Importance of histological tumor response assessment in predicting the outcome in patients with colorectal liver metastases treated with neo-adjuvant chemotherapy followed by liver surgery

Modified scoring system for the quantitative assessment of histological regression in peritoneal carcinomatosis after pressurized intraperitoneal aerosol chemotherapy: A pilot study

Peritoneal carcinomatosis is one of the leading causes of death in patients with gastrointestinal cancer. Newer locoregional treatment concepts include pressurized intraperitoneal aerosol chemotherapy (PIPAC), the regional application of pressurized chemotherapeutic agents to the abdominal cavity, which is usually performed every 4 to 8 weeks. One of the main challenges of PIPAC therapy remains the objective assessment of treatment response. The present study describes a new scoring system to histologically assess the regression of peritoneal cancer following PIPAC therapy, quantitative assessment of histological regression in peritoneal carcinomatosis (QARP). Peritoneal biopsies from 27 patients with peritoneal metastases undergoing PIPAC were obtained and processed in a standardized fashion. Biopsies were scored according to the QARP grading system. The five-tiered system was graded as follows, Grade 0, no residual tumor cells with regressive changes present; grade 1, 1-25% viable tumor cells per tumor focus with regressive changes present; grade 2, 26-50% viable tumor cells per tumor focus with regressive changes present; grade 3, 51-75% viable tumor cells per tumor focus with few regressive changes; grade 4, >75% viable tumor cells per tumor focus with minimal or no regressive changes. Based on the new grading system, the study cohort was divided into QARP responders and QARP non-responders following PIPAC treatment. Higher QARP scores were significantly correlated with higher PCI scores (r=0.32; P=0.007). However, no difference in overall survival was detected between QARP responders and QARP non-responders. Further studies are required to ascertain the reproducibility and prognostic significance of QARP.

Adjuvant chemotherapy is associated with better oncological outcomes after ALPPS for colorectal liver metastases

ALPPS enables complete tumor resection in a shorter interval and a larger number of patients than classic two-stage hepatectomies. However, there is little evidence regarding long-term outcomes in patients with colorectal liver metastases (CLM). This study aims to evaluate the short and long-term outcomes of ALPPS in patients with CRM. Single-cohort, prospective, observational study. Patients with unresectable CLM due to insufficient liver remnant who underwent ALPPS between June 2011 and June 2021 were included. Of 32 patients treated, 21 were male (66%) and the median age was 56 years (range = 29-81). Both stages were completed in 30 patients (93.7%), with an R0 rate of 75% (24/32). Major morbidity was 37.5% and the mortality nil. Median overall survival (OS) and recurrence-free survival (RFS) were 28.1 and 8.8 months, respectively. The 1-3, and 5-year OS was 86%, 45%, and 21%, and RFS was 42%, 14%, and 14%, respectively. The only independent risk factor associated with poor RFS (5.7 vs 11.6 months; p = 0.038) and OS (15 vs 37 months; p = 0.009) was not receiving adjuvant chemotherapy. KRAS mutation was associated with worse OS from disease diagnosis (24.3 vs. 38.9 months; p = 0.025). ALPPS is associated with favorable oncological outcomes, comparable to traditional strategies to increase resectability in patients with CLM and high tumor burden. Our results suggest for the first time that adjuvant chemotherapy is independently associated with better short- and long-term outcomes after ALPPS. Selection of patients with KRAS mutations should be performed with caution, as this could affect oncological outcomes.

Pre-hepatectomy dynamic circulating tumor DNA to predict pathologic response to preoperative chemotherapy and post-hepatectomy recurrence in patients with colorectal liver metastases

OBJECTIVE

To evaluate the predictive value of pre-hepatectomy dynamic circulating tumor DNA (ctDNA) on pathologic response to preoperative chemotherapy and recurrence after liver resection for colorectal liver metastases (CRLM).

BACKGROUND

Pathologic response is a predictor of clinical outcomes for patients undergoing hepatectomy for CRLM. Postoperative ctDNA has been proven to be sensitive for recurrence detection. However, few studies investigate the impact of pre-hepatectomy ctDNA on pathologic response and recurrence.

METHODS

Patients with potential resectable CRLM underwent preoperative chemotherapy and hepatectomy between 2018 and 2021 was considered for inclusion. Plasma ctDNA was collected before and after preoperative chemotherapy. Pathologic response was analyzed for all patients after liver resection. Recurrence free survival was compared between patients with different ctDNA status and different pathologic response. The relation between ctDNA and pathologic response was also analyzed.

RESULTS

A total of 114 patients were included. ctDNA was detectable in 108 of 114 patients (94.7%) before chemotherapy, in 56 of 114 patients (49.1%) after chemotherapy. Patients with ctDNA positive at baseline and negative after chemotherapy had significantly longer RFS (median RFS 17 vs 7 months, p = 0.001) and HRFS (median HRFS unreached vs 8 months, p < 0.001) than those with ctDNA persistently positive after chemotherapy. Two patients (1.6%) had a pathologic complete response and 56 patients (45.2%) had a pathologic major response. Post-chemotherapy ctDNA- was associated with improved major pathologic response (53.4% vs 32.1%, p = 0.011). In the multivariable analysis, ctDNA- after chemotherapy (HR 0.51, 95% CI 0.28-0.93), major pathologic response (HR 0.34, 95% CI 0.19-0.62) and surgery combined with radiofrequency ablation (HR 2.62, 95% CI 1.38-5.00) were independently associated with RFS (all p < 0.05).

CONCLUSIONS

Pre-hepatectomy dynamic monitoring of ctDNA could predict pathologic response to preoperative chemotherapy and post-hepatectomy recurrence in CRLM patients. Negative ctDNA after preoperative chemotherapy was associated with better tumor regression grade and recurrence-free survival, which might be used to guide pre-hepatectomy chemotherapy and predict prognosis.

Mechanisms of metastatic colorectal cancer

Despite extensive research and improvements in understanding colorectal cancer (CRC), its metastatic form continues to pose a substantial challenge, primarily owing to limited therapeutic options and a poor prognosis. This Review addresses the emerging focus on metastatic CRC (mCRC), which has historically been under-studied compared with primary CRC despite its lethality. We delve into two crucial aspects: the molecular and cellular determinants facilitating CRC metastasis and the principles guiding the evolution of metastatic disease. Initially, we examine the genetic alterations integral to CRC metastasis, connecting them to clinically marked characteristics of advanced CRC. Subsequently, we scrutinize the role of cellular heterogeneity and plasticity in metastatic spread and therapy resistance. Finally, we explore how the tumour microenvironment influences metastatic disease, emphasizing the effect of stromal gene programmes and the immune context. The ongoing research in these fields holds immense importance, as its future implications are projected to revolutionize the treatment of patients with mCRC, hopefully offering a promising outlook for their survival.

Preoperative MRI radiomic analysis for predicting local tumor progression in colorectal liver metastases before microwave ablation

PURPOSE

Radiomics may aid in predicting prognosis in patients with colorectal liver metastases (CLM). Consistent data is available on CT, yet limited data is available on MRI. This study assesses the capability of MRI-derived radiomic features (RFs) to predict local tumor progression-free survival (LTPFS) in patients with CLMs treated with microwave ablation (MWA).

METHODS

All CLM patients with pre-operative Gadoxetic acid-MRI treated with MWA in a single institution between September 2015 and February 2022 were evaluated. Pre-procedural information was retrieved retrospectively. Two observers manually segmented CLMs on T2 and T1-Hepatobiliary phase (T1-HBP) scans. After inter-observer variability testing, 148/182 RFs showed robustness on T1-HBP, and 141/182 on T2 (ICC > 0.7).Cox multivariate analysis was run to establish clinical (CLIN-mod), radiomic (RAD-T1, RAD-T2), and combined (COMB-T1, COMB-T2) models for LTPFS prediction.

RESULTS

Seventy-six CLMs (43 patients) were assessed. Median follow-up was 14 months. LTP occurred in 19 lesions (25%).CLIN-mod was composed of minimal ablation margins (MAMs), intra-segment progression and primary tumor grade and exhibited moderately high discriminatory power in predicting LTPFS (AUC = 0.89, p = 0.0001). Both RAD-T1 and RAD-T2 were able to predict LTPFS: (RAD-T1: AUC = 0.83, p = 0.0003; RAD-T2: AUC = 0.79, p = 0.001). Combined models yielded the strongest performance (COMB-T1: AUC = 0.98, p = 0.0001; COMB-T2: AUC = 0.95, p = 0.0003). Both combined models included MAMs and tumor regression grade; COMB-T1 also featured 10th percentile of signal intensity, while tumor flatness was present in COMB-T2.

CONCLUSION

MRI-based radiomic evaluation of CLMs is feasible and potentially useful for LTP prediction. Combined models outperformed clinical or radiomic models alone for LTPFS prediction.

Preoperative chemotherapy in upfront resectable colorectal liver metastases: New elements for an old dilemma?

The use of preoperative or "neoadjuvant" chemotherapy (NAC) has long been controversial for resectable colorectal liver metastases (CRLM). The European Society of Medical Oncology (ESMO) 2023 guidelines on metastatic colorectal cancer (CRC) indicate a combination of surgical/technical and oncologic/prognostic criteria as the two determinants for allocating patients to NAC or upfront hepatectomy. However, surgical and technical criteria have evolved, and oncologic prognostic criteria date from the pre-modern chemotherapy era and lack prospective validation. The traditional literature is interpreted as not supporting the use of NAC because several studies fail to demonstrate a benefit in overall survival (OS) compared to upfront surgery; however, OS may not be the most appropriate endpoint to consider. Moreover, the commonly quoted studies against NAC contain many limitations that may explain why NAC failed to demonstrate its value. The query of the recent literature focused primarily on other aspects than OS, such as surgical technique, the impact of side effects of chemotherapy, the histological growth pattern of metastases, or the detection of circulating tumor DNA, shows data that support a more widespread use of NAC. These should prompt a critical reappraisal of the use of NAC, leading to a more precise selection of patients who could benefit from it.

Prediction of Clinical Precision Chemotherapy by Patient-Derived 3D Bioprinting Models of Colorectal Cancer and Its Liver Metastases

Methods accurately predicting the responses of colorectal cancer (CRC) and colorectal cancer liver metastasis (CRLM) to personalized chemotherapy remain limited due to tumor heterogeneity. This study introduces an innovative patient-derived CRC and CRLM tumor model for preclinical investigation, utilizing 3d-bioprinting (3DP) technology. Efficient construction of homogeneous in vitro 3D models of CRC/CRLM is achieved through the application of patient-derived primary tumor cells and 3D bioprinting with bioink. Genomic and histological analyses affirm that the CRC/CRLM 3DP tumor models effectively retain parental tumor biomarkers and mutation profiles. In vitro tests evaluating chemotherapeutic drug sensitivities reveal substantial tumor heterogeneity in chemotherapy responses within the 3DP CRC/CRLM models. Furthermore, a robust correlation is evident between the drug response in the CRLM 3DP model and the clinical outcomes of neoadjuvant chemotherapy. These findings imply a significant potential for the application of patient-derived 3DP cancer models in precision chemotherapy prediction and preclinical research for CRC/CRLM.

Histopathological growth patterns and tumor-infiltrating lymphocytes in breast cancer liver metastases

Liver is the third most common organ for breast cancer (BC) metastasis. Two main histopathological growth patterns (HGP) exist in liver metastases (LM): desmoplastic and replacement. Although a reduced immunotherapy efficacy is reported in patients with LM, tumor-infiltrating lymphocytes (TIL) have not yet been investigated in BCLM. Here, we evaluate the distribution of the HGP and TIL in BCLM, and their association with clinicopathological variables and survival. We collect samples from surgically resected BCLM (n = 133 patients, 568 H&E sections) and post-mortem derived BCLM (n = 23 patients, 97 H&E sections). HGP is assessed as the proportion of tumor liver interface and categorized as pure-replacement ('pure r-HGP') or any-desmoplastic ('any d-HGP'). We score the TIL according to LM-specific guidelines. Associations with progression-free (PFS) and overall survival (OS) are assessed using Cox regressions. We observe a higher prevalence of 'any d-HGP' (56%) in the surgical samples and a higher prevalence of 'pure r-HGP' (83%) in the post-mortem samples. In the surgical cohort, no evidence of the association between HGP and clinicopathological characteristics is observed except with the laterality of the primary tumor (p value = 0.049) and the systemic preoperative treatment before liver surgery (p value = .039). TIL is less prevalent in 'pure r-HGP' as compared to 'any d-HGP' (p value = 0.001). 'Pure r-HGP' predicts worse PFS (HR: 2.65; CI: (1.45-4.82); p value = 0.001) and OS (HR: 3.10; CI: (1.29-7.46); p value = 0.011) in the multivariable analyses. To conclude, we demonstrate that BCLM with a 'pure r-HGP' is associated with less TIL and with the worse outcome when compared with BCLM with 'any d-HGP'. These findings suggest that HGP could be considered to refine treatment approaches.

TP53 Alteration and Its Effect on Pathologic Response Are Associated with Survival after Resection of Colorectal Liver Metastases

The aims of this study were to assess the effect of known gene alterations (RAS, TP53, APC, SMAD4, BRAF, and FBXW7) on pathologic response (PR) and their combined association with survival in patients with colorectal liver metastases (CLM). From a prospectively maintained database, we collected data on 458 patients who underwent curative-intent hepatectomy after receiving the first-line preoperative chemotherapy between 2004 and 2020. Major PR was defined as tumor viability of less than 50% in all tumors. Multivariate logistic regression revealed that oxaliplatin-containing regimen (OR: 2.54, 95% CI: 1.58-4.07, P < 0.001), bevacizumab-containing regimen (OR: 2.15, 95%CI: 1.36-3.39, P = 0.001), and TP53 alteration (OR: 0.42, 95%CI: 0.27-0.66, P < 0.001) were independently associated with major PR. Multivariate Cox regression also revealed that patients with TP53 wild-type and major PR (HR: 0.49, 95%CI: 0.31-0.77, P = 0.002) and those with TP53 alteration and major PR (HR: 0.70, 95%CI: 0.49-1.00, P = 0.048) had significantly better overall survival compared to those with minor PR. Further studies targeting the association of TP53 with PR and survival can help clarify the role of TP53 in CLM.

Colorectal liver metastases that survive radioembolization display features of aggressive tumor behavior

BACKGROUND

Radiation lobectomy is a therapeutic approach that involves targeted radiation delivery to induce future liver remnant hypertrophy and tumor control. In patients with colorectal liver metastases, only 30-40% have complete tumor regression. The importance of tumor biology in treatment response remains elusive.

METHODS

Patients with colorectal liver metastases who received radiation lobectomy were selected from surgical pathology files. Using a machine learning scoring protocol, pathological response was correlated to tumor absorbed dose and expression of markers of radioresistance Ki-67 (proliferation), CAIX (hypoxia), Olfm4 (cancer stem cells) and CD45 (leukocytes).

RESULTS

No linear association was found between tumor dose and response (ρ < 0.1, P = 0.73 (90Y), P = 0.92 (166Ho)). Response did correlate with proliferation (ρ = 0.56, P = 0.012), and non-responsive lesions had large pools (>15%) of Olfm4 positive cancer stem cells (Fisher's exact test, P = 0.0037). Responding lesions (regression grade ≤2) were highly hypoxic compared to moderate and non-responding lesions (P = 0.011). Non-responsive lesions had more tumor-infiltrating leukocytes (3240 cells/mm2 versus 650 cells/mm2), although this difference was not significant (P = 0.08).

CONCLUSION

The aggressive phenotype of a subset of surviving cancer cells emphasizes the importance of prompt resection after radiation lobectomy.

Integration of Next-Generation Sequencing in the Surgical Management of Colorectal Liver Metastasis

Hepatic resection remains the treatment of choice for colorectal liver metastases. The advancement of surgical technique and use of perioperative systemic therapy has expanded the number and complexity of patients eligible for surgical resection. In recent years, investigation into gene mutations, such as RAS/RAF pathway, have led to targeted therapies that have significantly improved outcomes. Next-generation sequencing allows analysis of large number of genes that may have potential prognostic relevance in the clinical setting. This review summarizes the current applications of next-generation sequencing technology in metastatic colorectal cancer, focusing on its prognostic implications on patient management.

Complete pathological response after chemotherapy or immune checkpoint inhibitors in deficient MMR metastatic colorectal cancer: Results of a retrospective multicenter study

About 5% of the patients with metastatic colorectal cancers (mCRC) present microsatellite instability (MSI)/deficient mismatch repair system (dMMR). While metastasectomy is known to improve overall and progression-free survival in mCRC, specific results in selected patients with dMMR/MSI mCRC are lacking. Our study aimed to describe metastasectomy results, characterize histological response and evaluate pathological complete response (pCR) rate in patients with dMMR/MSI mCRC. We retrospectively reviewed data from all consecutive patients with dMMR/MSI mCRC who underwent surgical metastasectomy between January 2010 and June 2021 in 17 French centers. Primary outcome was to assess the pCR rate defined by tumor regression grade (TRG) 0. Secondary endpoints included relapse-free survival (RFS) and overall survival (OS), and explored TRG as predictive factor for RFS and OS. Among the 88 patients operated, 109 metastasectomies were performed in 81 patients after neoadjuvant treatment [chemotherapy ± targeted therapy (CTT): 69, 85.2%; immunotherapy (ICI): 12, 14.8%], and pCR was achieved in 13 (16.1%) patients. Among the latter, pCR rate were 10.2% in the patients having received CTT (N = 7) and 50.0% in the patients treated with ICI (N = 6). Radiological response did not predict TRG. With a median follow-up of 57.9 (IQR 34.2-81.6) months, median RFS was 20.2 (15.4-not reached) months, median OS was not reached. Major pathological responses (TRG0 + TRG1) were significantly associated with longer RFS (HR 0.12, 95% CI 0.03-0.55; P = .006). The pCR rate of 16.1% achieved with neoadjuvant treatment in patients with dMMR/MSI mCRC is consistent with previously reported rates in pMMR/MSS mCRC. Immunotherapy showed better pCR rate than chemotherapy ± targeted therapy. Further prospective trials are needed to validate immunotherapy as neoadjuvant treatment in resectable/potentially resectable dMMR/MSI mCRC and identify predictive factors for pCR.

Vessel-Guided Mesohepatectomy for Liver Partition and Staged Major Parenchyma-Sparing Hepatectomies with Super-Selective Portal Vein Embolization or Enhanced ALPPS to Achieve R0 Resection for Colorectal Liver Metastases at the Hepatocaval Confluence

Background. R0 minor parenchyma-sparing hepatectomy (PSH) is feasible for colorectal liver metastases (CRLM) in contact with hepatic veins (HV) at hepatocaval confluence since HV can be reconstructed, but in the case of contact with the first-order glissonean pedicle (GP), major hepatectomy is mandatory. To pursue an R0 parenchyma-sparing policy, we proposed vessel-guided mesohepatectomy for liver partition (MLP) and eventually combination with liver augmentation techniques for staged major PSH. Methods. We analyzed 15 consecutive vessel-guided MLPs for CRLM at the hepatocaval confluence. Patients had a median of 11 (range: 0-67) lesions with a median diameter of 3.5 cm (range: 0.0-8.0), bilateral in 73% of cases. Results. Grade IIIb or more complications occurred in 13%, median hospital stay was 14 (range: 6-62) days, 90-day mortality was 0%. After a median follow-up of 17.5 months, 1-year OS and RFS were 92% and 62%. In nine (64%) patients, MLP was combined with portal vein embolization (PVE) or ALPPS to perform staged R0 major PSH. Future liver remnant (FLR) volume increased from a median of 15% (range: 7-20%) up to 41% (range: 37-69%). Super-selective PVE was performed in three (33%) patients and enhanced ALPPS (e-ALPPS) in six (66%). In two e-ALPPS an intermediate stage of deportalized liver PSH was necessary to achieve adequate FLR volume. Conclusions. Vessel-guided MLP may transform the liver in a paired organ. In selected cases of multiple bilobar CRLM, to guarantee oncological radicality (R0), major PSH is feasible combining advanced surgical parenchyma sparing with liver augmentation techniques when FLR volume is insufficient.

Homogeneity in immune features between colorectal liver metastases better identifies patients with good prognosis compared to pathological response to preoperative chemotherapy

In colorectal cancer liver metastases (CRLM), the density of tumor-infiltrating lymphocytes, the expression of class I major histocompatibility complex (MHC-I), and the pathological response to preoperative chemotherapy have been associated with oncological outcomes after complete resection. However, the prognostic significance of the heterogeneity of these features in patients with multiple CRLMs remains under investigation. We used a tissue microarray of 220 mismatch repair-gene proficient CRLMs resected in 97 patients followed prospectively to quantify CD3+ T cells and MHC-I by immunohistochemistry. Histopathological response to preoperative chemotherapy was assessed using standard scoring systems. We tested associations between clinical, immunological, and pathological features with oncologic outcomes. Overall, 29 patients (30.2%) had CRLMs homogeneous for CD3+ T cell infiltration and MHC-I. Patients with immune homogeneous compared to heterogeneous CRLMs had longer median time to recurrence (TTR) (30 vs. 12 months, p = .0018) and disease-specific survival (DSS) (not reached vs. 48 months, p = .0009). At 6 years, 80% of the patients with immune homogeneous CRLMs were still alive. Homogeneity of response to preoperative chemotherapy was seen in 60 (61.9%) and 69 (80.2%) patients according to different grading systems and was not associated with TTR or DSS. CD3 and MHC-I heterogeneity was independent of response to pre-operative chemotherapy and of other clinicopathological variables for their association with oncological outcomes. In patients with multiple CRLMs resected with curative intent, similar adaptive immune features seen across metastases could be more informative than pathological response to pre-operative chemotherapy in predicting oncological outcomes.

LM02 trial Perioperative treatment with panitumumab and FOLFIRI in patients with wild-type RAS, potentially resectable colorectal cancer liver metastases-a phase II study

Background

Twenty percent of colorectal cancer liver metastases (CLMs) are initially resectable with a 5-year survival rate of 25%-40%. Perioperative folinic acid, 5-fluorouracil, oxaliplatin (FOLFOX) increases progression-free survival (PFS). In advanced disease, the addition of targeting therapies results in an overall survival (OS) advantage. The aim of this study was to evaluate panitumumab and FOLFIRI as perioperative therapy in resectable CLM.

Methods

Patients with previously untreated, wild-type Rat sarcoma virus (RAS), and resectable CLM were included. Preoperative four and postoperative eight cycles of panitumumab and folinic acid, 5-fluorouracil, irinotecan (FOLFIRI) were administered. Primary objectives were efficacy and safety. Secondary endpoints included PFS and OS.

Results

We enrolled 36 patients in seven centers in Austria (intention-to-treat analyses, 35 patients). There were 28 men and seven women, and the median age was 66 years. About 91.4% completed preoperative therapy and 82.9% underwent liver resection. The R0 resection rate was 82.7%. Twenty patients started and 12 patients completed postoperative chemotherapy. The objective radiological response rate after preoperative therapy was 65.7%. About 20% and 5.7% of patients had stable disease and progressive disease, respectively. The most common grade 3 adverse events were diarrhea, rash, and leukopenia during preoperative therapy. One patient died because of sepsis, and one had a pulmonary embolism grade 4. After surgery, two patients died because of hepatic failure. Most common grade 3 adverse events during postoperative therapy were skin toxicities/rash and leukopenia/neutropenia, and the two grade 4 adverse events were stroke and intestinal obstruction. Median PFS was 13.2 months. The OS rate at 12 and 24 months were 85.6% and 73.3%, respectively.

Conclusions

Panitumumab and FOLFIRI as perioperative therapy for resectable CLM result in a radiological objective response rate in 65.7% of patients with a manageable grade 3 diarrhea rate of 14.3%. Median PFS was 13.2 months, and the 24-month OS rate was 73.3%. These data are insufficient to widen the indication of panitumumab from the unresectable setting to the setting of resectable CLM.

Early Circulating Tumor DNA Dynamics Predict Neoadjuvant Therapy Response and Recurrence in Colorectal Liver Metastases: A Prospective Study

BACKGROUND

For patients with colorectal liver metastases (CRLM) who receive neoadjuvant therapy (NAT), reliable indicators that can early and accurately predict treatment response are lacking. This study was conducted to prospectively investigate the potential of early circulating tumor DNA (ctDNA) dynamics as a precise predictor of NAT response and recurrence in CRLM.

METHODS

This study prospectively enrolled 34 patients with CRLM who received NAT, with blood samples collected and subjected to deep targeted panel sequencing at two time points: 1 day before the first and the second cycles of NAT. Correlations of ctDNA mean variant allele frequency (mVAF) dynamics and treatment response were assessed. The performance of early ctDNA dynamics in predicting treatment response was assessed and compared with those of carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9).

RESULTS

The baseline ctDNA mVAF was significantly associated with pre-NAT tumor diameter (r = 0.65; P < 0.0001). After one cycle of NAT, the ctDNA mVAF declined remarkably (P < 0.0001). The dynamic change in ctDNA mVAF of 50% or more was significantly correlated with better NAT responses. The discriminatory capacity of ctDNA mVAF changes was superior to that of CEA or CA19-9 in predicting radiologic response (area under the curve [AUC], 0.90 vs 0.71 vs 0.61) and pathologic tumor regression grade (AUC, 0.83 vs 0.64 vs 0.67). The early changes in ctDNA mVAF but not CEA or CA19-9 were an independent indicator of recurrence-free survival (RFS) (hazard ratio, 4.0; P = 0.023).

CONCLUSIONS

For CRLM patients receiving NAT, an early ctDNA change is a superior predictor of treatment response and recurrence compared with conventional tumor markers.

Radiomics using computed tomography to predict CD73 expression and prognosis of colorectal cancer liver metastases

BACKGROUND

Finding a noninvasive radiomic surrogate of tumor immune features could help identify patients more likely to respond to novel immune checkpoint inhibitors. Particularly, CD73 is an ectonucleotidase that catalyzes the breakdown of extracellular AMP into immunosuppressive adenosine, which can be blocked by therapeutic antibodies. High CD73 expression in colorectal cancer liver metastasis (CRLM) resected with curative intent is associated with early recurrence and shorter patient survival. The aim of this study was hence to evaluate whether machine learning analysis of preoperative liver CT-scan could estimate high vs low CD73 expression in CRLM and whether such radiomic score would have a prognostic significance.

METHODS

We trained an Attentive Interpretable Tabular Learning (TabNet) model to predict, from preoperative CT images, stratified expression levels of CD73 (CD73^High vs. CD73^Low) assessed by immunofluorescence (IF) on tissue microarrays. Radiomic features were extracted from 160 segmented CRLM of 122 patients with matched IF data, preprocessed and used to train the predictive model. We applied a five-fold cross-validation and validated the performance on a hold-out test set.

RESULTS

TabNet provided areas under the receiver operating characteristic curve of 0.95 (95% CI 0.87 to 1.0) and 0.79 (0.65 to 0.92) on the training and hold-out test sets respectively, and outperformed other machine learning models. The TabNet-derived score, termed rad-CD73, was positively correlated with CD73 histological expression in matched CRLM (Spearman's ρ = 0.6004; P < 0.0001). The median time to recurrence (TTR) and disease-specific survival (DSS) after CRLM resection in rad-CD73^High vs rad-CD73^Low patients was 13.0 vs 23.6 months (P = 0.0098) and 53.4 vs 126.0 months (P = 0.0222), respectively. The prognostic value of rad-CD73 was independent of the standard clinical risk score, for both TTR (HR = 2.11, 95% CI 1.30 to 3.45, P < 0.005) and DSS (HR = 1.88, 95% CI 1.11 to 3.18, P = 0.020).

CONCLUSIONS

Our findings reveal promising results for non-invasive CT-scan-based prediction of CD73 expression in CRLM and warrant further validation as to whether rad-CD73 could assist oncologists as a biomarker of prognosis and response to immunotherapies targeting the adenosine pathway.

MRI Apparent Diffusion Coefficient (ADC) as a Biomarker of Tumour Response: Imaging-Pathology Correlation in Patients with Hepatic Metastases from Colorectal Cancer (EORTC 1423)

Background: Tumour apparent diffusion coefficient (ADC) from diffusion-weighted magnetic resonance imaging (MRI) is a putative pharmacodynamic/response biomarker but the relationship between drug-induced effects on the ADC and on the underlying pathology has not been adequately defined. Hypothesis: Changes in ADC during early chemotherapy reflect underlying histological markers of tumour response as measured by tumour regression grade (TRG). Methods: Twenty-six patients were enrolled in the study. Baseline, 14 days, and pre-surgery MRI were performed per study protocol. Surgical resection was performed in 23 of the enrolled patients; imaging-pathological correlation was obtained from 39 lesions from 21 patients. Results: There was no evidence of correlation between TRG and ADC changes at day 14 (study primary endpoint), and no significant correlation with other ADC metrics. In scans acquired one week prior to surgery, there was no significant correlation between ADC metrics and percentage of viable tumour, percentage necrosis, percentage fibrosis, or Ki67 index. Conclusions: Our hypothesis was not supported by the data. The lack of meaningful correlation between change in ADC and TRG is a robust finding which is not explained by variability or small sample size. Change in ADC is not a proxy for TRG in metastatic colorectal cancer.

Mapping Tumor Heterogeneity via Local Entropy Assessment: Making Biomarkers Visible

Advanced imaging and analysis improve prediction of pathology data and outcomes in several tumors, with entropy-based measures being among the most promising biomarkers. However, entropy is often perceived as statistical data lacking clinical significance. We aimed to generate a voxel-by-voxel visual map of local tumor entropy, thus allowing to (1) make entropy explainable and accessible to clinicians; (2) disclose and quantitively characterize any intra-tumoral entropy heterogeneity; (3) evaluate associations between entropy and pathology data. We analyzed the portal phase of preoperative CT of 20 patients undergoing liver surgery for colorectal metastases. A three-dimensional core kernel (5 × 5 × 5 voxels) was created and used to compute the local entropy value for each voxel of the tumor. The map was encoded with a color palette. We performed two analyses: (a) qualitative assessment of tumors' detectability and pattern of entropy distribution; (b) quantitative analysis of the entropy values distribution. The latter data were compared with standard Hounsfield data as predictors of post-chemotherapy tumor regression grade (TRG). Entropy maps were successfully built for all tumors. Metastases were qualitatively hyper-entropic compared to surrounding parenchyma. In four cases hyper-entropic areas exceeded the tumor margin visible at CT. We identified four "entropic" patterns: homogeneous, inhomogeneous, peripheral rim, and mixed. At quantitative analysis, entropy-derived data (percentiles/mean/median/root mean square) predicted TRG (p < 0.05) better than Hounsfield-derived ones (p = n.s.). We present a standardized imaging technique to visualize tumor heterogeneity built on a voxel-by-voxel entropy assessment. The association of local entropy with pathology data supports its role as a biomarker.

Improving the response to oxaliplatin by targeting chemotherapy-induced CLDN1 in resistant metastatic colorectal cancer cells

BACKGROUND

Tumor resistance is a frequent cause of therapy failure and remains a major challenge for the long-term management of colorectal cancer (CRC). The aim of this study was to determine the implication of the tight junctional protein claudin 1 (CLDN1) in the acquired resistance to chemotherapy.

METHODS

Immunohistochemistry was used to determine CLDN1 expression in post-chemotherapy liver metastases from 58 CRC patients. The effects of oxaliplatin on membrane CLDN1 expression were evaluated by flow cytometry, immunofluorescence and western blotting experiments in vitro and in vivo. Phosphoproteome analyses, proximity ligation and luciferase reporter assays were used to unravel the mechanism of CLDN1 induction. RNAseq experiments were performed on oxaliplatin-resistant cell lines to investigate the role of CLDN1 in chemoresistance. The "one-two punch" sequential combination of oxaliplatin followed by an anti-CLDN1 antibody-drug conjugate (ADC) was tested in both CRC cell lines and murine models.

RESULTS

We found a significant correlation between CLDN1 expression level and histologic response to chemotherapy, CLDN1 expression being the highest in resistant metastatic residual cells of patients showing minor responses. Moreover, in both murine xenograft model and CRC cell lines, CLDN1 expression was upregulated after exposure to conventional chemotherapies used in CRC treatment. CLDN1 overexpression was, at least in part, functionally related to the activation of the MAPKp38/GSK3β/Wnt/β-catenin pathway. Overexpression of CLDN1 was also observed in oxaliplatin-resistant CRC cell lines and was associated with resistance to apoptosis, suggesting an anti-apoptotic role for CLDN1. Finally, we demonstrated that the sequential treatment with oxaliplatin followed by an anti-CLDN1 ADC displayed a synergistic effect in vitro and in in vivo.

CONCLUSION

Our study identifies CLDN1 as a new biomarker of acquired resistance to chemotherapy in CRC patients and suggests that a "one-two punch" approach targeting chemotherapy-induced CLDN1 expression may represent a therapeutic opportunity to circumvent resistance and to improve the outcome of patients with advanced CRC.

Effect of 5-Fluoro-Uracile + Oxaliplatin chemotherapy on the histological response of PEritoneal and hePatIc corectal metasTases in a mOuse model: PEPITO experimental study

BACKGROUND

The histological responses (HRs) after systemic chemotherapy should be used to determine the optimal management of patients with peritoneal and liver metastasis from colorectal cancer (cPM, cLM), in curative intent. We aimed to compare HRs of cPM and cLM in metastatic mice model after chemotherapy.

METHODS

Colon carcinoma CT26-luc cells were transplanted into syngeneic BALB/c mice by intraperitoneal (leading to cPM), intrasplenic (leading to cLM), or intraperitoneal + intrasplenic (leading to cPM cLM) injections and follow up using bioluminescence during 21 days. Bi-chemotherapeutic treatment (5-fluorouracil at D11, D17, and D20, and oxaliplatin at D13 and D19) was administered. The peritoneal cancer index (PCI) and HRs using Peritoneal Regression Grading Score (PRGS) and Tumor Regression Grade (TRG) classifications were analyzed at day 21.

RESULTS

Unlike bioluminescence rate, PCI was reduced after chemotherapy in all treated groups with cPM comparatively to controls (33 ± 9.5 vs. 19.8 ± 5, p = 0.002 for cPM groups; 37.7 ± 3.6 vs. 25.2 ± 10.8, p = 0.0003 for the cPM + cLM groups). The complete or major HR rates were higher in all treated groups compared to the non-treated mice (cPM, 2.29 ± 0.55 vs. 3.56 ± 1.01; cLM, 2.43 ± 1.89 vs. 4.86 ± 0.378; cPM + cLM, 2.73 ± 1.03 and 2.2 ± 0.65 vs. 3.79 ± 0.75 and 4.36 ± 0.43). The complete or major HR rates after chemotherapy were similar across the metastatic sites in 60% for cPM + cLM group.

CONCLUSIONS

The efficacy of chemotherapeutic treatment did not differ between the metastatic sites. Murine models are suitable in histological analyses to study tumor development and regression but clinical study will be performed to confirm these results.

Comparison of Neoadjuvant Systemic Chemotherapy Protocols for the Curative-Intent Management of Peritoneal Metastases from Colorectal Cancer, Regarding Morphological Response, Pathological Response, and Long-Term Outcomes: A Retrospective Study

BACKGROUND

Selected patients with colorectal cancer peritoneal metastases (CRPM) could be offered a curative-intent strategy based on complete cytoreductive surgery (CRS), potentially combined with hyperthermic intraperitoneal chemotherapy (HIPEC) and perioperative systemic chemotherapy. The impact of different neoadjuvant systemic chemotherapy (NACT) regimens remains unclear due to a lack of comparative data.

METHODS

Consecutive CRPM patients from a monocentric database who were treated with complete CRS after single-line NACT were included in this study. Chemotherapy regimens were tailored as a doublet drug (FOLFOX/FOLFIRI) with/without targeted therapy (anti-epidermal growth factor receptor/bevacizumab) and triplet-drug combination (FOLFIRINOX). Morphological response (MR) was assessed using the Response Evaluation Criteria in Solid Tumors criteria, and pathological response (PR) was assessed using the Peritoneal Regression Grading Score (PRGS). Long-term oncologic outcomes were compared.

RESULTS

The cohort comprised 388 patients, including 127, 202, and 59 patients in the doublet, doublet + targeted, and triplet groups, respectively. MR rates were higher in the triplet (68.0%) and doublet + targeted groups (64.2%) when compared with the doublet group (42.4%, p = 0.003). Complete and major PRs were observed in 13.6% and 32.0% of patients, respectively. Higher MR rates were observed after doublet + targeted or triplet regimens, while no difference was observed for PR rates. In multivariate analysis, FOLFIRINOX was independently associated with better overall survival (hazard ratio 0.49, 95% confidence interval 0.25-0.96; p = 0.037). FOLFIRINOX also resulted in a higher rate of severe postoperative complications.

CONCLUSIONS

In this retrospective study, a FOLFIRINOX regimen as NACT seemed to result in better long-term outcomes for CRPM patients after complete CRS/HIPEC, although with higher morbidity. Prospective studies are needed, including groups without NACT and those with FOLFIRINOX + bevacizumab.

Treatment of Peritoneal Metastasis with Pressurized Intraperitoneal Aerosol Chemotherapy: Results from the Prospective PIPAC-OPC2 Study

BACKGROUND

Pressurized Intraperitoneal Aerosol chemotherapy (PIPAC) is a local treatment for peritoneal metastasis (PM). Prospective data are scarce and evaluation of treatment response remains difficult. This study evaluated the use of the Peritoneal Regression Grading score (PRGS) and its prognostic value.

PATIENTS AND METHODS

This was a prospective, controlled phase II trial in patients with PM from gastrointestinal, gynaecological, hepatopancreatobiliary, primary peritoneal, or unknown primary cancer. Patients in performance status 0-1, with a non-obstructed gastrointestinal tract, and a maximum of one extraperitoneal metastasis were eligible. Colorectal or appendiceal PM had PIPAC with oxaliplatin, other primaries had PIPAC with cisplatin and doxorubicin. Biopsies were taken at each PIPAC and evaluated using the PRGS. Quality-of-life questionnaires were reported at baseline and after three PIPACs.

RESULTS

One hundred ten patients were treated with 336 PIPACs (median 3, range 1-12). One hundred patients had prior palliative chemotherapy and 45 patients received bidirectional treatment. Complete or major histological response to treatment (PRGS 1-2) was observed in 38 patients (61%) who had three PIPACs, which was the only independent prognostic factor in a multivariate analysis. The median overall survival (mOS) from PIPAC 1 was 10 months, while patients with PM from gastric, colorectal, and pancreatic cancer had a mOS of 7.4, 16.7, and 8.2 months, respectively. Global health scores were significantly reduced, but patients were less fatigued, nauseated, constipated, and had better appetite after three PIPACs.

CONCLUSIONS

PIPAC with oxaliplatin or cisplatin and doxorubicin was able to induce a major or complete histological response during three PIPACs, which may provide significant prognostic information, both at baseline and after treatment.

Case report: Complete pathologic response with first-line immunotherapy combination in a young adult with massive liver dissemination of mismatch repair-deficient metastatic colorectal cancer: Immunological and molecular profiling

The current level of evidence for immunotherapy in previously untreated microsatellite unstable metastatic colorectal cancer is based on recent pieces of evidence of few studies that demonstrated durable response and clinical benefit, in terms of objective response rate, disease control rate, and progression-free survival in this subgroup of patients. On the basis of combinatorial immunotherapy with nivolumab plus ipilimumab, we report the exceptional case of a complete pathological response in a 21-year-old woman presenting a clinically aggressive stage IV colorectal cancer with massive nodal and liver involvement. Extensive molecular analyses based on whole genome next-generation DNA sequencing, RNA sequencing, fluorescent multiplex immunohistochemistry, and flow cytometry provided a detailed description of tumoral and immunological characteristics of this noteworthy clinical case.

Impacts of primary tumor location on outcomes in patients undergoing hepatectomy for colorectal liver metastasis vary according to tumor burden

PURPOSE

The purpose of this study was to verify whether the prognostic value of primary tumor location (PTL) for patients undergoing resection for colorectal liver metastasis (CRLM) is affected by tumor burden.

METHODS

Patients who underwent a first curative-intent surgery for CRLM from 2006 to 2017 were enrolled. The imaging tumor burden score (TBS) was calculated as TBS2 = (maximum tumor diameter in cm)2 + (number of lesions)2. Then, the prognostic role of PTL was assessed in different TBS zones.

RESULTS

The patient population consisted of 524 left-sided (LS) and 118 right-sided (RS) primary tumors. The distribution of TBS in the patient cohort was: Zone1: TBS <3 [n = 161 (25.1%)], zone 2: TBS ≥3 to <7 [n = 343 (53.4%)], and zone 3: TBS ≥7 [n = 138 (21.5%)]. In the whole cohort, the 5-year overall survival (OS) in the RS group was worse than that in the LS group (35.6% vs. 45.4%). However, after adjustment for known prognostic confounders, the RS group was not independently associated with a poorer OS (HR 1.18, p = 0.247). Among patients with TBS <7, OS in the RS group was significantly shorter than that in the LS group in both univariate and multivariate analyses. The prognostic role of PTL remained significant after propensity score matching or excluding patients who received anti-EGFR agents. Conversely, the association between PTL and OS was no longer evident in patients with TBS ≥7.

CONCLUSION

The current study demonstrates that the prognostic value of PTL varies by TBS, and RS tumors are only associated with shorter survival in patients with low or medium TBS.

Assessment of Treatment Response after Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) for Appendiceal Peritoneal Metastases

Background The aim of this study was to analyse survival and surrogates for oncological response after PIPAC for appendiceal tumours. Methods This retrospective cohort study included consecutive patients with appendiceal peritoneal metastases (PM) treated in experienced PIPAC centers. Primary outcome measure was overall survival (OS) from the date of diagnosis of PM and from the start of PIPAC. Predefined secondary outcome included radiological response (RECIST criteria), repeat laparoscopy and peritoneal cancer index (PCI), histological response assessed by the Peritoneal regression grading system (PRGS) and clinical response. Results Final analysis included 77 consecutive patients (208 PIPAC procedures) from 15 centres. Median OS was 30 months (23.00-46.00) from time of diagnosis and 19 months (13.00-28.00) from start of PIPAC. 35/77 patients (45%) had ≥3 procedures (pp: per protocol). Objective response at PIPAC3 was as follows: RECIST: complete response 4 (11.4%), 11 (31.4%) partial/stable; mean PRGS at PIPAC3: 1.8 ± 0.9. Median PCI: 21 (IQR 18-27) vs. 22 (IQR 17-28) at baseline (p = 0.59); 21 (60%) and 18 (51%) patients were symptomatic at baseline and PIPAC3, respectively (p = 0.873). Median OS in the pp cohort was 22.00 months (19.00-NA) from 1st PIPAC. Conclusion Patients with PM of appendiceal origin had objective treatment response after PIPAC and encouraging survival curves call for further prospective evaluation.

Histopathological growth patterns of liver metastasis: updated consensus guidelines for pattern scoring, perspectives and recent mechanistic insights

The first consensus guidelines for scoring the histopathological growth patterns (HGPs) of liver metastases were established in 2017. Since then, numerous studies have applied these guidelines, have further substantiated the potential clinical value of the HGPs in patients with liver metastases from various tumour types and are starting to shed light on the biology of the distinct HGPs. In the present guidelines, we give an overview of these studies, discuss novel strategies for predicting the HGPs of liver metastases, such as deep-learning algorithms for whole-slide histopathology images and medical imaging, and highlight liver metastasis animal models that exhibit features of the different HGPs. Based on a pooled analysis of large cohorts of patients with liver-metastatic colorectal cancer, we propose a new cut-off to categorise patients according to the HGPs. An up-to-date standard method for HGP assessment within liver metastases is also presented with the aim of incorporating HGPs into the decision-making processes surrounding the treatment of patients with liver-metastatic cancer. Finally, we propose hypotheses on the cellular and molecular mechanisms that drive the biology of the different HGPs, opening some exciting preclinical and clinical research perspectives.

Pathological Evaluation of Resected Colorectal Liver Metastases: mFOLFOX6 Plus Bevacizumab versus mFOLFOX6 Plus Cetuximab in the Phase II ATOM Trial

We compared the preplanned histopathological responses of resected liver metastases from patients who received modified FOLFOX6 plus bevacizumab or modified FOLFOX6 plus cetuximab for liver-limited colorectal metastases in the ATOM trial. Fibrosis and viable tumor cells in tumor regression grade (TRG), infarct-like necrosis in modified TRG (mTRG), and dangerous halo (DH) were assessed. Fifty-five patients (28 and 27 patients in the bevacizumab and cetuximab arms, respectively) were divided into the low (viable tumor cells ≤ 50%) and high (>50%) TRG or mTRG groups. DH was characterized as absent/rare or focal/diffuse. Compared to the bevacizumab arm, the cetuximab arm was more effective, with respect to low TRG (13 vs. 23 patients) and absent/rare DH (14 vs. 19 patients), respectively. Low mTRG was similarly observed in both arms. Low TRG/mTRG and absent/rare DH showed better relapse-free survival (RFS) than high TRG/mTRG and focal/diffuse DH. In the bevacizumab arm, a significant difference in RFS existed between the low and high TRG groups, while in the cetuximab arm, for TRG, mTRG, and DH, the low and absent/rare groups demonstrated significantly longer RFS than the high and focal/diffuse groups, respectively. TRG could estimate RFS in patients who underwent liver metastasectomy after bevacizumab or cetuximab chemotherapy.

The desmoplastic growth pattern is associated with second-stage completion and longer survival in 2-stage hepatectomy for colorectal cancer liver metastases

BACKGROUND

Two-stage hepatectomy for bilobar colorectal cancer liver metastases is potentially curative for selected patients. Histological growth patterns of colorectal liver metastases (desmoplastic, replacement, and pushing) have prognostic value. Our aim was to evaluate their association with pathologic response to preoperative treatment, second-stage hepatectomy completion, and survival in patients treated with a curative-intent 2-stage hepatectomy.

METHODS

In 67 patients planned for 2-stage hepatectomy, colorectal liver metastases resected from the first-stage hepatectomy were retrospectively evaluated for growth patterns and pathologic response according to Tumor Regression Grading, modified Tumor Regression Grading, and Blazer grading. Tumor Regression Grading 1 to 3, modified Tumor Regression Grading 1 to 3, and Blazer 0 and 1 defined good responders.

RESULTS

Desmoplastic growth patterns (GP) were more frequent among good responders (P < .001). Second-stage hepatectomy completion was associated with desmoplastic growth patterns and pathologic response on univariate analysis and multivariable analyses (P = .017 and P = .041, respectively). Median follow-up was 84 months (95% confidence interval: 53.4 [not reached]). Nondesmoplastic GP patients and nonresponders had a poorer overall survival (hazard ratio = 3.86, 95% confidence interval: 2.11-7.07, P < .001 and hazard ratio = 2.14, 95% confidence interval: 1.19-3.83, P = .009, respectively) on univariate analysis. Nondesmoplastic growth pattern was the only factor associated with a poorer overall survival on multivariable analysis (hazard ratio = 4.17, 95% confidence interval: 1.79-9.74, P < .001). Nondesmoplastic GP was also associated with a poorer recurrence-free survival (hazard ratio = 2.05, 95% confidence interval: 1.13-3.70, P = .017).

CONCLUSION

Desmoplastic GP could represent a useful morphological marker for early identification of patients who might benefit from 2-stage hepatectomy completion.

The Pathologic Complete Response Ratio of Liver Metastases Represents a Valuable Prognostic Indicator

Background and Objectives: The aim of this study was to evaluate the role of the pathologic complete response ratio of liver metastases (PCRRLM) in predicting the prognosis and recurrence of colorectal cancer liver metastases (CRLM).

Methods: A total of 305 CRLM patients who underwent preoperative chemotherapy followed by hepatectomy were included. PCRRLM was defined as the number of liver metastases exhibiting pathologic complete response (PCR) divided by the number of total resected liver metastases. The Kaplan–Meier method was used to calculate survival, and differences were examined by the log-rank test. Univariate and multivariate analyses were performed to identify the predictors of PCRRLM, recurrence-free survival (RFS) and overall survival (OS).

Results: Among the 305 included patients, 44 (14.4%) achieved a PCRRLM ≥0.50 (including PCRRLM = 1), and 261 (85.6%) achieved a PCRRLM <0.50 (including PCRRLM = 0). Patients of an older age (≥55 years old) and those with higher carcinoembryonic antigen (CEA) levels (≥5 ng/ml) were less likely to achieve a PCRRLM ≥0.50. In the multivariate analysis, PCRRLM≥ 0.50 (vs. < 0.50, HR [95% CI]: 0.67 [0.46–0.99], p = 0.043) was associated with better RFS. Positive lymph node status (vs. negative, HR [95% CI]: 1.46 [1.04–2.05], p = 0.028) and TBS ≥5 (vs. < 5, HR [95% CI]: 1.44 [1.02–2.04], p = 0.038) were associated with worse RFS.

Conclusion: PCRRLM was significantly associated with long-term RFS after preoperative chemotherapy and CRLM resection. Thus, it may be a valuable indicator of recurrence in CRLM patients.

A Comprehensive Prognostic Model for Colorectal Cancer Liver Metastasis Recurrence After Neoadjuvant Chemotherapy

Background

For patients with colorectal cancer liver metastases (CRLMs), it is important to stratify patients according to the risk of recurrence. This study aimed to validate the predictive value of some clinical, imaging, and pathology biomarkers and develop an operational prognostic model for patients with CRLMs with neoadjuvant chemotherapy (NACT) before the liver resection.

Methods

Patients with CRLMs accompanied with primary lesion and liver metastases lesion resection were enrolled into this study. A nomogram based on independent risk factors was identified by Kaplan–Meier analysis and multivariate Cox proportional hazard analysis. The predictive ability was evaluated by receiver operating characteristic (ROC) curves and decision curve analysis (DCA). Calibration plot were also used to explore the consistency between prediction and reality.

Results

A total of 118 patients were enrolled into the study. Multivariable Cox analysis found that histopathological growth patterns (HGPs) [Hazard Rate (HR) = 2.130], radiology response (stable disease vs. partial response, HR = 2.207; progressive disease vs. partial response, HR = 3.824), lymph node status (HR = 1.442), and age (HR = 0.576) were independent risk factors for disease-free survival (DFS) (p < 0.05). Corresponding nomogram was constructed on the basis of the above factors, demonstrating that scores ranging from 5 to 11 presented better prognosis than the scores of 0–4 (median DFS = 14.3 vs. 4.9 months, p < 0.0001). The area under ROC curves of the model for 1-, 2-, and 3-year DFS were 0.754, 0.705, and 0.666, respectively, and DCA confirmed that the risk model showed more clinical benefits than clinical risk score. Calibration plot for the probability of DFS at 1 or 3 years verified an optimal agreement between prediction and actual observation. In the course of our research, compared with pure NACT, a higher proportion of desmoplastic HGP (dHGP) was detected in patients treated with NACT plus cetuximab (p = 0.030), and the use of cetuximab was an independent factor for decreased replacement HGP (rHGP) and increased dHGP (p = 0.049).

Conclusion

Our model is concise, comprehensive, and high efficient, which may contribute to better predicting the prognosis of patients with CRLMs with NACT before the liver resection. In addition, we observed an unbalanced distribution of HGPs as well.

Importance of biopsy site selection for peritoneal regression grading score (PRGS) in peritoneal metastasis treated with repeated pressurized intraperitoneal aerosol chemotherapy (PIPAC)

Objectives

The four-tiered peritoneal regression grading score (PRGS) is used for histological response evaluation in patients with peritoneal metastasis (PM) treated with pressurized intraperitoneal aerosol chemotherapy (PIPAC). Four quadrant biopsies (QBs) from the parietal peritoneum should be assessed by PRGS, but consensus on biopsy site strategy for follow-up biopsies during repeated PIPACs is lacking. We aimed to evaluate whether there is a difference between PRGS in QBs from clips marked PM (QB-CM) compared to biopsies from PM with the visually most malignant features (worst biopsy, WB).

Methods

Prospective, descriptive study. During the first PIPAC, index QBs sites were marked with metal clips. During the second PIPAC, an independent surgical oncologist selected biopsy site for WB and biopsies were taken from QB-CM and WB. One blinded pathologist evaluated all biopsies according to PRGS. From each biopsy, three step sections were stained H&E, followed by an immunostained section, and another three step sections stained H&E.

Results

Thirty-four patients were included from March 2020 to May 2021. Median age 64 years. Maximum mean PRGS in QB-CM at PIPAC 1 was 3.3 (SD 1.2). Maximum mean PRGS in QB-CM at PIPAC 2 was 2.6 (SD 1.2), whereas mean PRGS in WB at PIPAC 2 was 2.4 (SD 1.3). At PIPAC 2, there was agreement between maximum PRGS from QB-CM and PRGS from WB in 21 patients. Maximum PRGS from QB-CM was higher in nine and lower in four patients, compared to PRGS from WB.

Conclusions

Biopsies from QB-CM did not overestimate treatment response compared to biopsies from WB.

The LiMAx Test as Selection Criteria in Minimally Invasive Liver Surgery

Background: Liver failure is a crucial predictor for relevant morbidity and mortality after hepatic surgery. Hence, a good patient selection is mandatory. We use the LiMAx test for patient selection for major or minor liver resections in robotic and laparoscopic liver surgery and share our experience here. Patients and methods: We identified patients in the Magdeburg registry of minimally invasive liver surgery (MD-MILS) who underwent robotic or laparoscopic minor or major liver surgery and received a LiMAx test for preoperative evaluation of the liver function. This cohort was divided in two groups: patients with normal (LiMAx normal) and decreased (LiMAx decreased) liver function measured by the LiMAx test. Results: Forty patients were selected from the MD-MILS regarding the selection criteria (LiMAx normal, n = 22 and LiMAx decreased, n = 18). Significantly more major liver resections were performed in the LiMAx normal vs. the LiMAx decreased group (13 vs. 2; p = 0.003). Hence, the mean operation time was significantly longer in the LiMAx normal vs. the LiMAx decreased group (356.6 vs. 228.1 min; p = 0.003) and the intraoperative blood transfusion significantly higher in the LiMAx normal vs. the LiMAx decreased group (8 vs. 1; p = 0.027). There was no significant difference between the LiMAx groups regarding the length of hospital stay, intraoperative blood loss, liver surgery related morbidity or mortality, and resection margin status. Conclusion: The LiMAx test is a helpful and reliable tool to precisely determine the liver function capacity. It aids in accurate patient selection for major or minor liver resections in minimally invasive liver surgery, which consequently serves to improve patients’ safety. In this way, liver resections can be performed safely, even in patients with reduced liver function, without negatively affecting morbidity, mortality and the resection margin status, which is an important predictive oncological factor.

Prognostic implications of adaptive immune features in MMR-proficient colorectal liver metastases classified by histopathological growth patterns

BACKGROUND

After resection, colorectal cancer liver metastases (CRLM) surrounded by a desmoplastic rim carry a better prognosis than the metastases replacing the adjacent liver. However, these histopathological growth patterns (HGPs) are insufficient to guide clinical decision-making. We explored whether the adaptive immune features of HGPs could refine prognostication.

METHODS

From 276 metastases resected in 176 patients classified by HGPs, tissue microarrays were used to assess intratumoral T cells (CD3), antigen presentation capacity (MHC class I) and CD73 expression producing immunosuppressive adenosine. We tested correlations between these variables and patient outcomes.

RESULTS

The 101 (57.4%) patients with dominant desmoplastic HGP had a median recurrence-free survival (RFS) of 17.1 months compared to 13.3 months in the 75 patients (42.6%) with dominant replacement HGP (p = 0.037). In desmoplastic CRLM, high vs. low CD73 was the only prognostically informative immune parameter and was associated with a median RFS of 12.3 months compared to 26.3, respectively (p = 0.010). Only in dominant replacement CRLM, we found a subgroup (n = 23) with high intratumoral MHC-I expression but poor CD3⁺ T cell infiltration, a phenotype associated with a short median RFS of 7.9 months.

CONCLUSIONS

Combining the assessments of HGP and adaptive immune features in resected CRLM could help identify patients at risk of early recurrence.

Tumoral and Parenchymal Morphological Assessment in Liver Metastases of Colorectal Carcinoma: Micrometastasis, Peritumoral Lymphocytes, Tumor Budding and Differentiation are Potential Prognostic Factors

Introduction: Various potential prognostic histopathologic factors for colorectal carcinoma liver metastasis have been proposed. However, there is still no consensus on pathological reporting of colorectal carcinoma liver metastasis resection materials. The aim of this study was to investigate the relation between selected tumoral and parenchymal histopathologic features and prognostic factors for better characterization and prognostic prediction of the patients with colorectal carcinoma liver metastasis. Methods: Hematoxylin-eosin stained slides from 100 patients who underwent hepatic resection were evaluated. Pathologic characteristics; including number of tumor nodules, largest tumor size, status of surgical margin, tumor distance to closest margin, tumor necrosis, the presence of tumor capsule, tumor differentiation, perineural and lymphovascular invasion, micrometastasis, tumor budding, peritumoral lymphocytic infiltrate and parenchymal features including steatosis, steatohepatitis, lobular inflammation, confluent necrosis, hepatocyte ballooning, portal inflammation were assessed. For 49 patients who were treated with preoperative chemotherapy, tumor regression grade and chemotherapy-related parenchymal changes such as sinusoidal damage, venous obstruction, nodular regenerative hyperplasia, steatosis and steatohepatitis were also evaluated. Results: The presence of lymphovascular invasion (p < 0.001), micrometastasis (p=0.004), absent or mild peritumoral lymphocytic infiltration (p =0.013), high tumor budding score (p=0.033) and moderate/poor differentiation (p=0.022) were significantly associated with shorter overall survival. Lymphovascular invasion (p < 0.001) was an independent predictor of mortality in multivariate analysis. Conclusions: We conclude that tumor differentiation, lymphovascular invasion, micrometastasis, peritumoral lymphocytic reaction and tumor budding score are potential prognostic histopathological features and candidates for inclusion in pathology reports of colorectal carcinoma liver metastasis resections.

Feasibility and Safety of Oxaliplatin-Based Pressurized Intraperitoneal Aerosol Chemotherapy With or Without Intraoperative Intravenous 5-Fluorouracil and Leucovorin for Colorectal Peritoneal Metastases: A Multicenter Comparative Cohort Study

BACKGROUND

This retrospective multicenter cohort study compared the feasibility and safety of oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy (PIPAC-Ox) with or without intraoperative intravenous 5-fluorouracil (5-FU) and leucovorin (L).

METHODS

Our study included consecutive patients with histologically proven unresectable and isolated colorectal peritoneal metastases (cPM) treated with PIPAC-Ox in seven tertiary referral centers between January 2015 and April 2020. Toxicity events and oncological outcomes (histological response, progression-free survival, and overall survival) were compared between patients who received intraoperative intravenous 5-FU/L (PIPAC-Ox + 5-FU/L group) and patients who did not (PIPAC-Ox group).

RESULTS

In total, 101 patients (263 procedures) were included in the PIPAC-Ox group and 30 patients (80 procedures) were included in the PIPAC-Ox + 5-FU/L group. Common Terminology Criteria for Adverse Events v4.0 grade 2 or higher adverse events occurred in 48 of 101 (47.5%) patients in the PIPAC-Ox group and in 13 of 30 (43.3%) patients in the PIPAC-Ox + 5-FU/L group (p = 0.73). The complete histological response rates according to the peritoneal regression grading score were 27% for the PIPAC-Ox + 5-FU/L group and 18% for the PIPAC-Ox group (p = 0.74). No statistically significant differences were observed in overall or progression-free survival between the two groups.

CONCLUSIONS

The safety and feasibility of PIPAC-Ox + 5-FU/L appears to be similar to the safety and feasibility of PIPAC-Ox alone in patients with unresectable cPM. Oncological outcomes must be evaluated in larger studies.

The management of colorectal liver metastases amenable of surgical resection: How to shape treatment strategies according to clinical, radiological, pathological and molecular features

Metastatic colorectal cancer (mCRC) patients have poor chances of long term survival, being < 15% of them still alive after 5 years from diagnosis. Nonetheless, patients with colorectal liver metastases (CRLM) may be eligible for metastases resection thus being able to achieve long-term disease remission and survival. The likelihood for patients with CRLM of being or becoming eligible for liver metastasectomy is increasing, thanks to the evolution of surgical techniques, the availability of active systemic treatments and the widespread diffusion of experienced multidisciplinary boards to manage these patients. However, disease relapse after liver surgery is common and occurs in two-thirds of resected patients. Therefore, adequate radiological staging and risk stratification is crucial for the optimal selection of patients candidate to surgery in order to maximize the benefit-risk ratio of liver metastasectomy and to individualize the treatment strategy. Based on the multidimensional assessment, three possible approaches are available: upfront liver surgery followed by adjuvant chemotherapy, perioperative chemotherapy preceding and following liver surgery, and an upfront systemic treatment including chemotherapy plus a targeted agent, both chosen according to patients' and tumours' characteristics, then followed by liver surgery if indicated. In this review, we describe the most important factors impacting the therapeutic choices in patients with resectable and potentially resectable CRLM, and we discuss the most promising factors that may reshape the future decision-making process of these patients.

A transcriptomic signature that predicts cancer recurrence after hepatectomy in patients with colorectal liver metastases

BACKGROUND

Cancer recurrence is an important predictor of survival outcomes in patients with colorectal cancer-associated liver metastasis (CRLM), who undergo radical hepatectomy. Therefore, identification of patients with the greatest risk of recurrence is critical for developing a precision oncology strategy that might include frequent surveillance (in low-risk patients) or a more aggressive treatment approach (in high-risk patients). We performed genome-wide expression profiling, to identify and develop a transcriptomic signature for predicting recurrence in patients with CRLM.

METHODS

We analysed a total of 383 patients with CRLM, including 63 patients from a publicly available data set (the NCBI's Gene Expression Omnibus with accession number GSE81423). and 320 patients from whom surgical specimens were collected for independent training (n = 169) and validation (n = 151) of identified biomarkers. Using Cox's proportional hazard regression analysis, we evaluated the clinical significance of the identified gene signature by comparing its performance with several key clinical factors.

RESULTS

We identified a six-gene panel that robustly categorised patients with recurrence in the discovery (area under the curve (AUC) = 0.90). We showed that the panel was a significant predictor of recurrence in the clinical training (AUC = 0.83) and validation cohorts (AUC = 0.81). By combining our panel with key clinical factors, we established a risk-stratification model that emerged as an independent predictor of recurrence (AUC = 0.85; univariate: hazard ratio (HR) = 4.34, 95% confidence interval (CI) = 2.71-6.93, P < 0.001; multivariate: HR = 3.40, 95% CI = 1.76-6.56, P < 0.001). The stratification model revealed recurrence prediction in 89% of high-risk group and non-recurrence in 62% of low-risk group.

CONCLUSIONS

We established a novel transcriptomic signature that robustly predicts recurrence, which has significant implications for the management of patients with CRLM.

Randomized Phase 2 Study Comparing Pathological Responses of Resected Colorectal Cancer Metastases after Bevacizumab with mFOLFOX6 or FOLFIRI (BEV-ONCO Trial)

Retrospective studies reported that preoperative oxaliplatin-based chemotherapy increased pathological response (PR) in patients resected for colorectal liver metastases (CRLM). This multicenter prospective randomized (1/1) phase II trial evaluated PR on resected CRLM after preoperative mFOLFOX6 (arm A) or FOLFIRI (arm B) + bevacizumab. The primary endpoint was the major pathological response rate (MPRR), defined as the percentage of patients presenting CRLMs with mean tumor regression grade (TRG) < 3. Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). Out of 65 patients, 57 patients (28 and 29 in arm A/B) were resected for CRLM (one patient with lung metastases). Clinical and treatment characteristics were similar in both arms. One-month postoperative complications were 39.3%/31.0% in arm A/B (p = 0.585). MPRR and complete PR were 32.1%/20.7% (p = 0.379) and 14.3%/0.0% (p = 0.052) in arm A/B, respectively. PFS and OS were not different. Patients with PR among all CRLMs (max TRG ≤ 3; 43.8% of patients) had a lower risk of relapse (PFS: HR = 0.41, 95%CI = 0.204−0.840, p = 0.015) and a tendency towards better survival (OS: HR = 0.34, 95%CI = 0.104−1.114, p = 0.075). The homogeneity of PR was associated with improved PFS/OS. This trial fails to demonstrate a significant increase in MPRR in patients treated with mFOLFOX6-bevacizumab but confirms PR as an important prognostic factor.

Chemotherapy in resectable or potentially resectable colon cancer with liver metastases

INTRODUCTION

The treatment of colorectal cancer liver metastases has seen significant improvement in recent years and, for certain patients, the long-term survival and even cure are possible. Despite this improvement, many more questions are yet to be answered: the optimal combination, duration, sequence of therapies, role of biologics and the timing of surgical resection are debated in the literature, with conflicting trial results.

AREAS COVERED

In this review, the authors highlight the current trial evidence for systemic chemotherapy and biologic therapy for colorectal cancer liver metastases in both the pre and post-resection setting.

EXPERT OPINION

The treatment of colorectal liver metastases requires a multidisciplinary approach. The role of adjuvant chemotherapy with 5 fluorouracil and oxaliplatin in stage 3 colon cancer is well established. However, the options for patients with resectable or borderline liver metastases, either in the neoadjuvant or adjuvant settings, require further study. For patients with borderline resectable metastases, the combination of triplet chemotherapy with 5 fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI) offers the best conversion rate. The role of biologic agents such as bevacizumab and EGFR inhibitors in these settings is less clear based on current evidence.

Evaluation of histopathological heterogeneity of colorectal cancer liver metastasis sites after preoperative chemotherapy

Patients with liver metastases from colorectal cancer (CRLMs) frequently receive chemotherapy prior to liver resection. Histopathological assessment of the resected specimen can evaluate the response to chemotherapy. The present study analyzed the association between histopathological changes in the primary site and liver metastases. The present study comprised 45 patients with resectable CRLMs at the Surgical Oncology Department of Gifu University School of Medicine (Gifu, Japan) between January 2006 and August 2015. The study included 24 men and 21 women. The primary colonic tumor was located in the right side in 13 (28.9%) patients and the left side in 32 (71.9%) patients. The present study evaluated patients with metastatic colorectal cancer (31/45) after excluding those in whom histopathological heterogeneity between the primary and liver metastasis changed to grade 3 after chemotherapy. The group that underwent hepatectomy after chemotherapy (n=25) was compared with the group that underwent hepatectomy alone (n=6). In 16 (53.3%) out of 25 patients, histopathological heterogeneity of the liver metastasis was lost (P=0.04). In conclusion, chemotherapy appeared to change histopathological heterogeneity. The present study suggested that the histopathological change of intratumoral heterogeneity is reflected by the response to chemotherapy.

Changes in apparent diffusion coefficient and pathological response in colorectal liver metastases after preoperative chemotherapy

BACKGROUND

The pathological response to preoperative chemotherapy of colorectal liver metastases (CRLMs) is predictive of long-term prognosis after liver resection. Accurate preoperative assessment of chemotherapy response could enable treatment optimization.

PURPOSE

To investigate whether changes in lesion-apparent diffusion coefficient (ADC) measured with diffusion-weighted magnetic resonance imaging (MRI) can be used to assess pathological treatment response in patients with CRLMs undergoing preoperative chemotherapy.

MATERIAL AND METHODS

Patients who underwent liver resection for CRLMs after preoperative chemotherapy between January 2011 and December 2019 were retrospectively included if they had undergone MRI before and after preoperative chemotherapy on the same 1.5-T MRI scanner with diffusion-weighted imaging with b-values 50, 400, and 800 s/mm². The pathological chemotherapy response was assessed using the tumor regression grade (TRG) by AJCC/CAP. Lesions were divided into two groups: pathological responding (TRG 0-2) and non-responding (TRG 3). The change in lesion ADC after preoperative chemotherapy was compared between responding and non-responding lesions.

RESULTS

A total of 27 patients with 49 CRLMs were included, and 24/49 lesions showed a pathological chemotherapy response. After chemotherapy, ADC increased in both pathological responding (pretreatment ADC: 1.26 [95% confidence interval (CI)=1.06-1.37] vs. post-treatment ADC: 1.33 [95% CI=1.13-1.56] × 10^-3 mm²/s; P = 0.026) and non-responding lesions (1.12 [95% CI=0.980-1.21] vs. 1.20 [95% CI=1.09-1.43] × 10^-3 mm²/s; P = 0.018). There was no difference in median relative difference in ADC after chemotherapy between pathological responding and non-responding lesions (15.8 [95% CI=1.42-26.3] vs. 7.17 [95% CI=-4.31 to 31.2]%; P = 0.795).

CONCLUSION

Changes in CRLM ADCs did not differ between pathological responding and non-responding lesions.

Can the computed tomography texture analysis of colorectal liver metastases predict the response to first-line cytotoxic chemotherapy?

BACKGROUND

Artificial intelligence in radiology has the potential to assist with the diagnosis, prognostication and therapeutic response prediction of various cancers. A few studies have reported that texture analysis can be helpful in predicting the response to chemotherapy for colorectal liver metastases, however, the results have varied. Necrotic metastases were not clearly excluded in these studies and in most studies the full range of texture analysis features were not evaluated. This study was designed to determine if the computed tomography (CT) texture analysis results of non-necrotic colorectal liver metastases differ from previous reports. A larger range of texture features were also evaluated to identify potential new biomarkers.

AIM

To identify potential new imaging biomarkers with CT texture analysis which can predict the response to first-line cytotoxic chemotherapy in non-necrotic colorectal liver metastases (CRLMs).

METHODS

Patients who presented with CRLMs from 2012 to 2020 were retrospectively selected on the institutional radiology information system of our private radiology practice. The inclusion criteria were non-necrotic CRLMs with a minimum size of 10 mm (diagnosed on archived 1.25 mm portal venous phase CT scans) which were treated with standard first-line cytotoxic chemotherapy (FOLFOX, FOLFIRI, FOLFOXIRI, CAPE-OX, CAPE-IRI or capecitabine). The final study cohort consisted of 29 patients. The treatment response of the CRLMs was classified according to the RECIST 1.1 criteria. By means of CT texture analysis, various first and second order texture features were extracted from a single non-necrotic target CRLM in each responding and non-responding patient. Associations between features and response to chemotherapy were assessed by logistic regression models. The prognostic accuracy of selected features was evaluated by using the area under the curve.

RESULTS

There were 15 responders (partial response) and 14 non-responders (7 stable and 7 with progressive disease). The responders presented with a higher number of CRLMs (P = 0.05). In univariable analysis, eight texture features of the responding CRLMs were associated with treatment response, but due to strong correlations among some of the features, only two features, namely minimum histogram gradient intensity and long run low grey level emphasis, were included in the multiple analysis. The area under the receiver operating characteristic curve of the multiple model was 0.80 (95%CI: 0.64 to 0.96), with a sensitivity of 0.73 (95%CI: 0.48 to 0.89) and a specificity of 0.79 (95%CI: 0.52 to 0.92).

CONCLUSION

Eight first and second order texture features, but particularly minimum histogram gradient intensity and long run low grey level emphasis are significantly correlated with treatment response in non-necrotic CRLMs.

Upper transversal hepatectomy with double hepatic vein resection and reconstruction to treat colorectal cancer liver metastases at the hepatocaval confluence: a strategy to achieve R0 liver-sparing resection

BACKGROUND

Repeated hepatectomies in the therapeutic route of patients with colorectal liver metastases (CRLM) may improve their long term survival. Hepatic vein (HV) resection and reconstruction allows parenchyma-sparing hepatectomy (PSH) and R0 resections for CRLM in contact with one HV. We aimed at verifying the feasibility of PSH with double HV resection and direct reconstruction for CRLM in contact with two HVs at the hepatocaval confluence.

METHODS

Out of 106 consecutive PSH performed for CRLM deep-located in segments I-IVa-VII-VIII, four (3.7%) PSH were performed with resection of CRLM en bloc with two adjacent HVs which were both reconstructed with double direct HV anastomosis: 3 cases between right-HV and middle-HV and 1 case between middle-HV and left-HV. Two patients had previously undergone liver resection. Three patients had one single lesion and one had 5 CRLMs.

RESULTS

Median size of CRLMs in contact with HVs was 25 mm (range 22-30 mm). At histological examination, all resections were R0 except one R1-vascular (detachment from glissonean pedicle): in all cases at least one HV and in 1 case both HVs were infiltrated by the tumor cells. After median follow-up of 18 (range 3.5-41.2) months, all HVs were patent. All patients were alive and in good general conditions, and 3 patients were disease free (one of them following a liver re-resection). One patient experienced a grade IIIa complication. Median hospital-stay was 11 (range 9-13) days.

CONCLUSION

In patients with CRLMs involving two adjacent HVs at the hepatocaval confluence, liver resection with double HV resection and direct reconstruction is feasible and may be considered to guarantee oncological radicality (R0) and spare health parenchyma.