Ascites and resistance to immune checkpoint inhibition in dMMR/MSI-H metastatic colorectal and gastric cancers

BACKGROUND

Despite unprecedented benefit from immune checkpoint inhibitors (ICIs) in patients with mismatch repair deficient (dMMR)/microsatellite instability high (MSI-H) advanced gastrointestinal cancers, a relevant proportion of patients shows primary resistance or short-term disease control. Since malignant effusions represent an immune-suppressed niche, we investigated whether peritoneal involvement with or without ascites is a poor prognostic factor in patients with dMMR/MSI-H metastatic colorectal cancer (mCRC) and gastric cancer (mGC) receiving ICIs.

METHODS

We conducted a global multicohort study at Tertiary Cancer Centers and collected clinic-pathological data from a cohort of patients with dMMR/MSI-H mCRC treated with anti-PD-(L)1 ±anti-CTLA-4 agents at 12 institutions (developing set). A cohort of patients with dMMR/MSI-high mGC treated with anti-PD-1 agents±chemotherapy at five institutions was used as validating dataset.

RESULTS

The mCRC cohort included 502 patients. After a median follow-up of 31.2 months, patients without peritoneal metastases and those with peritoneal metastases and no ascites had similar outcomes (adjusted HR (aHR) 1.15, 95% CI 0.85 to 1.56 for progression-free survival (PFS); aHR 0.96, 95% CI 0.65 to 1.42 for overall survival (OS)), whereas inferior outcomes were observed in patients with peritoneal metastases and ascites (aHR 2.90, 95% CI 1.70 to 4.94; aHR 3.33, 95% CI 1.88 to 5.91) compared with patients without peritoneal involvement. The mGC cohort included 59 patients. After a median follow-up of 17.4 months, inferior PFS and OS were reported in patients with peritoneal metastases and ascites (aHR 3.83, 95% CI 1.68 to 8.72; aHR 3.44, 95% CI 1.39 to 8.53, respectively), but not in patients with only peritoneal metastases (aHR 1.87, 95% CI 0.64 to 5.46; aHR 2.15, 95% CI 0.64 to 7.27) when compared with patients without peritoneal involvement.

CONCLUSIONS

Patients with dMMR/MSI-H gastrointestinal cancers with peritoneal metastases and ascites should be considered as a peculiar subgroup with highly unfavorable outcomes to current ICI-based therapies. Novel strategies to target the immune-suppressive niche in malignant effusions should be investigated, as well as next-generation ICIs or intraperitoneal approaches.

Homologous Recombination Deficiency Alterations in Colorectal Cancer: Clinical, Molecular, and Prognostic Implications

BACKGROUND

Tumors with homologous recombination (HR) deficiency (HRD) show high sensitivity to platinum salts and PARP-inhibitors in several malignancies. In colorectal cancer (CRC), the role of HRD alterations is mostly unknown.

METHODS

Next generation sequencing, whole transcriptome sequencing and whole exome sequencing were conducted using CRC samples submitted to a commercial Clinical Laboratory Improvement Amendments (CLIA) certified laboratory. Tumors with pathogenic/presumed pathogenic mutations in 33 genes involved in the HR pathway were considered HRD, the others HR proficient (HRP). Furthermore, tumor samples from patients enrolled in the phase III TRIBE2 study comparing upfront FOLFOXIRI/bevacizumab versus FOLFOX/bevacizumab were analyzed with next generation sequencing. The analyses were separately conducted in microsatellite stable/proficient mismatch repair (MSS/pMMR) and microsatellite instable-high/deficient mismatch repair (MSI-H/dMMR) groups. All statistical tests were 2-sided.

RESULTS

Of 9321 CRC tumors, 1270 (13.6%) and 8051 (86.4%) were HRD and HRP, respectively. HRD tumors were more frequent among MSI-H/dMMR than MSS/pMMR tumors (73.4% vs 9.5%, p and q < 0.001). In MSS/pMMR group, HRD tumors were more frequently tumor mutational burden high (8.1% vs 2.2% P and q < 0.001) and PD-L1 positive (5.0% vs 2.4%, P and q = 0.001), enriched in all immune cell and fibroblast populations, and genomic loss of heterozygosity-high (16.2% vs 9.5%, P = .03). In the TRIBE2 study, patients with MSS/pMMR and HRD tumors (10.7%) showed longer overall survival compared to MSS/pMMR and HRP ones (40.2 vs 23.8 months; hazard ratio = 0.66; 95% confidence interval = 0.45-0.98, P = .04). Consistent results were reported in the multivariable model (hazard ratio = 0.67; 95% confidence ratio = 0.45-1.02, P = .07). No interaction effect was evident between HR groups and treatment arm.

CONCLUSIONS

HRD tumors are a distinctive subgroup of MSS/pMMR CRCs with specific molecular and prognostic characteristics. The potential efficacy of agents targeting the HR system and immune check-point inhibitors in this subgroup is worth of clinical investigation.

Upfront Modified Fluorouracil, Leucovorin, Oxaliplatin, and Irinotecan Plus Panitumumab Versus Fluorouracil, Leucovorin, and Oxaliplatin Plus Panitumumab for Patients With RAS/BRAF Wild-Type Metastatic Colorectal Cancer: The Phase III TRIPLETE Study by GONO

To verify whether the intensification of the upfront chemotherapy backbone with a modified schedule of modified fluorouracil, leucovorin, oxaliplatin, and irinotecan (mFOLFOXIRI) increases the activity of fluorouracil, leucovorin, and oxaliplatin when both regimens are combined with panitumumab as initial treatment for RAS and BRAF wild-type (wt) metastatic colorectal cancer (mCRC).

Immune-Checkpoint Inhibitors (ICIs) in Metastatic Colorectal Cancer (mCRC) Patients beyond Microsatellite Instability

Immune-checkpoint inhibitors (ICIs) showed impressive results in terms of activity and efficacy in metastatic colorectal cancer (mCRC) patients bearing tumors with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H). Despite that microsatellite status is the major predictive biomarker for the efficacy of ICIs, a proportion of dMMR/MSI-H mCRC tumors do not achieve benefit from immunotherapy due to the primary resistance. Deeper knowledge of biological mechanisms regulating dMMR/MSI-H CRC tumors and immune response may be useful to find new predictive biomarkers of ICIs benefit and tailor the use of immunotherapy even in dMMR/MSI-H mCRC patients. Moreover, several issues are still open, such as the secondary resection of metastases and the optimal duration of ICIs therapy in dMMR/MSI-H mCRC patients. Looking beyond microsatellite status, in a future perspective, several tools (i.e., Tumor Mutational Burden and PD-L1 expression) have been investigated to clarify their possible role as predictive biomarkers. Furthermore, a small subgroup of pMMR/MSS CRC tumors with a POLE mutation of the proofreading domain is characterized by hypermutated phenotype and might derive benefit from immune checkpoint inhibition. In the present work, we aim to review the most recent literature regarding treatment with ICIs in mCRC, focusing on dMMR/MSI-H and special subgroups of CRC patients. Hence, we summarize possible future targets and the most promising predictive biomarkers.

A knowledge discovery framework to predict the N2O emissions in the wastewater sector

Data Analytics is being deployed to predict the dissolved nitrous oxide (N₂O) concentration in a full-scale sidestream sequence batch reactor (SBR) treating the anaerobic supernatant. On average, the N₂O emissions are equal to 7.6% of the NH₄-N load and can contribute up to 97% to the operational carbon footprint of the studied nitritation-denitritation and via-nitrite enhanced biological phosphorus removal process (SCENA). The analysis showed that average aerobic dissolved N₂O concentration could significantly vary under similar influent loads, dissolved oxygen (DO), pH and removal efficiencies. A combination of density-based clustering, support vector machine (SVM), and support vector regression (SVR) models were deployed to estimate the dissolved N₂O concentration and behaviour in the different phases of the SBR system. The results of the study reveal that the aerobic dissolved N₂O concentration is correlated with the drop of average aerobic conductivity rate (spearman correlation coefficient equal to 0.7), the DO (spearman correlation coefficient equal to -0.7) and the changes of conductivity between sequential cycles. Additionally, operational conditions resulting in low aerobic N₂O accumulation (<0.6 mg/L) were identified; step-feeding, control of initial NH₄⁺ concentrations and aeration duration can mitigate the N₂O peaks observed in the system. The N₂O emissions during aeration shows correlation with the stripping of accumulated N₂O from the previous anoxic cycle. The analysis shows that N₂O is always consumed after the depletion of NO₂^- during denitritation (after the "nitrite knee"). Based on these findings SVM classifiers were constructed to predict whether dissolved N₂O will be consumed during the anoxic and anaerobic phases and SVR models were trained to predict the N₂O concentration at the end of the anaerobic phase and the average dissolved N₂O concentration during aeration. The proposed approach accurately predicts the N₂O emissions as a latent parameter from other low-cost sensors that are traditionally deployed in biological batch processes.

Dissecting tumor lymphocyte infiltration to predict benefit from immune-checkpoint inhibitors in metastatic colorectal cancer: lessons from the AtezoT RIBE study

BACKGROUND

Tumor immune cells influence the efficacy of immune-checkpoint inhibitors (ICIs) and many efforts aim at identifying features of tumor immune microenvironment able to predict benefit from ICIs in proficient mismatch repair (pMMR)/microsatellite stable (MSS) metastatic colorectal cancer (mCRC).

METHODS

We characterized tumor immune cell infiltrate, by assessing tumor-infiltrating lymphocytes (TILs), Immunoscore, Immunoscore-IC, and programmed death ligand-1 (PD-L1) expression in tumor samples of patients with mCRC enrolled in the AtezoTRIBE study, a phase II randomized trial comparing FOLFOXIRI/bevacizumab/atezolizumab to FOLFOXIRI/bevacizumab, with the aim of evaluating the prognostic and predictive value of these features.

RESULTS

Out of 218 patients enrolled, 181 (83%), 77 (35%), 157 (72%) and 162 (74%) specimens were successfully tested for TILs, Immunoscore, Immunoscore-IC and PD-L1 expression, respectively, and 69 (38%), 45 (58%), 50 (32%) and 21 (13%) tumors were classified as TILs-high, Immunoscore-high, Immunoscore-IC-high and PD-L1-high, respectively. A poor agreement was observed between TILs and Immunoscore or Immunoscore-IC (K of Cohen <0.20). In the pMMR population, longer progression-free survival (PFS) was reported for Immunoscore-high and Immunoscore-IC-high groups compared with Immunoscore-low (16.4 vs 12.2 months; HR: 0.55, 95% CI: 0.30 to 0.99; p=0.049) and Immunoscore-IC-low (14.8 vs 11.5 months; HR: 0.55, 95% CI: 0.35 to 0.85; p=0.007), respectively, with a significant interaction effect between treatment arms and Immunoscore-IC (p for interaction: 0.006) and a trend for Immunoscore (p for interaction: 0.13). No PFS difference was shown according to TILs and PD-L1 expression. Consistent results were reported in the overall population.

CONCLUSIONS

The digital evaluation of tumor immune cell infiltrate by means of Immunoscore-IC or Immunoscore identifies the subset of patients with pMMR mCRC achieving more benefit from the addition of the anti-PD-L1 to the upfront treatment. Immunoscore-IC stands as the most promising predictor of benefit from ICIs.

Rationale and Study Design of the PARERE Trial: Randomized phase II Study of Panitumumab Re-Treatment Followed by Regorafenib Versus the Reverse Sequence in RAS and BRAF Wild-Type Chemo-Refractory Metastatic Colorectal Cancer Patients

BACKGROUND

A recent phase II randomized Japanese study reported better survival with regorafenib followed at progression by cetuximab ± irinotecan compared with the reverse standard sequence in chemo-refractory and anti-EGFR-naïve, RAS wild-type (wt) mCRC patients. Nowadays the use of anti-EGFR antibodies is more frequently anticipated to the first-line of therapy especially in patients with left-sided RAS/BRAF wt tumours. However, retrospective analyses and phase II single-arm trials showed promising activity of re-using anti-EGFRs in metastatic colorectal cancer (mCRC) patients who previously achieved benefit from a first-line anti-EGFR-based treatment. Post-hoc analyses of these trials revealed that the detection of RAS mutations in circulating tumour DNA (ct-DNA) at the time of re-treatment may be useful to identify resistant patients.

PATIENTS AND METHODS

PARERE (NCT04787341) is a prospective, open label, multicentre phase II study in which 214 RAS/BRAF wt chemo-refractory mCRC patients with previous benefit from first-line anti-EGFR-based treatment and RAS/BRAF wt ct-DNA in the liquid biopsy collected at the time of inclusion will be randomized in a 1:1 ratio to receive panitumumab followed after progression by regorafenib versus the reverse sequence. Primary endpoint is overall survival. Secondary endpoints are 1st-progression free-survival (PFS), 2nd-PFS, time to failure strategy, objective response rate, and safety.

AIM OF THE STUDY

The aim of this study is to validate the role of anti-EGFR retreatment and its proper placement in the therapeutic route of mCRC patients selected according to the analysis of ct-DNA in liquid biopsy. Results are expected at the end of 2023.

Treatments after second progression in metastatic colorectal cancer: A pooled analysis of the TRIBE and TRIBE2 studies

BACKGROUND

The availability of new drugs in the chemo-refractory setting opened the way to the concepts of treatment sequencing in mCRC. However, the impact of later line options in the therapeutic route of metastatic colorectal cancer (mCRC) patients and the attrition rate across subsequent lines of therapy are not well established.

METHODS

We performed a pooled analysis of treatments administered after the 2nd disease progression in 1187 mCRC patients enrolled in the randomized phase III TRIBE and TRIBE2 studies, where upfront FOLFOXIRI/bev was compared with FOLFOX or FOLFIRI/bev. Per each line, we assessed the attrition rate, treatment choices and clinical outcomes.

RESULTS

625 (53%), 326 (27%) and 136 (11%) patients received a systemic treatment after the 2nd, 3rd and 4th disease progression, respectively. PFS and objective response rate decreased along each line. RAS/BRAF wild-type patients received more likely a 3rd line (75%) compared with RAS (66%, p = 0.005) and BRAF (66%, p = 0.11) mutants. In 3rd line, 67% of RAS/BRAF wild-type patients received anti-EGFRs, achieving longer PFS with respect to other therapies (6.4 vs 3.9 months, p = 0.02). A trend towards longer 3rd line OS was observed in TRIBE patients (9.9 vs 7.2 months, p = 0.05).

CONCLUSIONS

A relevant attrition rate across subsequent lines of therapy is evident, and more pronounced in RAS and BRAF mutated patients, thus highlighting the relevance of the choice of the upfront treatment. The efficacy of anti-EGFR agents among RAS/BRAF wild-type patients unexposed to anti-EGFRs is higher than other options. The reintroduction of chemotherapy remains frequent in clinical practice.

TRIAL REGISTRATION

Clinicaltrials. gov Identifiers NCT00719797, NCT02339116.

Upfront Fluorouracil, Leucovorin, Oxaliplatin, and Irinotecan Plus Bevacizumab With or Without Atezolizumab for Patients With Metastatic Colorectal Cancer: Updated and Overall Survival Results of the ATEZOTRIBE Study

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report 4-year results of the phase II randomized AtezoTRIBE study. Eligible patients with metastatic colorectal cancer (mCRC) received first-line fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI)/bevacizumab (control group, n = 73) or FOLFOXIRI/bevacizumab plus atezolizumab (experimental group, n = 145). We present overall survival (OS) and updated outcomes according to tumor immune-related biomarkers, both in the intention-to-treat (ITT) population and the cohort of patients with proficient mismatch repair (pMMR) tumors. Median follow-up was 45.2 months (IQR, 42.6-49.2). In the ITT population, median OS was 33.0 and 27.2 months for experimental and control groups, respectively (hazard ratio [HR], 0.78 [80% CI, 0.61 to 0.98]; P = .084). An interaction effect between Immunoscore Immune-Checkpoint (IC) and treatment arm was observed (Pint, .089), with higher benefit from atezolizumab in the Immunoscore IC-high group. In the pMMR cohort (N = 202), median OS was 30.8 and 29.2 months for experimental and control groups, respectively (HR, 0.80 [80% CI, 0.63 to 1.02]; P = .117). Interactions between treatment group and tumor mutational burden (TMB) and Immunoscore IC were reported (Pint, .043 and .092, respectively), with patients bearing TMB-high and Immunoscore IC-high tumors deriving higher benefit from the addition of atezolizumab. First-line FOLFOXIRI/bevacizumab plus atezolizumab improves OS in patients with mCRC. In the pMMR group, patients with Immunoscore IC-high and/or TMB-high tumors are identified as a subgroup of interest to further develop this treatment.

Negative Hyperselection of Patients with HER2+ and RAS Wild-Type Metastatic Colorectal Cancer Receiving Dual HER2 Blockade: the PRESSING-HER2 Study

PURPOSE

To demonstrate the negative prognostic impact of a panel of genomic alterations (PRESSING-HER2 panel) and lack of HER2 amplification by next-generation sequencing (NGS) in patients with HER2+, RAS wild-type metastatic colorectal cancer receiving dual HER2 blockade.

EXPERIMENTAL DESIGN

The PRESSING-HER2 panel of HER2 mutations/rearrangements and RTK/MAPK mutations/amplifications was assessed by NGS. HER2 amplification was confirmed by NGS if copy-number variation (CNV) was ≥ 6. With a case-control design, hypothesizing 30% and 5% PRESSING-HER2 positivity in resistant [progression-free survival (PFS) <4 months and no RECIST response] versus sensitive cohorts, respectively, 35 patients were needed per group.

RESULTS

PRESSING-HER2 alterations included HER2 mutations/rearrangements, EGFR amplification, and BRAF mutations and had a prevalence of 27% (9/33) and 3% (1/35) in resistant versus sensitive patients (P = 0.005) and 63% predictive accuracy. Overall, HER2 nonamplified status by NGS had 10% prevalence. Median PFS and overall survival (OS) were worse in PRESSING-HER2+ versus negative (2.2 vs. 5.3 months, P < 0.001; 5.4 vs. 14.9 months, P = 0.001) and in HER2 nonamplified versus amplified (1.6 vs. 5.2 months, P < 0.001; 7.4 vs. 12.4 months, P = 0.157). These results were confirmed in multivariable analyses [PRESSING-HER2 positivity: PFS HR = 3.06, 95% confidence interval (CI), 1.40-6.69, P = 0.005; OS HR = 2.93, 95% CI, 1.32-6.48, P = 0.007]. Combining PRESSING-HER2 and HER2 CNV increased the predictive accuracy to 75%.

CONCLUSIONS

PRESSING-HER2 panel and HER2 nonamplified status by NGS warrant validation as potential predictive markers in this setting. See related commentary by Raghav et al., p. 260.

Bevacizumab-induced hypertension as a predictor of clinical outcome in metastatic colorectal cancer: An individual patient data-based pooled analysis of two randomized studies and a systematic review of the literature

BACKGROUND

Retrospective series suggest that bevacizumab-induced hypertension (HTN) is a prognostic and potentially predictive biomarker of efficacy of the antiangiogenic drug in the upfront treatment of metastatic colorectal cancer (mCRC) patients. The immortal-time bias and the effect of pre-existing HTN might affect these findings. We conducted a pooled, post hoc analysis of 2 prospective randomized trials of chemotherapy plus bevacizumab in mCRC, and performed a systematic review of the available literature focusing on how the immortal-time bias was taken into account and how pre-existing HTN potentially requiring the use of antihypertensive drugs was managed.

METHODS

The pooled-analysis included patients enrolled in the phase III TRIBE and TRIBE-2 studies that compared upfront FOLFOXIRI + bevacizumab to FOLFIRI or FOLFOX + bevacizumab, respectively. Association between HTN and survival outcomes was assessed by incorporating a time-dependent Cox regression model to consider the time-dependency of the probability of HTN onset during the treatment. The systematic review was conducted according to PRISMA guidelines.

RESULTS

The systematic review retrieved 14 eligible and highly heterogeneous studies. A positive prognostic impact of bevacizumab-induced HTN was reported in the 58% of the analyses reporting Progression Free Survival (PFS) and in the 54% of the analyses reporting Overall Survival (OS) data. Immortal-time bias was incorporated in 4 studies (28%). In TRIBE and TRIBE-2 study populations (N = 1175), patients experiencing ≥ G2 HTN during first-line bevacizumab administration showed longer PFS (median: 14.7 versus 10.3 months, p < 0.001) and OS (median: 31.7 versus 24.2 months, p < 0.001). The association with OS retained statistical significance after correction for time-dependency (p = 0.003) and was confirmed in the multivariable model including HTN as a time-dependent variable (p = 0.02). Moreover, in patients with pre-existing HTN, no difference in terms of PFS and OS was observed compared with the subgroup of patients who never experienced ≥G2 HTN (HR 1.01, p = 0.86 and HR 1.02, p = 0.78 respectively.

CONCLUSIONS

Bevacizumab-induced HTN during the first-line treatment of mCRC is an independent prognostic factor, also adopting a time-dependency correction. Toxicity should be interpreted as a time-dependent variable when exploring its association with clinical outcome.

FOLFOXIRI and bevacizumab in patients with early-onset metastatic colorectal cancer. A pooled analysis of TRIBE and TRIBE2 studies

BACKGROUND

We performed a pooled analysis of TRIBE and TRIBE2 studies to assess the efficacy and safety of the intensification of upfront chemotherapy backbone - from doublets to the triplet FOLFOXIRI - in combination with bevacizumab (bev) in patients with early-onset metastatic colorectal cancer (EO-mCRC; aged <50 years) and to explore whether EO-mCRCs have a peculiar tumour genomic profiling.

MATERIALS AND METHODS

Subgroup analyses according to age (<50 versus ≥50 years) and treatment (FOLFOXIRI/bev versus doublets/bev) were carried out for rates of any grade and grade ≥3 (≥G3) overall and singular adverse events, progression-free survival (PFS), overall survival (OS) and objective response rate (ORR). Tumour genomic profiling was obtained using a DNA-based next-generation sequencing platform.

RESULTS

Of 1187 patients included, 194 (16%) patients were aged <50 years. Females were more frequently diagnosed with EO-mCRC (P = 0.04). Patients aged <50 years showed a lower risk of ≥G3 neutropenia (P = 0.07), diarrhoea (P = 0.04), asthenia (P = 0.008) and a higher risk of any grade nausea (P < 0.01) and vomiting (P < 0.01). Patients receiving FOLFOXIRI/bev more frequently experienced ≥G3 chemotherapy-related adverse events respect to doublets/bev, regardless of age (Pinteraction = 0.60). FOLFOXIRI/bev was associated to a lower incidence of neutropenia (P = 0.04) and asthenia (P = 0.01) in patients <50 years old, than those aged ≥50 years. PFS, OS and ORR did not differ according to age (PFS P = 0.81, OS P = 0.44, ORR P = 0.50) and no interaction between age and the benefit from the intensification of upfront chemotherapy was observed (PFS Pinteraction = 0.72, OS Pinteraction = 0.54, ORR Pinteraction = 0.65). Genomic profiling was assessed in 296 patients, showing an enrichment of FBXW7 and POLE mutations in EO-mCRC.

CONCLUSIONS

Upfront FOLFOXIRI/bev shows a favourable efficacy/safety balance in EO-mCRC.

TRIAL REGISTRATION

Clinicaltrials.gov Identifiers NCT00719797, NCT0233-9116.

Trop-2 and Nectin-4 immunohistochemical expression in metastatic colorectal cancer: searching for the right population for drugs' development

BACKGROUND

Trop-2 and Nectin-4 are transmembrane proteins overexpressed in many tumours and targets of antibody-drug conjugates (ADC). In metastatic colorectal cancer (mCRC), the role of Trop-2 and Nectin-4 has been poorly investigated.

METHODS

Tumour samples of patients randomised in the phase III TRIBE2 were assessed for Trop-2 and Nectin-4 expression.

RESULTS

Three hundred eighty-six tumours were assessed for Trop-2 expression. 90 (23%), 115 (30%) and 181 (47%) were Trop-2 high, medium and low, respectively. Patients with low Trop-2 tumours achieved longer PFS (12 versus 9.9 months, p = 0.047) and OS (27.3 versus 21.3 months, p = 0.015) than those with high/medium Trop-2 tumours. These findings were confirmed in multivariate analysis (p = 0.022 and p = 0.023, respectively). A greater OS benefit from treatment intensification with FOLFOXIRI/bevacizumab was observed in patients with high/medium Trop-2 tumours (p-for-interaction = 0.041). Two hundred fifty-one tumours were assessed for Nectin-4 expression. Fourteen (5%), 67 (27%) and 170 (68%) were high, medium and low, respectively. No prognostic impact was observed based on Nectin-4 expression and no interaction effect was reported between Nectin-4 expression groups and treatment arm.

CONCLUSIONS

In mCRC, expression levels of Trop-2 and Nectin-4 are heterogeneous, suggesting a target-driven development of anti-Trop2 and anti-Nectin-4 ADCs. Medium/high Trop-2 expression is associated with worse prognosis and higher benefit from chemotherapy intensification.

Consensus molecular subtypes and CRCassigner classifications in metastatic colorectal cancer (mCRC): Prognostic and predictive impact in the TRIBE2 study

4016

Background: The TRIBE2 study (NCT02339116) recently demonstrated the superiority of upfront FOLFOXIRI/bevacizumab (bev) when compared to a pre-planned strategy of doublets/bev in molecularly unselected but mostly (74%) RAS/ BRAF mutant mCRC patients. The Consensus Molecular Subtypes (CMS) and CRCAssigner (CRCA) demonstrated prognostic value in multiple studies, but their predictive role has not been established so far. Given the poor prognosis associated with early stage mesenchymal/stem-like subtypes, we hypothesized that the CMS/CRCA classifiers could predict benefit from the upfront intensified strategy in patients included in the TRIBE2 study. Methods: Untreated formalin-fixed paraffin-embedded samples were classified into CMS/CRCA subtypes using a custom nCounter assay (NanoString Technologies). The impact of subtypes on progression free survival (PFS), progression free survival 2 (PFS2, defined as the time from randomization until the second evidence of disease progression) or overall survival (OS) was evaluated in the profiled population. Results: 426 and 428 (63%) patients enrolled in the TRIBE2 study were profiled according to CMS and CRCA classifications, respectively. The distribution of CMS/CRCA subtypes differed according to primary tumour site (both p < 0.001 for CMS/CRCA) and RAS/ BRAF mutational status (both p < 0.001 for CMS/CRCA). Significant associations of both CMS/CRCA classifiers with PFS, PFS2 and OS were demonstrated (Table). The effect of treatment intensification was independent of CMS subtypes (p for interaction for PFS/PFS2/OS: ns). Significant interaction effect between CRCA subtypes and treatment arm was reported in terms of PFS (p = 0.017), PFS2 (p = 0.010) and OS (p = 0.008). The benefit from the intensification of the upfront chemotherapy seemed more relevant in the stem-like (PFS, HR = 0.60; p = 0.03) and mixed subtypes (HR = 0.44; p = 0.002). Conclusions: CMS subtypes have a prognostic role in mCRC independently of RAS/ BRAF status. CRCA classification may help identifying subgroups of patients who may derive a more substantial benefit from upfront FOLFOXIRI/bev. [Table: see text]

Exploring clinical and gene expression markers of benefit from FOLFOXIRI/bevacizumab in patients with BRAF-mutated metastatic colorectal cancer: Subgroup analyses of the TRIBE2 study

BACKGROUND

Recent data from the TRIBE2 study have failed to suggest a higher magnitude of benefit from upfront FOLFOXIRI/bevacizumab in patients with BRAF-mutant metastatic colorectal cancer (mCRC) as previously reported in the TRIBE study.

PATIENTS AND METHODS

Clinical characteristics and gene expression signatures of patients with BRAF-mutant mCRC enrolled in the TRIBE2 study were evaluated with the aim of understanding that patients may derive benefit from the intensification of the upfront chemotherapy.

RESULTS

Of 46 BRAF-mutant tumour samples analysed, 24 (52%) and 22 (48%) were classified as BM1 and BM2, respectively, and 27 (59%) and 19 (41%) were assigned to ligand-independent (LI) and ligand-dependent (LD) Wnt pathway subgroups, respectively. No prognostic impact was shown for both BM1/BM2 and LI/LD subtypes. No interaction was evident between BM1/BM2 or LI/LD signatures and the benefit provided by FOLFOXIRI/bevacizumab. Significant interaction effect was evident in terms of progression-free survival between treatment arm and primary tumour sidedness (P = 0.05) and Eastern Cooperative Oncology Group performance status (ECOG-PS; P < 0.001).

CONCLUSIONS

Gene expression analysis failed to identify patients with BRAF-mutant mCRC candidate to upfront FOLFOXIRI/bevacizumab. ECOG-PS >0 and left-sidedness seem associated with no benefit from the intensified treatment.

The prognostic value of radiomic features in liver-limited metastatic colorectal cancer patients from the TRIBE2 study

Aims: Evaluating the prognostic role of radiomic features in liver-limited metastatic colorectal cancer treated with first-line therapy at baseline and best response among patients undergoing resection. Patients & methods: Among patients enrolled in TRIBE2 (NCT02339116), the association of clinical and radiomic data, extracted by SOPHiA-DDM™ with progression-free and overall survival (OS) in the overall population and with disease-free survival/postresection OS in those undergoing resection was investigated. Results: Among 98 patients, radiomic parameters improved the prediction accuracy of our model for OS (area under the curve: 0.83; sensitivity: 0.85; specificity: 0.73; accuracy: 0.78), but not progression-free survival. Of 46 resected patients, small-distance high gray-level emphasis was associated with shorter disease-free survival and high gray-level zone emphasis/higher kurtosis with shorter postresection OS. Conclusion: Radiomic features should be implemented as tools of outcome prediction for liver-limited metastatic colorectal cancer.

Clinical impact of neutropenia and febrile neutropenia in metastatic colorectal cancer patients treated with FOLFOXIRI/bevacizumab: a pooled analysis of TRIBE and TRIBE2 studies by GONO

BACKGROUND

TRIBE and TRIBE-2 studies demonstrated higher benefit from FOLFOXIRI (fluorouracil, leucovorin, oxaliplatin, and irinotecan)/bevacizumab compared with FOLFIRI (fluorouracil, leucovorin, and irinotecan) or FOLFOX/bevacizumab as an upfront option for metastatic colorectal cancer patients, with more toxicities. We focused on the incidence and longitudinal dynamics of neutropenia and febrile neutropenia (FN) in the two studies, to evaluate their clinical relevance, the magnitude of impact of FOLFOXIRI/bevacizumab, and the role of risk factors in predicting their occurrence.

METHODS

The overall incidence of grade 3-4 (G3-4) neutropenia and FN, the time to their onset, the use of granulocyte colony-stimulating factor, and the association with risk factors were evaluated in the overall population and according to treatment arm. FN episodes were assessed by Multinational Association for Supportive Care in Cancer (MASCC) score.

RESULTS

Among 1155 patients, 568 (49%) received FOLFOXIRI/bevacizumab. Overall, 410 (35%) experienced G3-4 neutropenia and 70 (6%) FN, 21 (2%) at high risk. FOLFOXIRI/bevacizumab was associated with higher incidence of neutropenia (51% versus 21%, P < 0.001), FN (8% versus 4%, P = 0.02), and high-risk FN [18 (3%) versus 3 (1%), P = 0.015]. No related deaths were observed. The first episode of G3-4 neutropenia and FN occurred mainly in the first 2 months in both arms. Longitudinal analysis showed different patterns of evolution over cycles between the arms (P < 0.001) G3-4 neutropenia being more frequent in the first cycles with FOLFOXIRI/bevacizumab. Older patients (P = 0.01) and females (P < 0.001) had a significantly higher risk of G3-4 neutropenia. No significant interaction effect between arm and analysed risk factors in terms of risk of G3-4 neutropenia or FN was observed. The incidence of FN among older females receiving FOLFOXIRI/bevacizumab was 12%. Neither G3-4 neutropenia nor FN impaired efficacy in terms of overall response rate, progression-free survival, and overall survival.

CONCLUSIONS

FOLFOXIRI/bevacizumab has a higher risk of G3-4 neutropenia and FN than doublets/bevacizumab. FN occurred in <10% of patients, mostly as low-risk episodes. A closer monitoring during the first 2 months is recommended; prophylactic use of granulocyte colony-stimulating factor may be considered for older females.

Malignant ascites as a marker of peritoneal carcinomatosis burden in patients with colorectal and gastroesophageal cancer

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Background: Malignant ascites occurs frequently in patients with gastric cancer (GC) and colorectal cancer (CRC) with peritoneal metastasis (PM). The presence of PM and malignant ascites have been independently reported to confer resistance to systemic therapy and poorer prognosis. However, the occurrence of malignant ascites as a function of increasing peritoneal carcinomatosis burden has been less studied and reported. Methods: We reviewed prospective cohorts of gastric cancer and colorectal cancer patients with PM. The first cohort was a prospective group of GCPM patients receiving bi-directional systemic and peritoneal-directed therapies (catheter-based intraperitoneal chemotherapy and/or pressurized intraperitoneal aerosol chemotherapy respectively) at a tertiary oncology center in Singapore. Clinico-pathological data, including Peritoneal Cancer Index (PCI) and the presence or absence of ascites based on diagnostic laparoscopy, was collected. To orthogonally validate the hypothesis of malignant ascites as a function of peritoneal carcinomatosis burden in gastrointestinal malignancies, we studied the relationship between ascites, PM and survival in an independent cohort of metastatic CRC patients eligible for first-line systemic treatment enrolled in two randomized clinical trials in different Italian cancer centers. Results: In the first cohort of 82 patients with GCPM, the median PCI was 19 (inter-quartile range (IQR) 8 – 26) in the group with ascites and 3 (IQR 1 – 12) in the group without ascites (p=0.005), suggesting ascites occurs with higher PM burden. The median overall survival (OS) was poorer in patients with ascites (13.4 vs 16.4 months, HR 1.6, 95% CI 0.9 – 2.8, p=0.082). The median OS in patients with PCI of <7 was 17.3 months (95% 12.0 – 22.7) and 13.8 months (95% CI 11.0 – 16.6) in those with PCI score >7. In the validation cohort of 900 CRC patients, presence of malignant ascites and PM resulted in poorer survival compared to patients with PM and no malignant ascites (HR for OS PM with ascites vs PM without ascites 2.01 (95% CI 1.37 - 2.96), p<0.001). Interestingly, those with PM and ascites had a poorer survival to those with stage IV disease without peritoneal involvement, while those with PM without ascites did not have a statistically significant difference (PM with malignant ascites vs. no peritoneal disease, HR for OS 2.14, 95% CI 1.57 – 3.01, p=0.007; PM without ascites vs no peritoneal disease, HR for OS 1.10, 95% CI 0.91 – 1.34). Conclusions: Our study of patients with colorectal or gastric cancer and peritoneal metastases suggest the presence of malignant ascites as a function of increased peritoneal carcinomatosis burden among patients with metastatic gastrointestinal malignancies, with correspondingly poorer survival outcomes.

Irinotecan- vs. Oxaliplatin-Based Doublets in KRASG12C-Mutated Metastatic Colorectal Cancer-A Multicentre Propensity-Score-Matched Retrospective Analysis

BACKGROUND

KRAS^G12C-mutated metastatic colorectal cancer (mCRC) has recently been recognized as a distinct druggable molecular entity; however, there are limited data on its sensitivity to standard chemotherapy. In the near future, the combination of chemotherapy plus a KRAS^G12C-inhibitor might become the standard of care; however, the optimal chemotherapy backbone is unknown.

METHODS

A multicentre retrospective analysis was conducted including KRAS^G12C-mutated mCRC patients treated with first-line FOLFIRI or FOLFOX +/- bevacizumab. Both unmatched and propensity-score-matched analysis (PSMA) were conducted, with PSMA controlling for: previous adjuvant chemotherapy, ECOG PS, use of bevacizumab in first line, timing of metastasis appearance, time from diagnosis to first-line start, number of metastatic sites, presence of mucinous component, gender, and age. Subgroup analyses were also performed to investigate subgroup treatment-effect interactions. KRAS^G12D-mutated patients were analysed as control.

RESULTS

One hundred and four patients treated with irinotecan-(N = 47) or oxaliplatin-based (N = 57) chemotherapy were included. In the unmatched population, objective response rate (ORR) and median (m) progression-free and overall survival (mPFS and mOS) were comparable between the treatment arms. However, a late (>12 months) PFS advantage was observed with irinotecan (HR 0.62, p = 0.02). In the PSMA-derived cohort, a significant improvement with irinotecan vs. oxaliplatin was observed for both PFS and OS: 12- and 24-month PFS rates of 55% vs. 31% and 40% vs. 0% (HR 0.40, p = 0.01) and mOS 37.9 vs. 21.7 months (HR 0.45, p = 0.045), respectively. According to the subgroup analysis, interaction effects between the presence of lung metastases and treatment groups were found in terms of PFS (p for interaction = 0.08) and OS (p for interaction = 0.03), with a higher benefit from irinotecan in patients without lung metastases. No difference between treatment groups was observed in the KRAS^G12D-mutated cohort (N = 153).

CONCLUSIONS

First-line irinotecan-based regimens provided better survival results in KRAS^G12C-mutated mCRC patients and should be preferred over oxaliplatin. These findings should also be considered when investigating chemotherapy plus targeted agent combinations.

Waiting for the "liquid revolution" in the adjuvant treatment of colon cancer patients: a review of ongoing trials

Since colon cancer has a high rate of shedding of tumour fragments into the blood, several research efforts are now focused on the investigation of the minimal residual disease through the detection of ctDNA to tailor the adjuvant therapy of colon cancer patients and optimize its cost/effectiveness balance. The negative prognostic impact of detectable ctDNA in patients' blood after radical surgery for colon cancer is well established. Several clinical trials adopting heterogeneous designs and techniques are now ongoing to translate promises into daily practice by answering five general questions: i) is a ctDNA-guided decision making efficacious in the post-operative management of colon cancer patients? ii) are de-escalation strategies possible in ctDNA-negative cases? iii) are escalation strategies useful to improve the prognosis of ctDNA-positive patients? iv) when MRD is identified at the end of the adjuvant chemotherapy, is another post-adjuvant systemic therapy efficacious? v) can we exploit ctDNA technologies in the follow up of colon cancer patients? This review focuses on currently ongoing trials and how their results may affect the ctDNA "liquid revolution" of early colon cancer.

ShorTrip Trial: A Prospective, Multicentric Phase II Single-Arm Trial of Short-Course Radiotherapy Followed by Intensified Consolidation Chemotherapy With the Triplet FOLFOXIRI as Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer

BACKGROUND

In patients with locally advanced rectal cancer (LARC) treated with preoperative (chemo) radiotherapy and surgery, adjuvant chemotherapy is poorly feasible and its benefit is questionable. In the last years, several total neoadjuvant treatment (TNT) strategies, moving the adjuvant chemotherapy to the neoadjuvant setting, have been investigated with the aim of improving compliance to systemic chemotherapy, treating micrometastases earlier and then reducing distant recurrence.

PATIENTS AND METHODS

ShorTrip (NTC05253846) is a prospective, multicentre, single-arm phase II trial where 63 patients with LARC will be treated with short-course radiotherapy followed by intensified consolidation chemotherapy with FOLFOXIRI regimen and surgery. Primary endpoint is pCR. Among the first 11 patients who started consolidation chemotherapy, a preliminary safety analysis showed a high rate of grade 3 to 4 neutropenia (N = 7, 64%) during the first cycle of FOLFOXIRI. Therefore, the protocol has been emended with the recommendation to omit irinotecan during the first cycle of consolidation chemotherapy. After amendment, in a subsequent safety analysis focused on the first 9 patients treated with FOLFOX as first cycle and then with FOLFOXIRI, grade 3 to 4 neutropenia was reported in only one case during the second cycle.

AIM OF THE STUDY

The aim of this study is to assess the safety and activity of a TNT strategy including SCRT, intensified consolidation treatment with FOLFOXIRI and delayed surgery. After protocol amendment, the treatment seems feasible without safety concern. Results are expected at the end of 2024.