Risk Factors and Outcomes of Early Relapse After Curative Resection of Intrahepatic Cholangiocarcinoma

Prognostic factors associated with early recurrence following liver resection for colorectal liver metastases: a systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) is the 3rd most common malignancy with the liver being the most common site of metastases. The recurrence rate of colorectal liver metastases (CRLM) after liver resection (LR) is notably high, with an estimated 40% of patients experiencing recurrence within 6 months. In this context, we conducted a meta-analysis to synthesize and evaluate the reliability of evidence pertaining to prognostic factors associated with early recurrence (ER) in CRLM following LR.

METHODS

Systematic searches were conducted from the inception of databases to July 14, 2023, to identify studies reporting prognostic factors associated with ER. The Quality in Prognostic Factor Studies (QUIPS) tool was employed to assess risk-of-bias for included studies. Meta-analysis was then performed on these prognostic factors, summarized by forest plots. The grading of evidence was based on sample size, heterogeneity, and Egger's P value.

RESULTS

The study included 24 investigations, comprising 12705 individuals, during an accrual period that extended from 2007 to 2023. In the evaluation of risk-of-bias, 22 studies were rated as low/moderate risk, while two studies were excluded because of high risk. Most of the studies used a postoperative interval of 6 months to define ER, with 30.2% (95% confidence interval [CI], 24.1-36.4%) of the patients experiencing ER following LR. 21 studies were pooled for meta-analysis. High-quality evidence showed that poor differentiation of CRC, larger and bilobar-distributed liver metastases, major hepatectomy, positive surgical margins, and postoperative complications were associated with an elevated risk of ER. Additionally, moderate-quality evidence suggested that elevated levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA199), lymph node metastases (LNM) of CRC, and a higher number of liver metastases were risk factors for ER.

CONCLUSION

This review has the potential to enhance the efficacy of surveillance strategies, refine prognostic assessments, and guide judicious treatment decisions for CRLM patients with high risk of ER. Additionally, it is essential to undertake well-designed prospective investigations to examine additional prognostic factors and develop salvage therapeutic approaches for ER of CRLM.

Outcomes of liver resection in hepatitis C virus-related intrahepatic cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND

Cholangiocarcinoma is the second most common primary liver malignancy. Its incidence and mortality rates have been increasing in recent years. Hepatitis C virus (HCV) infection is a risk factor for development of cirrhosis and cholangiocarcinoma. Currently, surgical resection remains the only curative treatment option for cholangiocarcinoma. We aim to study the impact of HCV infection on outcomes of liver resection (LR) in intrahepatic cholangiocarcinoma (ICC).

AIM

To study the outcomes of curative resection of ICC in patients with HCV (i.e., HCV+) compared to patients without HCV (i.e., HCV-).

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies to assess the outcomes of LR in ICC in HCV+ patients compared to HCV- patients in tertiary care hospitals. PubMed, EMBASE, The Cochrane Library and Scopus were systematically searched from inception till August 2023. Included studies were RCTs and non-RCTs on patients ≥ 18 years old with a diagnosis of ICC who underwent LR, and compared outcomes between patients with HCV+ vs HCV-. The primary outcomes were overall survival (OS) and recurrence-free survival. Secondary outcomes include perioperative mortality, operation duration, blood loss, intrahepatic and extrahepatic recurrence.

RESULTS

Seven articles, published between 2004 and 2021, fulfilled the selection criteria. All of the studies were retrospective studies. Age, incidence of male patients, albumin, bilirubin, platelets, tumor size, incidence of multiple tumors, vascular invasion, bile duct invasion, lymph node metastases, and stage 4 disease were comparable between HCV+ and HCV- group. Alanine transaminase [MD 22.20, 95%confidence interval (CI): 13.75, 30.65, P < 0.00001] and aspartate transaminase levels (MD 27.27, 95%CI: 20.20, 34.34, P < 0.00001) were significantly higher in HCV+ group compared to HCV- group. Incidence of cirrhosis was significantly higher in HCV+ group [odds ratio (OR) 5.78, 95%CI: 1.38, 24.14, P = 0.02] compared to HCV- group. Incidence of poorly differentiated disease was significantly higher in HCV+ group (OR 2.55, 95%CI: 1.34, 4.82, P = 0.004) compared to HCV- group. Incidence of simultaneous hepatocellular carcinoma lesions was significantly higher in HCV+ group (OR 8.31, 95%CI: 2.36, 29.26, P = 0.001) compared to HCV- group. OS was significantly worse in the HCV+ group (hazard ratio 2.05, 95%CI: 1.46, 2.88, P < 0.0001) compared to HCV- group.

CONCLUSION

This meta-analysis demonstrated significantly worse OS in HCV+ patients with ICC who underwent curative resection compared to HCV- patients.

Prognostic Value of Systemic Immune-Inflammation Index-Based Nomogram in Patients with Extrahepatic Cholangiocarcinoma Treated by Percutaneous Transhepatic Biliary Stenting Combined with 125I Seed Intracavitary Irradiation

Purpose

This study aimed to investigate the prognostic value of systemic immune-inflammation index (SII) in patients with extrahepatic cholangiocarcinoma (EHCC) treated by percutaneous transhepatic biliary stenting (PTBS) combined with 125I seed intracavitary irradiation and further develop a predictive model related to SII.

Methods

A total of 145 patients with EHCC who received PTBS combined with 125I seed implantation were retrospectively analyzed. The optimal cut-off value of SII was identified by receiver operating characteristic (ROC) curve analysis. Kaplan-Meier curves and Cox regression were applied to estimate the prognostic value of SII and identify other significant factors of overall survival (OS). Additionally, a novel nomogram was constructed. The concordance index (C-index), calibration plots and decision curve analysis were used to evaluate the performance of the nomogram model.

Results

The optimal cut-off value for preoperative SII of 890.2 stratified the patients into High-SII (H-SII) and Low-SII (L-SII) groups. Univariate and multivariate analyses demonstrated that SII was an independent factor for OS. We also found that better therapeutic effect could be obtained with combined postoperative chemotherapy (P < 0.001). Moreover, we revealed that elevated preoperative CA19-9 (P = 0.038) and TBIL level (P = 0.024) were reason for poor prognosis of EHCC. A well-discriminated and calibrated nomogram was developed to predict the 1-year and 2-year OS of EHCC (C-index: 0.709).

Conclusion

The SII may be a feasible and convenient prognosis predictor for EHCC. The comprehensive nomogram based on SII presented in this study is a promising model for predicting OS in EHCC patients after PTBS combined with 125I seed intracavitary irradiation.

Current Role and Future Perspectives of Immunotherapy and Circulating Factors in Treatment of Biliary Tract Cancers

Biliary tract cancers (BTCs) are a heterogenous group of malignancies arising from the epithelial cells of the biliary tree and the gallbladder. They are often locally advanced or already metastatic at the time of the diagnosis and therefore prognosis remains dismal. Unfortunately, the management of BTCs has been limited by resistance and consequent low response rate to cytotoxic systemic therapy. New therapeutic approaches are needed to improve the survival outcomes for these patients. Immunotherapy, one of the newest therapeutic options, is changing the approach to the oncological treatment. Immune checkpoint inhibitors are by far the most promising group of immunotherapeutic agents: they work by blocking the tumor-induced inhibition of the immune cellular response. Immunotherapy in BTCs is currently approved as second-line treatment for patients whose tumors have a peculiar molecular profile, such as high levels of microsatellites instability, PD-L1 overexpression, or high levels of tumor mutational burden. However, emerging data from ongoing clinical trials seem to suggest that durable responses can be achieved in other subsets of patients. The BTCs are characterized by a highly desmoplastic microenvironment that fuels the growth of cancer tissue, but tissue biopsies are often difficult to obtain or not feasible in BTCs. Recent studies have hence proposed to use liquid biopsy approaches to search the blood circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA) to use as biomarkers in BTCs. So far studies are insufficient to promote their use in clinical management, however trials are still in progress with promising preliminary results. Analysis of blood samples for ctDNA to research possible tumor-specific genetic or epigenetic alterations that could be linked to treatment response or prognosis was already feasible. Although there are still few data available, ctDNA analysis in BTC is fast, non-invasive, and could also represent a way to diagnose BTC earlier and monitor tumor response to chemotherapy. The prognostic capabilities of soluble factors in BTC are not yet precisely determined and more studies are needed. In this review, we will discuss the different approaches to immunotherapy and tumor circulating factors, the progress that has been made so far, and the possible future developments.

Lymphocyte-to-Monocyte Ratio and Clinical Outcomes in Cholangiocarcinoma: A Systematic Review and Meta-Analysis

Lymphocyte-to-Monocyte ratio (LMR) has shown an association with survival outcomes in several oncological diseases. This study aimed to evaluate the association between LMR and clinical outcomes for cholangiocarcinoma patients. A systematic review and meta-analysis were performed to assess the association between LMR values and overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS) and time to recurrence (TTR) in cholangiocarcinoma patients. We used Hazard ratio (HR) and their 95% confidence interval (CI) as a measure of effect for the random effect model meta-analysis. The Newcastle-Ottawa Scale was used for quality assessment. The Egger test and funnel plot were developed for approaching publication bias. A total of 19 studies were included in this study (n = 3860). The meta-analysis showed that cholangiocarcinoma patients with low values of LMR were associated with worse OS (HR: 0.82; 95% CI: 0.71-0.96; I2 = 86%) and worse TTR (HR: 0.71; 95% CI: 0.58-0.86; I2 = 0%). DFS and RFS also were evaluated; however, they did not show statistically significant associations. Low LMR values were associated with a worse OS and TTR.

Association between Metabolic Disorders and Cholangiocarcinoma: Impact of a Postulated Risk Factor with Rising Incidence

Introduction and objectives: The incidence of cholangiocarcinoma (CCA) has been increasing globally. Although a concomitant increase in the incidence of metabolic disorders might suggest a causal relationship, the data are scarce. We aimed to describe the prevalence of metabolic disorders in patients with CCA and report the clinical features and outcomes. Patients and Methods: Retrospective study including patients with CCA. Patients were divided into: (1) past history of diabetes or/and overweight/obesity (“metabolic disorder group”) and (2) without any of these features (“non-metabolic-disorder group”). A Cox regression model was used to determine the prognostic factors. Results: 122 patients were included. In total, 36 (29.5%) had overweight/obesity, 24 (19.7%) had diabetes, and 8 (6.6%) had both. A total of 29 (23.8%) patients had resectable disease and received upfront surgery. A total of 104 (85.2%) received chemotherapy for advanced/recurrent disease. The overall survival of the cohort was 14.3 months (95% CI: 10.1−17.3). ECOG-PS 0 (p < 0.0001), resectable disease (p = 0.018) and absence of vascular invasion (p = 0.048) were independently associated with better prognosis. The “metabolic disorder group” (n = 52) had a median survival of 15.5 months (95% CI 10.9−33.9) vs. 11.5 months (95% CI 8.4−16.5) in the “non-metabolic-disorder group” (n = 70) (HR: 1.10; 95% CI 0.62−1.94). Patients with resectable disease in the “metabolic group” had longer survival than patients in the “non-metabolic group” (43.4 months (95% CI 33.9-NR) vs. 21.8 months (95% CI 8.6−26.9); HR = 0.12, 95% CI 0.03−0.59). Conclusion: Metabolic disorders are frequent among CCA patients. Underlying metabolic comorbidities may be associated with prognosis in resectable CCA. There is a need to explore the mechanism that drives CCA carcinogenesis in a metabolic background.

A blood-based noninvasive miRNA signature for predicting survival outcomes in patients with intrahepatic cholangiocarcinoma

BACKGROUND

The prognosis in patients with intrahepatic cholangiocarcinoma (ICC) is generally poor. To improve treatment selection, we sought to identify microRNA (miRNA) signature associated with survival outcomes in ICC.

METHODS

We first analysed the miRNA expression profiles of primary ICC from two public datasets to identify a miRNA panel to detect patients for short-term survival. We then analysed 309 specimens, including 241 FFPE samples from two clinical cohorts (training: n = 177; validation: n = 64) and matched plasma samples (n = 68), and developed a risk-stratification model incorporating the panel and CA 19-9 levels to predict survival outcomes in ICC.

RESULTS

We identified a 7-miRNA panel that robustly classified patients with poor outcomes in the discovery cohorts (AUC = 0.80 and 0.88, respectively). We subsequently trained this miRNA panel in a clinical cohort (AUC = 0.83) and evaluated its performance in an independent validation cohort (AUC = 0.82) and plasma samples from the additional validation cohort (AUC = 0.78). Patients in both clinical cohorts who were classified as high-risk had significantly worse prognosis (p < 0.01). The risk-stratification model demonstrated superior performance compared to models (AUC = 0.85).

CONCLUSIONS

We established a novel miRNA signature that could robustly predict survival outcomes in resected tissues and liquid biopsies to improve the clinical management of patients with ICC.

Clinical online nomogram for predicting prognosis in recurrent hepatolithiasis after biliary surgery: A multicenter, retrospective study

BACKGROUND

Methods for predicting the prognosis of patients undergoing surgery for recurrent hepatolithiasis after biliary surgery are currently lacking.

AIM

To establish a nomogram to predict the prognosis of patients with recurrent hepatolithiasis after biliary surgery.

METHODS

In this multicenter, retrospective study, data of consecutive patients in four large medical centers who underwent surgery for recurrent hepatolithiasis after biliary surgery were retrospectively analyzed. We constructed a nomogram to predict the prognosis of recurrent hepatolithiasis in a training cohort of 299 patients, following which we independently tested the nomogram in an external validation cohort of 142 patients. Finally, we used the concordance index (C-index), calibra-tion, area under curve, decision curve analysis, clinical impact curves, and visual fit indices to evaluate the accuracy of the nomogram.

RESULTS

Multiple previous surgeries [2 surgeries: Odds ratio (95% confidence interval), 1.451 (0.719-2.932); 3 surgeries: 4.573 (2.015-10.378); ≥ 4 surgeries: 5.741 (1.347-24.470)], bilateral hepatolithiasis [1.965 (1.039-3.717)], absence of immediate clearance [2.398 (1.304-4.409)], neutrophil-to-lymphocyte ratio ≥ 2.462 [1.915 (1.099-3.337)], and albumin-to-globulin ratio ≤ 1.5 [1.949 (1.056-3.595)] were found to be independent factors influencing the prognosis. The nomogram constructed on the basis of these variables showed good reliability in the training (C-index: 0.748) and validation (C-index: 0.743) cohorts. Compared with predictions using traditional classification models, those using our nomogram showed better agreement with actual observations in the calibration curve for the probability of endpoints and the receiver operating characteristic curve. Dichloroacetate and clinical impact curves showed a larger net benefit of the nomogram.

CONCLUSION

The nomogram developed in this study demonstrated superior performance and discriminative power compared to the three traditional classifications. It is easy to use, highly accurate, and shows excellent calibration.

A Nomogram in Predicting Risks of Intrahepatic Cholangiocarcinoma After Partial Hepatectomy for Hepatolithiasis

BACKGROUND

Hepatolithiasis is associated with the development of intrahepatic cholangiocarcinoma (ICC). This study sought to investigate risk factors of ICC for hepatolithiasis after partial hepatectomy (PH) and to develop a model for predicting ICC risk.

METHODS

Data on consecutive patients who underwent PH for hepatolithiasis at the Eastern Hepatobiliary Surgery Hospital between January 2009 and December 2011 were reviewed. Independent risk factors of ICC identified by Cox regression model were used to develop a nomogram in predicting ICC after PH for hepatolithiasis.

RESULTS

Of 2056 patients, 168 developed ICC at a median follow-up of 7.2 years. The cumulative incidences of ICC at 3, 5, and 8 years after PH for hepatolithiasis were 3.0%, 6.5%, and 12.9%, respectively. Independent risk factors of ICC were identified to be a long duration of hepatolithiasis-related symptoms (hazard ratio, 1.088 [95% confidence interval, 1.057-1.120]), metabolic syndrome (2.036 [1.210-3.425]), a high neutrophil-to-lymphocyte ratio (1.250 [1.009-2.816] for 3-5 vs ≤3; 1.538 [1.048-2.069] for ≥5 vs ≤3), hepatic atrophy (1.711 [1.189-2.462]), segmental intensity differences (1.513 [1.052-2.176]), persistent biliary strictures (2.825 [1.480-5.391]), and residual stone disease (2.293 [1.511-3.481]). By incorporating these factors, a constructed nomogram showed a concordance index of 0.721 to predict ICC. The calibration plots demonstrated good agreement between observed and predicted morbidities. The optimal cutoff point for the nomogram was 48 in differentiating between high and low-risk of ICC.

CONCLUSIONS

A nomogram for predicting ICC after PH for hepatolithiasis was constructed based on risk factors of developing ICC. Patients with a nomogram point of ≥48 were predicted to have a high risk of ICC.

Integration of global metabolomics and lipidomics approaches reveals the molecular mechanisms and the potential biomarkers for postoperative recurrence in early-stage cholangiocarcinoma

Background

Cholangiocarcioma (CCA) treatment is challenging because most of the patients are diagnosed when the disease is advanced, and cancer recurrence is the main problem after treatment, leading to low survival rates. Therefore, our understanding of the mechanism underlying CCA recurrence is essential in order to prevent CCA recurrence and improve patient outcomes.

Methods

We performed ¹H-NMR and UPLC-MS-based metabolomics on the CCA serum. The differential metabolites were further analyzed using pathway analysis and potential biomarker identification.

Results

At an early stage, the metabolites involved in energy metabolisms, such as pyruvate metabolism, and the TCA cycle, are downregulated, while most lipids, including TGs, PCs, PEs, and PAs, are upregulated in recurrence patients. This metabolic feature has been described in cancer stem-like cell (CSC) metabolism. In addition, the CSC markers CD44v6 and CD44v8-10 are associated with CD36 (a protein involved in lipid uptake) as well as with recurrence-free survival. We also found that citrate, sarcosine, succinate, creatine, creatinine and pyruvate, and TGs have good predictive values for CCA recurrence.

Conclusion

Our study demonstrates the possible molecular mechanisms underlying CCA recurrence, and these may associate with the existence of CSCs. The metabolic change involved in the recurrence pathway might be used to determine biomarkers for predicting CCA recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40170-021-00266-5.

Integrating intratumoral and peritumoral features to predict tumor recurrence in intrahepatic cholangiocarcinoma

Previous studies have suggested that the intratumoral texture features may reflect the tumor recurrence risk in intrahepatic cholangiocarcinoma (ICC). The peritumoral features may be associated with the distribution of microsatellites. Therefore, integrating the imaging features based on intratumoral and peritumoral areas may provide more accurate predictions in tumor recurrence (both early and late recurrences) than the predictions conducted based on the intratumoral area only. This retrospective study included 209 ICC patients. We divided the patient population into two sub-groups according to the order of diagnosis time: a training cohort (159 patients) and an independent validation cohort (50 patients). The MR imaging features were quantified based on the intratumoral and peritumoral (3 and 5 mm) areas. The radiomics signatures, clinical factor-based models and combined radiomics-clinical models were developed to predict the tumor recurrence. The prediction performance was measured based on the validation cohort using the area under receiver operating characteristic curve (AUC) index. For the prediction of early recurrence, the combined radiomics-clinical model of intratumoral area with 5 mm peritumoral area showed the highest performance (0.852(95% confidence interval (CI), 0.724-0.937)). The AUC for the clinical factor-based model was 0.805(95%CI, 0.668-0.903). For the prediction of late recurrence, the radiomics signature of intratumoral area with 5 mm peritumoral area had the optimal performance with an AUC of 0.735(95%CI, 0.591-0.850). The clinical factor-based showed inferior performance (0.598(95%CI, 0.450-0.735)). For both early and late recurrences prediction, the optimal models were all constructed using imaging features extracted based on intratumoral and peritumoral areas together. These suggested the importance of involving the intratumoral and peritumoral areas in the radiomics studies.

Preoperative CA19-9: a competitive predictor of recurrence in patients with colorectal cancer liver metastases after hepatectomy

PURPOSE

The role of preoperative carbohydrate antigen 19-9 (CA19-9) in colorectal cancer liver metastases (CRLM) patients is still unclear. The present study aimed to explore the prognostic significance of preoperative CA19-9 in those patients.

METHODS

A total of 691 CRLM patients were included in this study. X-tile analyses were performed to determine the optimal cut-off values of CA19-9 and carcinoembryonic antigen (CEA). Prognostic predictors were identified by multivariate analyses.

RESULTS

The optimal cut-off values of CA19-9 and CEA for 5-year recurrence-free survival (RFS) were 35.24 U/ml and 20.4 ng/ml, respectively. Patients with high-level CA19-9 had significantly worse RFS and overall survival (OS) than those with low-level CA19-9 (P = 0.001 and P = 0.002, respectively). In addition, patients with high-level CA19-9 had poor RFS and OS (P = 0.028 and P = 0.011, respectively) at low-level CEA. Multivariate analyses confirmed that preoperative CA19-9 was an independent predictor for RFS (hazard ratio [HR] 1.295; 95% confidence interval [CI] 1.043-1.607; P = 0.019) but not for OS (HR 1.213; 95% CI 0.902-1.631; P = 0.201).

CONCLUSION

CA19-9 is a promising predictor of recurrence for CRLM patients undergoing hepatectomy, and an effective supplement for patients with low-level CEA.

Immunotherapy in Advanced Biliary Tract Cancers

Biliary tract cancers are rare tumors with a poor prognosis. Two-thirds of these primary liver malignancies are diagnosed at advanced stages where therapeutic options are limited. Whereas several molecular targeted therapies emerge in biliary tract cancers, immunotherapy is still investigational, the only approved immunotherapy to date being the immune checkpoint inhibitor pembrolizumab for the small fraction of patients with microsatellite-instable tumors. In microsatellite-stable, pre-treated biliary tract cancers, single-agent immune checkpoint blockade has a limited albeit often long-lasting clinical activity in a still ill-defined subgroup of patients. The identification of predictive biomarkers will allow a better selection of patients that may benefit from immunotherapy. Combinations of immunotherapies with each other, with chemotherapy or targeted molecular therapies are being investigated in early lines of therapy, including first-line.

Molecular Profiling and Targeted Therapy in Cholangiocarcinoma: An Observational, Retrospective Multicenter Study

PURPOSE

Cholangiocarcinoma (CCA) is an aggressive biliary tract malignancy and overall prognosis remains poor, with a median survival of less than 24 months. Sequencing studies have revealed a high prevalence of genomic alterations in CCA, with multiple potential therapeutic targets. Next-generation sequencing (NGS) can identify actionable mutations such as FGFR, IDH, BRAF, ERBB2, ROS1, or microsatellite instability (MSI-H), among others.

METHODS

We conducted a retrospective multicenter study in Spain in 2019. Thirty consecutive patients from 15 centers were included. All patients were diagnosed with advanced CCA and underwent NGS (FoundationOne®) in 2019. Twenty-four patients underwent tissue-based NGS (FoundationOne® CDx), and 6 patients underwent blood-based NGS (FoundationOne®Liquid) with sequencing panels of 324 and 70 genes, respectively RESULTS: We identified 12 patients (40%) with an actionable genetic alteration in tissue: 2 FGFR2 fusions, 6 IDH1 mutations, 1 ERBB2 mutation, 1 ROS1 fusion, 1 PIK3CA mutation, and 1 MSI-H.

CONCLUSION

Comprehensive genomic profiling (CGP) in cholangiocarcinoma can identify, in a high proportion of patients, clinically relevant genomic alterations that can lead to targeted therapies, expanding treatment options.

Neoadjuvant Immunotherapy for High-Risk, Resectable Malignancies: Scientific Rationale and Clinical Challenges

Neoadjuvant immunotherapy involves administering immune checkpoint inhibitors before surgical resection in high-risk resectable disease. This strategy was shown to have a high pathological response rate and prolonged relapse-free survival in randomized trials in melanoma, glioblastoma, and colon cancer with small numbers of patients. In resectable cancers, immune checkpoint inhibitors such as anti-programmed cell death-1 (PD1) and anti-cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) can enhance antitumor immunity by activating antigen-specific T cells found in the primary tumor. These tumor-reactive T cells continue to exert antitumor effects on remaining neoplastic cells after the resection of the primary tumor, potentially preventing relapses from occurring. Based on the scientific rationale and early clinical observations with surrogate survival endpoints, neoadjuvant immunotherapy may provide an effective alternative to other therapeutic strategies such as adjuvant treatment. However, this can be determined only by conducting randomized controlled trials comparing neoadjuvant immunotherapy with the current standard of care for each tumor site. This review discusses the cellular mechanisms that occur during successful neoadjuvant immunotherapy and highlights the clinical data from the available human studies that support the preclinical mechanistic data. Here we also discuss strategies required for successful neoadjuvant immunotherapy, including combination treatment strategies and resistance mechanisms to neoadjuvant treatment.