The challenge of molecular selection in liver-limited metastatic colorectal cancer for surgical resection: a systematic review and meta-analysis in the context of current and future approaches.

Objectives: Treatment of metastatic colorectal cancer (mCRC) includes resection of liver metastases (LM), however, no validated biomarker identifies patients most likely to benefit from this procedure. This meta-analysis aimed to assess the impact of the most relevant molecular alterations in cancer-related genes of CRC (i.e., RAS, BRAF, SMAD4, PIK3CA) as prognostic markers of survival and disease recurrence in patients with mCRC surgically treated by LM resection. Methods: A systematic literature review was performed to identify studies reporting data regarding survival and/or recurrence in patients that underwent complete liver resection for CRC LM, stratified according to RAS, BRAF, PIK3CA, and SMAD4 mutational status. Hazard ratios (HRs) from multivariate analyses were pooled in the meta-analysis and various adjustment strategies for confounding factors were combined. The search was conducted in numerous databases, including MEDLINE (PubMed), Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO host), and WHO Global Index Medicus, through March 18th, 2022. Meta-analyses, editorials, letters to the editor, case reports, studies on other primary cancers, studies with primary metastatic sites other than the liver, studies lacking specific oncological outcome variables or genetic data, non-English language studies, and studies omitting residual disease data from liver metastasectomy were excluded. The remaining 47 studies were summarized in a descriptive table which outlines the key characteristics of each study and final results were graphically presented. Results: RAS mutation status was negatively associated with overall survival (OS) (HR, 1.68; 95% CI, 1.54-1.84) and recurrence free survival (RFS) (HR, 1.46; 95% CI, 1.33-1.61). A negative association was also found for BRAF regarding OS (HR, 2.64; 95% CI, 2.15-3.24) and RFS (HR, 1.89; 95% CI, 1.32-2.73) and SMAD4 regarding OS (HR, 1.93; 95% CI, 1.56-2.38) and RFS (HR, 1.95; 95% CI, 1.31-2.91). For PIK3CA only three studies were eligible and no significant association with either OS or RFS could be highlighted. Conclusion: RAS, BRAF, and SMAD4 are negatively associated with OS and RFS in patients undergoing curative liver metastasectomy from colorectal cancer. No conclusion can be drawn for PIK3CA due to the limited literature availability. These data support the integration of RAS, BRAF, and SMAD4 mutational status in the surgical decision-making for colorectal liver metastasis. Nevertheless, we have to consider several limitations, the major ones being the pooling of results from studies that evaluated patient outcomes as either disease-free survival (DFS) or RFS; the inclusion of patients with minimal residual disease and unconsidered potential confounding factors, such as variability in resectability definitions, chemotherapy use, and a potential interaction between biological markers and pre- and post-resection pharmacological treatments.

Clinical Evaluation of Oral Midazolam Containing Cyclodextrin in Pediatric Magnetic Resonance: A Retrospective Cohort Study.

BACKGROUND: Reducing a child's level of anxiety before magnetic resonance imaging (MRI) procedures allows for better behavioral outcomes. The aim of this retrospective study was to evaluate anxiolytic efficacy of Midazolam/γ-cyclodextrin oral formulation. METHODS: We retrospectively reviewed 100 medical charts of children who, between 1 February and 31 July 2022, underwent MRI under general anesthesia with or without premedication with midazolam/γ-cyclodextrin. Primary outcome was comparison of behavior to facemask positioning, while secondary endpoints were degree of drugs acceptance, anxiolytic effect evaluation, child's behavior on separation, and sevoflurane need. RESULTS: Facemask positioning was accepted by 58% of the midazolam/γ-cyclodextrin group compared to 22% of children in the control group. The rate of acceptance was >90%. At the moment of separation from parent, none of the premedicated children needed to be restrained compared to 18% in the control group. A lower percentage of sevoflurane was needed for eye-closure at induction of anesthesia and for anesthesia maintenance. At emergence from anesthesia, 46% of children in the premedicated group compared to 66% of children in the control group showed transient agitation. CONCLUSIONS: Midazolam/γ-cyclodextrin showed a good profile of acceptance, satisfactory anxiolytic properties, and reduced need for anesthetics when administered to children before MRI under general anesthesia.

Incidence and clinical progression of asymptomatic peripherally inserted central catheter-related thrombosis in solid neoplasm patients: ultrasound insights from a prospective cohort study.

Background: Managing central venous catheters in patients with neoplasms is challenging, and peripherally inserted central catheter PORT (PICC-PORT) has emerged as a promising option for safety and efficacy. However, understanding the clinical progression of catheter-related thrombosis (CRT) in cancer patients with central venous catheters remains limited, especially in certain neoplasm types associated with a higher risk of venous thrombosis. Objectives: This study aims to assess the effectiveness of ultrasound-guided management in detecting and treating asymptomatic CRT in cancer patients with PICC. Methods: In this prospective cohort study of 120 patients with solid neoplasms receiving chemotherapy, we investigated the incidence of isolated upper-extremity superficial vein thrombosis, upper-extremity deep vein thrombosis, and fibrin sheath formation through ultrasound follow-up at 30 and 90 days after catheter insertion. We analyzed risk factors associated with CRT and compared incidence rates between PICC-PORT and traditional PICC. Results: Among the cohort, 69 patients (57.5%) had high-risk thromboembolic neoplasm, and 31 cases (25.8%) of CRT were observed, mostly within 30 days, with only 7 cases (22.6%) showing symptoms. Traditional PICC use (odds ratio, 5.86; 95% CI, 1.14-30) and high-risk thromboembolic neoplasm (odds ratio, 4.46; 95% CI, 1.26-15.81) were identified as independent risk factors for CRT. Conclusion: The majority of CRT present asymptomatically within the first 30 days of venous catheter insertion in patients with solid neoplasms. Ultrasound follow-up is valuable for detecting asymptomatic CRT. The risk of CRT was lower with PICC-PORT than with PICC. Additionally, the risk of CRT was found to be higher in patients with high-risk thromboembolic neoplasms. It is crucial for larger studies to confirm the utility of treating asymptomatic thromboses and isolated superficial thrombosis.

Ongoing Clinical Trials and Future Research Scenarios of Circulating Tumor DNA for the Treatment of Metastatic Colorectal Cancer.

Liquid biopsy using circulating tumor DNA (ctDNA) has emerged as a minimally invasive, timely approach to provide molecular diagnosis and monitor tumor evolution in patients with cancer. Since the molecular landscape of metastatic colorectal cancer (mCRC) is substantially heterogeneous and dynamic over space and time, ctDNA holds significant advantages as a biomarker for this disease. Numerous studies have demonstrated that ctDNA broadly recapitulates the molecular profile of the primary tumor and metastases, and have mainly focused on the genotyping of RAS and BRAF, that is propaedeutic for anti-EGFR treatment selection. However, ctDNA soon broadened its scope towards the assessment of early tumor response, as well as the identification of drug resistance biomarkers to drive potential molecular actionability. In this review article, we provide an overview of the current state-of-the-art of this methodology and its applications, focusing on ongoing clinical trials that employ ctDNA to prospectively guide treatment in patients with mCRC.

Clinicopathological characterisation of MTAP alterations in gastrointestinal cancers.

BACKGROUND: Methylthioadenosine phosphorylase (MTAP) is an essential metabolic enzyme in the purine and methionine salvage pathway. In cancer, MTAP gene copy number loss (MTAP loss) confers a selective dependency on the related protein arginine methyltransferase 5. The impact of MTAP alterations in gastrointestinal (GI) cancers remains unknown although hypothetically druggable. Here, we aim to investigate the prevalence, clinicopathological features and prognosis of MTAP loss GI cancers. METHODS: Cases with MTAP alterations were retrieved from The Cancer Genome Atlas (TCGA) and a real-world cohort of GI cancers profiled by next-generation sequencing. If MTAP alterations other than loss were found, immunohistochemistry was performed. Finally, we set a case-control study to assess MTAP loss prognostic impact. RESULTS: Findings across the TCGA dataset (N=1363 patients) and our cohort (N=508) were consistent. Gene loss was the most common MTAP alteration (9.4%), mostly co-occurring with CDKN2A/B loss (97.7%). Biliopancreatic and gastro-oesophageal cancers had the highest prevalence of MTAP loss (20.5% and 12.7%, respectively), being mostly microsatellite stable (99.2%). In colorectal cancer, MTAP loss was rare (1.1%), while most MTAP alterations were mutations (5/7, 71.4%); among the latter, only MTAP-CDKN2B truncation led to protein loss, thus potentially actionable. MTAP loss did not confer worse prognosis. CONCLUSIONS: MTAP alterations are found in 5%-10% of GI cancers, most frequently biliopancreatic and gastro-oesophageal. MTAP loss is the most common alteration, identified almost exclusively in MSS, CDKN2A/B loss, upper-GI cancers. Other MTAP alterations were found in colorectal cancer, but unlikely to cause protein loss and drug susceptibility.

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.

Corrigendum: Case report: MAP2K1 K57N mutation is associated with primary resistance to anti-EGFR monoclonal antibodies in metastatic colorectal cancer.

[This corrects the article DOI: 10.3389/fonc.2022.1030232.].

Needleless inhaled anesthesia with sevoflurane: Advantages of a simplified approach for children with spinal muscular atrophy undergoing intrathecal administration of nusinersen.

BACKGROUND: Intrathecal nusinersen administration, a fundamental step in the treatment of spinal muscular atrophy, is challenging in children. AIMS: This retrospective monocentric analysis of prospectively collected data evaluated the feasibility of needleless general anesthesia exclusively with sevoflurane, without imaging guidance, for children undergoing nusinersen administration in a 24-month period. METHODS: Clinical data included demographics, type of spinal muscular atrophy, presence and severity of scoliosis. Primary outcome was defined by the number of predefined sentinel adverse events related to anesthesia. Secondary outcomes were assessed by duration of the procedure, number of lumbar puncture attempts, and number of failures. Other measures included number and type of moderate, minor and minimal adverse events, as well as number and type of puncture-related adverse events. RESULTS: 116 patients (mean age: 8.7 (SD 6.9) years; with scoliosis: 49.1%) underwent 250 lumbar punctures; two cases of prolonged desaturation, considered as sentinel adverse events, (0.8%) were recorded during anesthesia (primary outcome). None of the patients underwent orotracheal intubation nor required an unplanned admission in the Pediatric Intensive Care Unit. No patient required an unplanned or prolonged hospitalization after the procedure. Mean number of puncture attempts was 1.6 (SD 1.3), and mean duration of the procedure was 14.1 (SD 8.3) minutes. No failure in the drug administration occurred (secondary outcomes). CONCLUSION: In this single-center experience, needleless general anesthesia with inhaled sevoflurane without imaging guidance has been shown to be feasible for children with spinal muscular atrophy undergoing lumbar puncture for nusinersen administration.

DOAC in the treatment of cancer-associated venous thromboembolism: a retrospective cohort study beyond the guidelines.

BACKGROUND: The emerging use of direct oral anticoagulants (DOAC) in the management of cancer-associated venous thromboembolism (CAT) is significantly improving therapeutic adherence and quality of life. Despite this, many conditions can restrict the therapeutic index of these drugs. For all these reasons the latest guidelines recommend the use of heparins in the treatment of CAT as the preferred treatment in some clinical settings. OBJECTIVES: We evaluated the efficacy and the safety of DOAC, in terms of recurrent venous thromboembolism (VTE) and major bleeding (MB), as a composite primary outcome. Mortality and clinically relevant non-major bleeding (CRNMB) were evaluated as secondary outcomes. METHODS: We performed a retrospective study on 209 patients to compare the effects of DOAC versus heparins for the treatment of CAT. 127 patients with a high bleeding risk neoplasia were enrolled. RESULTS: A primary-outcome event occurred in 11.3% of patients treated with heparins and in 10.5% treated with DOAC (Relative Risk 0.92; 95% CI 0.42-2.01, p = 0.84). Recurrent VTE occurred in 6.1% in the heparins group and in 8.4% in the DOAC group (RR 1.37; 95% CI 0.51-3.64, p = 0.52). MB occurred in 5.2% in the heparins group and in 2.1% in the DOAC group (RR 0.40; 95% CI 0.08-1.93, p = 0.25). CONCLUSIONS: DOAC seem to be as effective and safe as heparins in the treatment of CAT. Most bleeding events occurred in patients with high-risk bleeding neoplasms regardless of the type of anticoagulant. Considering the characteristics and satisfaction of patients using DOAC in this setting, this approach should be considered as a first choice.

Case Report: MAP2K1 K57N mutation is associated with primary resistance to anti-EGFR monoclonal antibodies in metastatic colorectal cancer.

Background: We aim to identify the prevalence and the role of the MAP2K1 K57N mutation in predicting resistance to anti-EGFR agents in metastatic colorectal cancer (mCRC) patients. Methods: We retrospectively reviewed tumor-based next generation sequencing (NGS) results from mCRC patients screened for enrollment in the GO40872/STARTRK-2 clinical trial between July 2019 and March 2021. Then, in patients harboring microsatellite stable (MSS) RAS and BRAF wild-type MAP2K1 mutant mCRC, we reviewed outcome to treatment with anti-EGFR monoclonal antibodies. Results: A total of 246 mCRC patients were screened. Most of them, 215/220 (97.7%), were diagnosed with MSS mCRC and 112/215 (52.1%) with MSS, RAS and BRAF wild-type mCRC. Among the latter, 2/112 (1.8%) had MAP2K1 K57N mutant mCRC and both received anti-EGFR monotherapy as third line treatment. In both patients, MAP2K1 K57N mutant tumors proved primary resistant to anti-EGFR agent panitumumab monotherapy. Of interest, one of these patients was treated with anti-EGFR agents three times throughout his course of treatment, achieving some clinical benefit only when associated with other cytotoxic agents (FOLFOX or irinotecan). Conclusion: We verified in a clinical real-world setting that MAP2K1 K57N mutation is a resistance mechanism to anti-EGFR agents in mCRC. Thus, we suggest avoiding the administration of these drugs to MSS RAS and BRAF wild-type MAP2K1 N57K mutant mCRC.

Children and neonates anesthesia in magnetic resonance environment in Italy: an active call survey.

BACKGROUND: Pediatric anesthesia care in the Magnetic Resonance Imaging is a challenge for clinicians. The recent debate about the role of anesthetic agent on neural development, encouraged an evaluation of their actual activity in this environment. In this active call survey, the authors sought to delineate the Italian situation regarding national centers, staff involved, monitoring tools available and sedation techniques. METHODS: A complete sample of all national centers performing almost a pediatric discharge in the 2014 was obtained from Health Ministry registers. All Institutions were contacted for a prospective phone investigation and a three-section survey was fill out with the Physician in charge. A descriptive and exploratory analyzes about the organization setting of the Centers were performed. RESULTS: Among 876 Institution screened, only 106 (37%) met minimal criteria for inclusion. Children are managed by anesthesiologists in the 95% of cases, while neonates in the 54%. A dedicated nurse is present in 74% of centers. While a pulse oximetry is present in 100% of centers, the rate of prevalence of other monitoring is lower. A specific MRI-compatible ventilator is available in the 95% of Centers, but many tools are not equally homogenously distributed. Pharmacological approach is preferred in pediatric age (98%), but its use for newborns is reduced to 43%. CONCLUSIONS: We found significant heterogeneity in the daily clinical practice of sedation in MRI. Our results could be a starting point to evaluate the further evolution of approach to children and neonates in magnetic resonance setting. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04775641.

Circulating tumor DNA to guide rechallenge with panitumumab in metastatic colorectal cancer: the phase 2 CHRONOS trial.

Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies are approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC), but the emergence of resistance mutations restricts their efficacy. We previously showed that RAS, BRAF and EGFR mutant alleles, which appear in circulating tumor DNA (ctDNA) during EGFR blockade, decline upon therapy withdrawal. We hypothesized that monitoring resistance mutations in blood could rationally guide subsequent therapy with anti-EGFR antibodies. We report here the results of CHRONOS, an open-label, single-arm phase 2 clinical trial exploiting blood-based identification of RAS/BRAF/EGFR mutations levels to tailor a chemotherapy-free anti-EGFR rechallenge with panitumumab (ClinicalTrials.gov: NCT03227926 ; EudraCT 2016-002597-12). The primary endpoint was objective response rate. Secondary endpoints were progression-free survival, overall survival, safety and tolerability of this strategy. In CHRONOS, patients with tissue-RAS WT tumors after a previous treatment with anti-EGFR-based regimens underwent an interventional ctDNA-based screening. Of 52 patients, 16 (31%) carried at least one mutation conferring resistance to anti-EGFR therapy and were excluded. The primary endpoint of the trial was met; and, of 27 enrolled patients, eight (30%) achieved partial response and 17 (63%) disease control, including two unconfirmed responses. These clinical results favorably compare with standard third-line treatments and show that interventional liquid biopsies can be effectively and safely exploited in a timely manner to guide anti-EGFR rechallenge therapy with panitumumab in patients with mCRC. Further larger and randomized trials are warranted to formally compare panitumumab rechallenge with standard-of-care therapies in this patient setting.

Temozolomide Treatment Alters Mismatch Repair and Boosts Mutational Burden in Tumor and Blood of Colorectal Cancer Patients.

The majority of metastatic colorectal cancers (mCRC) are mismatch repair (MMR) proficient and unresponsive to immunotherapy, whereas MMR-deficient (MMRd) tumors often respond to immune-checkpoint blockade. We previously reported that the treatment of colorectal cancer preclinical models with temozolomide (TMZ) leads to MMR deficiency, increased tumor mutational burden (TMB), and sensitization to immunotherapy. To clinically translate these findings, we designed the ARETHUSA clinical trial whereby O6-methylguanine-DNA-methyltransferase (MGMT)-deficient, MMR-proficient, RAS-mutant mCRC patients received priming therapy with TMZ. Analysis of tissue biopsies and circulating tumor DNA (ctDNA) revealed the emergence of a distinct mutational signature and increased TMB after TMZ treatment. Multiple alterations in the nucleotide context favored by the TMZ signature emerged in MMR genes, and the p.T1219I MSH6 variant was detected in ctDNA and tissue of 94% (16/17) of the cases. A subset of patients whose tumors displayed the MSH6 mutation, the TMZ mutational signature, and increased TMB achieved disease stabilization upon pembrolizumab treatment. SIGNIFICANCE: MMR-proficient mCRCs are unresponsive to immunotherapy. We provide the proof of concept that inactivation of MMR genes can be achieved pharmacologically with TMZ and molecularly monitored in the tissue and blood of patients with mCRC. This strategy deserves additional evaluation in mCRC patients whose tumors are no longer responsive to standard-of-care treatments. See related commentary by Willis and Overman, p. 1612. This article is highlighted in the In This Issue feature, p. 1599.

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.

Efficacy of Retreatment with Oxaliplatin-Based Regimens in Metastatic Colorectal Cancer Patients: The RETROX-CRC Retrospective Study.

BACKGROUND: oxaliplatin with fluoropyrimidine is a "mainstay" regarding the upfront treatment of metastatic colorectal cancer (mCRC). In contrast, the efficacy and safety of oxaliplatin-based regimens in late-care settings have been poorly reported. METHODS: we identified a real-world mCRC patient cohort who were re-treated with oxaliplatin, and in which clinicopathological features were retrospectively analyzed to identify efficacy-predictive determinants (RETROX-CRC study). RESULTS: of 2606 patients, 119 fulfilled the eligibility criteria. Oxaliplatin retreatment response rate (RR) and disease control rate (DCR) were 21.6% (CI 14.4-31.0%), and 57.8% (CI 47.7-67.4). A trend towards better RR and DCR was observed among patients who had first oxaliplatin in an adjuvant setting; a poorer outcome was observed if two or more intervening treatments were delivered. Median progression-free survival (PFS) was 5.1 months (95%CI 4.3-6.1), reducing to 4.0 months (95%CI 3.07-5.13) if oxaliplatin was readministered beyond third-line (HR 2.02; 1.25-3.25; p = 0.004). Safety data were retrieved in 65 patients (54.6%); 18.5% (12/65) and 7.7% (5/65) had G3-4 toxicities. Toxicities led to discontinuation in 34/119 (28.6%). CONCLUSIONS: oxaliplatin retreatment produced further RR in around one-fifth of patients and DCR 57.8%. Efficacy decreased in more pre-treated patients and around one-third of patients discontinued treatment due to adverse events. Translational studies improving patient selection are warranted.

The evolving panorama of HER2-targeted treatments in metastatic urothelial cancer: A systematic review and future perspectives.

PURPOSE: HER2 alterations are potential candidates for targeted treatments in metastatic urothelial/bladder cancer (mUC). ERBB2 gene amplification and mutations are found in around 6% and 4% of mUC, respectively. METHODS: This is a systematic review of clinical trials evaluating HER2-targeting (amplification and mutations) in mUC. We assigned each study to one of the following strategies: HER2-targeting with single agents, anti-HER2 agents in combination with cytotoxic chemotherapy, dual HER2 blockade, HER2-targeted antibody-drug conjugates (ADCs), and other novel therapeutic approaches. RESULTS: 36 clinical trials (17 with results and 19 ongoing) were included. As for ERBB2 amplification, anti-HER2 single agents (5 studies) and combinations with chemotherapy (4 studies) failed to provide any benefit, whereas dual HER2 blockade through monoclonal antibodies proved active in one trial in pretreated patients. Two studies assessed single-agent targeting for ERBB2 mutations with negative results. Most promising data come from 2 studies with ADCs in ERBB2 amplified tumors (disitamab-vedotin and trastuzumab-duocarmazine), while 2 other studies with TDM-1 and ADCT-502 was discontinued due to toxicity. In this category, trastuzumab-deruxtecan and other ADCs are still under investigation for either ERBB2-amplified or mutated mUC. Novel approaches include ADCs with immunotherapy (1 study with results), CAR-T cells, and HER2-sensitising vaccines. CONCLUSIONS: ERBB2 amplification could become a novel target in mUC, although the magnitude of clinical benefit remains to be clarified. To this regard, novel ADCs are the most promising strategy. ERBB2 mutations are still at very early stage of clinical study.

Impaired seroconversion after SARS-CoV-2 mRNA vaccines in patients with solid tumours receiving anticancer treatment.

BACKGROUND: Patients with solid tumours have high COVID-19 mortality. Limited and heterogeneous data are available regarding the immunogenicity of SARS-CoV-2 mRNA vaccines in this population. METHODS AND FINDINGS: This is a prospective, single-centre cohort study aiming at evaluating seroconversion in terms of anti-spike antibodies in a population of patients with solid tumours undergoing cancer therapy within 2 months before the second vaccine dose, as compared with a cohort of controls. Subjects who were not SARS-CoV-2 naïve were excluded, and 171 patients were included in the final study population (150 vaccinated with BNT162b2, 87.7%; 21 with mRNA-1273, 12.3%) and compared with 2406 controls. The median follow-up time from the second dose of vaccination was 30 days (12-42; IQR: 26-34). Most patients had metastatic disease (138, 80.7%). Seroconversion rate was significantly lower in cancer patients than in controls (94.2% versus 99.8%, p < 0.001). At univariate logistic regression analysis, Odds ratio (OR) for seroconversion was also reduced in older individuals (>70 years). A multivariate logistic model confirmed cancer as the only significant variable in impairing seroconversion (OR 0.03, p < 0.001). In the cancer population, a multivariate analysis among clinical variables, including the type of cancer treatment, showed ECOG PS > 2 as the only one of impact (OR 0.07, p = 0.012). CONCLUSIONS: There is a fraction of 6% of patients with solid tumours undergoing cancer treatment, mainly with poorer performance status, who fail to obtain seroconversion after SARS-CoV-2 mRNA vaccines. These patients should be considered for enhanced vaccination strategies and carefully monitored for SARS-CoV-2 infection during cancer treatment.

Personalized therapeutic strategies in HER2-driven gastric cancer.

BACKGROUND: Trastuzumab is the only approved targeted therapy in patients with HER2-amplified metastatic gastric cancer (GC). Regrettably, in clinical practice, only a fraction of them achieves long-term benefit from trastuzumab-based upfront strategy. To advance precision oncology, we investigated the therapeutic efficacy of different HER2-targeted strategies, in HER2 "hyper"-amplified (≥ 8 copies) tumors. METHODS: We undertook a prospective evaluation of HER2 targeting with monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates, in a selected subgroup of HER2 "hyper"-amplified gastric patient-derived xenografts (PDXs), through the design of ad hoc preclinical trials. RESULTS: Despite the high level of HER2 amplification, trastuzumab elicited a partial response only in 2 out of 8 PDX models. The dual-HER2 blockade with trastuzumab plus either pertuzumab or lapatinib led to complete and durable responses in 5 (62.5%) out of 8 models, including one tumor bearing a concomitant HER2 mutation. In a resistant PDX harboring KRAS amplification, the novel antibody-drug conjugate trastuzumab deruxtecan (but not trastuzumab emtansine) overcame KRAS-mediated resistance. We also identified a HGF-mediated non-cell-autonomous mechanism of secondary resistance to anti-HER2 drugs, responsive to MET co-targeting. CONCLUSION: These preclinical randomized trials clearly indicate that in HER2-driven gastric tumors, a boosted HER2 therapeutic blockade is required for optimal efficacy, leading to complete and durable responses in most of the cases. Our results suggest that a selected subpopulation of HER2-"hyper"-amplified GC patients could strongly benefit from this strategy. Despite the negative results of clinical trials, the dual blockade should be reconsidered for patients with clearly HER2-addicted cancers.