Comprehensive genomic profiling by liquid biopsy captures tumor heterogeneity and identifies cancer vulnerabilities in patients with RAS/BRAFV600E wild-type metastatic colorectal cancer in the CAPRI 2-GOIM trial

BACKGROUND

Emerging evidence supports tumor tissue-based comprehensive genomic profiling (CGP) in metastatic colorectal cancer (mCRC). Data on liquid biopsy-based circulating tumor DNA (ctDNA) CGP are scarce and mainly retrospective. Prospective comparison between the two tests is not currently available.

MATERIALS AND METHODS

The CAPRI 2-GOIM trial investigates efficacy and safety of ctDNA-driven, cetuximab-based sequence of three treatment lines in patients with RAS/BRAFV600E wild-type (WT) mCRC, as determined by the local laboratory. Before first-line therapy, CGP is carried out with FoundationOne (F1) CDx and F1 Liquid (F1L) CDx (324 genes) on tumor tissue DNA and plasma ctDNA, respectively.

RESULTS

For 2/207 (0.96%) patients, no ctDNA was detected by F1L CDx. No patient displayed tumor fraction (TF) below 1%, whereas elevated ctDNA (TF ≥ 10%) was detected among 140/205 (68.3%) patients. One thousand and thirteen genomic variants were identified. F1L CDx found KRAS, NRAS, or BRAFV600E alterations in 19 patients, whose tumors were classified as RAS/BRAFV600E WT by the local laboratory. Both F1 CDx and F1L CDx were available for 164/205 (80%) patients. A concordance of 61.4% between the two tests was observed. The concordance increased to 72.7% for F1L CDx with TF ≥ 10%. Concordance for genes potentially involved in anti-epidermal growth factor receptor resistance was found in 137/164 (83%) patients, increasing to 91.5% for F1L CDx with TF ≥ 10%. A higher number of genomic alterations was detected by F1L CDx compared with F1 CDx, including six cases with KRAS and NRAS alterations. Overall, 109/205 (53.2%) patients displayed at least one actionable genomic alteration (I to IIIB), according to the European Society for Medical Oncology Scale for Clinical Actionability of Molecular Targets (ESCAT).

CONCLUSION

Baseline liquid biopsy-based CGP is feasible, has high concordance with tumor tissue-based CGP, could better recapitulate tumor heterogeneity, and is clinically informative by identifying additional actionable genomic alterations in approximately half of RAS/BRAFV600E WT mCRC patients.

Connective tissue nevus misdiagnosed as juvenile localized scleroderma

BACKGROUND

Connective tissue nevi (CTN) are congenital hamartomas caused by excessive proliferation of dermis components. In children, CTN can mimic juvenile localized scleroderma (JLS), an immune mediated skin disorder that requires aggressive immunosuppression.

OBJECTIVES

Aim of our study was to describe a series of pediatric patients with CTN misdiagnosed as JLS and the discerning characteristics between the two conditions.

METHODS

Retrospective analysis of children referred to our Center during the last two decades for JLS who received a final diagnosis of CTN. Clinical, laboratory, histopathological and instrumental data (MRI and thermography) were collected and compared with those with JLS.

RESULTS

Seventeen patients with mean age at onset 4.6 years entered the study. All came to our Center with a certain diagnosis of JLS (n = 15) or suspected JLS (n = 2). The indurated skin lesions were flat and resembled either circumscribed morphea or pansclerotic morphea. In 14 patients (82.4%) they were mainly localized at the lower limbs and in three (17.6%) at the upper limbs. No patient had laboratory inflammatory changes or positive autoantibodies. Skin biopsies confirmed the diagnosis of CTN: non-familial collagenoma in eleven (64.7%), mixed CTN in four (23.5%) and familial CTN in two (11.8%). Mean age at final diagnosis was 9.5 years, with a mean diagnostic delay of 4.8 years (range 1-15 years). Sixteen patients underwent musculoskeletal MRI that was normal in all except two who showed muscle perifascial enhancement. Thermography was normal in all patients. At our first evaluation, eleven patients (64.7%) were on systemic treatment (methotrexate 11, corticosteroids 7, biologics 2), three (17.6%) on topical corticosteroids and three untreated.

CONCLUSIONS

CTN can be misdiagnosed as JLS and therefore aggressively treated with prolonged and inappropriate immunosuppression. The absence of inflammatory appearance of the skin lesions, normal instrumental and laboratory findings and the accurate evaluation of skin biopsy are crucial to address the right diagnosis.

Solving classification tasks by a receptron based on nonlinear optical speckle fields

Among several approaches to tackle the problem of energy consumption in modern computing systems, two solutions are currently investigated: one consists of artificial neural networks (ANNs) based on photonic technologies, the other is a different paradigm compared to ANNs and it is based on random networks of non-linear nanoscale junctions resulting from the assembling of nanoparticles or nanowires as substrates for neuromorphic computing. These networks show the presence of emergent complexity and collective phenomena in analogy with biological neural networks characterized by self-organization, redundancy, and non-linearity. Starting from this background, we propose and formalize a generalization of the perceptron model to describe a classification device based on a network of interacting units where the input weights are non-linearly dependent. We show that this model, called "receptron", provides substantial advantages compared to the perceptron as, for example, the solution of non-linearly separable Boolean functions with a single device. The receptron model is used as a starting point for the implementation of an all-optical device that exploits the non-linearity of optical speckle fields produced by a solid scatterer. By encoding these speckle fields we generated a large variety of target Boolean functions. We demonstrate that by properly setting the model parameters, different classes of functions with different multiplicity can be solved efficiently. The optical implementation of the receptron scheme opens the way for the fabrication of a completely new class of optical devices for neuromorphic data processing based on a very simple hardware.

Intrasacral meningoceles: Clinical presentation, surgical management, and postoperative outcome: The Giannina Gaslini Hospital's experience

INTRODUCTION

Intrasacral meningoceles are cysts associated with herniating arachnoid with no nerve root within due to an area of weakness of the dura mater. They are thought to be congenital, but they are usually not symptomatic until adulthood. Surgical treatment is generally indicated in the presence of symptoms.

METHODS

We selected cases belonging to the IB category of Nabors et al.'s classification who underwent surgery between 2008 and 2021 at Giannina Gaslini Hospital. Exclusion criteria were prior history of trauma, infections, or operations. Patients' clinical details, associated conditions, surgical techniques, peri- and postoperative complications, and outcomes were collected retrospectively from clinical charts. We compared our series to literature: keywords "intrasacral meningocele" were used on the search engine MEDLINE - Pubmed.

RESULTS

We identified 23 cases: 5 of the 14 symptomatic patients had a complete resolution, and 5 had a substantial clinical improvement after surgery. Cyst recurrence and major postoperative complication occurred in none. Among 59 articles considered for evaluation, 50 were excluded and remaining 9 articles underwent full-text analysis.

DISCUSSION AND CONCLUSION

The pathogenesis of instrasacral meningoceles is still not completely understood and the spectrum of symptoms is wide. A posterior surgical approach with sacral laminectomy is preferred, although in selected cases it is possible to perform a supplemental anterior approach (sometimes endoscopic). In our surgical series, the largest one published in the literature, a good clinical outcome was achieved in most patients with no cyst's recurrence, pointing out the importance of surgical interruption of communication between cyst and subdural space.

Plasmatic BRAF-V600E allele fraction as a prognostic factor in metastatic colorectal cancer treated with BRAF combinatorial treatments

BACKGROUND

Combination of a BRAF inhibitor (BRAFi) and an anti-epidermal growth factor receptor (EGFR), with or without a MEK inhibitor (MEKi), improves survival in BRAF-V600E-mutant metastatic colorectal cancer (mCRC) over standard chemotherapy. However, responses are heterogeneous and there are no available biomarkers to assess patient prognosis or guide doublet- or triplet-based regimens. In order to better characterize the clinical heterogeneity observed, we assessed the prognostic and predictive role of the plasmatic BRAF allele fraction (AF) for these combinations.

PATIENTS AND METHODS

A prospective discovery cohort including 47 BRAF-V600E-mutant patients treated with BRAFi-anti-EGFR ± MEKi in clinical trials and real-world practice was evaluated. Results were validated in an independent multicenter cohort (n= 29). Plasmatic BRAF-V600E AF cut-off at baseline was defined in the discovery cohort with droplet digital PCR (ddPCR). All patients had tissue-confirmed BRAF-V600E mutations.

RESULTS

Patients with high AF have major frequency of liver metastases and more metastatic sites. In the discovery cohort, median progression-free survival (PFS) and overall survival (OS) were 4.4 and 10.1 months, respectively. Patients with high BRAF AF (≥2%, n = 23) showed worse PFS [hazard ratio (HR) 2.97, 95% confidence interval (CI) 1.55-5.69; P = 0.001] and worse OS (HR 3.28, 95% CI 1.58-6.81; P = 0.001) than low-BRAF AF patients (<2%, n = 24). In the multivariable analysis, BRAF AF levels maintained independent significance. In the validation cohort, high BRAF AF was associated with worse PFS (HR 3.83, 95% CI 1.60-9.17; P = 0.002) and a trend toward worse OS was observed (HR 1.86, 95% CI 0.80-4.34; P = 0.15). An exploratory analysis of predictive value showed that high-BRAF AF patients (n = 35) benefited more from triplet therapy than low-BRAF AF patients (n = 41; PFS and OS interaction tests, P < 0.01).

CONCLUSIONS

Plasmatic BRAF AF determined by ddPCR is a reliable surrogate of tumor burden and aggressiveness in BRAF-V600E-mutant mCRC treated with a BRAFi plus an anti-EGFR with or without a MEKi and identifies patients who may benefit from treatment intensification. Our results warrant further validation of plasmatic BRAF AF to refine clinical stratification and guide treatment strategies.

Establishment of patient-derived tumor organoids to functionally inform treatment decisions in metastatic colorectal cancer

BACKGROUND

Metastatic colorectal cancer (mCRC) patients tend to have modest benefits from molecularly driven therapeutics. Patient-derived tumor organoids (PDTOs) represent an unmatched model to elucidate tumor resistance to therapy, due to their high capacity to resemble tumor characteristics.

MATERIALS AND METHODS

We used viable tumor tissue from two cohorts of patients with mCRC, naïve or refractory to treatment, respectively, for generating PDTOs. The derived models were subjected to a 6-day drug screening assay (DSA) with a comprehensive pipeline of chemotherapy and targeted drugs against almost all the actionable mCRC molecular drivers. For the second cohort DSA data were matched with those from PDTO genotyping.

RESULTS

A total of 40 PDTOs included in the two cohorts were derived from mCRC primary tumors or metastases. The first cohort included 31 PDTOs derived from patients treated in front line. For this cohort, DSA results were matched with patient responses. Moreover, RAS/BRAF mutational status was matched with DSA cetuximab response. Ten out of 12 (83.3%) RAS wild-type PDTOs responded to cetuximab, while all the mutant PDTOs, 8 out of 8 (100%), were resistant. For the second cohort (chemorefractory patients), we used part of tumor tissue for genotyping. Four out of nine DSA/genotyping data resulted applicable in the clinic. Two RAS-mutant mCRC patients have been treated with FOLFOX-bevacizumab and mitomycin-capecitabine in third line, respectively, based on DSA results, obtaining disease control. One patient was treated with nivolumab-second mitochondrial-derived activator of caspases mimetic (phase I trial) due to high tumor mutational burden at genotyping, experiencing stable disease. In one case, the presence of BRCA2 mutation correlated with DSA sensitivity to olaparib; however, the patient could not receive the therapy.

CONCLUSIONS

Using CRC as a model, we have designed and validated a clinically applicable methodology to potentially inform clinical decisions with functional data. Undoubtedly, further larger analyses are needed to improve methodology success rates and propose suitable treatment strategies for mCRC patients.

Cetuximab as third-line rechallenge plus either irinotecan or avelumab is an effective treatment in metastatic colorectal cancer patients with baseline plasma RAS/BRAF wild-type circulating tumor DNA: Individual patient data pooled analysis of CRICKET and CAVE trials

The rechallenge strategy is based on the concept that a subset of patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC) could still benefit of epidermal growth factor receptor (EGFR) inhibition, after progression to an anti-EGFR based-therapy. We performed a pooled analysis of two-phase II prospective trials to determine the role of rechallenge in third-line mCRC patients with RAS/BRAF WT baseline circulating tumor DNA (ctDNA). Individual data of 33 and 13 patients from CAVE and CRICKET trials that received as third-line therapy cetuximab rechallenge were collected. Overall survival (OS), Progression-free survival (PFS), Overall response rate (ORR), Stable disease (SD) >6 months were calculated. Adverse events were reported. For the whole 46 patient population, median PFS (mPFS) was 3.9 months (95% Confidence Interval, CI 3.0-4.9) with median OS (mOS) of 16.9 months (95% CI 11.7-22.1). For CRICKET patients, mPFS was 3.9 months (95% CI 1.7-6.2); mOS was 13.1 months (95% CI 7.3-18.9) with OS rates at 12, 18, and 24 months of 62%, 23%, and 0%, respectively. For CAVE patients, mPFS was 4.1 months (95% CI 3.0-5.2); mOS was 18.6 months (95% CI 11.7-25.4) with OS rates at 12, 18, 24 months of 61%, 52%, 21%, respectively. Skin rash was more frequently reported in CAVE trial (87.9% vs. 30.8%; p = 0.001), whereas a increased incidence of hematological toxicities was observed in CRICKET trial (53.8%% vs. 12.1%; p = 0.003). Third-line cetuximab rechallenge in combination with either irinotecan or avelumab in RAS/BRAF WT ctDNA mCRC patients represents a promising therapy.

A clinical and echocardiographic score to differentiate pulmonary hypertension due to heart failure with preserved ejection fraction from idiopathic pulmonary hypertension: the PH-HFPEF score

Background

One of the most challenging differential diagnoses in pulmonary hypertension clinical practice, is the discrimination between idiopathic pulmonary arterial hypertension (IPAH) and pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF).

Aim

We elaborate a score (considering patient clinical history, demographics, and echocardiographic characteristics) that can predict, noninvasively, PH-HFpEF vs IPAH diagnosis.

Methods

Data were prospectively collected on 466 consecutive patients with a final diagnosis of IPAH or PH-HFpEF referred to a single tertiary pulmonary vascular disease centre. Data included clinical history, demographics, and parameters of an electrocardiogram and a transthoracic echocardiogram. A multivariate regression model was developed to predict a PH-HFpEF diagnosis, and an integer risk score was generated using adjusted regression coefficients of the multivariate logistic regression analysis.

Results

At the multivariate logistic regression a high ratio between left and right ventricular dimensions, a history of atrial fibrillation (AF), a high body mass index (BMI), a reduced mitral deceleration time and a high E-wave at trans-mitral doppler, an advanced age and a high right ventricular fractional area change (FAC) were predictors of PH-HFpEF. The derived PH-HFPEF score is shown in Table 1 and, with a cut-point ≥11, it yielded a specificity/sensitivity, respectively, for the diagnosis of PH-HFpEF, of 100%/49% with an AUC of 0.987.

Conclusions

The PH-HFPEF score can predict PH-HFpEF vs IPAH. The PH-HFPEF score may be used to potentially avoid an invasive diagnostic testing in almost half of PH-HFpEF patients.

Funding Acknowledgement

Type of funding sources: None.

Clinical efficacy of sequential treatments in KRASG12C-mutant metastatic colorectal cancer: findings from a real-life multicenter Italian study (CRC-KR GOIM)

Background

The presence of KRASG12C mutation in metastatic colorectal cancer (mCRC) correlates with poor outcome. Although different selective inhibitors are under clinical development, the optimal treatment remains uncertain. Thus, we conducted a retrospective analysis in a large cohort of patients with KRASG12C mCRC treated in 12 Italian oncology units.

Patients and methods

Patients with unresectable mCRC harboring KRASG12C mutation receiving a first-line chemotherapy doublet or triplet between 2011 and 2021 were included in the study. Evaluation of overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) analysis was carried out.

Results

A total of 256/6952 (3.7%) patients with mCRC displayed KRASG12C mutation; of these, 111 met the inclusion criteria. The ORR of first-line therapy was 38.7% (43/111). Median PFS (mPFS) was 9 months [95% confidence interval (CI) 7.5-10.5 months]. After progression, only 62% and 36% of the patients are fit to receive second or third lines of treatment, with limited clinical benefit. Median OS (mOS) was 21 months (95% CI 17.4-24.6 months). In patients receiving first-line triplet chemotherapy, ORR was 56.3% (9/16), mPFS was 13 months (95% CI 10.3-15.7 months) and mOS was 32 months (95% CI 7.7-56.3 months). For irinotecan-based doublets, ORR was 34.5 (10/29), mPFS was 9 months (95% CI 6.4-11.6 months) and mOS was 22 months (95% CI 16.0-28.0 months). With oxaliplatin-based doublets ORR was 36.4% (24/62), mPFS was 7 months (95% CI 4.6-9.4 months) and mOS was 18 months (95% CI, 13.6-22.4 months).

Conclusion

Patients with KRASG12C-mutant mCRC had a disappointing response to standard treatments. Within the limitations of a retrospective study, these results suggest that first-line chemotherapy intensification with FOLFOXIRI is a valid option in fit patients.

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KRASG12C mutation is rare and occurs in 3.7% of the study population.

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The presence of KRASG12C mutation is correlated with an aggressive disease, with reduced response to chemotherapy.

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Only 62% and 36% of patients with KRASG12C-mutant mCRC are fit to receive second or third lines of treatment, respectively.

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The use of chemotherapy triplets is associated with improved outcomes compared with chemotherapy doublets.

Dynamical stochastic simulation of complex electrical behavior in neuromorphic networks of metallic nanojunctions

Nanostructured Au films fabricated by the assembling of nanoparticles produced in the gas phase have shown properties suitable for neuromorphic computing applications: they are characterized by a non-linear and non-local electrical behavior, featuring switches of the electric resistance whose activation is typically triggered by an applied voltage over a certain threshold. These systems can be considered as complex networks of metallic nanojunctions where thermal effects at the nanoscale cause the continuous rearrangement of regions with low and high electrical resistance. In order to gain a deeper understanding of the electrical properties of this nano granular system, we developed a model based on a large three dimensional regular resistor network with non-linear conduction mechanisms and stochastic updates of conductances. Remarkably, by increasing enough the number of nodes in the network, the features experimentally observed in the electrical conduction properties of nanostructured gold films are qualitatively reproduced in the dynamical behavior of the system. In the activated non-linear conduction regime, our model reproduces also the growing trend, as a function of the subsystem size, of quantities like Mutual and Integrated Information, which have been extracted from the experimental resistance series data via an information theoretic analysis. This indicates that nanostructured Au films (and our model) possess a certain degree of activated interconnection among different areas which, in principle, could be exploited for neuromorphic computing applications.