Association of two BRM promoter polymorphisms and smoking status with malignant pleural mesothelioma risk and prognosis.

Brahma (BRM), of the SWI/SNF complex, has two 6 to 7 bp insertion promoter polymorphisms (BRM-741/BRM-1321) that cause epigenetic BRM suppression, and are associated with risk of multiple cancers. BRM polymorphisms were genotyped in malignant pleural mesothelioma (MPM) cases and asbestos-exposed controls. Multivariable logistic regression (risk) and Cox regression (prognosis) were performed, including stratified analyses by smoking status to investigate the effect of polymorphisms on MPM risk and prognosis. Although there was no significant association overall between BRM-741/BRM-1321 and risk in patients with MPM, a differential effect by smoking status was observed (P-interaction < .001), where homozygous variants were protective (aOR of 0.18-0.28) in ever smokers, while never smokers had increased risk when carrying homozygous variants (aOR of 2.7-4.4). While there was no association between BRM polymorphisms and OS in ever-smokers, the aHR of carrying homozygous-variants of BRM-741, BRM-1321 or both were 4.0 to 8.6 in never-smokers when compared to wild-type carriers. Mechanistically, lower mRNA expression of BRM was associated with poorer general cancer prognosis. Electrophoretic mobility shift assays and chromatin immunoprecipitation experiments (ChIP) revealed high BRM insertion variant homology to MEF2 regulatory binding sites. ChIP experimentation confirmed MEF2 binding only occurs in the presence of insertion variants. DNA-affinity purification assays revealed YWHA scaffold proteins as vital to BRM mRNA expression. Never-smokers who carry BRM homozygous variants have an increased chance of developing MPM, which results in worse prognosis. In contrast, in ever-smokers, there may be a protective effect, with no difference in overall survival. Mechanisms for the interaction between BRM and smoking require further study.

New ARCHITECT plasma pro-gastrin-releasing peptide assay for diagnosing and monitoring small-cell lung cancer.

BACKGROUND: Progastrin-releasing peptide (ProGRP) is a potential marker for small-cell lung cancer (SCLC) in serum; however, it may be more stable in plasma. We investigated a new plasma assay (ProGRPp) and its usefulness in diagnosing and monitoring SCLC. METHODS: The marker concentrations were determined on the ARCHITECT i system. RESULTS: The assay could distinguish SCLC from non-small-cell lung cancer (NSCLC: area under the curve 0.931, 95% CI 0.893-0.969; cross-validated accuracy 0.813; sensitivity 84.0%, specificity 96.3%; at 140 pg ml(-1) cutoff). The probability of SCLC when ProGRPp was >140 pg ml(-1) was 91.8%, after adjusting for age, gender, and renal dysfunction. The NSCLC patients with ProGRPp >140 pg ml(-1) were at high risk (odds ratio=37.0, P<0.001) for tumours with neuroendocrine features. False negatives in SCLC were associated with a lack of thyroid transcription factor-1 (P<0.001). A decrease of ProGRPp to <140 pg ml(-1) during chemotherapy was significantly associated with the image-based response (P<0.001), and independently affected progression-free survival (PFS, relative risk=2.51, P=0.04) and overall survival (OS, relative risk=4.38, P=0.003), after adjustment for imaging response, performance status, and stage. CONCLUSIONS: The ProGRPp assay is specific and sensitive for diagnosing SCLC. Changes in ProGRPp during chemotherapy are significantly associated with image-based response, PFS, and OS.

EGFR mutation testing practice in advanced non-small cell lung cancer.

PURPOSE: Testing tumor samples for the presence of a mutation in the epithelial growth factor receptor (EGFR) gene is recommended for advanced non-squamous non-small cell lung cancer (NSCLC) patients. We aimed to collect data about common practice among Medical Oncologists treating lung cancer patients, regarding EGFR mutation testing in advanced NSCLC patients. METHODS: An internet-based survey was conducted among members of the Israeli Society for Clinical Oncology and Radiotherapy involved in the treatment of lung cancer patients. RESULTS: 24 Oncologists participated in the survey. The participants encompass the Oncologists treating most of the lung cancer patients in Israel. 79% of them use EGFR testing routinely for all advanced NSCLC patients. Opinions were split regarding the preferable biopsy site for EGFR testing material. 60% of participants recommend waiting for EGFR test results prior to initiation of first-line therapy. CONCLUSIONS: EGFR testing is requested in Israel routinely by most treating Oncologists for all advanced NSCLC patients, regardless of histology. In most cases, systemic treatment is deferred until the results of this test are received.

Gut microbial signature in lung cancer patients highlights specific taxa as predictors for durable clinical benefit.

We aimed to determine microbial signature linked with lung cancer (LC) diagnosis and to define taxa linked with durable clinical benefit (DCB) of advanced LC patients. Stool samples for microbial 16S amplicon sequencing and clinical data were collected from 75 LC patients (50 of which were treated with checkpoint inhibitors) and 31 matched healthy volunteers. We compared LC to healthy controls and patients with DCB to those without. LC patients had lower α-diversity and higher between-subject diversity. Random Forests model to differentiate LC cases from controls ROC-AUC was 0.74. Clostridiales, Lachnospiraceae, and Faecalibacterium prausnitzii taxa abundance was decreased in LC compared to controls. High Akkermansia muciniphila correlated with DCB (HR 4.26, 95% CI 1.98-9.16), not only for the immunotherapy-treated patients. In addition, high Alistipes onderdonkii (HR 3.08, 95% CI 1.34-7.06) and high Ruminococcus (HR 7.76, 95% CI 3.23-18.65) correlated with DCB.Our results support the importance of gut microbiome in LC. We have validated the apparent predictive value of Akkermansia muciniphila, and highlighted Alistipes onderdonkii and Ruminococcus taxa correlation with DCB. Upon additional validations those can be used as biomarkers or as targets for future therapeutic interventions.

Driver mutation characteristics of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) in advanced non-small cell lung cancer.

OBJECTIVES: The identification and targeting of actionable genomic alterations (AGA) have revolutionized the treatment of cancer in general and mostly for non-small cell lung cancer (NSCLC). We investigated whether in NSCLC patients PIK3CA mutations are actionable. MATERIALS AND METHODS: Chart review was performed of advanced NSCLC patients. PIK3CA mutated patients were analyzed as two groups: Group A: without any non-PIK3CA established AGA; Group B: with coexisting AGA. Group A was compared to a cohort of non-PIK3CA patients (group C), using t-test and chi-square. To evaluate the impact of PIK3CA mutation on outcome, we compared Group A survival to age/sex/histology matched cohort of non-PIK3CA mutated patients (group D) by Kaplan-Meier method. A patient with a PIK3CA mutation was treated with a PI3Ka-isoform selective inhibitor BYL719 (Alpelisib). RESULTS: Of a cohort of 1377 patients, 57 are PIK3CA mutated (4.1%). Group A: n-22, group B: n-35. Group A median age is 76 years, 16 (72.7%) men, 10 (45.5%) squamous, 4 (18.2%) never smokers. Two never-smoker female adenocarcinoma patients had solitary PIK3CA mutation. One of them was treated with a PI3Ka-isoform selective inhibitor BYL719 (Alpelisib), with rapid clinical and partial radiological improvement. Group B, compared with Group A, included younger patients (p = 0.030), more females (p = 0.028) and more adenocarcinoma cases (p < 0.001). Compared to group C, group A patients were older (p = 0.030) and had more squamous histology (p = 0.011). CONCLUSION: In a small minority of NSCLC patients with PIK3CA mutation there are no additional AGA. PIK3CA mutations may be actionable in these cases.

Effects of EGFR driver mutations on pathologic regression in resectable locally advanced non-small cell lung cancer treated with neoadjuvant chemoradiation and completion surgery.

OBJECTIVE: We hypothesized that driver mutations in epidermal growth factor receptor (EGFR) are associated with decreased pathologic response to neoadjuvant chemoradiation (NA-ChRT) in locally advanced non-small cell lung cancer (LA-NSCLC). METHODS: Patients with Stage IIB-IIIA NSCLC treated with NA-ChRT, completion surgery, and underwent molecular profile testing were identified in a lung cancer database. Pathologic response was quantified using: (i) major pathologic response (MPR), (ii) complete pathologic response (pCR), and (iii) mean residual viable tumor cells (MRTC). Two groups were formed based on the presence or absence of driver mutations. Clinical and pathological correlations between the groups were studied. RESULTS: Forty-seven patients underwent tumor molecular profile testing, NA-ChRT, and completion surgery. Compared to the no-driver mutation group, the driver mutation group had lower MPR (23% vs 71%, p = 0.003), pCR (0% vs 26%, p = 0.02), and higher MRTC (43.4% vs 15.8%, p = 0.009). Univariate analysis showed an increased MPR rate for smokers, squamous cell histology, ChRT-surgery interval >65 days, and no-driver mutations. Multivariate analysis showed that only no-driver mutations (OR 0.39, p = 0.02) remained significant for MPR. PD-L1 status did not affect MPR. At 2 years, the driver mutation group had lower rates of local control (Hazard ration [HR] 0.67, p = 0.17) and disease-free survival (HR 0.5, p = 0.001). Overall survival was similar for both groups (HR = 1.04, p = 0.86). CONCLUSION: Following 60 Gray NA-ChRT, tumors with a driver mutation had lower MPR and pCR rates than tumors without a driver mutation. PD-L1 was not associated with tumor regression. ADVANCES IN KNOWLEDGE: Patients with resectable LA-NSCLC and an EGFR driver mutation treated with neoadjuvant-ChRT and completion surgery have reduced pathologic regression, lower local control rates, and shorter disease-free survival than patients without a driver mutation. Evaluation of molecular testing should be introduced in LA-NSCLC intended for prognostication and treatment decisions.

UNcommon EGFR Mutations: International Case Series on Efficacy of Osimertinib in Real-Life Practice in First-LiNe Setting (UNICORN).

INTRODUCTION: Approximately 10% of EGFR mutations (EGFRmuts) are uncommon (ucEGFRmuts). We aimed to collect real-world data about osimertinib for patients with ucEGFRmuts. METHODS: This is a multicenter, retrospective study of ucEGFRmut (exon 20 insertions excluded) metastatic NSCLC treated with osimertinib as first EGFR inhibitor. The Response Evaluation Criteria in Solid Tumors and response assessment in neuro-oncology brain metastases brain objective response rate (ORR) were evaluated by the investigators. Median progression-free survival (mPFS), median overall survival, and median duration of response (mDOR) were calculated from osimertinib initiation. Mutations found at resistance were collected. RESULTS: A total of 60 patients were included (22 centers, nine countries), with median age of 64 years, 75% females, and 83% Caucasian. The largest subgroups were G719X (30%), L861Q (20%), and de novo Thr790Met (T790M) (15%). The ORR was 61%, mPFS 9.5 months, mDOR 17.4 months, and median overall survival 24.5 months. Regarding patients with no concurrent common mutations or T790M (group A, n = 44), ORR was 60%, mPFS 8.6 months, and mDOR 11 months. For G719X, ORR was 47%, mPFS 8.8 months, and mDOR 9.1 months. For L861Q, ORR was 80%, mPFS 16 months, and mDOR 16 months. For de novo T790M, ORR was 44%, mPFS 12.7 months, and mDOR 46.2 months. Compound EGFRmut including common mutations had better outcome compared with only ucEGFRmut. For 13 patients with a response assessment in neuro-oncology brain metastases-evaluable brain metastases, brain ORR was 46%. For 14 patients, rebiopsy results were analyzed: four patients with additional EGFR mutation (C797S, D585Y, E709K), three with new TP53 mutation, one with c-Met amplification, one with PIK3CA mutation, and one with neuroendocrine transformation. CONCLUSIONS: Osimertinib was found to have an activity in ucEGFRmut with a high rate of disease control systemically and intracranially. Several resistance mechanisms were identified. This report comprises, to the best of our knowledge, the largest data set of its kind.

RCC Real-World Data: Prognostic Factors and Risk Stratification in the Immunotherapy Era.

Immunotherapy has transformed the landscape of treatment in metastatic renal cell carcinoma (mRCC) in the last decade. Currently, prognostic risk stratification is based on the model developed in the era of vascular endothelial growth factor receptor inhibitors (VEGFRi) by Heng in 2009. Our study aims to find the most relevant risk criteria for mRCC patients treated with checkpoint inhibitors (CPI). In a retrospective cohort study, laboratory, pathology, demographic, and clinical data were retrieved from electronic medical records of consecutive mRCC patients treated with CPI in a tertiary center between 2015 and 2020. An unbiased multivariate analysis was performed to define predictive variables with a bootstrap validation step. We analyzed data on 127 patients with a median follow-up of 60 months. The median overall survival (OS) since the diagnosis of metastatic disease was 57 months. The response rate for CPI was 39%. Five risk factors were correlated with worse OS: intact primary kidney tumor (HR 2.33, p = 0.012), liver metastasis (HR 3.33, p = 0.001),

Immune-Related Thyroiditis as a Predictor for Survival in Metastatic Renal Cell Carcinoma.

Immune checkpoint inhibitors (CPI) are indicated for metastatic renal cell carcinoma (mRCC). Immune-related thyroiditis (irT), an immune-related adverse event (irAE), affects up to 30% of patients. We aimed to determine whether irT is associated with overall survival in mRCC. A retrospective cohort study of 123 consecutive patients treated with CPI for mRCC in a single center between 2015 and 2020 was conducted. Disease risk stratification was assessed by two methods: Heng criteria and a novel dichotomic stratification system to "Low risk" versus "High risk" adding number of metastatic sites. Thirty-eight percent of patients developed irT. In the general cohort, irT was not associated with a survival benefit. However, irT was associated with better survival in the poor risk group per Heng criteria (n = 17, HR = 0.25, p = 0.04) and in the novel "High risk" group (HR = 0.28, n = 42, p = 0.01), including after accounting for covariates in multivariate analysis (HR = 0.27, p = 0.003). Having any irAE was associated with improved survival in the whole cohort, with no significant correlation of any specific irAE, in either the whole cohort or the "High risk" group. We conclude that irT is an early and prevalent irAE, associated with prolonged survival in patients with poor/"High" risk mRCC.

Liquid First Is "Solid" in Naïve Non-Small Cell Lung Cancer Patients: Faster Turnaround Time With High Concordance to Solid Next-Generation Sequencing.

Purpose: Molecular profiling is crucial in naïve non-small cell lung cancer (NSCLC). While tissue-based analysis is challenged by turnaround time and scarcity of tissue, there is increasing demand for liquid biopsy. We aimed to analyze the use of upfront liquid biopsy as a molecular profiling approach. Methods: This retrospective multicenter, non-interventional study compared findings and turnaround times of liquid vs. standard-of-care (SOC) tissue-biopsy molecular profiling. The study included naïve advanced NSCLC patients with available liquid biopsy (Guardant360 CDx). Results: A total of 42 consecutive patients (60% men; median age, 69.5 [39-87] years; 86% stage IV NSCLC) were identified between September 2017 and December 2020. Liquid-biopsy analysis provided results for all 42 patients, whereas the tissue-based analysis failed in 5 (12%) patients due to insufficient tumor samples. In 17 patients, 18 actionable driver mutations were identified. Eleven mutations were detected by both approaches (i.e., concordance of 61%), 4 only by liquid biopsy and 3 only by tissue biopsy. The median time from the molecular request to receiving the molecular solid report on the last biomarker was 21 (range: 5-66) days, whereas the median time from blood draw to the liquid-biopsy results was 10.5 (7-19) days. The median time between the availability of liquid-biopsy findings and that of the last biomarker was 5 days. Treatment changes following the liquid-biopsy results were observed in 3 (7%) patients. Conclusion: Performing liquid-biopsy upfront is feasible and accurate and allows a shorter time for treatment in NSCLC, especially when tumor tissue is scarce.

Chemoradiation followed by adjuvant durvalumab in stage III non-small cell lung cancer: Real-world comparison of treatment outcomes to historical controls treated with chemoradiation alone.

OBJECTIVE: Compare outcomes in patients with stage III non-small cell lung cancer (NSCLC) treated with chemoradiation and adjuvant durvalumab to historical controls treated with chemoradiation alone. METHODS: The records of patients with stage III NSCLC treated with definitive chemoradiation ± adjuvant durvalumab were reviewed retrospectively. Primary endpoints were progression free survival (PFS), overall survival (OS), and adverse events (AE). RESULTS: Between September 2009 and September 2020, 215 patients were treated with concurrent chemoradiation (n = 144) or concurrent chemoradiation followed by adjuvant durvalumab (n = 71). Compared to historical controls, durvalumab use was associated with improved PFS: median (27 months vs. 10 months, p < 0.0001), 1-year (83.1% vs. 43.8, p < 0.0001); and improved OS; median (not reached vs. 24 months, p < 0.0001), 1-year (85.9% vs. 81.9%, p < 0.0001). Multivariate analysis showed adjuvant durvalumab was associated with increased OS (p = 0.005) and PFS (p = 0.001). Within the durvalumab group, only clinical stage IIIA versus IIIB/C was associated with improved OS (p = 0.049), but not PFS. There was no association between PFS or OS and Eastern Cooperative Oncology Group (ECOG) score, prior history of immune disease, programmed death-ligand 1 (PD-L1) receptor status, delay in starting durvalumab beyond 42 days, or development of an AE. During durvalumab treatment, 63 AE were reported in 52 patients with treatment discontinuation in 11. Pneumonitis was the most common AE reported (n = 35, 49%). Most AE were grade 1-2 (n = 57). Grade 3-4 AE were uncommon (n = 6) and none were grade 5. CONCLUSION: Treatment with adjuvant durvalumab following chemoradiation was associated with improved PFS and OS compared to chemoradiation alone.

Real-world experience with capmatinib in MET exon 14-mutated non-small cell lung cancer (RECAP): a retrospective analysis from an early access program.

Background: Patients with non-small cell lung cancer (NSCLC) presenting with mesenchymal-epithelial transition (MET) exon 14 skipping mutation have an unfavorable prognosis with standard treatments. Capmatinib is a selective MET inhibitor, which showed promising efficacy in this patient population in early trials. Methods: We performed a retrospective, international, multicenter efficacy and safety analysis in patients with NSCLC treated with capmatinib in an early access program between March 2019 and December 2021. Results: Data from 81 patients with advanced MET exon 14 mutated NSCLC treated with capmatinib in first- or later-line therapy were analyzed. Median age was 77 years (range, 48-91), 56% were women, 86% had stage IV disease, and 27% had brain metastases. For all patients, the objective response rate (ORR) to capmatinib was 58% (95% CI, 47-69), whereas it was 68% (95% CI, 50-82) in treatment-naïve and 50% (95% CI, 35-65) in pretreated patients. The median progression-free survival was 9.5 months (95% CI, 4.7-14.3), whereas it was 10.6 months (95% CI, 5.5-15.7) in first-line and 9.1 months (95% CI, 3.1-15.1) in pretreated patients. After a median follow-up of 11.0 months, the median overall survival was 18.2 months (95% CI, 13.2-23.1). In patients with measurable brain metastases (n = 11), the intracranial ORR was 46% (95% CI, 17-77). Capmatinib showed a manageable safety profile. Grade ⩾ 3 treatment-related adverse events included peripheral edema (13%), elevated creatinine (4%), and elevated liver enzymes (3%). Conclusion: In patients with MET exon 14 skipping mutation, capmatinib showed durable systemic and intracranial efficacy and a manageable safety profile. This analysis confirms previously reported phase II data in a real-world setting.

Real World Outcomes and Hepatotoxicity of Infliximab in the Treatment of Steroid-Refractory Immune-Related Adverse Events.

BACKGROUND AND AIMS: Current guidelines state that infliximab is contraindicated for the treatment of immune checkpoint inhibitor-related hepatitis (ir-hepatitis) due to the risk of inducing further liver damage. As this recommendation is largely based on the use of infliximab for rheumatologic diseases, we evaluated the efficacy and hepatotoxicity of infliximab in patients with steroid-refractory immune-related adverse events (irAEs). METHODS: We retrospectively reviewed consecutive patients treated with infliximab for irAEs at Princess Margaret Cancer Centre. To assess hepatotoxicity, we compared the mean value of ALT, AST, and total bilirubin (BT) before and after infliximab treatment. We used logistic regression to assess factors associated with infliximab efficacy. RESULTS: Between January 2010 and February 2019, 56 patients were identified. The median age of the patients was 63 (27-84) years. Colitis was the most frequent toxicity (66%), followed by pneumonitis (11%). Infliximab was used to treat ir-hepatitis in one patient. The median number of infliximab doses was 1 (1-3) and led to toxicity resolution in 43 (76%) patients. The mean ALT, AST, and BT levels before and after infliximab treatment were not statistically different. The patient treated for ir-hepatitis had a complete recovery, with no incremental liver toxicity. CONCLUSIONS: In this dose-limited setting, infliximab was effective in resolving irAEs and did not induce hepatotoxicity.

Genomic Landscape of Malignant Peripheral Nerve Sheath Tumor‒Like Melanoma.

Malignant peripheral nerve sheath tumor (MPNST)-like melanoma is a rare malignancy with overlapping characteristics of both neural sarcoma and melanoma. Although the genomics of cutaneous melanoma has been extensively studied, those of MPNST-like melanoma have not. To characterize the genomic landscape of MPNST-like melanoma, we performed a single-center, retrospective cohort study at a tertiary academic cancer center. Consecutive patients with a confirmed histologic diagnosis of MPNST-like melanoma were screened, and those whose tissues were locally available were included in this analysis. Archival tissue from six patients (eight samples) was submitted for whole-exome and transcriptome sequencing analysis. We compared these data with available genomic studies of cutaneous melanoma and MPNST. NF1 was altered (mutated, deleted, or amplified) in 67% of patients. Genes related to cell cycle regulation were frequently altered, with frequent deletion of ZNF331, which, to the best of our knowledge, has not been previously described in cutaneous melanoma. The serine protease inhibitor SERPINB4 was deleted in 100% of the patients. We show that MPNST-like melanoma presents overlapping genomic features with cutaneous melanoma and MPNST, but it is unique by the frequency of loss of function of ZNF331 and SERPINB4.

Cancer Patient-Reported Preferences and Knowledge for Liquid Biopsies and Blood Biomarkers at a Comprehensive Cancer Center.

BACKGROUND: Blood-based biomarkers (liquid biopsy) are increasingly used in precision oncology. Yet, little is known about cancer patients' perspectives in clinical practice. We explored patients' depth of preferences for liquid vs tissue biopsies and knowledge regarding the role of blood biomarkers on their cancer. METHODS: Three interviewer-administered trade-off scenarios and a 54-item self-administered questionnaire were completed by cancer outpatients across all disease sites at the Princess Margaret Cancer Centre. RESULTS: Of 413 patients, 54% were female; median age was 61 (range 18-101) years. In trade-off scenario preference testing, 90% (n=372) preferred liquid over tissue biopsy at baseline; when wait times for their preferred test were increased from 2 weeks, patients tolerated an additional mean of 1.8 weeks (SD 2.1) for liquid biopsy before switching to tissue biopsy (with wait time 2 weeks). Patients also tolerated a 6.2% decrease (SD 8.8) in the chance that their preferred test would conclusively determine optimal treatment before switching from the baseline of 80%. 216 patients (58%) preferred liquid biopsy even with no chance of adverse events from tissue biopsy. Patients' knowledge of blood-based biomarkers related to their cancer was low (mean 23%); however, the majority viewed development of blood biomarkers as important. CONCLUSION: Patients had limited understanding of cancer-specific blood-based biomarkers, but 90% preferred liquid over tissue biopsies to assess biomarkers. There was little tolerance to wait longer for results, or for decreased test-conclusiveness. Developing accurate, low-risk tests for cancer diagnosis and management for blood biomarkers is therefore desirable to patients.

RET Fusion Lung Carcinoma: Response to Therapy and Clinical Features in a Case Series of 14 Patients.

BACKGROUND: RET (rearranged during transfection) fusions have been reported in 1% to 2% of lung adenocarcinoma (LADC) cases. In contrast, KIF5B-RET and CCDC6-RET fusion genes have been identified in 70% to 90% and 10% to 25% of tumors, respectively. The natural history and management of RET-rearranged LADC are still being delineated. MATERIALS AND METHODS: We present a series of 14 patients with RET-rearranged LADC. The response to therapy was assessed by the clinical response and an avatar model in 2 cases. Patients underwent chemotherapy, targeted therapy, and immunotherapy. RESULTS: A total of 14 patients (8 women; 10 never smokers; 4 light smokers; mean age, 57 years) were included. KIF5B-RET and CCDC6-RET variants were diagnosed in 10 and 4 cases, respectively. Eight patients had an early disseminated manifestation, seven with KIF5B-RET rearranged tumor. The features of this subset included bilateral miliary lung metastases, bone metastases, and unusual early visceral abdominal involvement. One such patient demonstrated an early and durable complete response to cabozantinib for 7 months. Another 2 patients treated with cabozantinib experienced a partial response, with rapid significant clinical improvement. Four patients with tumors harboring CCDC6-RET and KIF5B-RET fusions showed pronounced and durable responses to platinum-based chemotherapy that lasted for 8 to 15 months. Two patients' tumors showed programmed cell death ligand 1-positive staining but did not respond to pembrolizumab. The median overall survival was 22.8 months. CONCLUSION: RET-rearranged LADC in our series tended to occur as bilateral disease with early visceral involvement, especially with KIF5B fusion. Treatment with cabozantinib achieved responses, including 1 complete response. However, further studies are required in this group of patients.

Serum thymidine kinase 1 activity in the prognosis and monitoring of chemotherapy in lung cancer patients: a brief report.

INTRODUCTION: Thymidine kinase 1 (TK1) is a metabolic enzyme involved in DNA synthesis. Most standard treatment protocols for lung cancer (LC) include cytotoxic agents, which are potential modulators of TK1. We aimed to assess the prognostic significance of serum TK1 activity and its role in monitoring chemotherapy in LC patients. METHODS: TK1 activity was measured using the DiviTum (Biovica) assay in sera from 233 patients with non-small-cell lung cancer (NSCLC), 91 with small-cell lung cancer (SCLC), and 90 with benign lung disease. RESULTS: TK1 activity was significantly associated with age, performance status, and stage in NSCLC and with stage and weight loss in SCLC. In multivariate analysis, pretreatment TK1 activity, adjusted for performance status, stage, and weight loss, independently affected survival in NSCLC (relative risk =1.45, p = 0.031) and SCLC (relative risk = 2.49, p = 0.001). In NSCLC patients, adjusted elevated TK1 activity (>100 Du/L) at pretreatment was a significant predictor of treatment failure (odds ratio = 2.55, p = 0.01). A small (less than twofold) increase in TK1 activity after the first and second cycle of chemotherapy was significantly associated with treatment failure and poor overall survival. CONCLUSIONS: Elevated pretreatment serum TK1 activity was an independent, adverse prognostic factor, based on survival, in the two main histological types of LC. A small (less than twofold) increase in TK1 activity after the first and second cycle of chemotherapy was associated with treatment failure and poor overall survival.