Modern trends in minimally invasive versus open hepatectomy for colorectal liver metastasis: an analysis of ACS-NSQIP.

BACKGROUND: Surgical resection of colorectal liver metastasis (CRLM) provides the best opportunity for prolonged survival. Eligibility for metastasectomy has expanded with technical advancements including parenchymal-sparing hepatectomy (PSH). Meanwhile, enthusiasm for minimally invasive surgery (MIS) has increased, though this approach may be preferentially utilized for technically straightforward cases. The purpose of this study is to characterize modern trends in open versus MIS approaches to partial hepatectomy and anatomic hepatectomy for CRLM within a nationwide cohort. METHODS: The American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) was used to investigate trends in MIS versus open hepatectomy for CRLM from 2015 to 2019. We examined baseline clinicopathologic and disease-related characteristics and compared trends in treatments over the study period. RESULTS: A total of 7457 patients undergoing hepatectomy for CRLM were identified (1367 MIS, 6090 open). Patients had similar clinicopathologic features between the two groups. Patients undergoing MIS resection less frequently received neoadjuvant therapy (51.1% vs 64.0%, p < 0.001) or concurrent intraoperative ablation (15.0% vs 21.3%, p < 0.001). Patients with tumors < 2 cm (34.9% vs 26.8%, p < 0.001) or only one to two tumors (82.8% vs 65.0%, p < 0.001) more commonly underwent MIS. MIS and open partial hepatectomies both significantly increased over the study period, but open partial hepatectomy increased at a greater rate than MIS (p < 0.001). Rates of anatomic resections have remained the same, with a greater proportion performed using an open approach (34.9% vs 16.4%, p < 0.001). Rates of operations consisting of > 1 concurrent partial hepatectomy are stable, but significantly more likely to be performed open (p < 0.001). CONCLUSIONS: Hepatectomy for CRLM has increased from a rise in partial hepatectomy, potentially translating to increased use of PSH. Current trends suggest MIS approaches appear to be increasing, but selectively implemented for patients with less technically demanding disease characteristics. Educational efforts should be directed towards increased dissemination of parenchymal-sparing MIS techniques for more complex resections.

Final report of the phase I/II clinical trial of the E75 (nelipepimut-S) vaccine with booster inoculations to prevent disease recurrence in high-risk breast cancer patients.

BACKGROUND: E75 (nelipepimut-S) is a human leukocyte antigen (HLA)-A2/A3-restricted immunogenic peptide derived from the HER2 protein. We have conducted phase I/II clinical trials vaccinating breast cancer patients with nelipepimut-S and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the adjuvant setting to prevent disease recurrence. All patients have completed 60 months follow-up, and here, we report the final analyses. PATIENTS AND METHODS: The studies were conducted as dose escalation/schedule optimization trials enrolling node-positive and high-risk node-negative patients with tumors expressing any degree of HER2 (immunohistochemistry 1-3+). HLA-A2/3+ patients were vaccinated; others were followed prospectively as controls. Local and systemic toxicity was monitored. Clinical recurrences were documented, and disease-free survival (DFS) was analyzed by Kaplan-Meier curves; groups were compared using log-rank tests. RESULTS: Of 195 enrolled patients, 187 were assessable: 108 (57.8%) in the vaccinated group (VG) and 79 (42.2%) in the control group (CG). The groups were well matched for clinicopathologic characteristics. Toxicities were minimal. Five-year DFS was 89.7% in the VG versus 80.2% in the CG (P = 0.08). Due to trial design, 65% of patients received less than the optimal vaccine dose. Five-year DFS was 94.6% in optimally dosed patients (P = 0.05 versus the CG) and 87.1% in suboptimally dosed patients. A voluntary booster program was initiated, and among the 21 patients that were optimally boosted, there was only one recurrence (DFS = 95.2%). CONCLUSION: The E75 vaccine is safe and appears to have clinical efficacy. A phase III trial evaluating the optimal dose and including booster inoculations has been initiated. CLINICAL TRIALS: NCT00841399, NCT00584789.

Using the Flipped Classroom Model in Surgical Education: Efficacy and Trainee Perception.

OBJECTIVE: To describe the feasibility, efficacy, and learner perception of the flipped classroom model for teaching conferences within surgical training programs. DESIGN: For the flipped classroom conferences, video lectures were prepared by a faculty member, and sent to all attendees at least 2 days prior to lecture. The conference time was then spent going over cases and questions, rather than traditional lecture. We conducted a qualitative survey to assess learner's perceptions and pre-lecture quizzes to assess trainee preparedness. SETTING: The comparison of pre-conference quizzes between flipped classroom and traditional models was carried out at Brooke Army Medical Center (BAMC) in San Antonio, TX, a tertiary care facility with a general surgery residency program. The survey was conducted at BAMC and within the Complex General Surgical Oncology fellowship program at University of Texas MD Anderson Cancer Center, where a flipped classroom model was similarly employed. PARTICIPANTS: Surgical residents BAMC participated in pre-lecture quizzes. BAMC residents and MD Anderson fellows were invited to complete the online survey. RESULTS: Lecture videos did not increase mean preparation time (1.53 vs. 1.46 hours without vs. with video, p = 0.858), but did increase mean quiz scores from 67% to 80% (p = 0.031) with 32/35 learners utilizing videos. Videos increased the proportion of learners who self-reported preparing at all from 42% to 95% (p = 0.28), and preparing for at least one hour for conference from 23% to 49% (p = 0.014). Of survey respondents, 90% said videos were very helpful, 90% would use them weekly if available, and 90% prefer this format to traditional lecture. CONCLUSIONS: Utilization of a flipped classroom method was well received and preferred by surgical trainees, and it increased performance on pre-conference quizzes without increasing preparation time. Although creation of video lectures is work-intensive for lecturers, these results suggest it is more effective for learner preparation. These results could be generalizable to surgical residents nationwide as technology utilization increases in surgical education.

Uneven substrates constrain walking speed in ants through modulation of stride frequency more than stride length.

Natural terrain is rarely flat. Substrate irregularities challenge walking animals to maintain stability, yet we lack quantitative assessments of walking performance and limb kinematics on naturally uneven ground. We measured how continually uneven 3D-printed substrates influence walking performance of Argentine ants by measuring walking speeds of workers from laboratory colonies and by testing colony-wide substrate preference in field experiments. Tracking limb motion in over 8000 videos, we used statistical models that associate walking speed with limb kinematic parameters to compare movement over flat versus uneven ground of controlled dimensions. We found that uneven substrates reduced preferred and peak walking speeds by up to 42% and that ants actively avoided uneven terrain in the field. Observed speed reductions were modulated primarily by shifts in stride frequency instead of stride length (flat R 2: 0.91 versus 0.50), a pattern consistent across flat and uneven substrates. Mixed effect modelling revealed that walking speeds on uneven substrates were accurately predicted based on flat walking data for over 89% of strides. Those strides that were not well modelled primarily involved limb perturbations, including missteps, active foot repositioning and slipping. Together these findings relate kinematic mechanisms underlying walking performance on uneven terrain to ecologically relevant measures under field conditions.

Evaluation of Attenuated Tumor Antigens and the Implications for Peptide-Based Cancer Vaccine Development.

INTRODUCTION: Peptide vaccines offer anti-tumor efficacy with very low toxicity. However, repeat stimulation with an immunogenic peptide leads to activation induced cell death (AICD), decreasing efficacy. We engineered variants of an immunogenic peptide (E39) and tested their ability to induce a robust, sustainable immune response. METHODS: Multiple variants of E39 were created by exchanging 1 or 2 amino acids. We tested the PBMC proliferation, cytokine production and cytolytic activity induced by each variant peptide. RESULTS: Repeated stimulation with E39 likely led to in vitro AICD, while stimulation with E39' led to T-cell proliferation with less evidence of AICD, modest cytokine production and high CTL activity. CONCLUSIONS: E39' appears to be the optimal variant of E39 for inducing effective long-term immunity.

Interim analysis of a phase I/IIa trial assessing E39+GM-CSF, a folate binding protein vaccine, to prevent recurrence in ovarian and endometrial cancer patients.

BACKGROUND: Folate binding protein(FBP) is an immunogenic protein over-expressed in endometrial(EC) and ovarian cancer(OC). We are conducting a phase I/IIa trial of E39 (GALE 301)+GM-CSF, an HLA-A2-restricted, FBP-derived peptide vaccine to prevent recurrences in disease-free EC and OC patients. This interim analysis summarizes toxicity, immunologic responses, and clinical outcomes to date. METHODS: HLA-A2+ patients were vaccinated(VG), and HLA-A2- or -A2+ patients were followed as controls(CG). Six monthly intradermal inoculations of E39+250mcg GM-CSF were administered to VG. Demographic, safety, immunologic, and recurrence rate(RR) data were collected and evaluated. RESULTS: This trial enrolled 51 patients; 29 in the VG and 22 in the CG. Fifteen patients received 1000mcg E39, and 14 received <1000mcg. There were no clinicopathologic differences between groups(all p ≥ 0.1). E39 was well-tolerated regardless of dose. DTH increased pre- to post-vaccination (5.7±1.5 mm vs 10.3±3.0 mm, p = 0.06) in the VG, and increased more in the 1000mcg group (3.8±2.0 mm vs 9.5±3.5 mm, p = 0.03). With 12 months median follow-up, the RR was 41% (VG) vs 55% (CG), p = 0.41. Among the 1000mcg patients, the RR was 13.3% vs 55% CG, p = 0.01. Estimated 2-year DFS was 85.7% in the 1000mcg group vs 33.6% in the CG (p = 0.021). CONCLUSIONS: This phase I/IIa trial reveals that E39+GM-CSF is well-tolerated and elicits a strong, dose-dependent in vivo immune response. Early efficacy results are promising in the 1000 mcg dose cohort. This study proves the safety and establishes the dose of E39 for a larger prospective, randomized, controlled trial in HLA-A2+ EC and OC patients to prevent recurrence.

Gaining ground on a cure through synergy: combining checkpoint inhibitors with cancer vaccines.

INTRODUCTION: The approval of multiple checkpoint inhibitors (CPIs) for the treatment of advanced malignancies has sparked an explosion of research in the field of cancer immunotherapy. Despite the success of these medications, a large number of patients with advanced malignancy do not benefit from therapy. Early research indicates that a therapeutic combination of cancer vaccines with checkpoint inhibitors may lead to synergistic effects and higher response rates than monotherapy. Areas covered: This paper summarizes the previously completed and ongoing research on this exciting combination, including the use of the tumor lysate, particle-loaded dendritic cell (TLPLDC) vaccine combined with checkpoint inhibitors in advanced melanoma. Expert commentary: Increasing experience with CPIs has led to improved understanding of which patients may benefit and it is increasingly clear that the presence of a pre-existing immune response to the tumor, along with tumor-infiltrating lymphocytes, is key to the success of CPIs. One exciting possibility for the future is the addition of a cancer vaccine to CPI therapy, eliciting these crucial T cells, which can then be augmented and protected by the CPI. A number of current and future studies are addressing this very exciting combination therapy.