Histopathologic evaluation of liver metastases from colorectal cancer in patients treated with FOLFOXIRI plus bevacizumab

Beyond CT: A Case Analysis of Serial [18F]FDG PET/CT for Assessment of Necrosis and Early Recurrence in Colorectal Liver Metastases

Colorectal cancer is a common malignancy, with the liver being the most frequent site of metastases. [18F] Fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a valuable tool in detecting and evaluating liver metastases and extrahepatic disease. Herein, we present a case of a 76-year-old male with colorectal cancer associated with lung and liver metastases. The patient received 12 chemoimmunotherapy cycles and was then put on maintenance cetuximab; serial [18F]FDG PET/CT scans were utilized to evaluate treatment response. The patient exhibited a positive response to chemoimmunotherapy, with regression of rectal disease and resolution of pulmonary metastatic nodules. Serial [18F]FDG PET/CT scans unveiled three distinct necrotic patterns. The case report advocates that [18F]FDG PET/CT plays an important role in evaluating colorectal liver metastases (CRLM) response to treatment, identifying transient necrosis, early recurrence, and emphasizing the limitations of post-treatment CT scans in identifying early CRLM recurrence. Integrating functional imaging, particularly [18F]FDG PET/CT, promises for management monitoring and surveillance of CRLM patients.

Assessment of the response to systemic treatment of colorectal liver metastases on cross-sectional imaging - a systematic review

Colorectal cancer (CRC) is one of the most common malignancies in the world. Nowadays many treatments are available to help control CRC, including surgery, radiation therapy, interventional radiology, and drug treatments. A multidisciplinary approach and the role of radiologists is needed to assist the surgeon in the management thanks to emerging technology and strategies. The Response Evaluation Criteria in Solid Tumours (RECIST) has been created to objectify and standardize cancer response assessment. Thus, in this article specific presumptions and practical aspects of evaluating responses according to the RECIST 1.1 are discussed. Furthermore, examples of possible response to systemic treatment of colorectal liver metastases (CRLM), including tumour necrosis, apparent diffusion coefficient (ADC) values, tumour calcification, tumour fibrosis and intratumoural fat deposition observed on cross-sectional imaging, are described. Disappearing liver metastases (DLM) presents a therapeutic dilemma. The optimal management of DLM remains controversial due to the uncertainty of residual microscopic disease and effective long-term outcomes. The article provides an overview of the CRLM phenomenon and current possible assessment methods of the response to systemic treatment.

Prognostic impact of R1 resection margin in synchronous and simultaneous colorectal liver metastasis resection: a retrospective cohort study

BACKGROUND

A margin ≥ 1 mm is considered a standard resection margin for colorectal liver metastasis (CRLM). However, microscopic incomplete resection (R1) is not rare since aggressive surgical resection has been attempted in multiple and bilobar CRLM. This study aimed to investigate the prognostic impact of resection margins and perioperative chemotherapy in patients with CRLM.

METHODS

A total of 368 of 371 patients who underwent simultaneous colorectal and liver resection for synchronous CRLM between 2006 and June 2017, excluding three R2 resections, were included in this study. R1 resection was defined as either abutting tumor on the resection line or involved margin in the pathological report. The patients were divided into R0 (n = 304) and R1 (n = 64) groups. The clinicopathological characteristics, overall survival, and intrahepatic recurrence-free survival were compared between the two groups using propensity score matching.

RESULTS

The R1 group had more patients with ≥ 4 liver lesions (27.3 vs. 50.0%, P < 0.001), higher mean tumor burden score (4.4 vs. 5.8%, P = 0.003), and more bilobar disease (38.8 vs. 67.2%, P < 0.001) than the R0 group. Both R0 and R1 groups showed similar long-term outcomes in the total cohort (OS, P = 0.149; RFS, P = 0.414) and after matching (OS, P = 0.097, RFS: P = 0.924). However, the marginal recurrence rate was higher in the R1 group than in the R0 group (26.6 vs. 16.1%, P = 0.048). Furthermore, the resection margin did not have a significant impact on OS and RFS, regardless of preoperative chemotherapy. Poorly differentiated, N-positive stage colorectal cancer, liver lesion number ≥ 4, and size ≥ 5 cm were poor prognostic factors, and adjuvant chemotherapy had a positive impact on survival.

CONCLUSIONS

The R1 group was associated with aggressive tumor characteristics; however, no effect on the OS and intrahepatic RFS with or without preoperative chemotherapy was observed in this study. Tumor biological characteristics, rather than resection margin status, determine long-term prognosis. Therefore, aggressive surgical resection should be considered in patients with CRLM expected to undergo R1 resection in this multidisciplinary approach era.

The Effect of Induction Chemotherapy with VEGF Inhibition on Tumor Response in Synchronously Metastasized Potentially Resectable Colorectal Cancer

(1) Background: The pathological tumor response of the primary tumor to induction chemotherapy in synchronously metastasized colorectal cancer (mCRC) patients has not been investigated. The aim of this study was to compare patients treated with induction chemotherapy combined with vascular endothelial growth factor (VEGF) or with epidermal growth factor receptor (EGFR) antibodies. (2) Methods: We present a retrospective analysis, where we included 60 consecutive patients with potentially resectable synchronous mCRC who received induction chemotherapy combined with either VEGF or EGFR antibodies. The primary endpoint of this study was the regression of the primary tumor, which was assessed by the application of the histological regression score according to Rödel. The secondary endpoints were recurrence-free survival (RFS) and overall survival (OS). (3) Results: A significantly better pathological response and a longer RFS for patients treated with the VEGF antibody therapy compared to those treated with the EGFR antibodies was demonstrated (p = 0.005 for the primary tumor and log-rank = 0.047 for RFS). The overall survival did not differ. The trial was registered with clinicaltrial.gov, number NCT05172635. (4) Conclusion: Induction chemotherapy combined with a VEGF antibody revealed a better pathological response of the primary tumor, leading to a better RFS compared to that with EGFR therapy; this has clinical relevance in patients with potentially resectable synchronously mCRC.

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 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.

Short-Term Outcomes of Secondary Liver Surgery for Initially Unresectable Colorectal Liver Metastases Following Modern Induction Systemic Therapy in the Dutch CAIRO5 Trial

Objective

To present short-term outcomes of liver surgery in patients with initially unresectable colorectal liver metastases (CRLM) downsized by chemotherapy plus targeted agents.

Background

The increase of complex hepatic resections of CRLM, technical innovations pushing boundaries of respectability, and use of intensified induction systemic regimens warrant for safety data in a homogeneous multicenter prospective cohort.

Methods

Patients with initially unresectable CRLM, who underwent complete resection after induction systemic regimens with doublet or triplet chemotherapy, both plus targeted therapy, were selected from the ongoing phase III CAIRO5 study (NCT02162563). Short-term outcomes and risk factors for severe postoperative morbidity (Clavien Dindo grade ≥ 3) were analyzed using logistic regression analysis.

Results

A total of 173 patients underwent resection of CRLM after induction systemic therapy. The median number of metastases was 9 and 161 (93%) patients had bilobar disease. Thirty-six (20.8%) 2-stage resections and 88 (51%) major resections (>3 liver segments) were performed. Severe postoperative morbidity and 90-day mortality was 15.6% and 2.9%, respectively. After multivariable analysis, blood transfusion (odds ratio [OR] 2.9 [95% confidence interval (CI) 1.1-6.4], P = 0.03), major resection (OR 2.9 [95% CI 1.1-7.5], P = 0.03), and triplet chemotherapy (OR 2.6 [95% CI 1.1-7.5], P = 0.03) were independently correlated with severe postoperative complications. No association was found between number of cycles of systemic therapy and severe complications (r = -0.038, P = 0.31).

Conclusion

In patients with initially unresectable CRLM undergoing modern induction systemic therapy and extensive liver surgery, severe postoperative morbidity and 90-day mortality were 15.6% and 2.7%, respectively. Triplet chemotherapy, blood transfusion, and major resections were associated with severe postoperative morbidity.

Predicting the Response to FOLFOX-Based Chemotherapy Regimen from Untreated Liver Metastases on Baseline CT: a Deep Neural Network Approach

In developed countries, colorectal cancer is the second cause of cancer-related mortality. Chemotherapy is considered a standard treatment for colorectal liver metastases (CLM). Among patients who develop CLM, the assessment of patient response to chemotherapy is often required to determine the need for second-line chemotherapy and eligibility for surgery. However, while FOLFOX-based regimens are typically used for CLM treatment, the identification of responsive patients remains elusive. Computer-aided diagnosis systems may provide insight in the classification of liver metastases identified on diagnostic images. In this paper, we propose a fully automated framework based on deep convolutional neural networks (DCNN) which first differentiates treated and untreated lesions to identify new lesions appearing on CT scans, followed by a fully connected neural networks to predict from untreated lesions in pre-treatment computed tomography (CT) for patients with CLM undergoing chemotherapy, their response to a FOLFOX with Bevacizumab regimen as first-line of treatment. The ground truth for assessment of treatment response was histopathology-determined tumor regression grade. Our DCNN approach trained on 444 lesions from 202 patients achieved accuracies of 91% for differentiating treated and untreated lesions, and 78% for predicting the response to FOLFOX-based chemotherapy regimen. Experimental results showed that our method outperformed traditional machine learning algorithms and may allow for the early detection of non-responsive patients.

Effect of Adding Bevacizumab to Chemotherapy on Pathologic Response to Preoperative Systemic Therapy for Resectable Colorectal Liver Metastases: A Systematic Review and Meta-analysis

BACKGROUND

Liver-limited metastatic colorectal cancer is a potentially curable disease. Pathologic response (pR) to preoperative chemotherapy (CT) for colorectal liver metastases (CLM) is a surrogate endpoint for overall survival (OS). We conducted the first meta-analysis of observational studies to estimate the overall effect of bevacizumab on pR in preoperative systemic therapy for CLM.

METHODS

We systematically searched PubMed, Cochrane Library, CINAHL, Web of Science, Embase, and LILACS for studies published between January 2004 and August 2019 that compared the pR of CT plus bevacizumab to CT alone as preoperative therapy for CLM. The primary endpoint was pathologic complete response (pCR). Secondary endpoints were pathologic major (pMaR) and minor (pMiR) response. Overall effects were expressed by odds ratios (ORs) and 95% confidence intervals (CIs) using a random-effects model.

RESULTS

Of the 1,452 studies yielded by the search, 9 were eligible, totaling 1,202 patients (516 CT plus bevacizumab and 686 CT alone). The addition of bevacizumab to CT increased the pCR rate without reaching statistical significance (OR: 1.24, 95% CI 0.81 to 1.92, P = .32). However, pMaR was significantly higher (OR: 2.45, 95% CI 1.85 to 3.25, P < .001), and pMiR was significantly lower (OR: 0.41, 95% CI 0.31 to 0.54, P < .001), in the bevacizumab group. The analyses showed a low level of heterogeneity (I² = 0% to 6%). Publication bias was not found.

CONCLUSIONS

This meta-analysis demonstrates that bevacizumab plus preoperative CT is associated with higher rates of pR in CLM. Antiangiogenics might improve the OS of CLM patients and should be evaluated in randomized clinical trials.

MICROABSTRACT

The benefit of perioperative chemotherapy for colorectal liver metastases (CLM) is uncertain, but pathologic response (pR) to preoperative chemotherapy is a strong prognostic factor. Our meta-analysis of observational studies compared the pR of bevacizumab plus chemotherapy to chemotherapy alone as preoperative systemic therapy in the management of CLM. The addition of bevacizumab was associated with significantly higher rates of pR.

Trial Watch: Tumor-targeting monoclonal antibodies in cancer therapy

In 1997, for the first time in history, a monoclonal antibody (mAb), i.e., the chimeric anti-CD20 molecule rituximab, was approved by the US Food and Drug Administration for use in cancer patients. Since then, the panel of mAbs that are approved by international regulatory agencies for the treatment of hematopoietic and solid malignancies has not stopped to expand, nowadays encompassing a stunning amount of 15 distinct molecules. This therapeutic armamentarium includes mAbs that target tumor-associated antigens, as well as molecules that interfere with tumor-stroma interactions or exert direct immunostimulatory effects. These three classes of mAbs exert antineoplastic activity via distinct mechanisms, which may or may not involve immune effectors other than the mAbs themselves. In previous issues of OncoImmunology, we provided a brief scientific background to the use of mAbs, all types confounded, in cancer therapy, and discussed the results of recent clinical trials investigating the safety and efficacy of this approach. Here, we focus on mAbs that primarily target malignant cells or their interactions with stromal components, as opposed to mAbs that mediate antineoplastic effects by activating the immune system. In particular, we discuss relevant clinical findings that have been published during the last 13 months as well as clinical trials that have been launched in the same period to investigate the therapeutic profile of hitherto investigational tumor-targeting mAbs.

Colorectal liver metastases: radiopathological correlation

With the development of chemotherapy regimens, targeted therapies, and hepatic surgery, the survival of patients with colorectal liver metastases (CRLM) has dramatically improved. Imaging plays a central role for the diagnosis, staging, and treatment allocation in these patients. To interpret CRLM on imaging, radiologists must be familiar with the main imaging features of untreated tumors as well as the modifications induced by systemic therapies, and their meaning in relation to pathological tumor response and tumor biology. CRLM have the same histological features as the primary tumor. Most are “non-otherwise specified” (NOS) adenocarcinomas. The mucinous tumor is the most common of the rare subtypes. In NOS tumors, imaging usually differentiates central areas of necrosis from peripheral proliferating tumors and desmoplastic reaction. Areas of mucin mixed with fibrosis are seen in mucinous subtypes to help differentiate the metastases from other tumors cysts or hemangiomas. After treatment, the viable tumor is gradually replaced by ischemic-like necrosis and fibrosis, and remnants cells are mainly located on the periphery of tumors. Imaging can help predict the degree of tumor response, but changes can be difficult to differentiate from the pretherapeutic appearance. When chemotherapy is interrupted or in case of resistance to treatment, a peripheral infiltrating halo of tumor growth may appear. The purpose of the article is to illustrate the significance of the imaging features of colorectal liver metastases during systemic therapy, using radiopathological correlations.

Synthesis, mechanisms of action, and toxicity of novel aminophosphonates derivatives conjugated irinotecan in vitro and in vivo as potent antitumor agents

Twenty novel aminophosphonates derivatives (5a-5j and 6a-6j) conjugated irinotecan were synthesized through esterification reaction, and evaluated their anticancer activities using MTT assay. In vitro evaluation revealed that they displayed similar or superior cytotoxicity compared to the positive drug irinotecan against A549, MCF-7, SK-OV-3, MG-63, U2OS and multidrug-resistant (MDR) SK-OV-3/CDDP cancer cell lines. Among them, 9b displayed the most potent activity, with IC₅₀ values of 0.92-3.23 μM against five human cancer cells, which exhibited a 5.4-19.1-fold increase in activity compared to the reference drug irinotecan, respectively. Moreover, cellular mechanism studies suggested that 9b arrested cell cycle at S stage and induced cell apoptosis along with the decrease of mitochondrial membrane potential (MMP). Interestingly, 9b significantly inhibited tumor growth in SK-OV-3 xenograft models in vivo without apparent toxicity, which was better than the positive drug irinotecan. Taken together, 9b possessed potent antitumor activity and may be a promising candidate for the potential treatment of human ovarian cancer cells.

Baseline 3D-ADC outperforms 2D-ADC in predicting response to treatment in patients with colorectal liver metastases

OBJECTIVES

To examine the value of baseline 3D-ADC and to predict short-term response to treatment in patients with hepatic colorectal metastases (CLMs).

METHODS

Liver MR images of 546 patients with CLMs (2008-2015) were reviewed retrospectively and 68 patients fulfilled inclusion criteria. Patients had received systemic chemotherapy (n = 17), hepatic trans-arterial chemoembolization or TACE (n = 34), and ⁹⁰Y radioembolization (n = 17). Baseline (pre-treatment) 3D-ADC (volumetric) of metastatic lesions was calculated employing prototype software. RECIST 1.1 was used to assess short-term response to treatment. Prediction of response to treatment by baseline 3D-ADC and 2D-ADC (ROI-based) was also compared in all patients.

RESULTS

Partial response to treatment (minimum 30% decrease in tumor largest transverse diameter) was seen in 35.3% of patients; 41.2% with systemic chemotherapy, 32.4% with TACE, and 35.3% with ⁹⁰Y radioembolization (p = 0.82). Median baseline 3D-ADC was significantly lower in responding than in nonresponding lesions. Area under the curve (AUC) of 3D-ADC was 0.90 in ⁹⁰Y radioembolization patients, 0.88 in TACE patients, and 0.77 in systemic chemotherapy patients (p < 0.01). Optimal prediction was observed with the 10th percentile of ADC (1006 × 10^-6 mm²/s), yielding sensitivity and specificity of 77.4% and 91.3%, respectively. 3D-ADC outperformed 2D-ADC in predicting response to treatment (AUC; 0.86 vs. 0.71; p < 0.001).

CONCLUSION

Baseline 3D-ADC is a highly specific biomarker in predicting partial short-term response to treatment in hepatic CLMs.

KEY POINTS

• Baseline 3D-ADC is a highly specific biomarker in predicting response to different treatments in hepatic CLMs. • The prediction level of baseline ADC is better for⁹⁰Y radioembolization than for systemic chemotherapy/TACE in hepatic CLMs. • 3D-ADC outperforms 2D-ADC in predicting short-term response to treatment in hepatic CLMs.

Predictive factors of histological response of colorectal liver metastases after neoadjuvant chemotherapy

BACKGROUND

Colorectal cancer is the third most common cancer in men and the second most common in women worldwide. Almost a third of the patients has or will develop liver metastases. Neoadjuvant chemotherapy (NAC) has recently become nearly systematic prior to surgery of colorectal livers metastases (CRLMs). The response to NAC is evaluated by radiological imaging according to morphological criteria. More recently, the response to NAC has been evaluated based on histological criteria of the resected specimen. The most often used score is the tumor regression grade (TRG), which considers the necrosis, fibrosis, and number of viable tumor cells.

AIM

To analyze the predictive factors of the histological response, according to the TRG, on CRLM surgery performed after NAC.

METHODS

From January 2006 to December 2013, 150 patients who had underwent surgery for CRLMs after NAC were included. The patients were separated into two groups based on their histological response, according to Rubbia-Brandt TRG. Based on their TRG, each patient was either assigned to the responder (R) group (TRG 1, 2, and 3) or to the non-responder (NR) group (TRG 4 and 5). All of the histology slides were re-evaluated in a blind manner by the same specialized pathologist. Univariate and multivariate analyses were performed.

RESULTS

Seventy-four patients were classified as responders and 76 as non-responders. The postoperative mortality rate was 0.7%, with a complication rate of 38%. Multivariate analysis identified five predictive factors of histological response. Three were predictive of non-response: More than seven NAC sessions, the absence of a radiological response after NAC, and a repeat hepatectomy (P < 0.005). Two were predictive of a good response: A rectal origin of the primary tumor and a liver-first strategy (P < 0.005). The overall survival was 57% at 3 yr and 36% at 5 yr. The disease-free survival rates were 14% at 3 yr and 11% at 5 yr. The factors contributing to a poor prognosis for disease-free survival were: No histological response after NAC, largest metastasis > 3 cm, more than three preoperative metastases, R1 resection, and the use of a targeted therapy with NAC (P < 0.005).

CONCLUSION

A non-radiological response and a number of NAC sessions > 7 are the two most pertinent predictive factors of non-histological response (TRG 4 or 5).

Angiogenic desmoplastic histopathological growth pattern as a prognostic marker of good outcome in patients with colorectal liver metastases

BACKGROUND

In patients with resectable colorectal liver metastases (CRLM), distinct histopathological growth patterns (HGPs) develop at the interface between the tumour and surrounding tissue. The desmoplastic (d) HGP is characterised by angiogenesis and a peripheral fibrotic rim, whereas non-angiogenic HGPs co-opt endogenous sinusoidal hepatic vasculature. Evidence from previous studies has suggested that patients with dHGP in their CRLM have improved prognosis as compared to patients with non-desmoplastic HGPs. However, these studies were relatively small and applied arbitrary cut-off values for the determination of the predominant HGP. We have now investigated the prognostic effect of dHGP in a large cohort of patients with CRLM resected either with or without neoadjuvant chemotherapy.

METHODS

All consecutive patients undergoing a first partial hepatectomy for CRLM between 2000 and 2015 at a tertiary referral centre were considered for inclusion. HGPs were assessed in archival H&E stained slides according to recently published international consensus guidelines. The dHGP was defined as desmoplastic growth being present in 100% of the interface between the tumour and surrounding liver.

RESULTS

In total, HGPs in CRLMs from 732 patients were assessed. In the chemo-naive patient cohort (n = 367), the dHGP was present in 19% (n = 68) and the non-dHGP was present in 81% (n = 299) of patients. This dHGP subgroup was independently associated with good overall survival (OS) (HR: 0.39, p < 0.001) and progression-free survival (PFS) (HR: 0.54, p = 0.001). All patients with any CRLM with a non-dHGP had significantly reduced OS compared to those patients with 100% dHGP, regardless of the proportion of non-dHGP (all p values ≤ 0.001). In the neoadjuvantly treated patient cohort (n = 365), more patients were found to express dHGP (n = 109, 30%) (adjusted odds ratio: 2.71, p < 0.001). On univariable analysis, dHGP was associated with better OS (HR 0.66, p = 0.009) and PFS (HR 0.67, p = 0.002). However, after correction for confounding by means of multivariable analysis no significant association of dHGP with OS (HR 0.92, p = 0.623) or PFS (HR 0.76, p = 0.065) was seen.

CONCLUSIONS

The current study demonstrates that the angiogenic dHGP in CRLM resected from chemo-naive patients acts as a strong, positive prognostic marker, unmatched by any other prognosticator. This observation warrants the evaluation of the clinical utility of HGPs in prospective clinical trials.

Correlation between CT morphologic appearance and histologic findings in colorectal liver metastasis after preoperative chemotherapy

PURPOSE

Radiological evaluation of the efficacy of preoperative chemotherapy for colorectal liver metastasis (CRLM) is the most important tool for determining treatment strategies. The aim of this study was to identify a correlation between morphologic appearance on computed tomography (CT) and histologic findings of CRLM after preoperative chemotherapy.

METHODS

We examined 47 patients who had undergone a first hepatic resection for CRLM after preoperative chemotherapy and had received contrast-enhanced CT scans. We assessed the morphologic appearance of the overall attenuation based on metastases changing from heterogeneous to mixed and homogenous lesions, the tumor-liver interface, and the peripheral rim enhancement on CT. Histologic parameters included usual necrosis (UN), infarct-like necrosis (ILN), three-zonal change, dangerous halo, mucous lake, shape of ILN, dominant type of necrosis, and presence of viable tumor cells. The relationship between morphologic appearance and histologic findings was evaluated.

RESULTS

CT overall attenuation revealed that UN predominance was more common in the heterogeneous group than in the mixed and homogeneous groups (P = 0.011). The frequency of ILN increased sequentially from ill-defined to variable and sharp at the tumor-liver interface (P = 0.038), and the frequency of UN decreased sequentially from present to partially resolved and completely resolved in the peripheral rim enhancement (P = 0.023). The histologic presence of viable tumor cells was closely associated with the tumor-liver interface (P = 0.0003) and the peripheral rim enhancement (P = 0.004).

CONCLUSIONS

CT morphologic appearance of CRLM after preoperative chemotherapy is correlated with histologic findings regarding necrosis.

DNA damage predicts prognosis and treatment response in colorectal liver metastases superior to immunogenic cell death and T cells

Preclinical models indicate that DNA damage induces type I interferon (IFN), which is crucial for the induction of an anti-tumor immune response. In human cancers, however, the association between DNA damage and an immunogenic cell death (ICD), including the release and sensing of danger signals, the subsequent ER stress response and a functional IFN system, is less clear.

Methods: Neoadjuvant-treated colorectal liver metastases (CLM) patients, undergoing liver resection in with a curative intent, were retrospectively enrolled in this study (n=33). DNA damage (γH2AX), RNA and DNA sensors (RIG-I, DDX41, cGAS, STING), ER stress response (p-PKR, p-eIF2α, CALR), type I and type II IFN- induced proteins (MxA, GBP1), mature dendritic cells (CD208), and cytotoxic and memory T cells (CD3, CD8, CD45RO) were investigated by an immunohistochemistry whole-slide tissue scanning approach and further correlated with recurrence-free survival (RFS), overall survival (OS), radiographic and pathologic therapy response.

Results: γH2AX is a negative prognostic marker for RFS (HR 1.32, 95% CI 1.04-1.69, p=0.023) and OS (HR 1.61, 95% CI 1.23-2.11, p<0.001). A model comprising of DDX41, STING and p-PKR predicts radiographic therapy response (AUC=0.785, p=0.002). γH2AX predicts prognosis superior to the prognostic value of CD8. CALR positively correlates with GBP1, CD8 and cGAS. A model consisting of γH2AX, p-eIF2α, DDX41, cGAS, CD208 and CD45RO predicts pathological therapy response (AUC=0.944, p<0.001).

Conclusion: In contrast to preclinical models, DNA damage inversely correlated with ICD and its associated T cell infiltrate and potentially serves as a therapeutic target in CLM.

A Review of Clinical Studies and Practical Guide for the Administration of Triplet Chemotherapy Regimens with Bevacizumab in First-line Metastatic Colorectal Cancer

Colorectal cancer is the third most common cancer worldwide. A significant proportion of patients presents with unresectable metastatic disease or develops metachronous metastases following surgical resection of the primary tumor. The prognosis of the disease has improved over the past two decades, with extended multimodality treatment options and the development of increasingly intensified chemotherapy regimens that now typically include targeted biologics. A recent advance in therapy is a treatment regimen composed of three chemotherapeutic agents (i.e., triplet chemotherapy: 5-fluorouracil [5-FU]/leucovorin [LV], oxaliplatin, and irinotecan; FOLFOXIRI) in combination with the vascular endothelial growth factor inhibitor bevacizumab. This regimen has been shown to elicit significantly improved objective response rates and median progression-free survival compared with 5-FU/LV and irinotecan in combination with bevacizumab. However, triplet chemotherapy has been associated with increased rates of chemotherapy-related adverse events, and treatment-emergent adverse events should be properly managed to minimize treatment interruption or discontinuation. We present herein a review of clinical studies evaluating the safety and efficacy of FOLFOXIRI with bevacizumab in metastatic colorectal cancer, and propose a practical guide for the management of adverse events associated with the regimen.

Aflibercept Plus FOLFIRI vs. Placebo Plus FOLFIRI in Second-Line Metastatic Colorectal Cancer: a Post Hoc Analysis of Survival from the Phase III VELOUR Study Subsequent to Exclusion of Patients who had Recurrence During or Within 6 Months of Completing Adjuvant Oxaliplatin-Based Therapy

The aim of this post hoc analysis of the VELOUR study (ClinicalTrials.gov NCT00561470) was to investigate the treatment effect of adding aflibercept to second-line infusional 5-fluorouracil (5-FU), leucovorin and irinotecan (FOLFIRI) in patients with metastatic colorectal cancer (mCRC) who had failed any prior oxaliplatin-containing regimen. Adjuvant rapid relapsers (ARR), who were enrolled directly following relapse during or within 6 months of completion of oxaliplatin-containing adjuvant chemotherapy (N = 124, including 17 patients who also received bevacizumab as part of their adjuvant therapy), were excluded from the original VELOUR intention-to-treat (ITT) population (N = 1226). After exclusion of the ARR, overall survival (OS) in the ITT minus ARR (ITT-ARR) population (N = 1102) was longer in the aflibercept plus FOLFIRI arm than in the placebo plus FOLFIRI arm [hazard ratio (HR) 0.78, 95 % confidence interval (CI) 0.68-0.90; median survival difference 1.87 months]. In the subgroup of patients assigned to the prior bevacizumab stratum at randomization, OS was numerically longer in the aflibercept plus FOLFIRI arm than in the placebo plus FOLFIRI arm (HR 0.81; 95 % CI 0.63-1.04; median survival difference 2.14 months). Comparison of the post hoc analysis results with the primary analysis from VELOUR suggests that the inclusion of the directly enrolled ARR may have understated the aflibercept treatment benefit for both bevacizumab-pretreated and bevacizumab-naïve patients in the strictly second-line setting although no definitive conclusion may be inferred. The benefit associated with the addition of aflibercept to second-line FOLFIRI in patients with mCRC was observed whatever the timing of first-line disease progression. There were no unexpected safety concerns.

Clinical Significance of Discordance between Carcinoembryonic Antigen Levels and RECIST in Metastatic Colorectal Cancer

Purpose

The purpose of this study was to investigate the prognostic implications of carcinoembryonic antigen (CEA) levels that are inconsistent with Response Evaluation Criteria in Solid Tumor (RECIST) responses in metastatic colorectal cancer patients.

Materials and Methods

We retrospectively evaluated 360 patients with at least one measurable lesion who received first-line palliative chemotherapy. CEA-response was defined as CEA-complete response (CR; CEA normalization), CEA-partial response (PR; ≥ 50% decrease in CEA levels), CEA-progressive disease (PD; ≥ 50% increase in CEA levels), and CEA-stable disease (SD; non-CR/PR/PD). Overall survival (OS) and progression-free survival (PFS) were evaluated according to CEA-response.

Results

In RECIST-PR patients, poorer CEA-response was associated with disease progression at the subsequent evaluation. In RECIST-SD patients, CEA-CR and -PR were associated with lower disease progression rates than CEA-PD at the subsequent evaluation. Correlations between survival outcome and CEA-response in same-category RECIST patients were assessed. In RECIST-PR patients, discordant CEA-response (CEA-PD/SD) was associated with poorer survival than CEA-CR/PR (median OS and PFS, 44.0 and 15.4 [CEA-CR], 28.9 and 12.5 [CEA-PR], 21.0 and 9.8 [CEA-SD], and 13.0 and 7.0 [CEA-PD] months, respectively; all p < 0.001). In RECIST-SD patients, favorable CEA-response produced better survival (median OS and PFS, 26.8 and 21.0 [CEA-CR], 21.0 and 11.0 [CEA-PR], 16.1 and 8.2 [CEA-SD], and 12.2 and 6.0 [CEA-PD] months, respectively; all p < 0.001). RECIST-PD patients with CEA-CR showed longer OS than those with CEA-PD. Multivariate analysis demonstrated that discordant CEA-response is a powerful prognostic factor for RECIST-PR and RECIST-SD patients.

Conclusion

Among patients of the same RECIST-response categories, CEA-response patterns are significantly prognostic and strongly predictive of subsequent evaluation outcomes.

Prognostic impact of margin status in liver resections for colorectal metastases after bevacizumab

BACKGROUND

Margin status with resection of colorectal liver metastasis (CRLM) was an important prognostic factor in the years before the introduction of biological chemotherapy. This study examined outcomes following CRLM resection in patients who received neoadjuvant chemotherapy with or without the monoclonal antiangiogenic antibody bevacizumab.

METHODS

Patients who underwent surgery for CRLM at the Johns Hopkins Hospital between 2000 and 2015 were identified from an institutional database. Data regarding surgical margin status, preoperative bevacizumab administration and overall survival (OS) were assessed using multivariable analyses.

RESULTS

Of 630 patients who underwent CRLM resection, 417 (66·2 per cent) received neoadjuvant chemotherapy with (214, 34·0 per cent) or without (203, 32·2 per cent) bevacizumab. The remaining 213 (33·8 per cent) did not receive neoadjuvant chemotherapy. Univariable analysis found that positive margins were associated with worse 5-year OS than R0 resection (36·2 versus 54·9 per cent; P = 0·005). After dichotomizing by the receipt of preoperative bevacizumab versus chemotherapy alone, the prognostic value of pathological margin persisted among patients who did not receive preoperative bevacizumab (5-year OS 53·0 versus 37 per cent after R0 versus R1 resection; P = 0·010). OS was not significantly associated with margin status in bevacizumab-treated patients (5-year OS 46·8 versus 33 per cent after R0 versus R1 resection; P = 0·081), in whom 5-year survival was slightly worse (presumably reflecting more advanced disease) than among patients treated with cytotoxic agents alone. Pathological margin status was not significantly associated with 5-year OS in patients with a complete or near-complete response to chemotherapy and bevacizumab (43 versus 30 per cent after R0 versus R1 resection; P = 0·917), but this may be due to a type II error.

CONCLUSION

The impact of margin status varied according to the receipt of bevacizumab. Bevacizumab may have a role to play in improving outcomes among patients with more advanced disease.

Pathological complete response after neoadjuvant chemotherapy for rectal cancer with synchronous multiple liver metastases: a report of an unusual case

Background

Systemic chemotherapy for stage IV colorectal cancer has advanced markedly in the recent years. We report an unusual case of 13 synchronous liver metastases for which a pathological complete response was achieved with neoadjuvant chemotherapy (NAC) consisting of a combination of 5-fluorouracil (5-FU), oxaliplatin, leucovorin (mFOLFOX6), and bevacizumab.

Case presentation

A 44-year-old man was diagnosed with colorectal cancer with synchronous liver metastases. We resected the primary rectal tumor first. Further, after providing NAC for hepatic metastases, lateral segmentectomy and partial resection of the liver were performed. The subsequent result was compatible with a complete pathological response. The postoperative course was uneventful, and the patient is currently alive 5 years after the first surgery without evidence of recurrence and without adjuvant chemotherapy.

Conclusions

For patients with initially resectable colorectal liver metastases, the survival benefits of NAC are still unclear. We report a rare case of 13 synchronous liver metastatic lesions from rectal cancer with a complete pathological response after neoadjuvant bevacizumab-containing chemotherapy.

Timing and extent of response in colorectal cancer: critical review of current data and implication for future trials

The identification of new surrogate endpoints for advanced colorectal cancer is becoming crucial and, along with drug development, it represents a research field increasingly studied. Although overall survival (OS) remains the strongest trial endpoint available, it requires larger sample size and longer periods of time for an event to happen. Surrogate endpoints such as progression free survival (PFS) or response rate (RR) may overcome these issues but, as such, they need to be prospectively validated before replacing the real endpoints; moreover, they often bear many other limitations. In this narrative review we initially discuss the role of time-to-event endpoints, objective response and response rate as surrogates of OS in the advanced colorectal cancer setting, discussing also how such measures are influenced by the tumor assessment criteria currently employed. We then report recent data published about early tumor shrinkage and deepness of response, which have recently emerged as novel potential endpoint surrogates, discussing their strengths and weaknesses and providing a critical comment. Despite being very compelling, the role of such novel response measures is yet to be confirmed and their surrogacy with OS still needs to be further investigated within larger and well-designed trials.

Irinotecan Delivery by Lipid-Coated Mesoporous Silica Nanoparticles Shows Improved Efficacy and Safety over Liposomes for Pancreatic Cancer

Urgent intervention is required to improve the 5 year survival rate of pancreatic ductal adenocarcinoma (PDAC). While the four-drug regimen, FOLFIRINOX (comprising irinotecan, 5-fluorouracil, oxaliplatin, and leucovorin), has a better survival outcome than the more frequently used gemcitabine, the former treatment platform is highly toxic and restricted for use in patients with good performance status. Since irinotecan contributes significantly to FOLFIRINOX toxicity (bone marrow and gastrointestinal tract), our aim was to reduce the toxicity of this drug by a custom-designed mesoporous silica nanoparticle (MSNP) platform, which uses a proton gradient for high-dose irinotecan loading across a coated lipid bilayer (LB). The improved stability of the LB-coated MSNP (LB-MSNP) carrier allowed less drug leakage systemically with increased drug concentrations at the tumor sites of an orthotopic Kras-derived PDAC model compared to liposomes. The LB-MSNP nanocarrier was also more efficient for treating tumor metastases. Equally important, the reduced leakage and slower rate of drug release by the LB-MSNP carrier dramatically reduced the rate of bone marrow, gastrointestinal, and liver toxicity compared to the liposomal carrier. We propose that the combination of high efficacy and reduced toxicity by the LB-MSNP carrier could facilitate the use of irinotecan as a first-line therapeutic to improve PDAC survival.

Diagnostic accuracy of diffusion-weighted magnetic resonance imaging versus positron emission tomography/computed tomography for early response assessment of liver metastases to Y90-radioembolization

Objectives

Patients with hepatic metastases who are candidates for Y90-radioembolization (Y90-RE) usually have advanced tumor stages with involvement of both liver lobes. Per current guidelines, these patients have usually undergone several cycles of potentially hepatotoxic systemic chemotherapy before Y90-RE is at all considered, requiring split (lobar) treatment sessions to reduce hepatic toxicity. Assessing response to Y90-RE early, that is, already after the first lobar session, would be helpful to avoid an ineffective and potentially hepatotoxic second lobar treatment. We investigated the accuracy with which diffusion- weighted magnetic resonance imaging (DWI-MRI) and positron emission tomography/computed tomography (PET/CT) can provide this information.

Methods

An institutional review board–approved prospective intraindividual comparison trial on 35 patients who underwent fluorodeoxyglucose PET/CT and DWI-MRI within 6 weeks before and 6 weeks after Y90-RE to treat secondary-progressive liver metastases from solid cancers (20 colorectal, 13 breast, 2 other) was performed. An increase of minimal apparent diffusion coefficient (ADCmin) or decrease of maximum standard uptake value (SUVmax) by at least 30% was regarded as positive response. Long-term clinical and imaging follow-up was used to distinguish true- from false-response classifications.

Results

On the basis of long-term follow-up, 23 (66%) of 35 patients responded to the Y90 treatment. No significant changes of metastases size or contrast enhancement were observable on pretreatment versus posttreatment CT or magnetic resonance images.However, overall SUVmax decreased from 8.0 ± 3.9 to 5.5 ± 2.2 (P < 0.0001), and ADCmin increased from 0.53 ± 0.13 × 10⁻³ mm²/s to 0.77 ± 0.26 × 10⁻³ mm²/s (P < 0.0001). Pretherapeutic versus posttherapeutic changes of ADCmin and SUVmax correlated moderately (r = −0.53). In 4 of the 35 patients (11%), metastases were fluorodeoxyglucose-negative such that no response assessment was possible by PET. In 25 (71%) of the 35 patients, response classification by PET and DWI-MRI was concordant; in 6 (17%) of the 35, it was discordant. In 5 of the 6 patients with discordant classifications, follow-up confirmed diagnoses made by DWI. The positive predictive value to predict response was 22 (96%) of 23 for MRI and 15 (88%) of 17 for PET. The negative predictive value to predict absence was 11 (92%) of 12 for MRI and 10 (56%) of 18 for PET. Sensitivity for detecting response was significantly higher for MRI (96%; 22/23) than for PET (65%; 15/23) (P < 0.02).

Conclusions

Diffusion-weighted magnetic resonance imaging appears superior to PET/CT for early response assessment in patients with hepatic metastases of common solid tumors. It may be used in between lobar treatment sessions to guide further management of patients who undergo Y90-RE for hepatic metastases.

FOLFOXIRI or FOLFOXIRI plus bevacizumab as first-line treatment of metastatic colorectal cancer: a propensity score-adjusted analysis from two randomized clinical trials

BACKGROUND

FOLFOXIRI plus bevacizumab is a valid option as upfront treatment for metastatic colorectal cancer (mCRC) patients. While several trials investigated the effect of combining bevacizumab with different chemotherapy regimens, including fluoropyrimidines monotherapy and oxaliplatin- or irinotecan-containing doublets, no randomized comparison assessing the impact of the addition of bevacizumab to FOLFOXIRI is available.

PATIENTS AND METHODS

A total of 122 mCRC patients received first-line FOLFOXIRI in the phase III trial by the GONO (FOLFOXIRI group) and 252 patients received first-line FOLFOXIRI plus bevacizumab in the TRIBE trial (FOLFOXIRI plus bevacizumab group). A propensity score-adjusted method was adopted to provide an estimation of the benefit from the addition of bevacizumab to FOLFOXIRI in terms of survival and activity parameters.

RESULTS

Patients in the FOLFOXIRI group had more frequently Eastern Cooperative Oncology Group performance status of one or two, high Köhne score, metachronous and liver-limited disease, had previously received adjuvant treatments and had their primary tumors resected. The median progression-free survival (PFS) was 12.3 months in the FOLFOXIRI plus bevacizumab group compared with 10.0 months in the FOLFOXIRI group {propensity score-adjusted hazard ratio (HR) 0.74 [95% confidence interval (CI) 0.59-0.94], P = 0.013}. This association was significant also in the multivariable model (P = 0.024). The median OS was 29.8 months in the FOLFOXIRI plus bevacizumab group compared with 23.6 months in the FOLFOXIRI group [propensity score-adjusted HR: 0.72 (95% CI 0.56-0.93), P = 0.014]. At the multivariable model, the addition of bevacizumab was still associated with significantly longer OS (P = 0.030). No significant differences in RECIST response rate (RR) [65.1% versus 55.7%; propensity score-adjusted odds ratio (OR): 1.29 (95% CI 0.81-2.05), P = 0.280], early RR [62.7% versus 57.8%; OR: 1.14 (95% CI 0.68-1.93), P = 0.619] and median depth of response (42.2% versus 53.8%, P = 0.259) were reported.

CONCLUSIONS

Though in the absence of a randomized comparison, the addition of bevacizumab to FOLFOXIRI provides significant benefit in PFS and OS, thus supporting the use of FOLFOXIRI plus bevacizumab as upfront treatment for mCRC patients.

TRIALS' NUMBERS

NCT01219920 and NCT00719797.

Tumor histopathology predicts outcomes after resection of colorectal cancer liver metastases treated with and without pre-operative chemotherapy

BACKGROUND AND OBJECTIVES

Study objectives, included determination of: (i) associations between radiologic and pathologic responses of colorectal cancer liver metastases (CRCLM) to chemotherapy; and (ii) whether CRCLM histopathology is associated with recurrence free survival (RFS) after resection among patients not treated with pre-operative chemotherapy (untreated).

METHODS

Demographics, clinicopathologic characteristics, and outcomes among patients who underwent CRCLM resection from 2007 to 2014 were reviewed. Tumor regression grade (TRG) of 1-2 and 4-5 depict low and high proportions of viable tumor relative to fibrosis, respectively.

RESULTS

Of 138 patients, 84 (60.9%) were treated with pre-operative chemotherapy. In these patients, there was no difference in proportions with TRG 1-2 among those with verses without radiologic response (26.9% vs. 18.8%, P = 0.393). TRG 1-2 was associated with superior RFS on univariable (median 15 vs. 6 months, P < 0.001) and multivariable (P = 0.005) analyses. Radiologic response was not associated with RFS. Among untreated patients (n = 54), TRG 4-5 was associated with poor RFS on univariable (median 44 vs. 15 months, P = 0.011) and multivariable (P = 0.012) analyses.

CONCLUSIONS

High proportions of CRCLM fibrosis occur in 20% of patients without radiologic response to chemotherapy. Among untreated patients, high proportion of viable tumor relative to fibrosis is associated with poor RFS after resection. J. Surg. Oncol. 2016;113:456-462. © 2016 Wiley Periodicals, Inc.

BEV-IP: Perioperative chemotherapy with bevacizumab in patients undergoing cytoreduction and intraperitoneal chemoperfusion for colorectal carcinomatosis

Background

Selected patients with peritoneal carcinomatosis (PC) from colorectal cancer (CRC) benefit from cytoreductive surgery (CRS) combined with intraperitoneal chemoperfusion (IPC). However, even after optimal cytoreduction, systemic and locoregional recurrence are common. Perioperative chemotherapy with bevacizumab (BEV) may improve the outcome of these patients.

Methods/Design

The BEV-IP study is a phase II, single-arm, open-label study aimed at patients with colorectal or appendiceal adenocarcinoma with synchronous or metachronous PC. This study evaluates whether perioperative chemotherapy including BEV in combination with CRS and oxaliplatin-based IPC results in acceptable morbidity and mortality (primary composite endpoint). Secondary endpoints are treatment completion rate, chemotherapy-related toxicity, pathological response, progression free survival, and overall survival.

Discussion

The BEV-IP trial is the first prospective assessment of the safety and efficacy of perioperative chemotherapy combined with anti-angiogenic treatment in patients undergoing CRS and IPC for colorectal peritoneal metastases.

Trial registration

ClinicalTrials.gov Identifier: NCT02399410 EudraCT number: 2015-001187-19 (registered March 9, 2015).

Evaluation of resectability after neoadjuvant chemotherapy for primary non-resectable colorectal liver metastases: A multicenter study

BACKGROUND/AIM

The Kyushu Study Group of Clinical Cancer (KSCC) previously reported the safety and efficacy of neoadjuvant chemotherapy with mFOLFOX6 + bevacizumab for H2/H3 liver metastases of colorectal cancer. The aim of the current study was to evaluate the resectability of these metastases before and after chemotherapy as determined by independent liver surgeons.

METHODS

Between May 2008 and April 2010, 40 patients were registered in a multicenter phase 2 trial of neoadjuvant chemotherapy (KSCC 0802). In Study 1, 5 independent liver surgeons from five different KSCC centers evaluated the resectability of liver metastases of colorectal cancer based on imaging studies performed before and after chemotherapy. Each surgeon was blinded to the other surgeons' evaluations. In addition, no information about the patients' characteristics was provided. In Study 2, 3 surgeons evaluated the resectability of these lesions based on imaging studies with discussion with each other, with the surgeons being provided with information on the patients' characteristics.

RESULTS

In Study 1, 13 patients (36.1%) were evaluated to be resectable at baseline, whereas 17 patients (47.2%) were evaluated to be resectable after chemotherapy. In Study 2, 4 patients (11.1%) were evaluated to be resectable at baseline, compared to 23 patients (63.9%) after chemotherapy.

CONCLUSION

Neoadjuvant chemotherapy with mFOLFOX6 + bevacizumab was confirmed to increase the resectability of non-resectable liver metastases of colorectal cancer according to the independent assessments of surgeons.

Bevacizumab and Combination Chemotherapy in rectal cancer Until Surgery (BACCHUS): a phase II, multicentre, open-label, randomised study of neoadjuvant chemotherapy alone in patients with high-risk cancer of the rectum

BACKGROUND

In locally advanced rectal cancer (LARC) preoperative chemoradiation (CRT) is the standard of care, but the risk of local recurrence is low with good quality total mesorectal excision (TME), although many still develop metastatic disease. Current challenges in treating rectal cancer include the development of effective organ-preserving approaches and the prevention of subsequent metastatic disease. Neoadjuvant systemic chemotherapy (NACT) alone may reduce local and systemic recurrences, and may be more effective than postoperative treatments which often have poor compliance. Investigation of intensified NACT is warranted to improve outcomes for patients with LARC. The objective is to evaluate feasibility and efficacy of a four-drug regimen containing bevacizumab prior to surgical resection.

METHODS/DESIGN

This is a multi-centre, randomized phase II trial. Eligible patients must have histologically confirmed LARC with distal part of the tumour 4-12 cm from anal verge, no metastases, and poor prognostic features on pelvic MRI. Sixty patients will be randomly assigned in a 1:1 ratio to receive folinic acid + flurourcil + oxaliplatin (FOLFOX) + bevacizumab (BVZ) or FOLFOX + irinotecan (FOLFOXIRI) + BVZ, given in 2 weekly cycles for up to 6 cycles prior to TME. Patients stop treatment if they fail to respond after 3 cycles (defined as ≥ 30 % decrease in Standardised Uptake Value (SUV) compared to baseline PET/CT). The primary endpoint is pathological complete response rate. Secondary endpoints include objective response rate, MRI tumour regression grade, involved circumferential resection margin rate, T and N stage downstaging, progression-free survival, disease-free survival, overall survival, local control, 1-year colostomy rate, acute toxicity, compliance to chemotherapy.

DISCUSSION

In LARC, a neoadjuvant chemotherapy regimen - if feasible, effective and tolerable would be suitable for testing as the novel arm against the current standards of short course preoperative radiotherapy (SCPRT) and/or fluorouracil (5FU)-based CRT in a future randomised phase III trial.

TRIAL REGISTRATION

Clinical trial identifier BACCHUS: NCT01650428.

Evading anti-angiogenic therapy: resistance to anti-angiogenic therapy in solid tumors

Vascular endothelial growth factor (VEGF) dependent tumor angiogenesis is an essential step for the initiation and promotion of tumor progression. The hypothesis that VEGF-driven tumor angiogenesis is necessary and sufficient for metastatic progression of the tumor, has been the major premise of the use of anti-VEGF therapy for decades. While the success of anti-VEGF therapy in solid tumors has led to the success of knowledge-based-therapies over the past several years, failures of this therapeutic approach due to the development of inherent/acquired resistance has led to the increased understanding of VEGF-independent angiogenesis. Today, tumor-angiogenesis is not a synonymous term to VEGF-dependent function. The extensive study of VEGF-independent angiogenesis has revealed several key factors responsible for this phenomenon including the role of myeloid cells, and the contribution of entirely new phenomenon like vascular mimicry. In this review, we will present the cellular and molecular factors related to the development of anti-angiogenic resistance following anti-VEGF therapy in different solid tumors.

Anti-angiogenic agents in metastatic colorectal cancer

Colorectal cancer (CRC) is a major public health concern being the third leading cause of cancer mortality in the United States. The availability of better therapeutic options has led to a decline in cancer mortality in these patients. Surgical resection should be considered in all stages of the disease. The use of conversion therapy has made surgery a potentially curative option even in patients with initially unresectable metastatic disease. In this review we discuss the role of various anti-angiogenic agents in patients with metastatic CRC (mCRC). We describe the mechanism of action of these agents, and the rationale for their use in combination with chemotherapy. We also review important clinical studies that have evaluated the safety and efficacy of these agents in mCRC patients. Despite the discovery of several promising anti-angiogenic agents, mCRC remains an incurable disease with a median overall survival of just over 2 years in patients exposed to all available treatment regimens. Further insights into tumor biology and tumor microenvironment may help improve outcomes in these patients.

Lymphatic Invasion is an Independent Adverse Prognostic Factor in Patients with Colorectal Liver Metastasis

BACKGROUND

For a selection of patients with colorectal liver metastases (CRLM), liver resection is a curative option. In order to predict long-term survival, clinicopathologic risk scores have been developed, but little is known about histologic factors and their prognostic value for disease-free and overall survival. The objective of the present study was to assess possible prognostic histologic factors in patients with solitary CRLM treated with liver resection who did not receive neoadjuvant treatment.

METHODS

Patients with solitary CRLM who underwent liver resection between 1992 and 2011 were evaluated for clinical prognostic factors. Histologic analyses on tumor thickness at the tumor-normal interface, presence of a fibrotic capsule, intrahepatic vascular invasion, lymphatic invasion, or bile duct invasion and perineural growth were performed, using immunohistochemistry.

RESULTS

A total of 124 patients were analyzed with a median follow-up of 41 months (range 1-232 months). There was no association between histologic factors and disease-free survival in multivariate analysis. In multivariate analysis, intrahepatic lymphatic invasion was associated with a decreased overall survival (41.9 vs. 61.0 months; p = 0.041), especially in combination with vascular invasion (n = 15) (28.1 vs. 62.2 months; p < 0.0001). In addition, size over 50 mm (29.2 vs. 65.9 months; p = 0.004) and interval less than 12 months between resection of the primary tumor and diagnosis of liver metastasis (49.0 vs. 91.5 months: p = 0.019) were also independent adverse prognostic factors.

CONCLUSIONS

Intrahepatic lymphatic invasion, especially in combination with vascular invasion, is an important adverse prognostic factor for overall survival in patients with solitary CRLM after liver resection.

Bevacizumab-based neoadjuvant chemotherapy for colorectal cancer liver metastases: Pitfalls and helpful tricks in a review for clinicians

Bevacizumab added to chemotherapy has shown encouraging efficacy in the neoadjuvant therapy of colorectal cancer liver metastases. In absence of biological predictor factors of efficacy to bevacizumab-based treatment, the assessment of response may be a crucial point to select patients who may benefit the most from surgery. At the same time the pathological response after liver resection could represent a guide for the next therapeutic plan. In the pre-surgical phase, conventional computed tomography and response evaluation with RECIST criteria may underestimate the response to anti-angiogenic drugs. Modified computed tomography criteria of response, morphologic changes as well as novel imaging techniques and metabolic assessment by fluorodeoxyglucose positron emission tomography seem to be promising methods for the assessment of response and for leading the clinical choices. Pathological response at the time of surgery is an important prognostic factor and a surrogate of survival for resected patients. Different classification criteria to assess pathological response have been developed, residual viable tumor, tumor regression grade (TRG), modified TRG and tumor thickness at the tumor-normal interface, but to date a superiority of one approach over the others has not been clearly established. In this review, we evaluate the available data with the aim to help the clinicians in the pre- and post-surgical care of patient with colorectal cancer liver metastases treated with bevacizumab-based neoadjuvant strategy.

Histological response, pattern of tumor destruction and clinical outcome after neoadjuvant chemotherapy including bevacizumab or cetuximab in patients undergoing liver resection for colorectal liver metastases

AIM

We investigated whether the type of antibody [bevacizumab (bev) or cetuximab (cet)] added to neoadjuvant combination chemotherapy before curative liver resection was associated with histological response, the pattern of tumor destruction and clinical outcome in patients with colorectal liver metastases (CLM).

METHODS

We investigated 138 patients with KRAS wild-type status (codon 12, 13 and 61) who received neoadjuvant chemotherapy including bev (n = 101) or cet (n = 37). The primary endpoint was histological response. Secondary endpoints were necrosis and fibrosis of metastases, radiological response, recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Histological response was not significantly different between the two groups (P = 0.19). A significantly higher fraction of patients in the bev group showed necrosis of the metastases of ≥ 50% (P < 0.001), while a higher fraction of patients in the cet group showed fibrosis of ≥ 40% (P = 0.030). Radiological response was not significantly different (P = 0.17). Median RFS was significantly shorter in the cet group in univariable analysis (HR 1.59 (95% CI 1.00, 2.51), P = 0.049), but this difference did not remain significant in multivariable analysis (P = 0.45). The 3-year OS rate was not significantly different (P = 0.73).

CONCLUSIONS

The addition of bevacizumab to combination chemotherapy showed more necrosis but less fibrosis of metastases compared to cetuximab and a trend towards higher histological and radiological response and longer RFS. Further investigations of biological tumor characteristics are required to individualize treatment combinations.

Challenges in the multidisciplinary management of stage IV colon and rectal cancer

Colorectal metastases still represent a challenge to all oncologists despite progresses achieved by improved resectability, systemic chemotherapy and targeted therapies. In particular in patients with oligo-metastases, the role of surgical resections has been redefined. Resection is the most effective treatment method for liver metastases performed with curative intent; however, primary rate of resectability is low. Several methods to increase resectability have been developed: conversion chemotherapy, portal vein embolization, two-stage resections, vascular reconstruction of the liver veins, combination of resection and intraoperative ablation. Liver resections can be performed at present with low mortality. Patients with isolated peritoneal metastases, no extra-abdominal disease, low volume tumor and complete surgical cytoreduction do benefit from surgery and hyperthermic intraperitoneal chemotherapy. Several national guidelines recommend multimodality treatment for highly selected patients. The management of stage IV colorectal cancer includes several disciplines with focus on resection. A multidisciplinary evaluation of all patients is of crucial importance to define the treatment sequence and individual strategies for each patient.

Advances in understanding of colorectal liver metastasis and implications for the clinic

Colorectal cancer is one of the most common cancers in both the USA and Europe. Over the course of diagnosis, treatment and surveillance, up to 50% of these patients will develop metastases to their liver. In the past 20 years alone, there have been multiple advances in the management of these colorectal metastases to the liver. These advances have been made in characterization of these tumors, diagnosis and in treatment, both locally and systemically. Because of this progress, there are subsets of patients with this stage IV disease who are cured of their disease. While significant progress has been made, there still exist limitations in the management of metastatic colorectal cancer to the liver. This review outlines current strategies and highlights recent advances in the management of colorectal liver metastases.

A proposed new method for assessing the pathological response to chemotherapy in resected colorectal liver metastases

Background:

Pathological response (PR) to preoperative chemotherapy for colorectal liver metastases (CLM) is recognised as a prognostic factor of outcome. However, the optimal system to assess this parameter is still debated. This study focuses on current methods and proposes a possibly better method for assessing PR.

Methods:

Among 223 patients resected for CLM between 2004 and 2011, after more than three cycles of chemotherapy, the percentage of tumour cells, necrosis and fibrosis, and the tumour regression grade were assessed for each of 802 nodules. Pathological response was evaluated according to validated methods and their combinations. A new method combined the percentage of tumour cells and the size of all nodules as follows: , where n is each separate nodule, % is the percentage of remaining tumour cells within nodule n (%) and s is the size of nodule n (cm).The prognostic value of each method was calculated.

Results:

After a median follow-up of 47 months (3–106), the cumulative 5-year overall survival rate after liver resection was 59%. The proposed method categorised as follows: 0 residual tumour; 0.1–6-cm residual tumour; >6-cm residual tumour, and necrosis rate >50% stratified prognosis (P=0.0027; P=0.02), while the other methods did not. At multivariate analysis, our method remained an independent predictor of outcome (P=0.001).

Conclusions:

Combining the percentage of tumour cells multiplied by the size of each separate tumour seems to be a better method for assessing PR. External validation is required.

Pathologic assessment of response to chemotherapy in colorectal cancer liver metastases after hepatic resection: which method to use?

BACKGROUND

Patients with metastatic colorectal cancer receive chemotherapy prior liver resection more and more frequently. Histopathologic assessment methods of the resected specimen could evaluate the response to chemotherapy. In this study it is analyzed if these histopathologic changes are specific to preoperative chemotherapy and if these methods have correlation with survival.

METHODS

Sixty three patients with available pathology slides, resected for colorectal cancer liver metastases were enrolled in this study. 46 patients (73%) received neoadjuvant chemotherapy. Five pathological evaluation methods were compared according to the literature: [1] residual tumor cell ratio, [2] tumor regression grade (TRG) scoring system, [3] modified tumor regression grade (mTRG) scoring system with the type of necrosis, [4] pattern of tumor regression and [5] the tumor thickness at the tumor-normal interface (TNI).

RESULTS

Analyzing the pathological methods between the chemotherapy (CTX) and the non-chemotherapy group (NC), we found that that four evaluation methods showed significant and one showed strong correlation with the use of chemotherapy. (Residual tumor cell ratio: p = 0.08; TRG: p <0.01; mTRG: p = 0.03; pattern of tumor regression: p <0.01; TNI: p = 0.02). In the chemotherapy group none of the analyzed pathological methods showed significant correlation with progression free survival (PFS) or with overall survival (OS). Residual tumor cell ratio, TRG and the pattern of tumor cells showed positive but not significant correlation with OS and PFS and a slight difference in the group of patients with TNI <2 mm could be documented.

CONCLUSIONS

Tumor regression grade (TRG) and tumor thickness at the tumor-normal interface (TNI) were the most useful methods for pathological response evaluation and these methods had some correlation with survival. According to these data, authors concluded, that a reproducible and well defined scoring system, based on different histopathological evaluation methods should be developed to predict more accurately the effect of neoadjuvant chemotherapy in CRCLM patients.

Anti-angiogenic therapy for cancer: current progress, unresolved questions and future directions

Tumours require a vascular supply to grow and can achieve this via the expression of pro-angiogenic growth factors, including members of the vascular endothelial growth factor (VEGF) family of ligands. Since one or more of the VEGF ligand family is overexpressed in most solid cancers, there was great optimism that inhibition of the VEGF pathway would represent an effective anti-angiogenic therapy for most tumour types. Encouragingly, VEGF pathway targeted drugs such as bevacizumab, sunitinib and aflibercept have shown activity in certain settings. However, inhibition of VEGF signalling is not effective in all cancers, prompting the need to further understand how the vasculature can be effectively targeted in tumours. Here we present a succinct review of the progress with VEGF-targeted therapy and the unresolved questions that exist in the field: including its use in different disease stages (metastatic, adjuvant, neoadjuvant), interactions with chemotherapy, duration and scheduling of therapy, potential predictive biomarkers and proposed mechanisms of resistance, including paradoxical effects such as enhanced tumour aggressiveness. In terms of future directions, we discuss the need to delineate further the complexities of tumour vascularisation if we are to develop more effective and personalised anti-angiogenic therapies.

Anti-VEGF antibody therapy induces tumor hypoxia and stanniocalcin 2 expression and potentiates growth of human colon cancer xenografts

Tumor angiogenesis plays a critical role in colorectal cancer progression. Recent randomized clinical trials have revealed the additive effect of bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF)-A, to conventional chemotherapy in the improved survival of patients with metastatic colorectal cancer. However, a number of preclinical reports indicate the development of resistance to anti-angiogenic therapy. In this study, we addressed the effects of anti-VEGF antibodies on the growth and malignant behavior of colorectal cancer cells. TK-4, a solid tumor strain derived from a colon cancer patient, was subcutaneously or orthotopically implanted into nude mice. Short-term administration of anti-VEGF antibodies inhibited the growth of cecal tumors at day 14 by suppressing mitosis, but prolonged treatment resulted in the recovery of cellular proliferation and suppression of apoptosis at day 35. Intratumoral hypoxia induced by anti-VEGF antibody treatment resulted in activation of hypoxia inducible factor-1α protein and an increased number of aldehyde dehydrogenase 1-positive tumor cells. In microarray analysis, stanniocalcin 2 (STC2) was the most highly upregulated gene in anti-VEGF antibody-treated tumors. In vitro analyses showed that the growth and migration of SW480 colon cancer cells under hypoxic conditions were significantly inhibited by knockdown of STC2. In vivo serial transplantation of TK-4 revealed that long-term administration of anti-VEGF antibodies increased the tumorigenicity of colon cancers and accelerated tumor growth when transplanted into secondary recipient mice. Our data provide a potential molecular explanation for the limited clinical effectiveness of anti-VEGF antibodies.

Evidence-based appraisal of the upfront treatment for unresectable metastatic colorectal cancer patients

Colorectal cancer (CRC) is a significant health problem, with around 1 million new cases and 500000 deaths every year worldwide. Over the last two decades, the use of novel therapies and more complex treatment strategies have contributed to progressively increase the median survival of patients with unresectable advanced CRC up to approximately 30 mo. The availability of additional therapeutic options, however, has created new challenges and generated more complicated treatment algorithms. Moreover, several clinically important points are still in debate in first-line, such as the optimal treatment intensity, the most appropriate maintenance strategy, the preferred biologic to be used upfront in patients with KRAS wild-type CRC, and the need for more detailed information on tumor biology. In this moving landscape, this review analyses why the first-line treatment decision is crucial and how the choice may impact on further treatment lines. In addition, it focuses on results of major phase III randomized trials.