Liquid Biopsy Response Evaluation Criteria in Solid Tumors (LB-RECIST)

Current evaluation of treatment response in solid tumors depends on dynamic changes in tumor diameters as measured by imaging. However, these changes can only be detected when there are enough macroscopic changes in tumor volume, which limits the usability of radiological response criteria in evaluating earlier stages of disease response and necessitates much time to lapse for gross changes to be notable. One promising approach is to incorporate dynamic changes in circulating tumor DNA (ctDNA), which occur early in the course of therapy and can predict tumor responses weeks before gross size changes manifest. However, several issues need to be addressed before recommending the implementation of ctDNA response criteria in daily clinical practice such as clinical, biological, and regulatory challenges and, most importantly, the need to standardize/harmonize detection methods and ways to define ctDNA response and/or progression for precision oncology. Herein, we review the use of liquid biopsy (LB) to evaluate response in solid tumors and propose a plan toward standardization of LB-RECIST.

Cardiopulmonary Toxicity from Intensity Modulated Proton Therapy for Thymic Malignancies

PURPOSE/OBJECTIVE(S)

Use of radiation therapy for thymic malignancies is limited by excess dose to organs at risk (OARs) including heart, lung, and esophagus. Intensity Modulated Proton Therapy with Pencil Beam Scanning (IMPT/PBS) allows the conformality benefits of volumetric modulated arc therapy (VMAT) combined with dosimetry benefits of protons making it an exciting tool to treat thymic tumors. Very limited clinical data are reported with the use of IMPT/PBS to treat thymic malignancies. This study evaluates the incidence of acute and delayed toxicities among patients who underwent IMPT/PBS for thymic tumors.

MATERIALS/METHODS

Our single center retrospective study identified 27 patients with diagnosis of either thymic carcinoma or thymoma who received IMPT/PBS between 2015 and 2022. Patient demographics, IMPT treatment details and clinical outcomes (toxicity, recurrence, and survival) were recorded. Frequency distributions are described for primary endpoints of acute (≤ 90 days) and late (>90 days) toxicity graded using CTCAE version 5.0. Specific toxicities assessed were dermatitis, esophagitis, pneumonitis, pulmonary fibrosis, and cardiac toxicity. Recurrence and survival data were analyzed as secondary endpoint using Kaplan-Meier method.

RESULTS

Median follow-up was 22 months. Median age of the patients was 59 years (range, 30-87), predominantly female (55%), and white (66%), and stage ¾ (72%). Histologically showed mainly thymoma (59%) and Masaoka stage ¾ (70%). Surgery prior to IMPT was performed in 19 (70%) patients; of whom 5 patients had positive margins. Chemotherapy was used in 12 (44%) patients. Median IMPT dose was 50.4 GyE. Patients were primarily planned with 2 or 3 fields (81%), coplanar distribution (74%), using SFO technique (70%). Robust planning was performed accounting for 5 mm margin and 3.5-5% range uncertainty. All patients required use of range shifter ranging from 2-5 cm. Median of Heart-mean (10.3 GyE), Heart-max (54 GyE), Lung-mean (8.1 GyE), Lung V20 Gy (16.1%), Lung-V30 Gy (11.4%), Esophagus-mean (10.3 GyE) and Cord-Max (1.4 GyE). QACT was performed in 21 (77%) patients with replan needed in 5 of them. Only 1 (3.7%) patient had a grade 3+ acute toxicity (dermatitis) and only 2 (7.4%) patients had a grade 3+ late toxicity (both pulmonary). No patients had any acute or delayed cardiac-related adverse effects following PBT treatment. One (3.7%) patient had an infield recurrence of malignancy and 6 had out-of-field metastatic failure. Local control and overall survival were 74.1% and 85.2%, respectively.

CONCLUSION

In this largest single-institution analysis of IMPT/PBS experience, we note extremely low incidence of grade 3+ acute or late toxicity with excellent local control and overall survival. No marginal failures were noted. In a patient population at high risk of cardiopulmonary radiation toxicities, IMPT/PBS should be strongly explored as a possible treatment option.

The Effect of Body Mass Index and Residence in Food Priority Areas on Patterns-of-Care and Cancer Outcomes in Patients With Stage III Non-Small Cell Lung Cancer

PURPOSE

Patients living in food priority areas (FPAs), where access to healthy meals is challenging, may be at greater risk of nutritional deficits, leading to poorer cancer outcomes. Currently, there are no published data analyzing how FPAs affect patterns-of-care or outcomes for patients with locally advanced non-small cell lung cancer (NSCLC). We aimed to analyze the effect of residing in an FPA on treatments rendered and cancer outcomes in patients with stage III NSCLC treated at a single institution.

METHODS AND MATERIALS

This is a retrospective study of 573 patients with locally advanced NSCLC consecutively treated from January 2000 to January 2020. χ² and Mann-Whitney U tests were performed to determine differences between select variables. Kaplan-Meier analysis and Cox proportional hazard models were used to analyze overall survival (OS) and freedom from recurrence. Cox regression with forward model selection was used for multivariate analysis.

RESULTS

Thirty-two percent of patients resided in an FPA (n = 183) and were more likely to self-identify as Black (P < .0001), single (P < .001), <60 years of age (P = .001), and uninsured (P < .0001), with a lower median income (P < .001). Patients in FPAs also had lower mean pre-chemoradiation (CRT) albumin (P = .002), lower pre-CRT body mass index (BMI) (P = .026), and were less likely to receive trimodality therapy (P ≤ .001) compared with patients not living in FPAs. There was no difference in OS or freedom from recurrence between the 2 cohorts. However, in patients with a normal BMI, either pre-CRT (median OS, 18.4 vs 25.0 months; P = .005) or after CRT (15.1 vs 28.1 months, P = .002), residing in an FPA resulted in an OS detriment.

CONCLUSIONS

We demonstrated a clear socioeconomic divide in our patient population with stage III NSCLC, where residing in FPAs was associated with less-aggressive therapy and an OS detriment for patients with a normal-weight BMI. We are currently conducting a prospective study characterizing the nutritional needs of patients, particularly those who live in FPAs.

External control cohorts for the single-arm LIBRETTO-001 trial of selpercatinib in RET+ non-small-cell lung cancer

Background

Data for selpercatinib [a selective REarranged during Transfection (RET) inhibitor] from a single-arm trial (LIBRETTO-001, NCT03157128) in RET-fusion-positive advanced/metastatic non-small-cell lung cancer (NSCLC) were used in combination with external data sources to estimate comparative efficacy [objective response rate (ORR), progression-free survival, and overall survival (OS)] in first- and second-line treatment settings.

Methods

Patient-level data were obtained from a de-identified real-world database. Patients diagnosed with advanced/metastatic NSCLC with no prior exposure to a RET inhibitor and one or more prior line of therapy were eligible. Additionally, individual patient-level data (IPD) were obtained from the pemetrexed + platinum arm of KEYNOTE-189 (NCT03950674, first line) and the docetaxel arm of REVEL (NCT01168973, post-progression). Patients were matched using entropy balancing, doubly robust method, and propensity score approaches. For patients with unknown/negative RET status, adjustment was made using a model fitted to IPD from a real-world database.

Results

In first-line unadjusted analyses of the real-world control, ORR was 87.2% for LIBRETTO-001 versus 66.7% for those with RET-positive NSCLC (P = 0.06). After adjustment for unknown RET status and other patient characteristics, selpercatinib remained significantly superior versus the real-world control for all outcomes (all P < 0.001 except unadjusted RET-fusion-positive cohort). Similarly, outcomes were significantly improved versus clinical trial controls (all P < 0.05).

Conclusions

Findings suggest improvement in outcomes associated with selpercatinib treatment versus the multiple external control cohorts, but should be interpreted with caution. Data were limited by the rarity of RET, lack of mature OS data, and uncertainty from assumptions to create control arms from external data.

•

Single-arm trials are limited by the lack of a comparison arm, and external controls are needed.

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Multiple methodological approaches with various external control arms evaluated the comparative efficacy of selpercatinib.

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Findings suggest that selpercatinib is associated with significantly improved clinical outcomes versus standard therapies.

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Results should be considered exploratory and hypothesis generating due to the limitations of this study.

Human papillomavirus infection and lung adenocarcinoma: special benefit is observed in patients treated with immune checkpoint inhibitors

BACKGROUND

Human papilloma virus (HPV) has been associated with the development and modulation of response in a series of neoplasms. In the case of lung adenocarcinoma, its role in etiology and pathogenesis is still controversial. Considering that this infection brings foreign epitopes, it could be of prognostic significance in patients with lung adenocarcinoma treated with immunotherapy.

METHODS

In a retrospective cohort study we evaluated the presence of HPV genomic material in lung adenocarcinoma primary lesions with the INNO-LiPA platform. Viral replication was also evaluated by detecting the presence of oncoprotein E6/E7 messenger RNA (mRNA) by quantitative RT-PCR. To confirm possible hypotheses regarding viral oncogenesis, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 (HIF1) were evaluated with stromal fibrosis and immunoscore.

RESULTS

A total of 133 patients were included in the analysis, of whom 34 tested positive for HPV, reaching an estimated prevalence of 25.6% [95% confidence interval (CI) 18.2% to 32.9%]. E6/7 mRNA was identified in 28 out of the 34 previously positive cases (82.3%). In immune checkpoint inhibitor (ICI)-treated patients, the median overall survival reached 22.3 months [95% CI 19.4 months- not reached (NR)] for HPV-negative and was not reached in HPV-positive (HPV+) ones (95% CI 27.7-NR; P = 0.008). With regard to progression-free survival, HPV- patients reached a median of 9.2 months (95% CI 7.9-11.2 months) compared to 14.3 months (95% CI 13.8-16.4 months) when HPV was positive (P = 0.001). The overall response rate for HPV+ patients yielded 82.4% compared to 47.1% in negative ones. No differences regarding programmed death-ligand 1, VEGF, HIF1, stromal fibrosis, or immunoscore were identified.

CONCLUSIONS

In patients with HPV+ lung adenocarcinoma, a significant benefit in overall response and survival outcomes is observed.

Impact of coronary anatomy and residual syntax score on arrhythmic events in patients with ischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

ICD implantation is a cornerstone for primary prevention in patients with ischemic cardiomyopathy and impaired left ventricular function; reduced ejection fraction alone, however, doesn’t seem enough to discriminate which patients will really experience arrhythmic events in the follow up.

Purpose

We hypothesized that coronary anatomy and the extent of residual coronary lesions, measured with syntax score, could be a better predictor of the outcome in this setting.

Materials and method

Data of all patients implanted with single or dual chamber ICD in primary prevention for ischemic cardiomyopathy from 2011 to 2020 were retrospectively collected, together with follow up data obtained from clinical visits and ICD remote monitoring. Residual syntax score (RSS) was calculated for each patient, taking into consideration the last coronary angiography performed before ICD implantation.

Results

110 patients were included in our registry. 90.1% were male, mean age was 66±7 years. 23.6% ICD were dual chamber devices. 96 (87.2%), 8 (7.3%) and 6 (5.5%) patients presented respectively with low (0-22), intermediate (23-32) or high (≥33) RSS. After a mean follow up of 4.4±2.9 years, 31 patients (28.2%) died; 20 patients (18.2%) and 27 patients (24.5%) received any appropriate ICD therapy, either shock or ATP. 12 patients (10.9%) experienced inappropriate shock. The composite outcome of death or any appropriate therapy (MACE) was observed in 47 patients (42.7%); left main or left descending artery stenosis were predictors of MACE (p = 0.026 and p = 0.040, respectively). Intermediate or high RSS was the only predictor of appropriate shock (p = 0.046).

Conclusions

Coronary anatomy and residual coronary stenosis quantified with syntax score are promising predictors of arrhytmic events during the follow up in patients with ischaemic cardiomyopathy and ICD implanted in primary prevention.

P71 LEFT MAIN ANGIOPLASTY: TWENTY YEARS OF EXPERIENCE OF A HIGH–VOLUME SINGLE CENTRE WITH ANGIOGRAPHIC FOLLOW–UP

Long term result of left main angioplasty nowadays is still debated. The retrospective analysis of our reporting software detected from 11/2000 to 11/2021 a total of 956 patients that underwent percutaneous transcatheter coronary angioplasty (PTCA) on unprotected left main with de–novo lesions. The average age of our sample was found to be 72 years old (+–10), mainly male (76,4%). The prevalence of hypertension was 74,6%, of diabetes was 26,2%, of dyslipidaemia was 51,7%, of smoke was 49,8%. The indication for PTCA was ACS in 63,8% of patients (610), in particular STEMI were the 19,5% (186) of patients, NSTEMI were the 29,4% (281) and unstable angina were the 15% (143). Of these ACS in 29 patient the presentation was with cardiac arrest. Patient with CCS were the 36,2% (346). Intubation was necessary in 36 patients. Intra–aortic balloon pump was used in 341 patients (35,7%), in 90,9% of cases before the beginning of the procedure. Radial (45,1%) and femoral access (54,9%) were equally used. Among 773 bifurcations (the 80% of patients), a single stent technique was used in the 66,5% of cases (provisional). Considering the two stent techniques, the Crush was used in 12,7% of cases, the Culottes in 11,1%, the TAP in 6,7%, and the SKS in the 3%. Final kissing balloon was achieved in the 80,2% of bifurcations. Intracoronary imaging was used in the 48,4% of cases (463 patients), mainly IVUS (457). In our centre, as experimental protocol, an angiographic follow–up at 1 year is performed in most of patients that undergo angioplasty on left main. Overall, an angiographic follow–up is available for 607 patients (the 63,5% of patients) with an average lenth of 546 days. The indication for the new angiography was STEMI in 1,9% of patients, NSTEMI in 4,1%, unstable angina in 2,4%, stable angina in 8,6%, and only protocol in the 46,5%. Re–stenosis with redo of angioplasty on left main happened in 89 patients (14,7%), but of these only in 50 patients (56%) was clinically driven. Stent thrombosis was in all cases very–late (average 1609 days) and happened only in 7 patients (1,2%). A new PTCA in non–left main segments was performed in 153 cases (25,2%) and was clinically driven only in 50,4% of patients. Angiographic follow–up of complex PTCA such as those on unprotected left main could, in addition to potentially preventing adverse events, also provide interesting and real–world data about the effectiveness of the procedures and of their various technical aspects.

C35 SUCCESSFUL PERCUTANEOUS TREATMENT OF A GIANT CORONARY ANEURYSM IN THE EMERGENCY SETTING

In 2008, a 60–year–old man with an anterior STEMI and cardiogenic shock underwent coronary angiography: a thrombotic occlusion in the mid–LAD, distal to a coronary aneurysm, was successfully treated with DES. (Fig. A). In 2020, the patient was readmitted with NSTE–ACS and cardiogenic shock. The coronary angiography showed severe stenosis after the proximal–LAD aneurysm and occlusion of the previously implanted stent (Fig. B, Panel B1 and B3). A very slow distal coronary flow was provided by a huge epicardial collateral branch emerging from a second giant coronary aneurysm; furthermore, a severe stenosis in the proximal–LCX was present (Fig. B. Panel B1,2). The patient was judged inoperable by the cardiac surgeon. After IABP positioning, a DES was implanted in the LCX. The LAD was then approached. TIMI 3 flow was achieved after a challenging procedure requiring both coronary and peripheral interventional tools: 3 DES (yellow dotted–lines), 8 coronary and 1 peripheral covered stents (green solid–lines) and 6 coils were used to treat the stenosis and exclude the coronary aneurysms. (Fig. B, Panel B3,4). Both DAPT and oral anticoagulation were prescribed at discharge. A 4–month coronary angiography confirmed the good procedural result. (Fig. C). This case shows the unexpected enlargement of a coronary aneurysm through the years and the presence of a new uncommon epicardial communication, necessary to overcome a chronic coronary occlusion. It highlights the importance of knowing different interventional techniques and using non–conventional tools to approach complex coronary anatomies, such as aneurysmatic disease, whose treatment is often challenging, especially in complicated clinical scenarios.

C30 IMPACT OF CORONARY ANATOMY AND RESIDUAL SYNTAX SCORE ON ARRHYTHMIC EVENTS IN PATIENTS WITH ISCHEMIC CARDIOMYOPATHY

Background

ICD implantation is a cornerstone for primary prevention in patients with ischemic cardiomyopathy and impaired left ventricular function; reduced ejection fraction alone, however, doesn’t seem enough to discriminate which patients will really experience arrhythmic events in the follow up. We hypothesized that coronary anatomy and the extent of residual coronary lesions, measured with syntax score, could be a better predictor of the outcome in this setting.

Materials and Methods

Data of all patients implanted with single or dual chamber ICD in primary prevention for ischemic cardiomyopathy from 2011 to 2020 were retrospectively collected, together with follow up data obtained from clinical visits and ICD remote monitoring. Residual syntax score (RSS) was calculated for each patient, taking into consideration the last coronary angiography performed before ICD implantation.

Results

110 patients were included in our registry. 90.1% were male, mean age was 66±7 years. 23.6% ICD were dual chamber devices. 96 (87.2%), 8 (7.3%) and 6 (5.5%) presented respectively with low (0–22), intermediate (23–32) or high (≥33) RSS. After a mean follow up of 4.4±2.9 years, 31 patients (28.2%) died; 20 patients (18.2%) and 27 patients (24.5%) received any appropriate ICD therapy, either shock or ATP. 12 patients (10.9%) experienced inappropriate shock. The composite outcome of death or any appropriate therapy (MACE) was observed in 47 patients (42.7%); left main or left descending artery stenosis were predictors of MACE (p = 0.026 and p = 0.040 respectively). Intermediate or high RSS was the only predictor of appropriate shock (p = 0.046).

Conclusions

Coronary anatomy and residual coronary stenosis quantified with syntax score are promising predictors of arrhythmic events during the follow up in patients with ischaemic cardiomyopathy and ICD implanted in primary prevention.

P67 MAGMARIS FRACTURE AND COLLAPSE DURING PCI: ACUTE TREATMENT AND FOLLOW–UP

Resorbable Magnesium Scaffold (RMS) Magmaris represents an attractive alternative to permanent metal stenting in young patients undergoing PCI. Despite the promising long–term results, especially in terms of scaffold thrombosis, no data on acute RMS deployment failure and subsequent treatment are available. A 44–year–old gentleman with history of effort angina was admitted to our Department to perform coronary angiography. The exam showed an intermediate stenosis in the mid–tract of Left Anterior Descending (LAD, Figure 1, Panel A1), functionally significant (Instantaneous wave–free ratio 0.85). After Optical Coherence Tomography (OCT) evaluation (Panel A2), a wire was placed in Second Diagonal Branch (DG2) and predilation with a NC 3.5mm balloon on mid–tract of LAD was performed, followed by 3.5x25mm Magmaris implantation. Multiple runs performed after removing the jailed guidewire on Dg2, showed a remarkable angiographic result (Panel B1). However, OCT showed struts fracture near the distal RMS segment resulting in scaffold collapse as confirmed by 3D–reconstruction (Panel B2, B3). Therefore, scaffold dilatation with NC 3.5mm balloon was performed, followed by Magmaris 3.5x20mm intra–scaffold implantation. Panel C1 and C2 showed good angiographic and OCT results after postdilatation with NC 3.5 and 4.0mm balloon in the distal and proximal part, respectively. A planned one–year angiography (Panel D1) revealed a small aneurismatic enlargement in the previous overlapped segment, while no residual struts were visible at OCT. (Panel D2) To our knowledge we reported the first case of Magmaris acute fracture (probably due to a forced removal of the Dg2 jailed guidewire) treated with a second intra–scaffold RMS. The present case should emphasize the importance of intracoronary imaging guidance while more data are needed to clarify the optimal treatment of acute RMS implantation failure.

The prognostic impact of tumor mutational burden (TMB) in the first-line management of advanced non-oncogene addicted non-small-cell lung cancer (NSCLC): a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The role of tumor mutational burden (TMB) is still debated for selecting advanced non-oncogene addicted non-small-cell lung cancer (NSCLC) patients who might benefit from immune checkpoint inhibitors (ICIs). Of note, TMB failed to predict a benefit in overall survival (OS) among such patients.

MATERIALS AND METHODS

The purpose of this meta-analysis was to compare efficacy outcomes among first-line immune-oncology (IO) agents versus standard platinum-based chemotherapy (CT) within two subgroups (TMB-low and TMB-high on either tissue or blood). We collected hazard ratios (HRs) to evaluate the association for progression-free survival (PFS) and OS, with the relative 95% confidence intervals (CIs). Risk ratios (RRs) were used as an association measure for objective response rate (ORR).

RESULTS

Eight different cohorts of five randomized controlled phase III studies (3848 patients) were analyzed. In TMB-high patients, IO agents were associated with improved ORR (RRs 1.37, 95% CI 1.13-1.66), PFS (HR 0.69, 95% CI 0.61-0.79) and OS (HR 0.67, 95% CI 0.59-0.77) when compared with CT, thus suggesting a possible predictive role of high TMB for IO regimens. In TMB-low patients, the IO strategy did not lead to any significant benefit in survival and activity, whereas the pooled results of both ORR and PFS were intriguingly associated with a statistical significance in favor of CT.

CONCLUSIONS

This meta-analysis resulted in a proven benefit in OS in favor of IO agents in the TMB-high population. Although more prospective data are warranted, we postulated the hypothesis that monitoring TMB, in addition to the existing programmed death-ligand 1 (PD-L1) expression level, could represent the preferable option for future clinical research in the first-line management of advanced non-oncogene addicted NSCLC patients.

Patient-reported outcomes from STARTRK-2: a global phase II basket study of entrectinib for ROS1 fusion-positive non-small-cell lung cancer and NTRK fusion-positive solid tumours

BACKGROUND

Patient-reported outcomes (PROs) are increasingly relevant endpoints in clinical trials, contributing to our understanding of risk-benefit profiles, in addition to efficacy and safety data. We investigated the impact of entrectinib on patient-reported symptoms, functioning, and health-related quality of life.

PATIENTS AND METHODS

STARTRK-2 is a phase II basket study in patients with locally advanced/metastatic neurotrophic receptor tyrosine kinase 1/2/3 (NTRK1/2/3) and ROS proto-oncogene 1 (ROS1) fusion-positive solid tumours. PROs (prespecified secondary endpoint) were evaluated using the European Organization for Research and Treatment of Cancer quality-of-life questionnaire (QLQ-C30), lung cancer module (QLQ-LC13), and colorectal cancer module (QLQ-CR29), and the EuroQoL 5-Dimension 3-Level instruments, completed before cycle 1 day 1 and each subsequent 4-week cycle of entrectinib dosing, and the end of treatment. Adverse events and treatment-related symptoms were assessed in the safety analysis (SA)-PRO population. Tumour-related symptoms, functioning, and global health status were assessed in the efficacy analysis (EA)-PRO population. Data cut-offs: 31 October 2018 NTRK cohort; 01 May 2019 ROS1 cohort.

RESULTS

SA-PRO populations comprised patients with NTRK fusion-positive solid tumours (N = 88) or ROS1 fusion-positive non-small-cell lung cancer (N = 180) who received one or more doses of entrectinib, completed PRO questionnaires on cycle 1 day 1 and answered one or more questions on-study. EA-PRO populations (N = 71) and (N = 145), respectively, comprised SA-PRO patients with measurable baseline disease. Moderate-to-high baseline global health status scores were maintained in EA-PRO populations during treatment. Role and physical functioning scores were moderate-to-high at baseline, with trends towards clinical improvement during treatment. Both cohorts reported low-to-moderate symptom burden at baseline, which was maintained or trended towards clinically meaningful improvement. Symptoms commonly associated with cancer treatment (e.g. nausea, fatigue) remained stable or improved during treatment. All SA-PRO patients experienced one or more adverse events, most frequently constipation or diarrhoea.

CONCLUSIONS

PRO findings were consistent with the favourable safety profile of entrectinib, and further reinforce the positive benefit-risk profile of this treatment, indicating minimal overall treatment burden.

Primary tumor sidedness has an impact on prognosis and treatment outcome in metastatic colorectal cancer: results from two randomized first-line panitumumab studies

Background

Previous studies have reported the prognostic impact of primary tumor sidedness in metastatic colorectal cancer (mCRC) and its influence on cetuximab efficacy. The present retrospective analysis of two panitumumab trials investigated a possible association between tumor sidedness and treatment efficacy in first-line mCRC patients with RAS wild-type (WT) primary tumors.

Materials and methods

Data from two randomized first-line panitumumab trials were analyzed for treatment outcomes by primary tumor sidedness for RAS WT patients. PRIME (phase 3; NCT00364013) compared panitumumab plus FOLFOX versus FOLFOX alone; PEAK (phase 2; NCT00819780) compared panitumumab plus FOLFOX versus bevacizumab plus FOLFOX. Primary tumors located in the cecum to transverse colon were coded as right-sided, while tumors located from the splenic flexure to rectum were considered left-sided.

Results

Tumor sidedness ascertainment (RAS WT population) was 83% (n = 559/675); 78% of patients (n = 435) had left-sided and 22% (n = 124) had right-sided tumors. Patients with right-sided tumors did worse for all efficacy parameters compared with patients with left-sided disease in the RAS WT population and also in the RAS/BRAF WT subgroup. In patients with left-sided tumors, panitumumab provided better outcomes than the comparator treatment, including on median overall survival (PRIME: 30.3 versus 23.6 months, adjusted hazard ratio = 0.73, P = 0.0112; PEAK: 43.4 versus 32.0 months, adjusted hazard ratio = 0.77, P = 0.3125).

Conclusion

The results of these retrospective analyses confirm that in RAS WT patients, right-sided primary tumors are associated with worse prognosis than left-sided tumors, regardless of first-line treatment received. RAS WT patients with left-sided tumors derive greater benefit from panitumumab-containing treatment than chemotherapy alone or combined with bevacizumab, including an overall survival advantage (treatment difference: PRIME 6.7 months; PEAK 11.4 months). No final conclusions regarding optimal treatment could be drawn for RAS WT patients with right-sided mCRC due to the relatively low number of paxtients. Further research in this field is warranted.

Trial registration (Clinicaltrials.gov)

PRIME (NCT00364013), PEAK (NCT00819780).

Relevance of small GTPase Rac1 pathway in drug and radio-resistance mechanisms: Opportunities in cancer therapeutics

Rac1 GTPase signaling pathway has a critical role in the regulation of a plethora of cellular functions governing cancer cell behavior. Recently, it has been shown a critical role of Rac1 in the emergence of resistance mechanisms to cancer therapy. This review describes the current knowledge regarding Rac1 pathway deregulation and its association with chemoresistance, radioresistance, resistance to targeted therapies and immune evasion. This supports the idea that interfering Rac1 signaling pathway could be an interesting approach to tackle cancer resistance.

Primary and metastatic brain cancer genomics and emerging biomarkers for immunomodulatory cancer treatment

Recent studies with immunomodulatory agents targeting both cytotoxic T-lymphocyte protein 4 (CTLA4) and programmed cell death 1 (PD1)/programmed cell death ligand 1 (PDL1) have shown to be very effective in several cancers revealing an unexpected great activity in patients with both primary and metastatic brain tumors. Combining anti-CTLA4 and anti-PD1 agents as upfront systemic therapy has revealed to further increase the clinical benefit observed with single agent, even at cost of higher toxicity. Since the brain is an immunological specialized area it's crucial to establish the specific composition of the brain tumors' microenvironment in order to predict the potential activity of immunomodulatory agents. This review briefly summarizes the basis of the brain immunogenicity, providing the most updated clinical evidences in terms of immune-checkpoint inhibitors efficacy and toxicity in both primary and metastatic brain tumors with the final aim of defining potential biomarkers for immunomodulatory cancer treatment.

Third generation EGFR TKIs in EGFR-mutated NSCLC: Where are we now and where are we going

The therapeutic landscape of Non Small Lung Cancer (NSCLC) has been profoundly changed over the last decade with the clinical introduction of Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) and the discovery of EGFR activating mutations as the major predictive factor to these agents. Despite impressive clinical activity against EGFR-mutated NSCLCs, the benefit seen with 1st and 2nd generation EGFR TKIs is usually transient and virtually all patients become resistant. Several different mechanisms of acquired resistance have been reported to date, but the vast majority of patients develop a secondary exon 20 mutation in the ATP-binding site of EGFR, namely T790M. The discovery of mutant-selective EGFR TKIs that selectively inhibit EGFR-mutants, including T790M-harboring NSCLCs, while sparing EGFR wild type, provide the opportunity for overcoming the major mechanism of acquired resistance to 1st and 2nd generation EGFR TKIs, with a relatively favorable toxicity profile. The development of this novel class of EGFR inhibitors poses novel challenges in the rapidly evolving therapeutic paradigm of EGFR-mutated NSCLCs and the next few years will witness the beginning of a new era for EGFR inhibition in lung cancer. The aim of this paper is to provide a comprehensive overview of the increasing body of data emerging from the ongoing clinical trials with this promising novel therapeutic class of EGFR inhibitors.

Is there a role for urokinase-type plasminogen activator inhibitors as maintenance therapy in patients with ovarian cancer?

There is abundant evidence that the urokinase-type plasminogen activator (uPA), its inhibitors PAI-1 and PAI-2 (plasminogen activator inhibitor type-1 and type-2) and its cells surface receptor (uPA-R, CD87) play a fundamental role in tumor invasion and metastasis and are of significant prognostic significance for many tumor types. We performed a systematic Med-line search on uPA, PAI, uPA-R and (epithelial) ovarian cancer (EOC). The majority of malignant EOC specimens show moderate to strong immunostating of tumor and stromal cells. Overexpression of u-PA and PAI-1 can be found in more the 75% of primary ovarian carcinomas, in most metastatic EOC samples and all examined epithelial ovarian cancer cell lines. uPA overexpression in primary specimens was significantly associated with tumor stage, grade, residual disease status after cytoreductive surgery, and poor clinical outcome. This may be explained by increased chemoresistance, a lower resectability and more aggressive tumor biology and tumor dissemination in patients with high uPA and PAI-1. Several therapeutical approaches aimed at inhibiting the uPA/uPAR functions have shown to possess anti-tumor effects in vitro and in animal models. When treating a patient with advanced ovarian cancer it may to be assumed that inhibiting the progression of established (micro) metastases may be more therapeutically relevant than trying to destroy all tumor cells which is not possible in most cases with current systemic treatment modalities. Taking into account the role of uPA and PAI in cell detachment, formation of new stroma, tumor cell reimplantation and metastasis uPA inhibition should be further investigated as maintenance treatment in patients with advanced EOC.