to determine the course and complications of patients discharged with OWDs, risk factors for complications, and to evaluate the utility of clamp trials before chest tube (CT) removal. METHODS: Single-institution, retrospective review of patients discharged with a OWD after pulmonary surgery between 2008 and 2022. Charts were examined for the presence of complications and CT duration. Differences in CT duration were compared by using the Wilcoxon rank-sum test. RESULT: Sixty-four of 1917 (3.3%) pulmonary surgeries resulted in OWD use. Twelve of 64 (19%) patients discharged with a OWD suffered a complication. Nine of 64 (14%) had a CT-related readmission, and seven of 64 (11%) required PAL intervention. Patients sustaining a complication demonstrated longer CT durations before complication compared with duration in patients without complications, with median days of 13 [IQR 6-21] vs. 7 [IQR 6-12], p = 0.04). Five (7.8%) OWD patients developed an empyema; only one (20%) occurred before a CT duration of 14 days. Sixteen of 64 (25%) patients underwent a clamp trial before CT removal. One of ten (10%) failed even with no air leak present, whereas one of six (17%) failed with a present/questionable air leak. CONCLUSIONS: One-way valve device use has a substantial complication rate, and chest tube duration is a risk factor. In-hospital interventions might benefit patients with larger leaks that likely require prolonged OWD use. Because clamp trials occasionally fail, we contend that a clamp trial is the safest course before CT removal.

The Impact of Immunotherapy Use in Stage IIIA (T1-2N2) NSCLC: A Nationwide Analysis.

Introduction: Multiple clinical trials have revealed the benefit of immunotherapy (IO) for NSCLC, including unresectable stage III disease. Our aim was to investigate the impact of IO use on treatment and outcomes of potentially resectable stage IIIA NSCLC in a broader nationwide patient cohort. Methods: We queried the National Cancer Database (2004-2019) for patients with stage IIIA (T1-2N2) NSCLC. Treatment and survival were evaluated with descriptive statistics, logistic regression, Kaplan-Meier analysis, and Cox proportional hazards modeling. Results: Overall, 5.5% (3777 of 68,335) of patients received IO. IO use was uncommon until 2017, but by 2019, it was given to 40.1% (1544 of 2308) of stage IIIA patients. The increased use of IO after 2017 was associated with increased definitive chemoradiation treatment (54.2% [6800 of 12,535] from years 2017 to 2019 versus 46.9% [26,251 of 55,914] from 2004 to 2016, p < 0.001) and less use of surgery (18.1% [2266 of 12,535] from years 2017 to 2019 versus 22.0% [12,300 of 55,914] from 2004 to 2016, p < 0.001). IO treatment was associated with significantly better 5-year survival in the entire cohort (36.9% versus 23.4%, p < 0.001) and the subsets of patients treated with chemoradiation (37.2% versus 22.7%, p < 0.001) and surgery (48.6% versus 44.3%, p < 0.001). Pneumonectomy use decreased with increased IO treatment (5.1% of surgical patients [116 of 2266] from years 2017 to 2019 versus 9.2% [1127 of 12,300] from 2004 to 2016, p < 0.001). Conclusions: Increased use of IO was associated with a change in treatment patterns and improved survival for patients with stage IIIA(N2) NSCLC.

Treatment of patients hospitalized for COVID-19 with remdesivir is associated with lower likelihood of 30-day readmission: a retrospective observational study.

Aim: This observational study investigated the association between remdesivir treatment during hospitalization for COVID-19 and 30-day COVID-19-related and all-cause readmission across different variants time periods. Patients & methods: Hospitalization records for adult patients discharged from a COVID-19 hospitalization between 1 May 2020 to 30 April 2022 were extracted from the US PINC AI Healthcare Database. Likelihood of 30-day readmission was compared among remdesivir-treated and nonremdesivir-treated patients using multivariable logistic regression models adjusted for age, corticosteroid treatment, Charlson comorbidity index and intensive care unit stay during the COVID-19 hospitalization. Analyses were stratified by maximum supplemental oxygen requirement and variant time period (pre-Delta, Delta and Omicron). Results: Of the 440,601 patients discharged alive after a COVID-19 hospitalization, 248,785 (56.5%) patients received remdesivir. Overall, remdesivir patients had a 30-day COVID-19-related readmission rate of 3.0% and all-cause readmission rate of 6.3% compared with 5.4% and 9.1%, respectively, for patients who did not receive remdesivir during their COVID-19 hospitalization. After adjusting for demographics and clinical characteristics, remdesivir treatment was associated with significantly lower odds of 30-day COVID-19-related readmission (odds ratio 0.60 [95% confidence interval: 0.58-0.62]), and all-cause readmission (0.73 [0.72-0.75]). Significantly lower odds of 30-day readmission in remdesivir-treated patients was observed across all variant time periods. Conclusion: Treating patients hospitalized for COVID-19 with remdesivir is associated with a statistically significant reduction in 30-day COVID-19-related and all-cause readmission across variant time periods. These findings indicate that the clinical benefit of remdesivir may extend beyond the COVID-19 hospitalization.

Surgical revision of the postesophagectomy gastric conduit to address poor emptying.

Introduction: The configuration of the gastric conduit after esophagectomy can lead to chronic gastrointestinal and respiratory issues. Surgical revision of the gastric conduit has been described in small series but appears to be infrequently used. We investigated outcomes of revising dilated or redundant conduit in patients with severe quality-of-life issues. Methods: We identified all patients from 2016 to 2022 at our institution who underwent gastric conduit revision after previous esophagectomy either at our or another institution. Chart review was performed to assess prerevision course and perioperative outcomes. Pre- and postrevision imaging was compared for all patients to assess the impact of surgery on anatomic configuration. Patient-reported gastrointestinal and respiratory issues before and after surgery were examined. Results: The use of right thoracotomy combined with laparotomy to reduce redundancy and improve gastric emptying was performed in 8 patients. The symptoms necessitating reoperation included intolerance to oral intake and poor gastric emptying associated with both acute and chronic aspiration episodes. The median length of stay was 8 [4, 25] days, and there were no perioperative mortalities. Seven (87.5%) patients were tolerating oral intake at discharge. All patients had improvement in their prerevision symptoms on follow-up. Conclusions: Gastric conduit revision can improve severe postesophagectomy gastrointestinal and respiratory symptoms in patients with dilated/redundant conduits with limited perioperative morbidity.

Racial and Ethnic Disparities in COVID-19 Treatments in the United States.

INTRODUCTION: Racial and ethnic disparities in patient outcomes following COVID-19 exist, in part, due to factors involving healthcare delivery. The aim of the study was to characterize disparities in the administration of evidence-based COVID-19 treatments among patients hospitalized for COVID-19. METHODS: Using a large, US hospital database, initiation of COVID-19 treatments was compared among patients hospitalized for COVID-19 between May 2020 and April 2022 according to patient race and ethnicity. Multivariate logistic regression models were used to examine the effect of race and ethnicity on the likelihood of receiving COVID-19 treatments, stratified by baseline supplemental oxygen requirement. RESULTS: The identified population comprised 317,918 White, 76,715 Black, 9297 Asian, and 50,821 patients of other or unknown race. There were 329,940 non-Hispanic, 74,199 Hispanic, and 50,622 patients of unknown ethnicity. White patients were more likely to receive COVID-19 treatments, and specifically corticosteroids, compared to Black, Asian, and other patients (COVID-19 treatment: 87% vs. 81% vs. 85% vs. 84%, corticosteroids: 85% vs. 79% vs. 82% vs. 82%). After covariate adjustment, White patients were significantly more likely to receive COVID-19 treatments than Black patients across all levels of supplemental oxygen requirement. No clear trend in COVID-19 treatments according to ethnicity (Hispanic vs. non-Hispanic) was observed. CONCLUSION: There were important racial disparities in inpatient COVID-19 treatment initiation, including the undertreatment of Black patients and overtreatment of White patients. Our new findings reveal the actual magnitude of this issue in routine clinical practice to clinicians, policymakers, and guideline developers. This is crucial to ensuring equitable and appropriate access to evidence-based therapies.

ACR Appropriateness Criteria® Incidentally Detected Indeterminate Pulmonary Nodule.

Incidental pulmonary nodules are common. Although the majority are benign, most are indeterminate for malignancy when first encountered making their management challenging. CT remains the primary imaging modality to first characterize and follow-up incidental lung nodules. This document reviews available literature on various imaging modalities and summarizes management of indeterminate pulmonary nodules detected incidentally. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Impact of hyperthermic intrathoracic chemotherapy (HITHOC) during resection of pleural mesothelioma on patient survival.

Background: Pleural mesothelioma (PM) is rare but portends a poor prognosis. Multimodal treatment, including aggressive surgical resection, may offer the best chance of treatment response and improved survival. Single-center studies suggest that hyperthermic intrathoracic chemotherapy (HITHOC) during surgical resection improves outcomes, but the impact of HITHOC on postoperative morbidity and survival has not been examined on a larger scale. Methods: The National Cancer Database was queried for patients undergoing resection for PM from 2006-2017. Patients were excluded if staging or survival data was incomplete. After propensity-score matching, patients who underwent HITHOC were compared to patients who did not (case-control study). Perioperative outcomes and survival were analyzed. Results: The final cohort consisted of 3,232 patients; of these, 365 patients underwent HITHOC. After propensity-score matching, receipt of HITHOC was associated with increased length of stay (12 vs. 7 days, P<0.001) and increased 30-day readmissions (9.9% vs. 4.9%, P=0.007), but decreased 30-day mortality (3.2% vs. 6.0%, P=0.017) and 90-day mortality (7.5% vs. 10.9%). Kaplan-Meier modeling demonstrated that HITHOC was associated with improved survival in the overall cohort (median 20.5 vs. 16.8 months, P=0.001). In multivariable analysis, HITHOC remained associated with improved overall survival [hazard ratio (HR) =0.80; 95% confidence interval (CI): 0.69-0.92; P=0.002], and this persisted in the propensity-matched analysis (HR =0.73; 95% CI: 0.61-0.88; P=0.001). Conclusions: Using a large national database, we describe the impact of HITHOC on survival in patients with PM. Despite observed increased short-term morbidity, in multivariable analysis HITHOC was associated with an overall survival advantage for patients undergoing surgical resection of PM.

Remdesivir Is Associated With Reduced Mortality in COVID-19 Patients Requiring Supplemental Oxygen Including Invasive Mechanical Ventilation Across SARS-CoV-2 Variants.

Background: This comparative effectiveness study investigated the effect of remdesivir on in-hospital mortality among patients hospitalized for coronavirus disease 2019 (COVID-19) requiring supplemental oxygen including low-flow oxygen (LFO), high-flow oxygen/noninvasive ventilation (HFO/NIV), or invasive mechanical ventilation/extracorporeal membrane oxygenation (IMV/ECMO) across variant of concern (VOC) periods. Methods: Patients hospitalized for COVID-19 between December 2020 and April 2022 and administered remdesivir upon admission were 1:1 propensity score matched to patients not administered remdesivir during their COVID-19 hospitalization. Analyses were stratified by supplemental oxygen requirement upon admission and VOC period. Cox proportional hazards models were used to derive adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for 14- and 28-day mortality. Results: Patients treated with remdesivir (67 582 LFO, 34 857 HFO/NIV, and 4164 IMV/ECMO) were matched to non-remdesivir patients. Unadjusted mortality rates were significantly lower for remdesivir-treated patients at 14 days (LFO: 6.4% vs. 8.8%; HFO/NIV: 16.8% vs. 19.4%; IMV/ECMO: 27.8% vs. 35.3%) and 28 days (LFO: 9.8% vs. 12.3%; HFO/NIV: 25.8% vs. 28.3%; IMV/ECMO: 41.4% vs. 50.6%). After adjustment, remdesivir treatment was associated with a statistically significant reduction in in-hospital mortality at 14 days (LFO: aHR, 0.72; 95% CI, 0.66-0.79; HFO/NIV: aHR, 0.83; 95% CI, 0.77-0.89; IMV/ECMO: aHR, 0.73; 95% CI, 0.65-0.82) and 28 days (LFO: aHR, 0.79; 95% CI, 0.73-0.85; HFO/NIV: aHR, 0.88; 95% CI, 0.82-0.93; IMV/ECMO: aHR, 0.74; 95% CI, 0.67-0.82) compared with non-remdesivir treatment. Lower risk of mortality among remdesivir-treated patients was observed across VOC periods. Conclusions: Remdesivir treatment is associated with significantly reduced mortality among patients hospitalized for COVID-19 requiring supplemental oxygen upon admission, including those requiring HFO/NIV or IMV/ECMO with severe or critical disease, across VOC periods.

The Role of Salvage Resection After Definitive Radiation Therapy for Non-small Cell Lung Cancer.

BACKGROUND: This study evaluated outcomes of patients who undergo extended delay to resection after definitive radiation therapy for non-small cell lung cancer (NSCLC). METHODS: Perioperative outcomes and 5-year overall survival of patients with NSCLC who underwent definitive radiation therapy, followed by resection, from 2004 to 2020 in the National Cancer Database were evaluated. Patients who underwent resection >180 days after the initiation of radiation therapy (including any external beam therapy at a total dose of >60 Gy) were included in the analysis. Subgroup analyses were conducted by operation type and pathologic nodal status. RESULTS: From 2004 to 2020, 293 patients had an extended delay to resection after definitive radiation therapy. The clinical stage distribution was stage I to II in 53 patients (18.1%), stage IIIA in 111 (37.9%), stage IIIB in 106 (36.2%), stage IIIC in 13 (4.4%), and stage IV in 10 (3.4%). Median dose of radiation therapy received was 64.8 Gy (interquartile range, 60.0-66.6 Gy). Median days from radiation therapy to resection were 221.0 (interquartile range, 193.0-287.0) days. Lobectomy (64.5%) was the most common operation, followed by pneumonectomy (17.1%) and wedge resection (7.5%). For wedge resection, lobectomy, and pneumonectomy, the 30-day readmission rate was 4.8%, 4.8%, and 8.3%, the 30-day mortality rate was 0%, 3.4%, and 6.4%, and the 90-day mortality rate was 0%, 6.2%, and 12.8%, respectively. Overall survival at 5 years for patients with pN0, pN1, and pN2 disease was 38.6% (95% CI, 30.0-47.2), 43.3% (95% CI, 16.3-67.9), and 24.0% (95% CI, 9.8-41.7), respectively. CONCLUSIONS: In this national analysis, extended delay to resection after definitive radiation therapy was associated with acceptable perioperative outcomes among a highly selected patient cohort.

Remdesivir Reduced Mortality in Immunocompromised Patients Hospitalized for COVID-19 Across Variant Waves: Findings From Routine Clinical Practice.

BACKGROUND: Immunocompromised patients are at high risk of severe coronavirus disease 2019 (COVID-19) and death, yet treatment strategies for immunocompromised patients hospitalized for COVID-19 reflect variations in clinical practice. In this comparative effectiveness study, we investigated the effect of remdesivir treatment on inpatient mortality among immunocompromised patients hospitalized for COVID-19 across all variants of concern (VOC) periods. METHODS: Data for immunocompromised patients hospitalized for COVID-19 between December 2020 and April 2022 were extracted from the US PINC AITM Healthcare Database. Patients who received remdesivir within 2 days of hospitalization were matched 1:1 using propensity score matching to patients who did not receive remdesivir. Additional matching criteria included admission month, age group, and hospital. Cox proportional hazards models were used to examine the effect of remdesivir on risk of 14- and 28-day mortality during VOC periods. RESULTS: A total of 19 184 remdesivir patients were matched to 11 213 non-remdesivir patients. Overall, 11.1% and 17.7% of remdesivir patients died within 14 and 28 days, respectively, compared with 15.4% and 22.4% of non-remdesivir patients. Remdesivir was associated with a reduction in mortality at 14 (hazard ratio [HR], 0.70; 95% confidence interval, .62-.78) and 28 days (HR, 0.75; 95% CI, .68-.83). The survival benefit remained significant during the pre-Delta, Delta, and Omicron periods. CONCLUSIONS: Prompt initiation of remdesivir in immunocompromised patients hospitalized for COVID-19 is associated with significant survival benefit across all variant waves. These findings provide much-needed evidence relating to the effectiveness of a foundational treatment for hospitalized COVID-19 patients among a high-risk population.

A short pre-conception bout of predation risk affects both children and grandchildren.

Traumatic events that affect physiology and behavior in the current generation may also impact future generations. We demonstrate that an ecologically realistic degree of predation risk prior to conception causes lasting changes in the first filial (F1) and second filial (F2) generations. We exposed male and female mice to a live rat (predator stress) or control (non-predator) condition for 5 min. Ten days later, stressed males and females were bred together as were control males and females. Adult F1 offspring from preconception-stressed parents responded to a mild stressor with more anxiety-like behavior and hyperarousal than offspring from control parents. Exposing these F1 offspring to the mild stressor increased neuronal activity (cFOS) in the hippocampus and altered glucocorticoid system function peripherally (plasma corticosterone levels). Even without the mild stressor, F1 offspring from preconception-stressed parents still exhibited more anxiety-like behaviors than controls. Cross-fostering studies confirmed that preconception stress, not maternal social environment, determined offspring behavioral phenotype. The effects of preconception parental stress were also unexpectedly persistent and produced similar behavioral phenotypes in the F2 offspring. Our data illustrate that a surprisingly small amount of preconception predator stress alters the brain, physiology, and behavior of future generations. A better understanding of the 'long shadow' cast by fearful events is critical for understanding the adaptive costs and benefits of transgenerational plasticity. It also suggests the intriguing possibility that similar risk-induced changes are the rule rather than the exception in free-living organisms, and that such multigenerational impacts are as ubiquitous as they are cryptic.