Assessment of Anti-tumor Efficacy of Osimertinib in Non-Small Cell Lung Cancer Patients by Liquid Biopsy Using Bronchoalveolar Lavage Fluid, Plasma, or Pleural Effusion.

PURPOSE: This study was to evaluate anti-tumor efficacy of osimertinib in patients positive for acquired epidermal growth factor receptor (EGFR) T790M mutation in liquid biopsy using plasma, bronchoalveolar lavage fluid (BALF) or bronchial washing fluid (BWF), and pleural effusion. MATERIALS AND METHODS: Among patients benefited from previous EGFR‒tyrosine kinase inhibitor treatment followed by treatment failure, patients in whom T790M mutations are detected in at least one of the samples including tumor tissues, BALF/BWF, plasma, and pleural effusion were enrolled. T790M mutation was detected by extracting cell free DNA from liquid biopsy samples, using PANA Mutyper. Objective response rate (ORR) and progression-free survival (PFS) with osimertinib treatment were evaluated. RESULTS: Between January 2018 and December 2019, 63 patients were enrolled and received osimertinib. Mean age was 63 years, and 38 (60.3%) were female. Twenty-six patients had T790M mutation in both liquid and tissue samples (group A), 19 patients had only in tissue biopsy samples (group B), and 18 patients had T790M mutation only in liquid biopsy samples (group C). ORR in overall population was 63.5%, and was 61.5% in group A, 68.4% in group B, and 61.1% in group C, respectively. Median PFS in overall patients was 15.6 months (95% confidence interval, 10.7 to 24.2). There was no significant difference in ORR or PFS between groups. CONCLUSION: Osimertinib showed favorable efficacy in lung cancer patients with acquired resistance to prior EGFR-TKI therapies, who screened positive for harboring T790M mutation detected from cell free DNA extracted from plasma, BALF/BWF, and pleural effusion.

Efficacy, safety, and resistance profile of osimertinib in T790M mutation-positive non-small cell lung cancer in real-world practice.

The efficacy and safety of osimertinib were demonstrated in clinical trials; however, real-world clinical data, particularly the resistance profile, are limited. Here, we investigated the efficacy, safety, and resistance profile of osimertinib in real-world practice. We reviewed medical records of T790M mutation-positive lung cancer patients who started osimertinib between February 2016 and June 2017. Molecular pathologic data of biopsy samples obtained after acquisition of resistance to osimertinib were also analyzed. The study included 23 patients with a median age of 59 years. The median follow-up duration was 11.9 months (IQR, 4.7-15.8). Objective response was achieved in 17 (73.9%) patients, and the disease was controlled in 22 (95.7%) patients. Median progression-free survival (PFS) was 7.4 months (95% CI, 3.6-11.0). Adverse events were minimal except for one case of pneumonitis. Of 14 patients experiencing disease progression, 10 underwent re-biopsy. The T790M mutation disappeared in seven patients (70%), and one showed wild-type conversion. PFS was shorter in the T790M-loss group than in the T790M-persistent group (4.4 vs. 7.7 months). Two patients with small cell transformation responded well to subsequent chemotherapy. One patient developed a C797S mutation that became undetectable after two cycles of gemcitabine and cisplatin followed by six cycles of pembrolizumab, after which the patient responded well to osimertinib. In conclusion, osimertinib showed favorable efficacy and safety in real-world practice comparable to those observed in clinical trials. Repeat biopsy after the acquisition of resistance to osimertinib is helpful to direct further treatment strategies.

Chest radiography surveillance for lung cancer: Results from a National Health Insurance database in South Korea.

BACKGROUND: Lung cancer screening with low-dose computed tomography reduced mortality in selected high risk patients. However, the use of chest radiography for lung cancer screening in Asian populations is still controversial. We investigated the effectiveness of chest radiographic surveillance using a nationwide health service data in South Korea. METHODS: Data from the Korean National Health Insurance Service examinee cohort of 2004 to 2013 were examined, and 63,228 patients with lung cancer were identified, 38,494 (57%) of whom underwent chest radiography screening. The others did not undergo lung cancer screening and were considered as a control group. Clinical data including age, smoking, screening intervals, lung cancer stages, treatments, and survival were collected. Survival gain from surveillance after adjustment for lead-time bias based on the sojourn time was calculated. Cox-proportional hazard analyses were performed to evaluate the effectiveness of screening and to determine the appropriate screening interval for chest radiography surveillance. RESULTS: Early lung cancer was found in 38% of patients receiving chest radiography versus 26% of those without surveillance. A patient age of more than 65 years (hazard ratio [HR], 1.53; 95% confidence limits [CL], 1.50-1.56), male (HR, 1.66; 95% CL, 1.62-1.70), and high lung cancer stages at the time of diagnosis were independent factors associated with mortality (each, P < 0.001). Chest radiography surveillance was a factor for decreasing mortality in female (HR, 0.81; 95% CL, 0.77-0.84, P < 0.001), with mortality reduction of 10% at the 3- and 5-year survival time-points. In female patients, chest radiography surveillance at intervals of less than 3 years was an independent predictor of improved survival. CONCLUSIONS: Surveillance chest radiography increased survival in a female screened population in South Korea. Chest radiography intervals of less than 3 years may help to detect lung cancer in female patients.

Disseminated Mycobacterium intracellulare Infection in an Immunocompetent Host.

Disseminated Mycobacterium avium complex (MAC) infection can occur in immunocompromised patients, and rarely in immunocompetent subjects. Due to the extensive distribution of the disease, clinical presentation of disseminated MAC may mimic malignancies, and thorough examinations are required in order to make accurate diagnosis. We report a case of disseminated Mycobacterium intracellulare disease in an immunocompetent patient, which involved the lung, lymph nodes, spleen, and multiple bones. F-18 fluorodeoxyglucose positron-emission tomography imaging showed multiple hypermetabolic lesions, which are suggestive of typical hematogenous metastasis. However, there was no evidence of malignancy in serial biopsies, and M. intracellulare was repeatedly cultured from respiratory specimens and bones. Herein, we should know that disseminated infection can occur in the immunocompetent subjects, and it can mimic malignancies.