Real-world evidence of efficacy of pembrolizumab plus chemotherapy and nivolumab plus ipilimumab plus chemotherapy as initial treatment for advanced non-small cell lung cancer.

BACKGROUND: For advanced non-small cell lung cancer (NSCLC), combination therapies including a PD-1 inhibitor plus chemotherapy or a PD-1 inhibitor, CTLA-4 inhibitor, and chemotherapy are standard first-line options. However, data directly comparing these regimens are lacking. This study compared the efficacy of pembrolizumab plus chemotherapy (CP) against nivolumab plus ipilimumab and chemotherapy (CNI) in a real-world setting. METHODS: In this multicenter retrospective study, we compared the efficacy and safety of CP and CNI as first-line therapies in 182 patients with stage IIIB-IV NSCLC. Primary outcomes were overall survival (OS) and progression-free survival (PFS), while secondary outcomes included the response rate (RR) and safety profiles. Kaplan-Meier survival curves and Cox proportional hazards models were utilized for data analysis, adjusting for confounding factors such as age, gender, and PD-L1 expression. RESULTS: In this study, 160 patients received CP, while 22 received CNI. The CP group was associated with significantly better PFS than the CNI group (median 11.7 vs. 6.6 months, HR 0.56, p = 0.03). This PFS advantage persisted after propensity score matching to adjust for imbalances. No significant OS differences were observed. Grade 3-4 adverse events occurred comparably, but immune-related adverse events were numerically more frequent in the CNI group. CONCLUSIONS: In real-world practice, CP demonstrated superior PFS compared with CNI. These findings can inform treatment selection in advanced NSCLC.

Tailoring Therapeutic Strategies in Non-Small-Cell Lung Cancer: The Role of Genetic Mutations and Programmed Death Ligand-1 Expression in Survival Outcomes.

BACKGROUND: This study aims to assess the real-world impact of advancements in first-line systemic therapies for non-small-cell lung cancer (NSCLC), focusing on the role of driver gene mutations and programmed death-ligand 1 (PD-L1) expression levels. METHODS: Conducted across eight medical facilities in Japan, this multicenter, retrospective observational research included 863 patients diagnosed with NSCLC and treated between January 2015 and December 2022. The patients were categorized based on the type of systemic therapy received: cytotoxic agents, molecular targeting agents, immune checkpoint inhibitors, and combination therapies. Comprehensive molecular and immunohistochemical analyses were conducted, and statistical evaluations were performed. RESULTS: The median overall survival (OS) shows significant variations among treatment groups, with targeted therapies demonstrating the longest OS. This study also revealed that high PD-L1 expression was common in the group treated with immune checkpoint inhibitors. Multivariate analysis was used to identify the type of anticancer drug and the expression of PD-L1 at diagnosis as the impactful variables affecting 5-year OS. CONCLUSIONS: This study underscores the efficacy of targeted therapies and the critical role of comprehensive molecular diagnostics and PD-L1 expression in affecting OS in NSCLC patients, advocating for their integration into routine clinical practice.

Atezolizumab addition to platinum doublet: evaluating survival outcomes for patients with extensive disease small cell lung cancer.

BACKGROUND: The efficacy of adding atezolizumab to the platinum doublet regimen for extensive disease small cell lung cancer (ED-SCLC) remains marginally limited. METHODS: We retrospectively assessed the real-world efficacy and safety of atezolizumab in addition to carboplatin and etoposide (EP + A), versus carboplatin and etoposide (EP) alone in previously untreated ED-SCLC patients. RESULTS: From a total of 99 patients, 46 were assigned to the EP + A group, and 53 to the EP group. No significant difference was observed in progression-free survival between the groups. However, the overall survival (OS) was significantly longer in the EP + A group (20.8 vs 12.1 months; HR: 0.52; p = 0.0127). Patients older than 70 years, male, with performance status 0-1, without liver metastasis, and low levels of C-reactive protein and neutrophil-lymphocyte ratio, experienced longer OS in the EP + A group compared to the EP group. CONCLUSION: The addition of atezolizumab to the platinum doublet regimen significantly extended OS in ED-SCLC patients, particularly among certain subgroups, suggesting its potential value in personalized treatment strategies. Further investigation is warranted to validate these findings.

Comparison of the slow-pull and aspiration methods of endobronchial ultrasound-guided transbronchial needle aspiration for next-generation sequencing-compatible tissue collection in non-small cell lung cancer.

BACKGROUND: Personalized treatment for non-small cell lung cancer (NSCLC) has advanced rapidly, and elucidating the genetic changes that trigger this disease is crucial for appropriate treatment selection. Both slow-pull and aspiration methods of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are accepted methods for collecting samples suitable for next-generation sequencing (NGS) to examine driver gene mutations and translocations in NSCLC. Here, we aimed to determine which of these two methods is superior for obtaining higher-quality samples from patients with NSCLC. METHODS: Seventy-one patients diagnosed with NSCLC via EBUS-TBNA using the slow-pull or aspiration (20-mL negative pressure) methods between July 2019 and September 2022 were included. A total of 203 tissue samples from the 71 patients were fixed in formalin, embedded in paraffin, and mounted on slides. The presence of tissue cores, degree of blood contamination, and number of tumor cells were compared between the groups. The success rate of NGS, using Oncomine Dx Target Test Multi-CDx, was also compared between the groups. RESULTS: The slow-pull method was associated with a higher yield of tissue cores, lower degree of blood contamination, and higher number of tumor cells than the aspiration method. The success rate of the NGS was also significantly higher for the slow-pull group (95%) than for the aspiration group (68%). CONCLUSION: Overall, these findings suggest that the slow-pull method is a superior technique for EBUS-TBNA to obtain high-quality tissue samples for NGS. The slow-pull method may contribute to the identification of driver gene mutations and translocations and facilitate personalized treatment of NSCLC.

Predictors of lung injury during durvalumab maintenance therapy following concurrent chemoradiotherapy in unresectable locally advanced non-small cell lung carcinoma.

BACKGROUND: Based on the results of the PACIFIC trial, maintenance with durvalumab has emerged as the standard treatment following concurrent chemoradiotherapy in patients with unresectable locally advanced non-small cell lung carcinoma (NSCLC). However, adverse events attributed to durvalumab, especially lung injuries, including immune-related adverse events, and radiation pneumonitis, are concerning. This study retrospectively investigated the factors related to lung injury in patients receiving the PACIFIC regimen. METHODS: Patients with unresectable locally advanced NSCLC who received durvalumab maintenance therapy following concurrent chemoradiotherapy at Yokohama City University Medical Centre between July 2018 and March 2022 were included. Clinical data, volume of normal lung receiving 20 or 5 Gy or more (V20 or V5), planning target volume (PTV), and relative lung parenchyma volume in emphysematous lung receiving 20 or 5 Gy or more (RLPV20 or 5; V20 or V5/100-percentage of low-attenuation volume) were evaluated. RESULTS: Performance status (PS), V20, V5, PTV, RLPV20, and RLPV5 were significantly higher in the lung injury group in the univariate analysis. Furthermore, RLPV20 was the most significant factor in the lung injury group in the multivariate analysis comprising PS, PTV, V20, and RLPV20. CONCLUSION: RLPV20 and RLPV5 are useful in estimating lung inflammation. RLPV20 could be considered the most reliable risk factor for maintenance therapy with durvalumab following concurrent chemoradiotherapy in patients with unresectable locally advanced NSCLC.

Thymic atypical carcinoid tumors with elevated mitotic counts in a patient with multiple endocrine neoplasia: A case report.

Thymic neuroendocrine tumors associated with multiple endocrine neoplasia are only defined as carcinoid and are not associated with large-cell neuroendocrine carcinoma (LCNEC). We report the case of a multiple endocrine neoplasia type 1 patient with atypical carcinoid tumors with elevated mitotic counts (AC-h), an intermediate condition between carcinoid and LCNEC. A 27-year-old man underwent surgery for an anterior mediastinal mass and was diagnosed with thymic LCNEC. Fifteen years later, a mass appeared at the same site, which was determined to be a postoperative recurrence based on the pathological results of a needle biopsy and the clinical course. The patient's disease remained stable for 10 months on anti-programmed death-ligand 1 antibody and platinum-containing chemotherapy. The needle biopsy specimen was submitted for next-generation sequencing, which revealed a MEN1 gene mutation, and after further examination, a diagnosis of multiple endocrine neoplasia type 1 was made. A re-examination of the surgical specimen from 15 years prior showed that it corresponded to AC-h. Although thymic AC-h is classified as thymic LCNEC according to the current definition, our data suggests that a search for multiple endocrine neoplasia is warranted in such patients.

Primary tracheal small-cell carcinoma detected 11 months after surgery for pulmonary large-cell neuroendocrine carcinoma: A case report.

Primary tracheal small-cell carcinoma is rare, and is often treated using small-cell lung cancer guidelines given that no standard treatment has been established for it. We report a patient in whom nodules appeared in the trachea and left main bronchus 11 months after surgery for pulmonary large-cell neuroendocrine carcinoma; a biopsy revealed small-cell carcinoma. Given the absence of malignant lesions elsewhere in the body, the lesions were diagnosed as primary tracheal small-cell carcinoma. Respiratory failure progressed rapidly owing to airway stenosis caused by the growing lesion, and the patient required nasal high-flow therapy. However, the lesions shrank a few days after commencing first-line chemotherapy, and his respiratory failure resolved. Accelerated hyperfractionated radiotherapy was administered in conjunction with the third course of chemotherapy, and the patient ultimately achieved a complete response. Although the lesions were initially suspected of being postoperative recurrence of pulmonary large-cell neuroendocrine carcinoma, the fact that the biopsy revealed them to be primary tracheal small-cell carcinoma indicates that intra-airway nodules that appear after lung cancer surgery may possibly be primary tracheal tumors.

Retrospective analysis of independent predictors of progression-free survival in patients with EGFR mutation-positive advanced non-small cell lung cancer receiving first-line osimertinib.

BACKGROUND: Clinically measurable factors affecting the progression-free survival (PFS) of patients receiving osimertinib as first-line therapy for epidermal growth factor receptor (EGFR) mutation-positive advanced non-small cell lung cancer (NSCLC) have not yet been established. METHODS: We retrospectively reviewed the medical records of 61 patients treated with osimertinib as primary therapy for EGFR mutation-positive advanced NSCLC at Yokohama City University Medical Center between August 2018 and March 2022. Our objective was to identify the independent predictors of PFS. RESULTS: The median age of participants was 74 years. Overall, 73.8% had good (0-1) Eastern Cooperative Oncology Group performance status (PS), and 98.4% had histology of adenocarcinoma. The EGFR mutation was exon19 deletion in 52.5% and exon21 L858R in 44.3% of patients. Programmed death-ligand 1 tumor proportion score >50% was observed in 21.3% and liver metastasis in 9.9% of patients. Median PFS was 19.5 months (95% confidence interval [CI]: 10.6-31.6), and overall survival was not reached. The objective response rate was 68.9%, and disease control rate was 93.4%. Multivariate analysis showed that poor PS (2-4) negatively impacted PFS (hazard ratio, 3.79; 95% CI: 1.46-9.87; p = 0.006). Median PFS in the good PS and poor PS groups was 20.4 months (95% CI: 12.4-not evaluable) and 7.2 months (95% CI: 7.2-19.5), respectively. Interstitial lung disease of all grades and grade 3 was observed as an adverse event in 6.6 and 4.9% of patients, respectively. CONCLUSION: Poor PS was associated with poor prognosis in patients with EGFR mutation-positive advanced NSCLC treated with osimertinib as first-line therapy.

Combination of Pembrolizumab With Platinum-containing Chemotherapy for Pulmonary Enteric Adenocarcinoma.

Background/Aim: Pulmonary enteric adeno-carcinoma (PEAC) is a rare type of non-small cell lung cancer (NSCLC), for which no established standard treatment exists. Combination therapy with the anti-programmed cell death protein 1 antibody pembrolizumab and platinum-containing chemotherapy is the standard treatment for NSCLC patients, but its effectiveness in PEAC is uncertain. Case Report: We present a 68-year-old man with chemotherapy-naïve advanced PEAC who responded to a combination of pembrolizumab and platinum-containing chemotherapy. Conclusion: The number of PEAC cases is small, and no clinical trials have been conducted to determine an optimal chemotherapy regimen. In this case, we showed that pembrolizumab combined with platinum-containing chemotherapy might effectively treat PEAC.

Pembrolizumab monotherapy versus pembrolizumab plus chemotherapy in patients with non-small-cell lung cancer: A multicenter retrospective trial.

BACKGROUND: Pembrolizumab alone or in combination with chemotherapy is a standard treatment for patients with non-small-cell lung cancer (NSCLC) with high programmed death-ligand 1 (PD-L1) expression. However, no study has compared the efficacies of these two regimens. Therefore, we aimed to compare the efficacy of pembrolizumab alone and in combination with chemotherapy in NSCLC patients with high PD-L1 expression. METHODS: We conducted a multicenter retrospective trial involving patients with diagnosed unresectable or recurrent NSCLCs who had received pembrolizumab with or without chemotherapy in the first-line setting. Patients were divided into monotherapy and combination therapy groups. The progression-free survival (PFS), overall survival (OS), and response rate (RR) were analyzed and compared between the groups. Clinical characteristics of patients were analyzed to assess their possible relationship with treatment outcomes. RESULTS: We enrolled 96 patients from five hospitals. Of these, 47 and 49 patients received monotherapy and combination therapy, respectively. The median PFS was 343 and 328 days in the monotherapy and combination therapy groups, respectively (hazard ratio 1.003, p = 0.99). No statistically significant differences were observed in the OS and RR between the two groups. However, in patients with metastases to the liver, lung, adrenal glands, bone, or lymph nodes, the PFS was longer in the monotherapy group than in the combination therapy group. CONCLUSION: Although the PFS, OS, and RR were not significantly different between patients treated with pembrolizumab alone and or with pembrolizumab in combination with chemotherapy, patients with NSCLC having metastases to specific sites may benefit more from monotherapy.

Nivolumab-induced Vogt-Koyanagi-Harada-like Syndrome and Adrenocortical Insufficiency with Long-term Survival in a Patient with Non-small-cell Lung Cancer.

A 58-year-old man was diagnosed with lung adenocarcinoma with a tumor proportion score of 10%. After six cycles of second-line chemotherapy with nivolumab, he achieved a complete response (CR) but developed uveitis and sensorineural hearing disorder, which were consistent with Vogt-Koyanagi-Harada (VKH)-like syndrome. Simultaneously, pituitary adrenocortical insufficiency was identified. Nivolumab discontinuation and systemic corticosteroid administration resolved these immune-related adverse events (irAEs). The patient has maintained a CR without any chemotherapy for approximately two years. We herein report a patient with a long-term progression-free survival despite chemotherapy discontinuation due to irAEs, including VKH-like syndrome, which were appropriately managed.

T-cell response to phytohemagglutinin in the interferon-γ release assay as a potential biomarker for the response to immune checkpoint inhibitors in patients with non-small cell lung cancer.

BACKGROUND: Immune checkpoint inhibitors are a standard treatment for advanced lung cancer, although it remains important to identify biomarkers that can accurately predict treatment response. Immune checkpoint inhibitors enhance the antitumor T-cell response, and interferon-γ plays an important role in this process. Therefore, this study evaluated whether the number of interferon-γ-releasing peripheral T cells after phytohemagglutinin stimulation in the interferon-γ release assay might act as a biomarker for the response of non-small cell lung cancer to immune checkpoint inhibitor treatment. METHODS: Data were retrospectively collected regarding 74 patients with non-small cell lung cancer who had received immune checkpoint inhibitors. Pretreatment screening tests had been performed using the T-SPOT.TB assay, which quantifies the number of interferon-γ-releasing T cells (as immunospots) in response to phytohemagglutinin and tuberculosis-specific antigen stimulation. Clinical factors and the number of spots in the T-SPOT fields were evaluated for associations with patient outcomes. The median number of spots was used to categorize patients as having high or low values, and the two groups were compared. RESULTS: Relative to patients with a low ratio, patients with a high ratio of phytohemagglutinin/tuberculosis-specific antigen spots (i.e. more responsive T cells) had significantly better progression-free survival after immune checkpoint inhibitor treatment. When we only considered patients with negative T-SPOT results, a high number of phytohemagglutinin-stimulated spots corresponded to significantly longer progression-free survival. CONCLUSION: The T-SPOT.TB assay can be used to quantify the number of immunospots in response to antigen stimulation, which may predict the response to immune checkpoint inhibitors in patients with non-small cell lung cancer.

Identification of a novel biomarker based on lymphocyte count, albumin level, and TBAg/PHA ratio for differentiation between active and latent tuberculosis infection in Japan.

Data from China have shown that the ratio of Mycobacterium tuberculosis-specific antigen (TBAg) spots obtained from the T-SPOT.TB test to the number of positive control phytohemagglutinin (PHA) spots (TBAg/PHA ratio) could help distinguish between active tuberculosis infection (ATBI) and latent tuberculosis infection (LTBI). As the applicability of the T-SPOT.TB test may differ according to region and race, we retrospectively verified the utility of the TBAg/PHA ratio in distinguishing between ATBI and LTBI in Japan. The TBAg/PHA ratio was significantly lower in the LTBI group than in the ATBI group. Area under the receiver operating characteristic curve (AUC) analysis between ATBI and LTBI according to the TBAg/PHA ratio was 0.76, with a sensitivity of 65.8% and a specificity of 75.6%. The best AUC was obtained when the TBAg/PHA ratio was divided by both lymphocyte count and albumin levels. Our results demonstrate that, in Japan, the TBAg/PHA ratio is superior to TBAg alone for distinguishing between ATBI and LTBI. In addition, the sensitivity and specificity were improved by combining the TBAg/PHA ratio with lymphocyte count and albumin levels.

MicroRNA-200b is a potential biomarker of the expression of PD-L1 in patients with lung cancer.

BACKGROUND: Advanced non-small cell lung cancer (NSCLC) has a high mortality rate and poor prognosis. However, outcomes have gradually improved after the introduction of novel immunotherapies, including immune checkpoint inhibitors (ICIs). Although programmed death-ligand 1 (PD-L1) expression in tumor tissues is a known biomarker for guiding ICI treatment of NSCLC, challenges such as difficulty of liquid biopsy and heterogeneous results during treatment persist. This study evaluated the potential of miR200b as a surrogate biomarker for PD-L1 expression. METHODS: We used the human lung cancer cell lines H226, H460, H520, A549, and H1975. miR200b expression in blood and bronchoscopy specimens of NSCLC patients was evaluated using reverse-transcription-quantitative PCR. Using flow cytometry, PD-L1 expression in vitro, as well as in tumor tissues, was evaluated after transfection with a mimic miR200b or siRNA. RESULTS: miR200b expression negatively correlated with PD-L1 expression in all cell lines. The induction or knockdown of miR200b also altered PD-L1 expression in vitro. The patient group with a PD-L1 tumor proportion score ≥ 50% had significantly lower miR200b expression in the bronchoscopy specimens (P = 0.025) and serum-derived exosomes (P = 0.022) than that with PD-L1 tumor proportion score < 50%. CONCLUSIONS: miR200b can regulate PD-L1 expression in lung cancer cells, and miR200b expression in clinical specimens negatively correlated with PD-L1 expression. Thus, miR200b may be a useful surrogate biomarker for PD-L1 expression in lung cancer patients. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: High PD-L1 expression was linked to low miR200b expression, whereas low PD-L1 expression was linked to high miR200b expression in human lung cancer patients. Thus, miR200b overexpression or silencing can control PD-L1 expression in cancer cells. What this study adds We demonstrated the potential of miR200b as a surrogate biomarker for PD-L1 expression in lung cancer patients.

Identification of Biomarkers for Non-small-cell Lung Cancer Patients Treated With an Immune Checkpoint Inhibitor.

BACKGROUND/AIM: Immune checkpoint inhibitors (ICIs) have an important role in lung cancer therapy. Although the programmed cell death protein-1 (PD-L1) tumor proportion score (TPS) and tumor mutational burden are known prognostic factors, they are insufficient to predict clinical outcomes. This study was conducted to identify novel biomarkers for ICI treatment. PATIENTS AND METHODS: We performed univariable and multivariable analyses of 110 patients with advanced non-small-cell lung cancer (NSCLC) who were treated with an ICI to identify novel biomarkers related to prognosis. We assessed their backgrounds, such as performance status (PS), PD-L1 TPS, smoking status, and peripheral white blood cell counts at baseline and on the day the second course of ICI administration. RESULTS: In the multivariable analysis, PS, driver gene, immune-related adverse events, and post-treatment absolute neutrophil counts (post-ANCs) were significantly associated with progression-free survival. CONCLUSION: A high level of post-ANCs was associated with poor outcome in ICI-treated NSCLC patients.

Afatinib + bevacizumab combination therapy in EGFR-mutant NSCLC patients with osimertinib resistance: Protocol of an open-label, phase II, multicenter, single-arm trial.

INTRODUCTION: As most patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) develop progressive disease after treatment with osimertinib, it is important to develop more effective treatment options. Afatinib has been shown to be more effective in in vitro studies than osimertinib when used in cancer cell lines containing some specific EGFR mutations. Therefore, afatinib may be an effective solution, especially when used in combination with an anti-VEGF agent such as bevacizumab. METHODS: A phase II multicenter, open-label, single-arm trial has been initiated to evaluate the efficacy and safety of afatinib and bevacizumab combination as salvage therapy for EGFR-mutated lung cancer in patients previously treated with osimertinib. The primary endpoint will be the objective response rate (ORR) and secondary endpoints are progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and adverse events (AEs). DISCUSSION: A previous study indicated that afatinib inhibits lung cancer cells with specific EGFR mutations more effectively than other EGFR-TKIs such as osimertinib. Therefore, we expect that combination therapy using afatinib and bevacizumab will be effective in patients previously treated with osimertinib (registration no. jRCTs031190077).

Class A CpG oligodeoxynucleotide inhibits IFN-γ-induced signaling and apoptosis in lung cancer.

BACKGROUND: Currently, anticancer immunotherapy based on PD-1/PD-L1 blockade with immune checkpoint inhibitors (ICIs) is being used as a standard therapy for non-small cell lung cancer (NSCLC). However, more effective treatments are required as these tumors are often resistant and refractory. Here, we aimed to determine the effects of immunomodulatory oligodeoxynucleotides (ODNs) in terms of the presence or absence of CpG motifs and the number of consecutive guanosines. METHODS: Western blots were used to measure the molecules which regulate the expression of PD-L1 in human lung cancer cell lines after incubation with several cytokines and ODNs. The expression of PD-L1 and ß2-microglobulin (ß2-MG) on A549 cells, and IFN-γ-induced apoptosis with ODNs were examined by flow cytometry. The relationship between IFN-γ receptor and ODN was analyzed by ELISA and immunofluorescence chemistry. RESULTS: Our results verified that A-CpG ODNs suppress the upregulation of IFN-γ-induced PD-L1 and ß2-MG expression. In addition, we found that ODNs with six or more consecutive guanosines (ODNs with poly-G sequences) may competitively inhibit the IFN-γ receptor and abolish the effect of IFN-γ, thereby suppressing apoptosis and indoleamine 2,3-dioxygenase 1 expression in human lung cancer cells. The tumor microenvironment regulates whether this action will promote or suppress tumor immunity. Thus, in immunotherapy with CpG ODNs, it is essential to consider the effect of ODNs with poly-G sequences. CONCLUSIONS: This study suggests that ODNs containing six or more consecutive guanosines may inhibit the binding of IFN-γ to IFN-γ receptor. However, it does not directly show that ODNs containing six or more consecutive guanosines competitively inhibit the IFN-γ receptor, and further studies are warranted to confirm this finding. KEY POINTS: Significant findings of the study: Oligodeoxynucleotides with a contiguous sequence of six or more guanosines may competitively inhibit the IFN-γ receptor and abolish the action of IFN-γ. This may suppress IFN-γ-induced apoptosis and indoleamine-2,3-dioxygenase-1 expression in human lung cancer cells. WHAT THIS STUDY ADDS: A-CpG and poly-G ODN may overcome tolerance if the cause of ICI tolerance is high IDO expression. However, IFN-γ also has the effect of suppressing apoptosis of cancer cells, and it is necessary to identify the cause of resistance.

Reproducibility of the T-SPOT.TB test for screening Mycobacterium tuberculosis infection in Japan.

OBJECTIVES: The interferon-gamma release assay (IGRA) is useful for diagnosing Mycobacterium tuberculosis infections, especially in countries where Bacille Calmette-Guérin vaccinations are performed. However, reproducibility of the IGRA is unclear, as recent data suggest high IGRA conversion and reversion rates in serial tests among healthcare workers. This longitudinal study aimed to evaluate reproducibility of T-SPOT.TB for screening M. tuberculosis infections in Japan. METHODS: Results of T-SPOT.TB tests performed between April 2014 and March 2016 at two hospitals in Yokohama, Japan, where the incidence of tuberculosis was 18.0 per 100,000 population in 2014, were analyzed. RESULTS: In total, 3890 T-SPOT.TB tests were included. Overall, positive and negative test rates were 8.4% and 87.6%, respectively. Among 373 serial tests within two years, conversion and reversion rates were only 1.1% and 12.5%, respectively. Almost all patients who were initially negative (98.9%) remained so. There was no statistically significant difference between the outcomes observed at the two hospitals. CONCLUSIONS: The conversion rate of T-SPOT.TB in Japan is as low as that recently reported in other countries where the incidence of tuberculosis is low. These data indicate that T-SPOT.TB is a reproducible tuberculosis screening tool at local hospitals in areas with a moderate incidence of tuberculosis.