CEA increase as a marker of disease progression after first-line induction therapy in metastatic colorectal cancer patients. A pooled analysis of TRIBE and TRIBE2 studies.

BACKGROUND: In mCRC, CEA is used to monitor response to systemic therapy together with imaging. After the end of induction, no major improvement in tumour shrinkage is expected, and the availability of a marker able to predict progressive disease (PD) versus no-PD might allow avoiding CT scans. METHODS: We pooled data from patients with baseline CEA ≥ 10 ng/mL included in TRIBE and TRIBE2 studies with the aim of identifying a threshold for percent increase of CEA from nadir able to predict PD after the end of the induction therapy. RESULTS: In total, 1178 paired CEA and radiological assessments from 434 patients were included. According to the optimal cut-off determined by ROC, a CEA increase of at least 120% from nadir differentiated between PD and no-PD with a sensitivity of 74% and a specificity of 78%, excluding PD in the 92% of radiological assessments and allowing to avoid the 67% of CT scans. However, CEA cut-off of 120% was not able to detect radiological PD in 26% of cases. In order to mitigate this issue, a different clinically relevant threshold was evaluated based on the best sensitivity cut-off. Therefore, using any CEA increase from nadir as a threshold, the sensitivity grew to 93% and only in the 7% of cases the radiological PD was not detected. CONCLUSIONS: In mCRC with baseline CEA ≥ 10 ng/mL, CEA values can accurately predict PD versus no-PD after the end of the first-line induction therapy.

Early modifications of circulating microRNAs levels in metastatic colorectal cancer patients treated with regorafenib.

Biomarkers able to improve the cost/benefit ratio are urgently needed for metastatic colorectal cancer patients that are eligible to receive regorafenib. Here, we measured plasma levels of ten circulating microRNAs (c-miRNAs) and we investigated their early changes during treatment, as well as possible correlation with clinical outcome. Ten literature-selected c-miRNAs were quantified by qRT-PCR on plasma samples collected at baseline (d1) and after 15 days of treatment (d15). C-miRNAs showing significant changes were further analyzed to establish correlations with outcome. A decision tree-based approach was employed to define a c-miRNA signature able to predict the outcome. Results achieved in an exploratory cohort were tested in a validation group. In the exploratory cohort (n = 34), the levels of c-miR-21 (p = 0.06), c-miR-141 (p = 0.04), and c-miR-601 (p = 0.01) increased at d15 compared with d1. A c-miRNA signature involving c-miR-21, c-miR-221, and c-miR-760 predicted response to treatment (p < 0.0001) and was significantly associated to PFS (HR = 10.68; 95% CI 3.2-35.65; p < 0.0001). In the validation cohort (n = 36), the increase in c-miR-21 (p = 0.02) and c-miR-601 (p = 0.02) levels at d15 was confirmed, but the associations with outcome were not. Our data indicate that early changes of c-miRNA levels might be influenced by regorafenib treatment. However, further studies are needed to establish the predictive power of such modifications.

Differential histopathologic parameters in colorectal cancer liver metastases resected after triplets plus bevacizumab or cetuximab: a pooled analysis of five prospective trials.

BACKGROUND: Many factors, including histopathologic parameters, seem to influence the prognosis of patients undergoing resection of colorectal cancer liver metastases (CRCLM), although their relative weight is unclear. Histopathologic growth patterns (HGPs) of CRCLM may affect sensitivity to antiangiogenics. We aimed at evaluating differences in histopathologic parameters of response according to the use of bevacizumab or cetuximab as first-line targeted agents, and at exploring the prognostic and predictive role of HGPs. METHODS: We performed a comprehensive histopathologic characterisation of CRCLM from 159 patients who underwent secondary resection, after receiving triplets FOLFOXIRI (folinic acid, 5-fluorouracil, oxaliplatin, and irinotecan) or COI (capecitabine, oxaliplatin, and irinotecan) plus bevacizumab (N = 103) vs cetuximab (N = 56) in five first-line no-profit clinical trials. RESULTS: Both major histopathologic response (tumour regression grade TRG1-2, 32 vs 14%, p = 0.013) and infarct-like necrosis (80 vs 64%, p = 0.035) were significantly higher in the bevacizumab than in the cetuximab group. Achieving major response positively affected relapse-free survival (RFS) (p = 0.012) and overall survival (OS) (p = 0.045), also in multivariable models (RFS, p = 0.008; OS, p = 0.033). In the desmoplastic HGP (N = 28), a higher percentage of major response was reported (57 vs 17% in pushing and 22% in replacement HGP, p < 0.001) and an unsignificant advantage from cetuximab vs bevacizumab was evident in RFS (p = 0.116). In the pushing HGP (N = 66), a significant benefit from bevacizumab vs cetuximab (p = 0.017) was observed. No difference was described in the replacement HGP (N = 65, p = 0.615). CONCLUSIONS: The histopathologic response is the only independent determinant of survival in patients resected after triplets plus a biologic. When associated with triplet chemotherapy, bevacizumab induces a higher histopathologic response rate than cetuximab. The assessment of HGPs should be further explored as a predictor of benefit from available targeted agents.

Trifluridine/Tipiracil (TAS-102) in Refractory Metastatic Colorectal Cancer: A Multicenter Register in the Frame of the Italian Compassionate Use Program.

BACKGROUND: TAS-102 is indicated for patients with metastatic colorectal cancer (mCRC) previously treated with, or not considered candidates for, available therapies. Given the complete inefficacy in half of patients, the lack of predictive factors, the palliative setting, and the financial and clinical toxicity, optimizing the cost-benefit ratio is crucial. The "ColonLife" nomogram allows an estimate of the 12-week life expectancy of patients with refractory mCRC. MATERIALS AND METHODS: We collected data from patients treated at eight Italian centers in the compassionate use program. Baseline characteristics of patients who were or were not progression free at 6 months were compared. The discriminative ability of the ColonLife nomogram was assessed. Among patients who received both TAS-102 and regorafenib, clinical outcomes of the two sequences were compared. RESULTS: This study included 341 patients. Six (2%) and 93 (27%) patients achieved response and disease stabilization, respectively. The median progression-free survival (PFS) was 2.4 months with an estimated 6-month PFS rate of 19%; the median overall survival (OS) was 6.2 months. An Eastern Cooperative Oncology Group performance status (ECOG PS) of 0, normal lactate dehydrogenase (LDH), and a time from the diagnosis of metastatic disease of >18 months were independently associated with higher chances of a patient being progression free at 6 months. The discriminative ability of ColonLife was confirmed. Among 121 patients who received both regorafenib and TAS-102, no differences in first or second PFS or OS were reported between the two sequences. CONCLUSION: One out of five patients achieves clinical benefit with TAS-102. ECOG PS, LDH, and time from diagnosis of metastatic disease may help to identify these patients. Excluding patients with very short life expectancy appears a reasonable approach. IMPLICATIONS FOR PRACTICE: Improving the cost-efficacy ratio of TAS-102 in metastatic colorectal cancer is needed to spare useless toxicities in a definitely palliative setting. Eastern Cooperative Oncology Group performance status, lactate dehydrogenase levels, and time from the diagnosis of metastatic disease may help to identify patients more likely to achieve benefit. Properly designed prognostic tools (i.e., the "ColonLife" nomogram) may enable excluding from further treatments patients with very limited life expectancy.

Early modulation of Angiopoietin-2 plasma levels predicts benefit from regorafenib in patients with metastatic colorectal cancer.

BACKGROUND: No biomarkers are currently available to predict the efficacy of trifluridine/tipiracil (FTD/TPI) in chemorefractory metastatic colorectal cancer. The multicohort REGOLAND study aims at exploring and validating circulating markers potentially able to predict benefit from regorafenib in this setting. MATERIAL AND METHODS: In the retrospective 'regorafenib exploratory cohort', including 105 patients treated with regorafenib, baseline (d1) plasma levels of angiogenesis-related biomarkers and their early modulation after 15 days (d15) of treatment were investigated for correlation with clinical outcome. Based on a pre-specified statistical hypothesis, main retrospective findings were prospectively challenged in the 'regorafenib validation cohort', including 100 patients treated with regorafenib. Prospectively validated putative biomarkers were then assessed in the control 'FTD/TPI cohort', including 93 patients treated with FTD/TPI. RESULTS: In the 'regorafenib exploratory cohort', the early (d15) increase of Angiopoietin-2 (Ang-2) was associated with longer progression-free survival (HR:0.57 [95%CI:0.38-0.88], P = 0.004) and a trend towards longer OS (HR:0.74 [95%CI:0.48-1.14], P = 0.165), than the early decrease. Similar results were prospectively confirmed in the 'regorafenib validation cohort' (HR for progression-free survival:0.72 [95%CI:0.48-1.08], P = 0.095; HR for OS:0.77 [95%CI:0.51-1.16], P = 0.204). No predictive impact was shown for the early modulation of Ang-2 in the 'FTD/TPI cohort'. High baseline Ang-2 levels predict poor prognosis in all the investigated cohorts, independently of other clinical prognostic variables. CONCLUSIONS: The early modulation of circulating Ang-2 predicts the efficacy of regorafenib. Baseline Ang-2 plasma levels are an independent prognostic biomarker in chemorefractory metastatic colorectal cancer.

Long Term Survival With Regorafenib: REALITY (Real Life in Italy) Trial - A GISCAD Study.

BACKGROUND: Regorafenib is a key agent in metastatic colorectal cancer (mCRC), but no validated factors predicting longer survival are available. PATIENTS AND METHODS: REALITY was a retrospective multicenter trial in regorafenib-treated mCRC patients with overall survival (OS) ≥ 6 months. We aimed to assess the association between clinical parameters and outcome to define a panel identifying long term survivors among regorafenib candidates. Primary and secondary endpoints were OS and progression free survival (PFS), respectively. Statistical analysis was performed with MedCalc (survival distribution: Kaplan-Meier; survival comparison: log-rank test; independent role of significant variables at univariate analysis: logistic regression). RESULTS: Hundred regorafenib-treated mCRC patients with OS ≥ 6 months were enrolled. Median OS was 11.5 m (95%CI:9.60-12.96); median PFS was 4.2 months (95% CI:3.43-43.03). The absence of liver progression and of dose and/or schedule changes during the first 4 cycles (mainly for good tolerability) were independently correlated at multivariate analysis with OS (Exp(b)1.8869, P= .0277and Exp(b)2.2000, P = .0313) and PFS (Exp(b)2.1583, P = .0065 and Exp(b)2.3036, P= .0169). Patients with neither of these variables had a significantly improved OS (n = 14, 20.8 months; 95% CI:12.967-55.267) versus others (n = 86, 10 months; 95% CI:8.367-12.167; HR = 0.4902, P = .0045) and PFS (11.3 months, 95%CI:4.267-35.8 vs. 3.9 months, 95% CI:3.167-43.033; HR = 0.4648, P = .0086). CONCLUSION: These 2 factors might allow clinicians to better identify patients more likely to benefit from regorafenib. Toxicity management remains crucial.

Immune Profiling of Deficient Mismatch Repair Colorectal Cancer Tumor Microenvironment Reveals Different Levels of Immune System Activation.

To understand the immune landscape of deficient mismatch repair colorectal cancer (dMMR CRC) tumor microenvironment, gene expression profiling was performed by the nCounter PanCancer Immune Profiling Panel. This study was conducted retrospectively on 89 dMMR-CRC samples. The expression of CD3, CD8, programmed death-1, and programmed death ligand-1 protein was evaluated on a subset of samples by immunohistochemistry, and lymphocyte density was calculated. A subset of deregulated genes was identified. Functional clustering analysis performed on these genes generated four main factors: antigen processing and presentation, with its major histocompatibility complex-II-related genes; genes correlated with the cytotoxic activity of immune system; T-cell chemotaxis/cell adhesion genes; and T-CD4+ regulator cell-related genes. A deregulation score (DS) was calculated for each sample. On the basis of their DS, tumors were then classified as COLD (DS ≤ -3) to select the samples with a strong down-regulation of the immune system and NOT COLD (DS ≥ -2). The COLD group of patients showed a worse prognosis in terms of survival considering all patients (P = 0.0172) and patients with metastatic disease (P = 0.0031). These results confirm that dMMR-CRCs do not constitute a homogeneous group as concerns the immune system activity of tumor microenvironment. In particular, the distinction between COLD and NOT COLD tumors may improve the management of these two subsets of patients.

Oligometastatic colorectal cancer: prognosis, role of locoregional treatments and impact of first-line chemotherapy-a pooled analysis of TRIBE and TRIBE2 studies by Gruppo Oncologico del Nord Ovest.

BACKGROUND: Oligometastatic disease (OMD) identifies tumours with limited metastatic spread. OMD definition is not univocal and no data from clinical trials are available about the prognostic effect of OMD in metastatic colorectal cancer (mCRC), the impact of locoregional treatments (LRTs) and the effect of chemotherapy intensification in these patients. The role of tumour burden (TB) in driving therapeutic choices is also debated. PATIENTS AND METHODS: We performed a pooled analysis of phase III TRIBE and TRIBE2 studies comparing FOLFOXIRI/bevacizumab (bev) to doublets (FOLFOX or FOLFIRI)/bev. Patients were grouped in OMD versus non-OMD based on the European Society for Medical Oncology definition. Among patients with OMD, those with OMD/low TB were compared with all the others. RESULTS: Of 1187 patients enrolled, 1096 were classified as OMD (N = 312 [28%]) or non-OMD (N = 784 [72%]). Among patients with OMD, 126 (40%) were OMD/low TB. OMD was associated with longer progression-free survival (14.0 versus 10.1 months; p < 0.01) and overall survival (38.2 versus 22.0 months; p < 0.01). These results were confirmed in multivariable models. The benefit provided by FOLFOXIRI/bev compared with doublets/bev did not differ in accordance with OMD and TB (p for interaction >0.05). Patients with OMD underwent LRTs more frequently (p < 0.01) and those with OMD/low TB had higher chance to undergo LRTs after the first progression (p < 0.01). CONCLUSIONS: OMD is a positive prognostic factor in mCRC. The benefit from the upfront treatment intensification is independent of the metastatic spread extent and TB. LRTs should be highly considered in these patients, mainly during the first-line therapy but also at later stages of treatment history in selected cases.

Lack of Benefit From Anti-EGFR Treatment in RAS and BRAF Wild-type Metastatic Colorectal Cancer With Mucinous Histology or Mucinous Component.

BACKGROUND: Adenocarcinoma with mucinous histology or mucinous component are histologic subtypes of metastatic colorectal cancers (mCRCs) with limited benefit from cytotoxic agents. Their sensitivity to anti-epithelial growth factor receptors (EGFRs) is not clear. PATIENTS AND METHODS: The activity and efficacy of anti-EGFRs was retrospectively evaluated among patients with RAS and BRAF wild-type mCRC with or without mucinous histology or mucinous component. Subgroup analyses according to primary tumor location were conducted. RESULTS: Overall, the study population included 22 mucinous or with mucinous component tumors (11 right- and 11 left-sided tumors) and 83 not mucinous tumors. One patient experienced partial response among mucinous tumors, whereas in the not mucinous group, 42 patients experienced partial response, with an overall response rate of 4% and 51%, respectively (P = .003). The median progression-free survival was 2.8 versus 6.7 months (hazard ratio, 0.28; 95% confidence interval, 0.13-0.59; P < .001), and the median overall survival was 6.5 and 16.7 months (hazard ratio, 0.58; 95% confidence interval, 0.33-1.00; P = .022), for the mucinous and not mucinous groups, respectively. Similar results were observed in subgroup analysis according to primary tumor location. CONCLUSION: Anti-EGFRs may not provide clinically meaningful benefit in mCRCs with mucinous histology or mucinous component compared with those without mucinous component, irrespective of sidedness.

Clinical and molecular determinants of extrahepatic disease progression in patients with metastatic colorectal cancer with liver-limited metastases deemed initially unresectable.

BACKGROUND: No tools to predict the probability of extrahepatic disease progression (ePD) of initially unresectable, liver-limited metastatic colorectal cancer (mCRC) are currently available. To estimate the likelihood to develop ePD and to identify clinical and molecular factors that could predict extrahepatic progression-free survival (ePFS), we conducted an observational, retrospective, multicentre cohort study. METHODS: We retrospectively identified a cohort of 225 patients with initially unresectable liver-limited disease (LLD), treated from January 2004 to December 2017 with first-line doublets or triplet plus a biological agent at two Italian institutions. RESULTS: 173 (77%) patients experienced ePD which occurred within 1, 2 or 3 years from the diagnosis of mCRC in 15%, 49% and 66% of patients, respectively. Globally, 164 (73%) patients underwent a liver resection at some point of their disease history, and 54 (33%) of them underwent a subsequent locoregional treatment. Age > 70 years, locoregional nodal involvement at diagnosis of colorectal cancer and ≥4 liver metastases were significantly associated with higher risk of ePD while liver resections were associated with reduced risk of ePD. In the multivariable model, number of liver metastases (subdistribution HR, SHR 1.63, 95% CI 1.12 to 2.36; p = 0.01) and liver resections (SHR 0.43, 95% CI 0.29 to 0.63; p = 0.001) were still associated with ePD. Number of liver metastases < 4, no nodal involvement at diagnosis and liver resections were also associated with prolonged ePFS. CONCLUSIONS: The identified clinical factors could help physicians in personalising the intensity and aggressiveness of liver-directed treatments in patients with mCRC with initially unresectable LLD.

Prognostic impact of ATM mutations in patients with metastatic colorectal cancer.

Tumors bearing homologous recombination deficiency are extremely sensitive to DNA double strand breaks induced by several chemotherapeutic agents. ATM gene, encoding a protein involved in DNA damage response, is frequently mutated in colorectal cancer (CRC), but its potential role as predictive and prognostic biomarker has not been fully investigated. We carried out a multicenter effort aimed at defining the prognostic impact of ATM mutational status in metastatic CRC (mCRC) patients. Mutational profiles were obtained by means of next-generation sequencing. Overall, 35 out of 227 samples (15%) carried an ATM mutation. At a median follow-up of 56.6 months, patients with ATM mutated tumors showed a significantly longer median overall survival (OS) versus ATM wild-type ones (64.9 vs 34.8 months; HR, 0.50; 95% CI, 0.29-0.85; P = 0.01). In the multivariable model, ATM mutations confirmed the association with longer OS (HR, 0.57; 95% CI, 0.33-0.98; P = 0.04). The prognostic impact of ATM mutations was independent from TP53 mutational status and primary tumor location. High heterogeneity score for ATM mutations, possibly reflecting the loss of wild-type allele, was associated with excellent prognosis. In conclusion, we showed that ATM mutations are independently associated with longer OS in patients with mCRC.

TRIPLETE: a randomised phase III study of modified FOLFOXIRI plus panitumumab versus mFOLFOX6 plus panitumumab as initial therapy for patients with unresectable RAS and BRAF wild-type metastatic colorectal cancer.

BACKGROUND: FOLFOXIRI plus bevacizumab is considered a standard option in the upfront treatment of clinically selected patients with metastatic colorectal cancer irrespective of RAS and BRAF molecular status. The randomised MACBETH and VOLFI studies showed that a modified FOLFOXIRI regimen in combination with cetuximab or panitumumab, respectively, achieved high therapeutic activity in RAS and BRAF wild-type patients with an acceptable toxicity profile. Drawing from these considerations, we designed TRIPLETE study aiming at comparing two different chemotherapy backbones (mFOLFOXIRI or mFOLFOX6) in combination with panitumumab in the first-line treatment of patients with RAS and BRAF wild-type metastatic colorectal cancer. METHODS: This is a prospective, open-label, multicentre phase III trial in which initially unresectable and previously untreated RAS and BRAF wild-type metastatic colorectal cancer patients are randomised to receive a standard treatment with mFOLFOX6 plus panitumumab or an experimental regimen with modified FOLFOXIRI (irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, L-leucovorin 200 mg/m2, 5-fluoruracil 2400 mg/m2 48-hour continuous infusion) plus panitumumab up to 12 cycles, followed by panitumumab plus 5-fluorouracil and L-leucovorin until disease progression. The primary endpoint is overall response rate according to RECIST 1.1 criteria. DISCUSSION: The relative benefit of chemotherapy intensification when using an anti-EGFR-based regimen in molecularly selected patients is unknown; TRIPLETE study aims at filling this gap of knowledge. The study is sponsored by the Gruppo Oncologico Nord Ovest Cooperative Group and is currently ongoing at 42 Italian centres. CLINICAL TRIAL INFORMATION: NCT03231722.

Efficacy of FOLFOXIRI plus bevacizumab in liver-limited metastatic colorectal cancer: A pooled analysis of clinical studies by Gruppo Oncologico del Nord Ovest.

Secondary resection is a chance of cure for a subgroup of metastatic colorectal cancer (mCRC) patients with unresectable liver-limited disease. Medical treatment has a dual goal: to induce tumour shrinkage and to prevent disease relapse. The aims of the present analysis were to assess the efficacy of FOLFOXIRI plus bevacizumab in this setting, and to investigate whether this regimen could revert the poor prognosis of high-risk patients defined by clinical and molecular factors. We performed a pooled analysis of patients with unresectable and liver-limited mCRC, treated with first-line FOLFOXIRI plus bevacizumab in three prospective clinical trials by Gruppo Oncologico del Nord Ovest. 205 (37.9%) patients with liver-limited disease were selected, out of 541 treated patients. Liver metastases were synchronous, ≥4 and bilobar in 90%, 61%, and 79% of cases, respectively. The largest diameter was >5 cm in 42% of cases, and ≥6 segments were involved in 25%. Seventy-four patients (36.1%) underwent R0 or R1 resection of metastases. R2 resections were performed in 17 cases (8.3%). Having <6 involved segments (p < 0.001) and achieving RECIST response (p = 0.019) were associated with higher chances of resection. R0/R1 resected patients had significantly longer median progression-free survival (PFS) (18.1 versus 10.7 months, HR: 0.48 [0.35-0.66], p < 0.001) and overall survival (OS) (44.3 versus 24.4 months, HR: 0.32 [0.22-0.48], p < 0.001) compared with other patients, both in the univariate and multivariate analyses (PFS p = 0.025; OS p < 0.001). The 5-year PFS and OS rate in R0 resected patients were 12% and 43%, respectively. Neither negative baseline characteristics nor high clinical risk scores or RAS/BRAF mutations were associated with poor post-resection outcomes. In conclusion, FOLFOXIRI plus bevacizumab demonstrates efficacy in the conversion setting with considerable long-term outcome results independent of clinical and molecular prognostic factors (NCT00719797, NCT01163396 and NCT02271464).