Readmissions After Surgery for Colorectal Liver Metastases: A Propensity Score Analysis From the Colorectal Liver Operative Metastasis International Collaborative (COLOMIC)
ABSTRACT Background Readmission is considered as a surgical quality indicator. More data regarding predictors of readmission and outcomes after surgery for colorectal liver metastasis are needed. Using a propensity score match to create a 1:2 match of cases:controls for 90‐day. Readmission, the matching variables used for balance included age, tumor size, estimated blood loss, and type of resection (minor or major). T‐tests were used for continuous measures, Fisher's exact test was used for categorical data, and the Kaplan–Meier method was used to estimate survival. p < 0.05 was considered significant. Methods Retrospectively examined 935 patients with CLM from 2000 to 2018. Using a propensity score match to create a 1:2 match of cases:controls for 90‐day. Readmission, the matching variables used for balance included age, tumor size, estimated blood loss, and type of resection (minor or major). T‐tests were used for continuous measures, Fisher's exact test was used for categorical data, and the Kaplan–Meier method was used to estimate survival. p < 0.05 was considered significant. Results 935 patients were included in the initial sample with 896 eligible for inclusion in the propensity matching. The average age of the population was 59% and 59% male. Overall readmission rate was 8.0%. Median time to readmission was 14 days. In the propensity score matched sample, readmitted patients had higher rates of organ space infection (28% vs 2% and p < 0.0001), bile leak (26% vs 1% and p < 0.0001), and liver failure (9% vs 2% and p = 0.042). There was no difference in LOS (7 days versus six days and p = 0.40), overall survival (median 39.7 vs 41.0 months and p = 0.79), or rate of adjuvant therapy (68% for both and p > 0.99). Conclusion Patients readmitted for intermediate and late complications after surgery for CLM can recover and receive adjuvant therapy with no adverse effect on overall survival. Organ space infection, bile leak, and liver failure are highly associated with readmission.
Pancreatic tumor microenvironment reprogramming via alloantigen-expressing virotherapy elicits tumor rejection and improves immunotherapy response
Background Pancreatic ductal adenocarcinoma (PDAC), the most common malignant type of pancreatic cancer, is characterized by a dense desmoplastic stroma, low neoantigen burden, and a highly immunosuppressive tumor microenvironment (TME). Methods We present a novel strategy harnessing acute transplant rejection mechanisms by employing a recombinant oncolytic rVMG vector engineered to express murine alloantigens H-2Kb (rVMG-H-2Kb) or H-2Kk (rVMG-H-2Kk), thereby inducing tumor-specific antigenic mismatch responses. Results In vitro, rVMG-H-2Kb and rVMG-H-2Kk exhibited strong replication and cytolytic activity while inducing cell surface expression of both H-2Kk and endogenous H-2Kb, in addition to upregulation of antigen presentation genes (β2-microglobulin, Tap1, and Tapbp). In two immunocompetent PDAC models, intratumoral and systemic delivery of rVMG-H-2Kb and rVMG-H-2Kk delayed tumor progression, with rVMG-H-2Kk conferring a survival advantage. Multiplex immunohistochemistry and immunophenotyping revealed substantial TME remodeling, marked by increased effector T-cell infiltration, regulatory T-cell depletion, and reduced fibrosis. Spatial transcriptomics further showed compartment-specific immune activation and epithelial metabolic reprogramming, corroborating with enhanced tumor immunogenicity. Despite these effects, rVMG-H-2Kk also induced compensatory immunosuppressive pathways, including upregulation of antiviral response genes and immune checkpoint receptors such as programmed death-ligand-2. Importantly, combination therapy with rVMG-H-2Kk and murine checkpoint blockade (anti-programmed cell death protein-1 and anti-cytotoxic T-lymphocyte-associated protein 4) drastically improved survival compared to checkpoint blockade alone. Strikingly, surviving mice resisted tumor rechallenge, indicating the establishment of durable antitumor memory. Conclusion These findings establish rVMG-mediated alloantigen delivery as a novel immunotherapeutic platform capable of converting immune-cold tumors into immune-hot, sensitizing tumors to immune checkpoint inhibitors, and establishing durable antitumor immunity in PDAC.
Comparative Proteomic Profiling of Responses to Standard Systemic Treatment Regimens in Pancreatic Cancer
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a 5-year survival rate of 13.3%. First-line treatment relies on two chemotherapy regimens, FOLFIRINOX (FOLFNX) or gemcitabine plus nab-paclitaxel (GEMPAC). However, direct clinical comparisons between these regimens have yielded inconsistent results across survival and toxicity endpoints, and the molecular basis of heterogeneous treatment responses remains poorly defined. To investigate regimen-specific tumor-cell-intrinsic mechanisms, we performed quantitative proteomic profiling of a primary PDAC-derived MIA PaCa-2 cell line following treatment with FOLFNX or GEMPAC. Differentially expressed proteins were analyzed using Gene Ontology, KEGG, and Ingenuity Pathway Analysis to define pathway-level alterations, and findings were contextualized using TCGA transcriptomic data. Proteomic analyses revealed that FOLFNX and GEMPAC engage in distinct cytotoxic programs. FOLFNX predominantly suppressed ribosome biogenesis and mitochondrial translation, consistent with sustained metabolic and biosynthetic stress, whereas GEMPAC preferentially disrupted mitotic cytokinesis and phosphatidylinositol phosphate biosynthesis, consistent with mitotic failure. Integration with TCGA data showed that FOLFNX-altered proteins aligned with favorable prognostic expression signatures, whereas GEMPAC-associated proteins were enriched among adverse profiles, reflecting engagement of distinct tumor-intrinsic programs. Together, these findings provide mechanistic insight into differential chemotherapy responses and establish a foundation for proteomics-based biomarkers to guide personalized chemotherapy selection in PDAC.
Prognostic implications of margin status in association with systemic treatment in a cohort study of patients with resection of colorectal liver metastases
AbstractBackgroundThis study investigates the impact of margin status after colorectal liver metastasis (CLM) resection on outcomes of patients after neoadjuvant treatment versus those who underwent upfront resection.MethodsAn international collaborative database of CLM patients who underwent surgical resection was used. Proportional hazard regression models were created for single and multivariable models to assess the relationship between independent measures and median overall survival (mOS).ResultsR1 was associated with worse OS in the neoadjuvant group (mOS: 51.8 m for R0 vs. 26.0 m for R1; HR: 2.18). In the patients who underwent upfront surgery, R1 was not associated with OS. (mOS: 46.7 m for R0 vs. 42.6 m for R1). When patients with R1 in each group were stratified by adjuvant treatment, there was no significant difference in the neoadjuvant group, while in the upfront surgery group with R1, adjuvant treatment was associated with significant improvement in OS (mOS: 42.6 m for adjuvant vs. 25.0 m for no adjuvant treatment; HR: 0.21).ConclusionR1 is associated with worse outcomes in the patients who receive neoadjuvant treatment with no significant improvement with the addition of adjuvant therapy, likely representing an aggressive tumor biology. R1 did not impact OS in patients with upfront surgery who received postoperative chemotherapy.
Resection versus resection with ablation: Analysis from the colorectal liver operative metastasis international collaborative
AbstractBackgroundThermal ablation has recently become a key therapy for the treatment of colorectal liver metastasis (CLM). However, the role of ablation in combination with resection has not yet been firmly established. We hypothesize that in patients with CLM, those who undergo liver resection with ablation (RA) have similar outcomes compared with those who undergo liver resection only.MethodsWe reviewed a multicenter international database of 906 surgical procedures for CLM from 5 high volume hepatobiliary surgical units. Patients undergoing RA (n = 63) were matched based on the number of lesions and tumor size using a 1:1 balanced propensity score analysis with those having resection only (n = 63). Our primary outcomes were overall survival (OS) and disease‐free survival (DFS).ResultsThe mean age of our cohort was 58 ± 11 years, with 43% females. With a median follow‐up of 70.8 months, patients in the resection and RA group had a median OS of 45.1 and 54.8 months (p = 0.71), respectively. The median DFS was 22.7 and 14.2 months (p = 0.045), respectively. Using a multivariate Cox proportional hazards regression model, the treatment approach was not associated with OS (p = 0.94) or DFS (p = 0.059). A higher number of lesions is independently associated with worse DFS (hazard ratio: 1.12, p < 0.01). When there was disease recurrence, the region of recurrence was similar between the RA versus resection only groups (p = 0.27), but there was a shorter time to recurrence in the RA group (p = 0.002).ConclusionFor CLM, the treatment approach was not significantly associated with OS or DFS, while tumor biology likely played an important role. Prospective research on the quality and effectiveness of thermal ablation combined with hepatic resection is warranted.
Machine Learning Models for Predicting the Outcomes of Surgical Treatment of Colorectal Liver Metastases
BACKGROUND: Surgical intervention remains the cornerstone of a multidisciplinary approach in the treatment of colorectal liver metastases (CLM). Nevertheless, patient outcomes vary greatly. While predictive tools can assist decision-making and patient counseling, decades of efforts have yet to result in generating a universally adopted tool in clinical practice. STUDY DESIGN: An international collaborative database of CLM patients who underwent surgical therapy between 2000 and 2018 was used to select 1,004 operations for this study. Two different machine learning methods were applied to construct 2 predictive models for recurrence and death, using 128 clinicopathologic variables: gradient-boosted trees (GBTs) and logistic regression with bootstrapping (LRB) in a leave-one-out cross-validation. RESULTS: Median survival after resection was 47.2 months, and disease-free survival was 19.0 months, with a median follow-up of 32.0 months in the cohort. Both models had good predictive power, with GBT demonstrating a superior performance in predicting overall survival (area under the receiver operating curve [AUC] 0.773, 95% CI 0.743 to 0.801 vs LRB: AUC 0.648, 95% CI 0.614 to 0.682) and recurrence (AUC 0.635, 95% CI 0.599 to 0.669 vs LRB: AUC 0.570, 95% CI 0.535 to 0.601). Similarly, better performances were observed predicting 3- and 5-year survival, as well as 3- and 5-year recurrence, with GBT methods generating higher AUCs. CONCLUSIONS: Machine learning provides powerful tools to create predictive models of survival and recurrence after surgery for CLM. The effectiveness of both machine learning models varies, but on most occasions, GBT outperforms LRB. Prospective validation of these models lays the groundwork to adopt them in clinical practice.
Outcomes after repeat hepatectomy for colorectal liver metastases from the colorectal liver operative metastasis international collaborative (COLOMIC)
AbstractBackgroundResection of colorectal liver metastasis (CLM) is beneficial when feasible. However, the benefit of second hepatectomy for hepatic recurrence in CLM remains unclear.MethodsThe Colorectal Liver Operative Metastasis International Collaborative retrospectively examined 1004 CLM cases from 2000 to 2018 from a total of 953 patients. Hepatic recurrence after initial hepatectomy was identified in 218 patients. Kaplan–Meier analysis was performed for overall survival (OS) and recurrence‐free survival (RFS). Propensity score matching (PSM) was performed to offset selection bias. Cox proportional‐hazards regression was performed to identify risk factors associated with OS.ResultsA total of 51 patients underwent second hepatectomy. Unadjusted median OS was 60.1 months in repeat‐hepatectomy versus 38.3 months in the single‐hepatectomy group (p = 0.015). In the PSM population, median OS remained significantly better in the repeat‐hepatectomy group (60.1 vs. 33.1 months; p = 0.0023); median RFS was 12.4 months for the repeat‐hepatectomy group, versus 9.8 months in the single‐hepatectomy group (p = 0.0050). Repeat hepatectomy was associated with lower risk of death (hazard ratio: 0.283; p = 0.000012). Obesity, tobacco use, and high intraoperative blood loss were associated with significant risk of death (p < 0.05).ConclusionIn CLM with hepatic recurrence, second hepatectomy was beneficial for OS. With PSM, the OS benefit of performing a second hepatectomy remained significant.
Perioperative chemotherapy for resectable colorectal liver metastases: Analysis from the Colorectal Operative Liver Metastases International Collaborative (COLOMIC)
AbstractBackgroundChemotherapy has been increasingly combined with surgery as multimodality treatment for resectable colorectal‐liver metastases (CLM). There is paucity of clinical data addressing optimal timing of chemotherapy relative to surgery. We examined outcomes of patients undergoing hepatectomy for resectable CLM.MethodsSeven hundred and eighteen patients treated with hepatectomy for CLM were analyzed from five hepatobiliary institutions between 2000 and 2018. Overall survival (OS) was measured from time of hepatectomy for patients receiving: surgery alone, neoadjuvant, adjuvant, and neoadjuvant‐plus‐adjuvant (perioperative) chemotherapy. Kaplan–Meier analysis was performed to detect differences in OS between treatment groups. Single‐ and multi‐variable analysis with Cox proportional hazards were run for OS between groups.ResultsOne hundred and thirty‐seven patients (19.08%) received surgery, 104 (14.48%) received neoadjuvant‐only, 214 (29.81%) received adjuvant‐only, and 263 (36.63%) received perioperative chemotherapy; with median OS of 48.20, 46.83, 56.27, and 49.93 months, respectively. No differences in median OS were seen between groups on Kaplan–Meier analysis. No significant difference in Charlson‐Deyo comorbidity status was seen between groups (p = 0.853), while significant difference was seen in maximum tumor size (p = 0.0023). On multivariate analysis, adjuvant (p = 0.010) and perioperative (p = 0.020) chemotherapy were independently associated with OS compared to surgery alone.DiscussionDespite group differences, chemotherapy after surgery was independently associated with improved OS in CLM.
Utility of hyperthermic intraperitoneal chemotherapy in cases of incomplete cytoreductive surgery
AbstractIntroductionHyperthermic intraperitoneal chemotherapy (HIPEC) during cytoreductive surgery (CRS) is typically reserved for a complete or optimal cytoreduction. There is the potential for therapeutic effect of HIPEC with an incomplete cytoreduction, particularly for near optimal cytoreductions.MethodsRetrospective review of incomplete cytoreductions (R2b, R2c) for appendiceal and colorectal primaries. Primary endpoints were overall survival (OS) and progression‐free survival (PFS). Subgroup analysis for primary etiology and specific cytoreductive score.ResultsA total of 121 cases of incomplete CRS, 74 CRS alone, and 47 CRS‐HIPEC. For the entire study group there was a survival benefit with HIPEC. OS and PFS were 2.3 versus 1.4 (p = 0.001) and 1.6 versus 0.7 (p < 0.0001) respectively for cases with and without HIPEC. Subgroup analysis of appendiceal neoplasms, 43 CRS‐HIPEC and 50 CRS alone, found HIPEC benefit persisted; OS and PFS were 2.4 versus 1.5 (p = 0.016) and 1.7 versus 0.8 (p < 0.0001), respectively for cases with and without HIPEC. Benefit most pronounced in low‐grade cases with doubling of the OS and PFS (p = 0.004). With colorectal primary cases, 10 CRS‐HIPEC and 18 CRS alone, no difference in OS and PFS. When stratifying out by cytoreduction scores, R2b and R2c, HIPEC only provided a benefit for R2b cases; OS and PFS for R2b cases were 2.28 versus 1.01 (p = 0.011) and 1.67 versus 0.75 (p = 0.001), respectively for cases with and without HIPEC.ConclusionHIPEC has utility for incomplete cytoreductions with appendiceal neoplasms, greatest effect with low‐grade appendiceal neoplasms. HIPEC is only beneficial for near optimal cytoreductions (R2b).
Strategies to Develop Potent Oncolytic Viruses and Enhance Their Therapeutic Efficacy
Despite advancements in cancer therapy that have occurred over the past several decades, successful treatment of advanced malignancies remains elusive. Substantial resources and significant efforts have been directed toward the development of novel therapeutic modalities to improve patient outcomes. Oncolytic viruses (OVs) are emerging tools with unique characteristics that have attracted great interest in developing effective anticancer treatment. The original attraction was directed toward selective replication and cell-specific toxicity, two unique features that are either inherent to the virus or could be conferred by genetic engineering. However, recent advancements in the knowledge and understanding of OVs are shifting the therapeutic paradigm toward a greater focus on their immunomodulatory role. Nonetheless, there are still significant obstacles that remain to be overcome to enhance the efficiency of OVs as effective therapeutic modalities and potentially establish them as part of standard treatment regimens. In this review, we discuss advances in the design of OVs, strategies to enhance their therapeutic efficacy, functional translation into the clinical settings, and various obstacles that are still encountered in the efforts to establish them as effective anticancer treatments.