Reduced Immune Response to Inactivated Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine in a Cohort of Immunocompromised Patients in Chile.

BACKGROUND: Inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been widely implemented in low- and middle-income countries. However, immunogenicity in immunocompromised patients has not been established. Herein, we aimed to evaluate immune response to CoronaVac vaccine in these patients. METHODS: This prospective cohort study included 193 participants with 5 different immunocompromising conditions and 67 controls, receiving 2 doses of CoronaVac 8-12 weeks before enrollment. The study was conducted between May and August 2021, at Red de Salud UC-CHRISTUS, Santiago, Chile. Neutralizing antibody (NAb) positivity, total anti-SARS-CoV-2 immunoglobulin G antibody (TAb) concentrations, and T-cell responses were determined. RESULTS: NAb positivity and median neutralizing activity were 83.1% and 51.2% for the control group versus 20.6% and 5.7% (both P < .001) in the solid organ transplant group, 41.5% and 19.2% (both P < .0001) in the autoimmune rheumatic diseases group, 43.3% (P < .001) and 21.4% (P<.01 or P = .001) in the cancer with solid tumors group, 45.5% and 28.7% (both P < .001) in the human immunodeficiency virus (HIV) infection group, 64.3% and 56.6% (both differences not significant) in the hematopoietic stem cell transplant group, respectively. TAb seropositivity was also lower for the solid organ transplant (20.6%; P < .0001), rheumatic diseases (61%; P < .001), and HIV groups (70.9%; P = .003), compared with the control group (92.3%). On the other hand, the number of interferon γ spot-forming T cells specific for SARS-CoV-2 tended to be lower in all immunocompromising conditions but did not differ significantly between groups. CONCLUSIONS: Diverse immunocompromising conditions markedly reduce the humoral response to CoronaVac vaccine. These findings suggest that a boosting vaccination strategy should be considered in these vulnerable patients. CLINICAL TRIALS REGISTRATION: NCT04888793.

Immune biomarkers and response to checkpoint inhibition of BRAFV600 and BRAF non-V600 altered lung cancers.

BACKGROUND: While 2-4% of lung cancers possess alterations in BRAF, little is known about the immune responsiveness of these tumours. METHODS: Clinical and genomic data were collected from 5945 patients with lung cancers whose tumours underwent next-generation sequencing between 2015 and 2018. Patients were followed through 2020. RESULTS: In total, 127 patients with metastatic BRAF-altered lung cancers were identified: 29 tumours had Class I mutations, 59 had Class II/III alterations, and 39 had variants of unknown significance (VUS). Tumour mutation burden was higher in Class II/III than Class I-altered tumours (8.8 mutations/Mb versus 4.9, P < 0.001), but this difference was diminished when stratified by smoking status. The overall response rate to immune checkpoint inhibitors (ICI) was 9% in Class I-altered tumours and 26% in Class II/III (P = 0.25), with median time on treatment of 1.9 months in both groups. Among patients with Class I-III-altered tumours, 36-month HR for death in those who ever versus never received ICI was 1.82 (1.17-6.11). Nine patients were on ICI for >2 years (two with Class I mutations, two with Class II/III alterations, and five with VUS). CONCLUSIONS: A subset of patients with BRAF-altered lung cancers achieved durable disease control on ICI. However, collectively no significant clinical benefit was seen.

[Liver transplantation for non-resectable colorectal liver metastases: A review]. / Trasplante hepático por metástasis hepáticas irresecables de cáncer colorrectal: revisión de la literatura.

In Chile, colorectal cancer ranks third in incidence and fifth in mortality. Half of these patients have liver metastases at the diagnosis, and only 30% of them are resectable. Despite the development of many complex hepatobiliary procedures to achieve the total resection of metastases, the long-term survival with these techniques is not good. Liver transplantation is an alternative to treat unresectable liver metastasis from colorectal cancer with a good outcome. Several prognostic scores allow the selection of patients with good tumor biology. These patients have better overall and disease-free survival after liver transplantation. The use of immunosuppressive treatment doesn't increase recurrence, and even the pattern of tumor growth is slower in liver transplant recipients. The purpose of this review is to summarize the current evidence in this topic and to highlight the need for a formal protocol for liver transplantation for unresectable colorectal liver metastases, using living donors or marginal grafts to avoid competition with the rest of the national waiting list.

Early versus deferred anti-SARS-CoV-2 convalescent plasma in patients admitted for COVID-19: A randomized phase II clinical trial.

BACKGROUND: Convalescent plasma (CP), despite limited evidence on its efficacy, is being widely used as a compassionate therapy for hospitalized patients with COVID-19. We aimed to evaluate the efficacy and safety of early CP therapy in COVID-19 progression. METHODS AND FINDINGS: The study was an open-label, single-center randomized clinical trial performed in an academic medical center in Santiago, Chile, from May 10, 2020, to July 18, 2020, with final follow-up until August 17, 2020. The trial included patients hospitalized within the first 7 days of COVID-19 symptom onset, presenting risk factors for illness progression and not on mechanical ventilation. The intervention consisted of immediate CP (early plasma group) versus no CP unless developing prespecified criteria of deterioration (deferred plasma group). Additional standard treatment was allowed in both arms. The primary outcome was a composite of mechanical ventilation, hospitalization for >14 days, or death. The key secondary outcomes included time to respiratory failure, days of mechanical ventilation, hospital length of stay, mortality at 30 days, and SARS-CoV-2 real-time PCR clearance rate. Of 58 randomized patients (mean age, 65.8 years; 50% male), 57 (98.3%) completed the trial. A total of 13 (43.3%) participants from the deferred group received plasma based on clinical aggravation. We failed to find benefit in the primary outcome (32.1% versus 33.3%, odds ratio [OR] 0.95, 95% CI 0.32-2.84, p > 0.999) in the early versus deferred CP group. The in-hospital mortality rate was 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17 p = 0.246), mechanical ventilation 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17, p = 0.246), and prolonged hospitalization 21.4% versus 30.0% (OR 0.64, 95% CI, 0.19-2.10, p = 0.554) in the early versus deferred CP group, respectively. The viral clearance rate on day 3 (26% versus 8%, p = 0.204) and day 7 (38% versus 19%, p = 0.374) did not differ between groups. Two patients experienced serious adverse events within 6 hours after plasma transfusion. The main limitation of this study is the lack of statistical power to detect a smaller but clinically relevant therapeutic effect of CP, as well as not having confirmed neutralizing antibodies in donor before plasma infusion. CONCLUSIONS: In the present study, we failed to find evidence of benefit in mortality, length of hospitalization, or mechanical ventilation requirement by immediate addition of CP therapy in the early stages of COVID-19 compared to its use only in case of patient deterioration. TRIAL REGISTRATION: NCT04375098.

Clinical implications of drug-induced liver injury in early-phase oncology clinical trials.

BACKGROUND: Data on drug-induced liver injury (DILI) and acute liver failure (ALF) in modern phase 1 oncology trials are limited, specifically with respect to the incidence and resolution of DILI and the safety of drug rechallenge. METHODS: This study reviewed all patients who were recruited to phase 1 oncology trials between 2013 and 2017 at Memorial Sloan Kettering Cancer Center. Clinicopathologic data were extracted to characterize DILI, and attribution was assessed on the basis of data prospectively generated during the studies. Logistic regression models were used to explore factors related to DILI and DILI recurrence after drug rechallenge. RESULTS: Among 1670 cases recruited to 85 phase 1 trials, 81 (4.9%) developed DILI. The rate of DILI occurrence was similar for patients in immune-based trials and patients in targeted therapy trials (5.0% vs 4.9%), as was the median time to DILI (5.5 vs 6.5 weeks; P = .48). Two patients (0.12%) met the criteria of Hy's law, although none developed ALF. The DILI resolved in 96% of the patients. Pretreatment factors were not predictive for DILI development. Thirty-six of the 81 patients underwent a drug rechallenge, and 28% of these patients developed DILI recurrence. Peak alanine aminotransferase during the initial DILI was associated with DILI recurrence (odds ratio, 1.04; 95% confidence interval, 1.0-1.09; P = .035). CONCLUSIONS: In modern phase 1 oncology trials, DILI is uncommon, may occur at any time, and often resolves with supportive measures. Rechallenging after DILI is feasible; however, the high rate of DILI recurrence suggests that clinicians should consider the severity of the DILI episode and treatment alternatives.

Lessons learned from routine, targeted assessment of liquid biopsies for EGFR T790M resistance mutation in patients with EGFR mutant lung cancers.

Background: Plasma cfDNA evaluation at acquired resistance to targeted therapies in lung cancer is routine, however, reports of extended clinical application and pitfalls in laboratory practice are still limited. In this study we describe our experience with cfDNA testing using EGFR T790M as a prototype.Methods: Patients with metastatic EGFR-mutant NSCLC patients who underwent plasma EGFR T790M testing at acquired resistance to EGFR tyrosine kinase inhibitors (EGFR-TKI) from January 2016 through August 2017 were identified. Molecular laboratory records were reviewed to assess performance of testing by digital PCR, concordance between plasma and tissue testing, turnaround time (TAT), plasma T790M variant allele frequency (VAF), and its correlations with metastatic sites and clinical outcomes.Results: 177 patients underwent T790M cfDNA testing during this period. Plasma T790M was positive in 32% of patients. The median TAT was shorter for plasma T790M compared to tissue PCR (9 vs. 15 days, p < .0001), and led to osimertinib use in 84% of positive patients. In 52 patients with plasma and tissue T790M evaluation, the concordance was 77%. Plasma T790M VAF did not correlate with time to osimertinib discontinuation (p = .4). Plasma T790M status correlated with a higher number of metastatic sites (4 vs. 3, p < .001) and bone metastases (p = .0002).Conclusion: Plasma EGFR T790M testing had shorter TAT compared to tissue testing, however, it was longer than anticipated. Test sensitivity is higher in patients with osseous metastases and with higher metastatic burden suggesting a more limited role for early detection. T790M VAF was not associated with clinical outcomes.

Phase II study of trastuzumab with modified docetaxel, cisplatin, and 5 fluorouracil in metastatic HER2-positive gastric cancer.

BACKGROUND: Trastuzumab with cisplatin and fluoropyrimidine is the standard treatment in metastatic HER2-positive gastric or gastroesophageal (GE) junction adenocarcinoma; however, there is limited data on the efficacy of trastuzumab in combination with a three-drug regimen in this setting. We examined the efficacy and safety of modified docetaxel, cisplatin and 5 fluorouracil (mDCF) plus trastuzumab in a single-arm multicenter phase II trial. METHODS: Previously untreated patients with HER2-positive metastatic gastric or GE junction adenocarcinoma were treated with mDCF and trastuzumab every 2 weeks. The primary endpoint was 6-month progression-free survival (PFS); secondary endpoints included objective response rate, overall survival (OS), and toxicity. RESULTS: We enrolled 26 patients with metastatic HER2-positive gastric or GE junction adenocarcinoma between February 2011 and June 2015. The median age of patients was 62 years; 96% had a Karnofsky performance status equal to or greater than 80%. With a median follow-up of 25.4 months, the 6-month PFS was 73% (95% CI 51-86%). The objective response rate was 65%, the median PFS was 13 months (95% CI 6.4-20.7) and the median OS was 24.9 months (95% CI 14.4-42.5). Grade 3/4 toxicities included neutropenia (42%), fatigue (23%), and hypophosphatemia (15%). There were no episodes of febrile neutropenia. CONCLUSION: The combination of mDCF and trastuzumab is effective and safe in patients with metastatic HER2-positive gastric or GE junction adenocarcinoma and can be considered as an option for selected patients. This trial is registered at ClinicalTrials.gov, number NCT00515411.

[Benefit of adjuvant 5-fluorouracil based chemotherapy for colon cancer: a retrospective cohort study]. / Beneficio de la quimioterapia adyuvante en pacientes con cáncer de colon: cohorte retrospectiva de un hospital clínico universitario.

BACKGROUND: Multiple clinical trials have demonstrated the benefits of adjuvant 5-fluorouracil-based chemotherapy for patients with resectable colon cancer (CC), especially in stage III. AIM: To describe the clinical characteristics of a cohort of CC patients treated at a single university hospital in Chile since 2002, and to investigate if chemotherapy had an effect on survival rates. MATERIAL AND METHODS: Review of a tumor registry of the hospital. Medical records of patients with CC treated between 2002 and 2012 were reviewed. Death certificates from the National Identification Service were used to determine mortality. Overall survival was described using the Kaplan-Meier method. A multivariate Cox proportional hazard regression model was also used. RESULTS: A total of 370 patients were treated during the study period (202 in stage II and 168 in stage III). Adjuvant chemotherapy was administered to 22 and 70% of patients in stage II and III respectively. The median follow-up period was 4.6 years. The 5-year survival rate for stage II patients was 79% and there was no benefit observed with adjuvant chemotherapy. For stage III patients, the 5-year survival rate was 81% for patients who received adjuvant chemotherapy, compared to 56% for those who did not receive chemotherapy (hazard ratio (HR): 0.29; 95% confidence interval (CI): 0.15-0.56). The benefit of chemotherapy was found to persist after adjustment for other prognostic variables (HR: 0.47; 95% CI: 0.23-0.94). CONCLUSIONS: Patients with colon cancer in stage III who received adjuvant chemotherapy had a better overall survival.

Quantitative Ocular Surface Changes in Patients Undergoing Immune Checkpoint Inhibitor Therapy.

PURPOSE: To describe the clinical course and evaluate treatment of ocular surface changes in patients receiving immune checkpoint inhibitor (ICI) therapy. METHODS: Multiple markers of ocular surface dryness were evaluated in 16 patients on ICI therapy. The Wilcoxon rank-sum test was used to determine the significant change in the initial and final ocular surface indices. RESULTS: Fifty percent of the eyes demonstrated worsening Schirmer I scores; 29% showed an increase in lissamine green staining. During follow-up, 43% of patients experienced a decline in OSDI scores. Treatments included preservative-free artificial tears (88%), cyclosporine (25%), topical corticosteroids (31%), warm compresses (25%); punctal plugs (13%). Median follow-up time was 3.4 months (range:0-79 ); median ICI treatment duration was 7 months (range:1-40). Four patients died during the observation period. CONCLUSION: A significant proportion of patients experience changes in ocular surface markers while treated with ICIs. Medical intervention can lead to stabilization of ocular surface disease.

Patterns of Recurrence of Cutaneous Melanoma: A Literature Review.

The incidence of melanoma has been dramatically increasing over the last decades. Melanoma is considered to have a high metastatic potential and it can progress via lymphatic vessels or through hematogenous metastasis. Different patterns of recurrence have been described, namely, local, satellite, and in transit metastasis (LCIT), lymphatic metastasis, and systemic metastasis. With a more advanced melanoma stage at diagnosis, there is a higher risk for systemic metastasis in comparison to LCIT; in contrast, early-stage melanoma tends to recur more frequently as LCIT and less commonly as systematic metastasis. The aim of this review was to summarize the patterns of recurrence of cuta-neous melanoma, giving the clinician a practical summary for diagnosis, prognosis, and surveillance. There is a knowledge gap of the common patterns of recurrence that needs to be addressed to better identify patients at high risk of disease recurrence and personalize surveillance strategies as well as patient counseling.

Impact of Adjuvant FOLFOX on Quality of Life and Peripheral Neuropathy Incidence in Patients With Gastric Cancer: A Prospective Cohort Study.

OBJECTIVES: Perioperative and adjuvant chemotherapy have demonstrated clinical benefits in localized gastric cancer. Nevertheless, the reports on their effects on patient's health-related quality of life (HRQoL) are scarce. Here, we prospectively assessed quality of life and the incidence of chemotherapy-induced peripheral neuropathy (CIPN) in a cohort of patients treated with adjuvant FOLFOX. METHODS: Localized stomach or gastroesophageal junction adenocarcinoma patients who underwent curative resection were recruited at a single center. All patients received adjuvant FOLFOX6, and HRQoL and CIPN were assessed using the European organization for research and treatment of cancer quality life (EORTC) C30 and the EORTC CIPN20 questionnaires, respectively. Clinically significant deterioration of HRQoL was also assessed as a coprimary outcome in a longitudinal analysis. RESULTS: We recruited a total of 63 patients. Median age was 62.5 years, and 75% had stomach tumors. Twenty-four weeks after the start of treatment, the probability of being free from HRQoL deterioration and CIPN was 29% (95% confidence interval [CI] 18%-42%) and 6% (95% CI 2%-17%), respectively. Five-year disease-free survival was 45% (95% CI 24%-64%) and 5-year overall survival was 63% (95% CI 48%-76%). CONCLUSIONS: Adjuvant FOLFOX is associated with a high rate of long-term survival in localized gastric cancer; nevertheless, it has detrimental effects on patients' quality of life.

Influence of SARS-CoV-2 mRNA Vaccine Booster among Cancer Patients on Active Treatment Previously Immunized with Inactivated versus mRNA Vaccines: A Prospective Cohort Study.

Cancer patients on chemotherapy have a lower immune response to SARS-CoV-2 vaccines. Therefore, through a prospective cohort study of patients with solid tumors receiving chemotherapy, we aimed to determine the immunogenicity of an mRNA vaccine booster (BNT162b2) among patients previously immunized with an inactivated (CoronaVac) or homologous (BNT162b2) SARS-CoV-2 vaccine. The primary outcome was the proportion of patients with anti-SARS-CoV-2 neutralizing antibody (NAb) seropositivity at 8-12 weeks post-booster. The secondary end points included IgG antibody (TAb) seropositivity and specific T-cell responses. A total of 109 patients were included. Eighty-four (77%) had heterologous vaccine schedules (two doses of CoronaVac followed by the BNT162b2 booster) and twenty-five had (23%) homologous vaccine schedules (three doses of BNT162b2). IgG antibody positivity for the homologous and heterologous regimen were 100% and 96% (p = 0.338), whereas NAb positivity reached 100% and 92% (p = 0.13), respectively. Absolute NAb positivity and Tab levels were associated with the homologous schedule (with a beta coefficient of 0.26 with p = 0.027 and a geometric mean ratio 1.41 with p = 0.044, respectively). Both the homologous and heterologous vaccine regimens elicited a strong humoral and cellular response after the BNT162b2 booster. The homologous regimen was associated with higher NAb positivity and Tab levels after adjusting for relevant covariates.

Differential expression of programmed cell death ligand 1 (PD-L1) and inflammatory cells in basal cell carcinoma subtypes.

Few studies have evaluated programmed cell death ligand (PD-L1) expression and lymphocytic infiltrates in Basal Cell Carcinoma (BCC). The objectives of this study are to assess PD-L1 expression and markers of local immune response in nodular, superficial, and morpheaform BCC, and compare it to normal, sun-exposed skin from the periphery of intradermal nevi. This was a retrospective study that included three histological subtypes of BCCs, and sun-exposed skin from the periphery of dermal nevi as quality controls. Tissue microarrays (TMA) were constructed with subsequent staining of H&E and immunohistochemistry (IHC) for CD4, CD8, FOXP3 and PD-L1. Non-automated quantification of the infiltrate in the intratumoral and stromal compartments on TMAs was performed. A total of 115 BCC (39 nodular, 39 morpheaform, and 37 superficial) and 41 sun-exposed skin samples were included (mean age 65.4 years; 52.6% females). BCC showed higher expression of PD-L1 (5.4 vs 0.7%, p < 0.001), CD8 (29.8 vs 19.7%, p = 0.002), and FOXP3 (0.3 vs 0.06%, p = 0.022) compared to sun-exposed skin. There was a higher PD-L1 expression in nodular BCC compared with other subtypes. Low-risk BCC subtypes (superficial and nodular) exhibited more PD-L1 expression in intratumoral and stromal immune infiltrates as compared to high-risk BCC subtypes. As a limitation, no immune cells function was evaluated in this study, only the presence/absence of T-lymphocyte sub-populations was recorded. Substantial differences in both PD-L1 expression and lymphocytic infiltrates were found amongst the histological subtypes of BCC and sun-exposed skin. Highest PD-L1 expression was found in nodular BCCs which suggests a potentially targetable strategy in the treatment of this most common BCC subtype.

SARS-CoV-2 vaccine booster in solid organ transplant recipients previously immunised with inactivated versus mRNA vaccines: A prospective cohort study.

Background: Solid-organ transplant (SOT) recipients have worse COVID-19 outcomes than general population and effective immunisation in these patients is essential but more difficult to reach. We aimed to determine the immunogenicity of an mRNA SARS-CoV-2 vaccine booster in SOT recipients previously immunised with either inactivated or homologous SARS-CoV-2 mRNA vaccine. Methods: Prospective cohort study of SOT recipients under medical care at Red de Salud UC-CHRISTUS, Chile, previously vaccinated with either CoronaVac or BNT162b2. All participants received a BNT162b2 vaccine booster. The primary study end point was anti-SARS-CoV-2 total IgG antibodies (TAb) seropositivity at 8-12 weeks (56-84 days) post booster. Secondary end points included neutralising antibodies (NAb) and specific T-cell responses. Findings: A total of 140 (50% kidney, 38% liver, 6% heart) SOT recipients (mean age 54 [13.6] years; 64 [46%] women) were included. Of them, 62 had homologous (three doses of BNT162b2) and 78 heterologous vaccine schedules (two doses of CoronaVac followed by BNT162b2 booster). Boosters were received at a median of 21.3 weeks after primary vaccination. The proportion achieving TAb seropositivity (82.3% vs 65.4%, P = 0.035) and NAb positivity (77.4% vs 55.1%, P = 0.007) were higher for the homologous versus the heterologous group. On the other hand, the number of IFN-γ and IL-2 secreting SARS-CoV-2-specific T-cells did not differ significantly between groups. Interpretation: This cohort study shows that homologous mRNA vaccine priming plus boosting in SOT recipients, reaches a significantly higher humoral immune response than inactivated SARS-CoV-2 vaccine priming followed by heterologous mRNA booster. Funding: School of Medicine, UC-Chile and ANID.ClinicalTrials.gov ID: NCT05124509.

Pathological complete response to neoadjuvant chemotherapy, but not the addition of carboplatin, is associated with improved survival in Chilean triple negative breast cancer patients: a report of real world data.

BACKGROUND: Breast cancer (BC) is the leading cause of cancer death for Chilean women. About 11% of cases are triple-negative (TN) BC. These are characterised by poor prognosis, higher risk of early recurrence and visceral dissemination versus other BC subtypes. Current standard treatment for early-stage non-metastatic TNBC patients consists of neoadjuvant chemotherapy (NACT) followed by surgery and radiotherapy. Pathological complete response (pCR) to NACT is associated with an increase in survival rates. In general, NACT and adjuvant regimens involve similar cytotoxic drugs. Recent studies have postulated that the use of platinum compounds in TNBC would increase response rates. However, their effects on patient survival remain uncertain. MATERIALS AND METHODS: We retrieved and analysed medical records from a total of 156 Chilean stage I-III TNBC female patients that received NACT and compared survival rates using carboplatin (Cb)-containing versus non-Cb-containing regimens at two health cancer centres. RESULTS: Median age was 51 years (range: 24-81); 13.5% (n = 21) received Cb-containing regimens, 80.1% (n = 125) received sequential anthracyclines plus taxanes; 29.5% (n = 46) of the total group achieved pCR, 28% for the standard treatment and 35% (n = 8) for the Cb-containing group (p = 0.59). We confirmed pCR was associated with prolonged overall survival, invasive and distant disease-free survival (Log-rank p = 0.0236). But the addition of Cb was not associated with differences in survival measures (Log-rank p = 0.5216). CONCLUSIONS: To the best of authors' knowledge, this is the first report on real-world data in the Chilean population assessing the effect of Cb-containing NACT in TNBC. The authors' results suggest no survival benefit by the addition of Cb to standard NACT. However, we confirm an increase in survival associated to pCR regardless of treatment.

Oncological resection, myasthenia gravis and staging as prognostic factors in thymic tumours: a Chilean case series.

BACKGROUND: Thymic epithelial tumours are rare and highly heterogeneous. Reports from the United States suggest an overall incidence of 0.15 per 100,000/year. In contrast, the incidence of these tumours in Latin America is largely unknown and reports are scarce, somewhat limited to case reports. METHODS: Herein, we report a series of 38 thymic tumours from a single institution, retrospectively incorporated into this study. Patient characteristics and outcomes including age, sex, stage, paraneoplastic syndromes, treatment regimens and the date of decease were obtained from medical records. RESULTS: Most cases in our series were females and young age (<50 years old) and early stage by Masaoka-Koga or the Moran staging systems. Also, a 34% of patients had myasthenia gravis (MG). Next, we analysed overall survival rates in our series and found that the quality of surgery (R0, R1 or R2), MG status and staging (Masaoka-Koga, Moran or TNM) were prognostic factors. Finally, we compared our data to larger thymic tumour series. CONCLUSIONS: Overall, our study confirms complete surgical resection as the standard, most effective treatment for thymic epithelial tumours. Also, the Masaoka-Koga staging system remains as a reliable prognostic factor but also the Moran staging system should be considered for thymomas.

Clinical utility of next-generation sequencing-based ctDNA testing for common and novel ALK fusions.

OBJECTIVES: Liquid biopsy for plasma circulating tumor DNA (ctDNA) next-generation sequencing (NGS) can detect ALK fusions, though data on clinical utility of this technology in the real world is limited. MATERIALS AND METHODS: Patients with lung cancer without known oncogenic drivers or who had acquired resistance to therapy (n = 736) underwent prospective plasma ctDNA NGS. A subset of this cohort (n = 497) also had tissue NGS. We evaluated ALK fusion detection, turnaround time (TAT), plasma and tissue concordance, matching to therapy, and treatment response. RESULTS: ctDNA identified an ALK fusion in 21 patients (3%) with a variety of breakpoints and fusion partners, including EML4, CLTC, and PON1, a novel ALK fusion partner. TAT for ctDNA NGS was shorter than tissue NGS (10 vs. 20 days; p < 0.001). Among ALK fusions identified by ctDNA, 93% (13/14, 95% CI 66%-99%) were concordant with tissue evaluation. Among ALK fusions detected by tissue NGS, 54% (13/24, 95% CI 33%-74%) were concordant with plasma ctDNA. ctDNA matched patients to ALK-directed therapy with subsequent clinical response, including four patients matched on the basis of ctDNA results alone due to inadequate or delayed tissue testing. Serial ctDNA analysis detected MET amplification (n = 2) and ALK G1202R mutation (n = 2) as mechanisms of acquired resistance to ALK-directed therapy. CONCLUSION: Our findings support a complementary role for ctDNA in detection of ALK fusions and other alterations at diagnosis and therapeutic resistance settings.