Biphenotypic lung carcinoma with coexpression of TTF-1 and ΔNP63/P40 within most of the same individual cells: a further case confirming poor prognosis and a review of literature.

The WHO Classification of Tumors, Thoracic Tumors, 5th edition, has outlined the use of TTF-1 and ΔNP63/P40 to discriminate between adenocarcinoma and squamous cell carcinoma. In 2015, the first description of a rare non-small cell lung carcinoma featuring co-expression of glandular and squamous differentiation within most of the same individual tumor cells was reported on, with ultrastructural and molecular demonstration of such a biphenotypic differentiation. We herein describe an additional case of this rare tumor entity, which is confirmed to be an aggressive neoplasm despite potential targets of therapy.

APOLLO 11 Project, Consortium in Advanced Lung Cancer Patients Treated With Innovative Therapies: Integration of Real-World Data and Translational Research.

INTRODUCTION: Despite several therapeutic efforts, lung cancer remains a highly lethal disease. Novel therapeutic approaches encompass immune-checkpoint inhibitors, targeted therapeutics and antibody-drug conjugates, with different results. Several studies have been aimed at identifying biomarkers able to predict benefit from these therapies and create a prediction model of response, despite this there is a lack of information to help clinicians in the choice of therapy for lung cancer patients with advanced disease. This is primarily due to the complexity of lung cancer biology, where a single or few biomarkers are not sufficient to provide enough predictive capability to explain biologic differences; other reasons include the paucity of data collected by single studies performed in heterogeneous unmatched cohorts and the methodology of analysis. In fact, classical statistical methods are unable to analyze and integrate the magnitude of information from multiple biological and clinical sources (eg, genomics, transcriptomics, and radiomics). METHODS AND OBJECTIVES: APOLLO11 is an Italian multicentre, observational study involving patients with a diagnosis of advanced lung cancer (NSCLC and SCLC) treated with innovative therapies. Retrospective and prospective collection of multiomic data, such as tissue- (eg, for genomic, transcriptomic analysis) and blood-based biologic material (eg, ctDNA, PBMC), in addition to clinical and radiological data (eg, for radiomic analysis) will be collected. The overall aim of the project is to build a consortium integrating different datasets and a virtual biobank from participating Italian lung cancer centers. To face with the large amount of data provided, AI and ML techniques will be applied will be applied to manage this large dataset in an effort to build an R-Model, integrating retrospective and prospective population-based data. The ultimate goal is to create a tool able to help physicians and patients to make treatment decisions. CONCLUSION: APOLLO11 aims to propose a breakthrough approach in lung cancer research, replacing the old, monocentric viewpoint towards a multicomprehensive, multiomic, multicenter model. Multicenter cancer datasets incorporating common virtual biobank and new methodologic approaches including artificial intelligence, machine learning up to deep learning is the road to the future in oncology launched by this project.

Repotrectinib Overcomes F2004V Resistance Mutation in ROS1-Rearranged NSCLC: A Case Report.

ROS1 tyrosine kinase inhibitors (TKIs) were found to provide a substantial clinical benefit for patients with advanced ROS1-positive (ROS1+) NSCLC. Nevertheless, TKI resistance inevitably develops with different mechanisms, preventing prolonged responses. For this reason, next-generation compounds are under clinical development. ROS1 F2004 substitutions have been previously detected on circulating tumor DNA of patients progressing to entrectinib. Hereby, we report the case of a patient with ROS1+ NSCLC in which F2004V-acquired mutation was detected on a site of disease progression, after entrectinib and crizotinib failure. A subsequent treatment with next-generation TKI repotrectinib led to disease response, providing the first clinical evidence of activity of repotrectinib against F2004V resistance mutation.

What to do after immune-checkpoint inhibitors failure in advanced non-small cell lung cancer: an expert opinion and review.

INTRODUCTION: Immune-checkpoint inhibitors (IO) have significantly improved outcomes of patients with non-oncogene-addicted non-small cell lung cancer (NSCLC), becoming the first-line agents for advanced disease. However, resistance remains a significant clinical challenge, limiting their effectiveness. AREAS COVERED: Hereby, we addressed standard and innovative therapeutic approaches for NSCLC patients experiencing progression after IO treatment, discussing the emerging resistance mechanisms and the ongoing efforts to overcome them. In order to provide a complete overview of the matter, we performed a comprehensive literature search across prominent databases, including PubMed, EMBASE (Excerpta Medica dataBASE), and the Cochrane Library, and a research of the main ongoing studies on clinicaltrials.gov. EXPERT OPINION: The dynamics of progression to IO, especially in terms of time to treatment failure and burden of progressive disease, should guide the best subsequent management, together with patient clinical conditions. Long-responders to IO might benefit from continuation of IO beyond-progression, in combination with other treatments. Patients who experience early progression should be treated with salvage CT in case of preserved clinical conditions. Finally, patients who respond to IO for a considerable timeframe and who later present oligo-progression could be treated with a multimodal approach in order to maximize the benefit of immunotherapy.

Exploring the Role of Immunotherapy-Based Treatments for Advanced Non-Small-Cell Lung Cancer With Novel Driver Alterations.

BACKGROUND: Immunotherapy (IO) single agent or combined with chemotherapy (CT-IO) is the standard treatment for advanced non-small-cell lung cancer (aNSCLC) without driver alterations. IO efficacy in patients with novel driver alterations is not well reported. MATERIALS AND METHODS: Data of aNSCLC patients treated with IO or CT-IO in any line from January 2016 to September 2022 were retrospectively collected. Patients harboring novel driver alterations (m-cohort), including MET exon 14 skipping, BRAF (V600E or atypical), RET rearrangements, HER2 point mutations/exon 20 insertions or uncommon EGFR mutations/EGFR exon 20 insertions, and wild type patients (wt-cohort) were eligible. Clinico-pathological data were extracted from Institutional databases and compared through chi square or Fisher's exact test. Survivals were estimated through Kaplan-Meier method and compared by log-rank test. RESULTS: m-cohort and wt-cohort included 84 and 444 patients, respectively. Progression free survival (PFS) was 5.53 vs. 4.57 months (P= .846) and overall survival (OS) was 25.1 vs. 9.37 months, (P < .0001) for m-cohort compared to wt-cohort. Within the m-cohort, BRAF atypical mutations had the better outcomes (Overall Response Rate [ORR], PFS), targeted agents timing did not affect response to IO and CT-IO had better ORR and disease control rate (DCR) compared to IO single agent (P = .0160 and P = .0152). In the PD-L1≥50% group, first line IO single agent resulted in inferior ORR (P = .027) and PFS (P = .022) in m-cohort compared to wt-cohort. CONCLUSION: IO based treatments seem not detrimental for patients harboring novel driver alteration. Adding CT could improve modest responses to IO alone. Confirmation on larger datasets is required.

Circulating Tumor DNA to Drive Treatment in Metastatic Colorectal Cancer.

In the evolving molecular treatment landscape of metastatic colorectal cancer (mCRC), the identification of druggable alterations is pivotal to achieve the best therapeutic opportunity for each patient. Because the number of actionable targets is expanding, there is the need to timely detect their presence or emergence to guide the choice of different available treatment options. Liquid biopsy, through the analysis of circulating tumor DNA (ctDNA), has proven safe and effective as a complementary method to address cancer evolution while overcoming the limitations of tissue biopsy. Even though data are accumulating regarding the potential for ctDNA-guided treatments applied to targeted agents, still major gaps in knowledge exist as for their application to different areas of the continuum of care. In this review, we recapitulate how ctDNA information could be exploited to drive different targeted treatment strategies in mCRC patients, by refining molecular selection before treatment by addressing tumor heterogeneity beyond tumor tissue biopsy; longitudinally monitoring early-tumor response and resistance mechanisms to targeted agents, potentially leading to tailored, molecular-driven, therapeutic options; guiding the molecular triage towards rechallenge strategies with anti-EGFR agents, suggesting the best time for retreatment; and providing opportunities for an "enhanced rechallenge" through additional treatments or combos aimed at overcoming acquired resistance. Besides, we discuss future perspectives concerning the potential role of ctDNA to fine-tune investigational strategies such as immuno-oncology.

Immune Checkpoint Inhibitors and the Exposome: Host-Extrinsic Factors Determine Response, Survival, and Toxicity.

Cancer immunotherapy, largely represented by immune checkpoint inhibitors (ICI), has led to substantial changes in preclinical cancer research and clinical oncology practice over the past decade. However, the efficacy and toxicity profiles of ICIs remain highly variable among patients, with only a fraction achieving a significant benefit. New combination therapeutic strategies are being investigated, and the search for novel predictive biomarkers is ongoing, mainly focusing on tumor- and host-intrinsic components. Less attention has been directed to all the external, potentially modifiable factors that compose the exposome, including diet and lifestyle, infections, vaccinations, and concomitant medications, that could affect the immune system response and its activity against cancer cells. We hereby provide a review of the available clinical evidence elucidating the impact of host-extrinsic factors on ICI response and toxicity.

The predictive role of ERBB2 point mutations in metastatic colorectal cancer: A systematic review.

ERBB2 amplification is a driver oncogenic alteration in many cancers and it has recently been incorporated among therapeutically actionable biomarkers also in metastatic colorectal cancer (mCRC). In contrast, the role of ERBB2 point mutations, which are detectable in up to 3% of CRC patients, remains to be assessed. In this systematic review, we collected preclinical and clinical data addressing the role of ERBB2 point mutations in mCRC patients as a predictive biomarker for anti-EGFR and anti-HER2 targeted agents, and as mechanism of acquired resistance to ERBB2 amplified mCRC treated with any anti-HER2 regimen. In both preclinical and clinical studies, most ERBB2 point mutations were associated with resistance to anti-EGFR agents, particularly L755S and R784G, which occur in the HER2 protein kinase domain. No ERBB2 mutation was associated with tumor response to HER2-targeted agents in mCRC patients, although signals of activity were observed in preclinical models. Eight ongoing clinical trials are underway to test different anti-HER2 treatments in ERBB2 mutant mCRC. Several reports documented the emergence of ERBB2 mutations in the circulating tumor DNA (ctDNA) of ERBB2 amplified mCRC progressing to anti-HER2 agents, thus hinting a role in acquired resistance.

Moving Immune Checkpoint Inhibitors to Early Non-Small Cell Lung Cancer: A Narrative Review.

Lung cancer is the leading cause of cancer-related death worldwide. Since prognosis of early-stage non-small cell lung cancer (NSCLC) remains dismal for common relapses after curative surgery, considerable efforts are currently focused on bringing immunotherapy into neoadjuvant and adjuvant settings. Previously, perioperative chemotherapy showed only a modest but significative improvement in overall survival. The presence of broad tumor neoantigens load at primary tumor prior to surgery as well as the known immunosuppressive status following resection represent the main rationale for immunotherapy in early disease. Several trials have been conducted in recent years, leading to atezolizumab and nivolumab approval in the adjuvant and neoadjuvant setting, respectively, and perioperative immunotherapy in NSCLC remains a field of active clinical and preclinical investigation. Unanswered questions in perioperative therapy in NSCLC include the optimal sequence and timing of chemotherapy and immunotherapy, the potential of combination strategies, the role of predictive biomarkers for patient selection and the choice of useful endpoints in clinical investigation.

Application of histology-agnostic treatments in metastatic colorectal cancer.

Cancer treatment is increasingly focused on targeting molecular alterations identified across different tumor histologies. While some oncogenic drivers such as microsatellite instability (MSI) and NTRK fusions are actionable with the very same approach regardless of tumor type ("histology-agnostic"), others require histology-specific therapeutic adjustment ("histology-tuned") by means of adopting specific inhibitors and ad hoc combinations. Among histology-agnostic therapies, pembrolizumab or dostarlimab demonstrated comparable activity in MSI metastatic colorectal cancer (mCRC) as in other tumors with MSI status (ORR 38% vs 40% and 36% vs 39%, respectively), while entrectinib or larotrectinib proved effective in NTRK rearranged mCRC even though less dramatically than in the overall population (ORR 20% vs 57%, and 50% vs 78%, respectively). Histology-tuned approaches in mCRC are those targeting BRAFV600E mutations and ERBB2 amplification, highlighting the need of simultaneous anti-EGFR blockade or careful choice of companion inhibitors in this tumor type. Anti-RET and anti-ALK therapies emerged as a potential histology-agnostic indications, while anti-KRASG12C strategies could develop as future histology-tuned therapies. Targeting of ERBB2 mutations and NRG1 fusion provided discrepant results. In conclusion, agnostic targets such as MSI and NTRK fusions are already exploitable in mCRC, while the plethora of emerging histology-tuned targets represent a challenging opportunity requiring concurrent evolution of molecular diagnostic tools.

Pneumatosis Intestinalis Induced by Anticancer Treatment: A Systematic Review.

Pneumatosis intestinalis (PI) is a rare condition due to the presence of gas within the bowel wall; it is mainly caused by endoscopic procedures, infections and other gastrointestinal diseases. Oncological therapies have been reported to be a cause of PI as well, but their role is not clearly defined. This systematic review investigates the concurrency of PI and antitumor therapy in cancer patients, considering both solid tumors and onco-hematological ones. We performed a literature review of PubMed, Embase and the Web of Science up to September 2021 according to the PRISMA guidelines. A total of 62 papers reporting 88 different episodes were included. PI was mainly reported with targeted therapies (sunitinib and bevacizumab above all) within the first 12 weeks of treatment. This adverse event mostly occurred in the metastatic setting, but in 10 cases, it also occurred also in the neoadjuvant and adjuvant setting. PI was mostly localized in the large intestine, being fatal in 11 cases, while in the remaining cases, symptoms were usually mild, or even absent. A significant risk of PI reoccurrence after drug reintroduction was also reported (6/18 patients), with no fatal outcomes. Potential pharmacological mechanisms underlying PI pathogenesis are also discussed. In conclusion, although uncommonly, PI can occur during oncological therapies and may lead to life-threatening complications; therefore, consideration of its occurrence among other adverse events is warranted in the presence of clinical suspicion.

Liquid Biopsy for Small Cell Lung Cancer either De Novo or Transformed: Systematic Review of Different Applications and Meta-Analysis.

BACKGROUND: The potential added value of liquid biopsy (LB) is not well determined in the case of small cell lung cancer (SCLC), an aggressive tumor that can occur either de novo or from the histologic transformation of non-small cell lung cancer (NSCLC). METHODS: A systematic review of studies adopting LB in patients with SCLC have been performed to assess the clinical utility of circulating tumor DNA (ctDNA) or circulating tumor cells (CTCs). RESULTS: After a screening of 728 records, 62 studies (32 evaluating CTCs, 27 ctDNA, and 3 both) met predetermined eligibility criteria. Only four studies evaluated LB in the diagnostic setting for SCLC, while its prognostic significance was evaluated in 38 studies and prominently supported by both ctDNA and CTCs. A meta-analysis of 11 studies as for CTCs enumeration showed an HR for overall survival of 2.63 (1.71-4.05), with a potential publication bias. The feasibility of tumor genomic profiling and the predictive role of LB in terms of response/resistance to chemotherapy was assessed in 11 and 24 studies, respectively, with greater consistency for those regarding ctDNA. Intriguingly, several case reports suggest that LB can indirectly capture the transition to SCLC in NSCLC treated with EGFR tyrosine kinase inhibitors. CONCLUSIONS: While dedicated trials are needed, LB holds potential clinical roles in both de novo and transformed SCLC. CtDNA analysis appears the most valuable and practicable tool for both disease monitoring and genomic profiling.

Chemotherapy in non-small cell lung cancer patients after prior immunotherapy: The multicenter retrospective CLARITY study.

OBJECTIVES: In the most of cases, for non-small cell lung cancer (NSCLC) patients who progressed to previous immune checkpoint inhibitors (CKI) administered as first- or as second-line therapy, chemotherapy (CT) remains the only viable options in the absence of "druggable" mutations. We aimed to explore the efficacy of salvage chemotherapy after immunotherapy (SCAI) in advanced NSCLC patients. MATERIALS AND METHODS: We designed a retrospective, multicenter study, involving 20 Italian centers, with the primary objective of describing the clinical outcome of advanced NSCLC patients treated with SCAI at the participating institutions from November 2013 to July 2019. The primary endpoint of the study was represented by overall survival (OS), defined as the time from CT initiation to death. Secondary outcome endpoints of the SCAI (progression free survival, PFS, objective response rate, ORR and toxicity) and explorative biomarkers (lactate dehydrogenase, LDH, and neutrophil-to-lymphocyte ratio, NLR during immunotherapy) were also analyzed. RESULTS: In our study population of 342 NSCLC patients, SCAI obtained a median OS of 6.8 months (95 % confidence interval, CI 5.5-8.1), median PFS of 4.1 months (95 % CI 3.4-4.8) and ORR of 22.8 %. A "Post-CKI score" was constructed by combining significant predictors of OS at the multivariate analyses (sex, ECOG PS, disease control with prior immunotherapy), Harrell'C was 0.65, (95 % CI:0.59-0.71). CONCLUSIONS: Despite the late-line settings, our findings support the hypothesis that previous immunotherapy might increase the sensitivity of the tumor to the subsequent chemotherapy. The "Post-CKI score" was clinically effective in successfully discriminating three distinct prognostic subgroups of patients after the failure of CKI, representing a possibly useful tool for the tailored decision-making process of advanced treatment-line settings in NSCLC.

Efficacy and Safety of Anti-PD-1 Immunotherapy in Patients Aged ≥ 75 Years With Non-small-cell Lung Cancer (NSCLC): An Italian, Multicenter, Retrospective Study.

INTRODUCTION: Non-small-cell lung cancer (NSCLC) is predominantly a disease of the elderly population. Over the past few years, immunotherapy with monoclonal antibodies named checkpoint inhibitors (ICIs) greatly improved the clinical management of a significant proportion of patients with metastatic NSCLC. However, pivotal trials excluded older patients, although, given the favorable clinical profile of ICIs, this treatment may be revealed to be a most valuable option also for these patients. To this aim, a multicenter retrospective analysis was performed on patients aged ≥ 75 years with NSCLC treated with anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunotherapy. MATERIAL AND METHODS: Inclusion criteria were: diagnosis of locally advanced or metastatic NSCLC (stage IIIB or IV, according to the American Joint Committee on Cancer (AJCC) classification system, version 8.0); age ≥ 75 years; treatment with anti-PD-1/PD-L1 monoclonal antibodies in first or subsequent lines of treatment; absence of epidermal growth factor receptor-activating mutations or anaplastic lymphoma kinase and ROS-1 rearrangements. The primary endpoints of the study were the efficacy, in terms of overall response rate, progression-free survival, and overall survival, and safety, by means of evaluations of the incidence of immune-related adverse events. RESULTS: Eighty-six patients were considered for the final analysis; 71 (82.6%) were male. The mean age was 78.5 years (range, 75-86 years; SD, 3.12 years). Of the 86 patients, 69 (80.2%) of patients had a performance status of 0 or 1. The overall median progression-free survival was 5.6 months (range 1-36 months; SD, 7.5 months,) whereas the median overall survival was 10.1 months (range, 1.7-34.8 months; SD, 8 months). At the Cox regression analysis, the only parameter significantly associated with survival was the smoking status (P = .008). No difference in survival was found between patients younger and older than 80 years. CONCLUSIONS: In the present real-world retrospective cohort, efficacy and toxicity profiles of ICIs in older patients with advanced NSCLC were comparable with those observed in younger patients enrolled in clinical trials.

Entrectinib for the treatment of metastatic NSCLC: safety and efficacy.

Introduction: Gene fusions are strong driver alterations in various cancers, increasingly diagnosed with multiple testing techniques. ROS1 fusions can be found in 1-2% of non-small cell lung cancer (NSCLC) and several tyrosine kinase inhibitors (TKIs) have been tested in this oncogene-driven disease. NTRK fusions are characteristic of a few rare types of cancer, also infrequently seen in some common cancers including NSCLC. Entrectinib is a newer ROS1 and NTRK inhibitor developed across different tumor types harboring rearrangements in these genes. Entrectinib was granted FDA accelerated approval in August 2019 for the treatment of ROS1+ NSCLC and NTRK-driven solid tumors.Areas covered: This review covers the mechanism of action, safety, and efficacy of entrectinib in patients with metastatic NSCLC.Expert opinion: Entrectinib is an orally bioavailable TKI of TrkA, TrkB, TrkC, and ROS1, with the ability to cross the blood-brain barrier. Entrectinib was effective and well-tolerated in patients harboring ROS1- or NTRK-rearranged NSCLC treated within phase I and II studies. Entrectinib appears to be the most appropriate treatment choice for TKIs-naïve patients, especially in those presenting brain metastasis. Conversely, in case of systemic progression with the evidence of acquired resistance mutations in ROS1 or Trk proteins, a sequential therapy with entrectinib could not be successful.

First-line pembrolizumab in advanced non-small cell lung cancer patients with poor performance status.

BACKGROUND: Pembrolizumab is the first-line standard of care for advanced non-small cell lung cancer (NSCLC) with a PD-L1 tumour proportion score (TPS) ≥ 50%. Eastern Cooperative Oncology Group performance status (PS) 2 patients may receive pembrolizumab, despite the absence of sustaining evidence. PATIENTS AND METHODS: GOIRC-2018-01 is a multicentre, retrospective, observational study. PS 2 NSCLC patients with a PD-L1 TPS ≥50% receiving first-line pembrolizumab from June 2017 to December 2018 at 21 Italian institutions were included. Clinical-pathological characteristics were correlated with disease response and survival outcomes; adverse events were recorded. The primary objective was 6-months progression-free rate (6-months PFR). RESULTS: One hundred fifty-three patients (median age 70 years) were enrolled. At a median follow-up of 18.2 months, median progression-free survival (PFS) and overall survival (OS) were 2.4 (95% confidence interval, 95% CI, 1.6-2.5) and 3.0 months (95% CI 2.4-3.5), respectively. 6-months PFR was 27% (95% CI 21-35%). Patients with a PS 2 determined by comorbidities (n = 41) had significantly better outcomes compared with disease burden-induced PS 2 (n = 112). Indeed, 6-months PFR was 49% versus 19%, median PFS 5.6 versus 1.8 months and OS 11.8 versus 2.8 months, respectively. Additional potential prognostic factors (radiotherapy, antibiotics, steroids received before pembrolizumab) correlated with clinical outcomes. The determinant of PS 2 resulted the only factor independently impacting on both PFS and OS. No toxicity issues emerged. CONCLUSIONS: Outcomes of PS 2 NSCLC patients with PD-L1 TPS ≥50% receiving first-line pembrolizumab were globally dismal but strongly dependent on the reason conditioning the poor PS itself.

Association of Steroids use with Survival in Patients Treated with Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis.

Immune checkpoint inhibitors (ICIs) can elicit toxicities by inhibiting negative regulators of adaptive immunity. Sometimes, management of toxicities may require systemic glucocorticoids. We performed a systematic review and meta-analysis of published studies to evaluate the correlation between steroids use, overall survival (OS), and progression-free survival (PFS) in cancer patients treated with ICIs. Publications that compared steroids with non-steroid users in cancer patients treated with ICIs from inception to June 2019 were identified by searching the EMBASE, PubMed, SCOPUS, Web of Science, and Cochrane Library databases. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Patients (studies, n = 16; patients, n = 4045) taking steroids were at increased risk of death and progression compared to those not taking steroids (HR = 1.54, 95% CI: 1.24-1.91; p = 0.01 and HR = 1.34, 95% CI: 1.02-1.76; p = 0.03, respectively). The main negative effect on OS was associated with patients taking steroids for supportive care (HR = 2.5, 95% CI 1.41-4.43; p < 0.01) or brain metastases (HR = 1.51, 95% CI 1.22-1.87; p < 0.01). In contrast, steroids used to mitigate adverse events did not negatively affect OS. In conclusion, caution is needed when steroids are used for symptom control. In these patients, a negative impact of steroid use was observed for both OS and PFS.

Liquid biopsy for rectal cancer: A systematic review.

BACKGROUND: The management of locally advanced rectal cancer (RC) is an evolving clinical field where the multidisciplinary approach can reach its best, and liquid biopsy for obtaining tumor-derived component such as circulating tumor DNA (ctDNA) might provide complementary informations. METHODS: A systematic review of studies available in literature of liquid biopsy in non-metastatic RC has been performed according to PRISMA criteria to assess the role of ctDNA as a diagnostic, predictive and prognostic biomarker in this setting. RESULTS: Twenty-five publications have been retrieved, of which 8 full-text articles, 7 abstracts and 10 clinical trials. Results have been categorized into three groups: diagnostic, predictive and prognostic. Few but promising data are available about the use of liquid biopsy for early diagnosis of RC, with the main limitation of sensitivity due to low concentrations of ctDNA in this setting. In terms of prediction of response to chemoradiation, still inconclusive data are available about the utility of a pre-treatment liquid biopsy, whereas some studies report a positive correlation with a dynamic (pre/post-treatment) monitoring. The presence of minimal residual disease by ctDNA was consistently associated with worse prognosis across studies. CONCLUSIONS: The use of liquid biopsy for monitoring response to chemoradiation and assess the risk of disease recurrence are the most advanced potential applications for liquid biopsy in RC, with implications also in the context of non-operative management strategies.

High Circulating Methylated DNA Is a Negative Predictive and Prognostic Marker in Metastatic Colorectal Cancer Patients Treated With Regorafenib.

Background: Regorafenib improves progression free survival (PFS) in a subset of metastatic colorectal cancer (mCRC) patients, although no biomarkers of efficacy are available. Circulating methylated DNA (cmDNA) assessed by a five-gene panel was previously associated with outcome in chemotherapy treated mCRC patients. We hypothesized that cmDNA could be used to identify cases most likely to benefit from regorafenib (i.e., patients with PFS longer than 4 months). Methods: Plasma samples from mCRC patients were collected prior to (baseline samples N = 60) and/or during regorafenib treatment (N = 62) for the assessment of cmDNA and total amount of cell free DNA (cfDNA). Results: In almost all patients, treatment with regorafenib increased the total cfDNA, but decreased cmDNA warranting the normalization of cmDNA to the total amount of circulating DNA (i.e., cmDNA/ml). We report that cmDNA/ml dynamics reflects clinical response with an increase in cmDNA/ml associated with higher risk of progression (HR for progression = 1.78 [95%CI: 1.01-3.13], p = 0.028). Taken individually, high baseline cmDNA/ml (above median) was associated with worst prognosis (HR for death = 3.471 [95%CI: 1.83-6.57], p < 0.0001) and also predicted shorter PFS (<16 weeks with PPV 86%). In addition, high cmDNA/ml values during regorafenib treatment predicted with higher accuracy shorter PFS (<16 weeks with a PPV of 96%), therefore associated with increased risk of progression (HR for progression = 2.985; [95%CI: 1.63-5.46; p < 0.0001). Conclusions: Our data highlight the predictive and prognostic value of cmDNA/ml in mCRC patients treated with regorafenib.

Retreatment with anti-EGFR monoclonal antibodies in metastatic colorectal cancer: Systematic review of different strategies.

BACKGROUND: Despite advances in precision oncology and immunotherapy of tumors, little progress has been made in metastatic colorectal cancer (mCRC) in recent years. Therefore, making the most of available therapies is a necessity. Several studies, based on the pulsatile behavior of RAS clones under EGFR blockade, investigated whether readministration of EGFR-targeted agents is effective beyond second line. METHODS: A systematic review of studies of retreatment with anti-EGFR monoclonal antibodies has been performed from January 2005 to December 2018 according to PRISMA criteria from PubMed, ESMO and ASCO meetings libraries and Clinicaltrial.gov. Efficacy has been evaluated as objective response rate and survival in available publications. In addition, type and incidence of side effects occurring during on anti-EGFR retreatment have been considered. RESULTS: 26 publications have been retrieved, of which 20 full-text articles and 6 abstracts and categorized as for the retreatment strategy into five groups: rechallenge (n = 10), reintroduction (n = 4), sequence (n = 5), dose escalation (n = 1) and mixed (n = 6). Data of efficacy displayed high heterogeneity across different strategies (objective response rate, ORR = 0.0-53.8%; disease control rate, DCR = 24.0-89.7%), with best results in the setting of rechallenge (ORR = 2.9-53.8%; DCR = 40.0-89.7%). CONCLUSIONS: Rechallenge with anti-EGFR provides clinical benefit in molecularly selected mCRC patients beyond second line. Further ctDNA-guided studies comparing this option of treatment with current approved advanced line treatments are warranted.