Prenatal features of congenital peribronchial myofibroblastic tumor.

Here, we report a case of a congenital peribronchial myofibroblastic tumor (CPMT). A 34-year-old primigravida was referred to our hospital at 31 gestation weeks because of suspected congenital pulmonary airway malformation (CPAM). Fetal ultrasonography showed a mass measuring 4.6 × 4.0 × 3.9 cm with mixed high and low echogenicity in the left lung, which was associated with microvascular blood flow in the tumor. Fetal magnetic resonance imaging (MRI) revealed a low-intensity left lobe lung lesion on a T2-weighted image. These findings suggested that the mass was a CPAM with atypical hypointense findings on MRI T2-weighted images or a rare primary pulmonary tumor, such as a CPMT. Unfortunately, the fetus died in utero at 34 gestation weeks due to cardiovascular failure, which could have resulted from direct encasement of the great vessels or cardiac compression due to rapid tumor growth. The autopsy findings confirmed the diagnosis of CPMT. Primary pulmonary tumors, such as CPMT, are extremely rare lung diseases that develop in utero. These tumors often rapidly grow during pregnancy, resulting in intrauterine fetal death. However, if the patient survives surgical mass resection, the prognosis is good. Given the adverse outcomes observed in our case, careful fetal monitoring is required in case of suspected CPMT during the third trimester of pregnancy. Moreover, in case the well-being of the fetus cannot be assured, immediate delivery should be considered, even in the preterm period, followed by surgery.

Real-world data on the comprehensive genetic profiling test for Japanese patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: comprehensive genomic profiling test has been covered by Japanese health insurance since June 2019. However, no real-world data on the test have been reported with a focus on Japanese patients with prostate cancer. METHODS: we retrospectively reviewed the data of 45 consecutive patients with metastatic castration-resistant prostate cancer, who underwent the comprehensive genomic profiling tests at Kitasato University Hospital between August 2019 and December 2022. Patients' characteristics, prevalence of gene alterations and therapeutic impact of genotype-matched therapy were assessed. RESULTS: genomic data were obtained using a tissue-based test (n = 32) and liquid-based test (n = 13). Actionable genomic alternations were identified in 51.1% of patients, and 22.2% were treated with genotype-matched therapy. The main reason for not receiving genotype-matched therapy was disease progression, accounting for 46.2% (6/13). Kaplan-Meier analysis showed significantly longer overall survival after the comprehensive genomic profiling tests in patients with genotype-matched therapy under public insurance (17.8%, n = 8) than those without it (median: not reached vs. 18.1 months; P = 0.003). Five (62.5%) out of the eight patients with genotype-matched therapy under public insurance had BRCA1 or 2 deleterious alteration. Multivariate analyses showed that BRCA deleterious alteration (17.8%, n = 8) was an independent risk factor for shorter time to castration-resistant prostate cancer (hazard ratio: 2.46, 95% confidence interval: 1.04-5.87; P = 0.041), and no patients with the alteration had ≤5 bone metastases. CONCLUSIONS: the results of this study showed the promising survival outcomes in patients with genotype-matched therapy under public insurance, even in the castration-resistant prostate cancer setting. Further detection of promising therapeutic target gene is expected to increase the number of patients who reach genotype-matched therapies.

Efficacy of endoscopic ultrasound-guided tissue acquisition using stereo-microscopic on-site evaluation for possible comprehensive genome profile in patients with advanced pancreatic cancer.

BACKGROUND AND AIM: Stereomicroscopic on-site evaluation (SOSE) is a rapid evaluation method for endoscopic ultrasound-guided tissue acquisition (EUS-TA) with a high diagnostic sensitivity when the stereomicroscopically visible white core (SVWC) cut-off value (≥ 11 mm) is met. We prospectively examined the association between SVWCs and the adequacy of tissue specimens, assuming subsequent comprehensive genome profiling (CGP). METHODS: This study included 66 consecutive patients with suspected unresectable pancreatic cancer who underwent EUS-TA. The primary endpoint was the frequency of combined samples with ≥ 20% tumor cell content that met over twice the SVWC (T-SVWC) cut-off value, achieved through multiple punctures. The secondary endpoints were the number of punctures, the percentage of SVWC cut-off values, adverse events, the positive diagnosis rate, and the tissue section area. RESULTS: The median number of EUS-TA punctures for suspected unresectable pancreatic cancer was 3 (range, 3-4); SVWC and T-SVWC cut-off values were obtained in 171/206 specimens and 65/66 patients, respectively. There were no EUS-TA-related adverse events. The positive diagnosis rate of EUS-TA was 95.5%. Among the 63 patients meeting the T-SVWC cut-off value in pathological diagnoses, the median tumor cell content was 40% (range, 5-80%), with 57 patients having tumor cell content ≥ 20%. The median tissue section area was 15 (range, 3-40) mm2. CONCLUSIONS: When performing EUS-TA for unresectable pancreatic cancer with the intention of subsequent CGP, obtaining a high tumor cell content (≥ 20%) by assessing the T-SVWC cut-off value via SOSE may serve as a novel indicator for on-site estimation of CGP suitability for EUS-TA specimens.

[Organizing Pneumonia with Difficult Differentiation from Lung Cancer:Report of a Case].

A 72-year-old woman underwent a close examination because of chest computed tomography (CT) scan revealed a nodule in the left lower lobe of the lung. Positron emission tomography( PET) showed strong accumulation of fluorodeoxyglucose (FDG) in the lesion. Since lung cancer was strongly suspected, video-assisted thoracoscopic lung biopsy was performed. The lesion was diagnosed as organizing pneumonia by pathology. PET is widely used to distinguish between benign and malignant lung nodules, but FDG accumulation can also be seen in benign diseases such as inflammatory lesions. Abnormal accumulation can also be seen in organizing pneumonia, but strong FDG accumulation such as in this case is relatively rare, and it was difficult to distinguish it from lung cancer.

A Strategic Translational Research System for Drug Discovery in Tottori University.

The probability of successful drug discovery is declining, and research and development costs are increasing. To solve these problems, pharmaceutical companies tend to in-license seeds from venture companies and academia. Therefore, academia's role in drug discovery is extremely important. Tottori University started a "Next-Generation Research Support Project (Strategic Research Support Project)" in 2020, developing a translational research system to promote drug discovery. In this project, we established a research and development infrastructure, such as seed registration, construction of drug research and development support, and research fund allocation. The registered seed were converted into project, and the project implemented this research and development system, and evaluated and verified its results. Twenty-two seeds were converted into projects and portfolios were constructed. Research funds were allocated to eight prioritized projects. Each project raised the research and development stages. From the overall portfolio, one project with the Japan Agency for Medical Research and Development (AMED) Drug Discovery Booster Project, and three projects with Seeds A of the AMED Translational Research Strategic Promotion Program were adopted. Additionally, a new low-molecular weight chaperone drug against GM1-gangliosidosis was out-licensed to an overseas pharmaceutical company. The strength of this system was the strategic allocation of research funds and the accompanying support that leveraged internal and external resources with the PM and researchers at its core. This system achieved certain results in promoting drug discovery; however, resource optimization of specialized personnel needs to be strengthened in the future. In this report, we summarized the efforts of translational research in Japan and around the world. In addition, the translational research efforts of Japanese academia and Tottori University were compared and the current status was summarized.

Pancreatic Cancer Cells May Adhere to the External Surface of the Puncture Needle After Endoscopic Ultrasound-Guided Fine-Needle Aspiration.

OBJECTIVE: We prospectively investigated whether cells derived from pancreatic cancers adhered to the puncture needle's external surface after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and whether wiping the needle with alcohol swabs removed residual cancer cells. METHODS: The participants were 100 consecutive patients who underwent EUS-FNA for suspected pancreatic ductal adenocarcinoma. In the first pass of EUS-FNA, we prepared aspiration and lavage cytological diagnosis materials from the lumen and external surface of the puncture needle, respectively. This was repeated in the second pass, although the needle's external surface was wiped with an alcohol swab. RESULTS: The positivity rates of aspiration cytological diagnosis for the first and second passes were 67% and 72%, respectively. The positivity rates of lavage cytological diagnosis of the needle's external surface on the first and second passes were 20% and 3%, respectively. Wiping the needle's external surface with alcohol swabs significantly reduced the proportion of cancer cells detected ( P < 0.001). The accuracy rate based on all the collected specimens was 90%. There were no EUS-FNA-related adverse events. CONCLUSION: Pancreatic cancer cells may adhere to the puncture needle's external surface after EUS-FNA. Wiping the needle with alcohol swabs after each puncture effectively removes residual cancer cells.

Utility of a rapid assay for prostaglandin E-major urinary metabolite as a biomarker in pediatric ulcerative colitis.

Prostaglandin E-major urinary metabolite (PGE-MUM) is a urinary biomarker reflecting ulcerative colitis (UC) activity. This prospective observational study aimed to evaluate the usefulness of PGE-MUM via rapid chemiluminescent enzyme immunoassay in detecting endoscopic remission (ER) and histologic remission (HR) in pediatric UC (6-16 years) in comparison with fecal calprotectin (FCP). ER and HR were defined as Mayo endoscopic score (MES) of 0 and Matts' histological grades (Matts) of 1 or 2, respectively. A total of 104 UC and 39 functional gastrointestinal disorder (FGID) were analyzed. PGE-MUM levels were significantly higher in the UC group than in the FGID group (P < 0.001). FCP levels were significantly elevated in the group without ER and HR than in the group with ER and HR (P < 0.001 and P = 0.001), whereas PGE-MUM levels were significantly higher in the group without ER compared to the group with ER (P < 0.001). No significant differences were noted in the AUCs for PGE-MUM and FCP in detecting ER and HR. Although PGE-MUM was inferior to FCP for the detection of HR, it might have the potential for application as a biomarker of endoscopic activity in pediatric UC owing to its noninvasive and rapid method.

[Pulmonary Tumorlet Associated with Atypical Mycobacterium].

A 55-year-old woman was referred to our department for further examination for chest abnormal shadow in the right lower lobe. Chest computed tomography (CT) showed two nodules in the right lower lobe and positron emission tomography( PET)-CT showed abnormal accumulation of fluorodeoxyglucose (FDG) only in the main lesion. Because of lung cancer could not be denied, she underwent a partial resection of the right lower lobe. The main lesion was diagnosed as granuloma and the other was tumorlet by pathology. Although pulmonary tumorlet is considered a proliferation of neuroendocrine cells rather than a neoplastic lesion, it is sometimes difficult to distinguish it from a neoplastic lesion because its histologic morphology resembles carcinoid or small cell carcinoma.

[Pneumothorax with Birt-Hogg-Dubé Syndrome Diagnosed by Family History:Report of a Case].

Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal and predominantly inherited disorder. A 43 year-old woman was admitted to our hospital for right spontaneous pneumothorax and the thoracoscopic pulumonary wedge resection was performed. A chest computed tomography (CT) scan before surgery showed multiple bilatetal thin walled pulmonary cysts predominant to the lower mediastinum side of the lung field. Since her brother had history of pneumothorax with BHD syndrome. Diagnosed by deoxyribonucleic acid (DNA) sequence analysis of his BHD gene, she was diagnosed as BHD syndrome.

[Clinical Outcome of Microsatellite Instability-High Patients Treated with Pembrolizumab and Genetic Counseling].

Prospective studies have demonstrated the efficacy of pembrolizumab in patients with previously treated unresectable or metastatic microsatellite instability-high(MSI-H)cancers. Pembrolizumab has been covered by the Japanese health insurance system since December 2018. The frequency of MSI-H in patients is as low as approximately 2%. In addition, some patients with MSI-H cancers are diagnosed with Lynch syndrome. In the present study, we retrospectively investigated patients who received MSI testing at Kitasato University Hospital from April 2019 to June 2020. We also investigated the therapeutic effect of pembrolizumab for MSI-H cancers and patients who received genetic counseling for Lynch syndrome. Results identified that 5 out of 263 patients who underwent MSI testing(1.9%)had MSI-H. The therapeutic outcomes of pembrolizumab in those patients were as follows: 1(20%)complete response, 3(60%)partial response, and 1(20%) progressive disease. The positive-outcome rate of MSI-H treatment in our institution was comparable to that in the previous reports. The high response rate of pembrolizumab was confirmed in the present study. Four out of 5 patients received genetic counseling at the genetic clinic, and 1 patient underwent genetic testing for Lynch syndrome. No deleterious variant of Lynch syndrome was detected in the genetic testing.

[Postoperative Recurrent Lung Cancer Successfully Treated with Alternate Day Administration of Gefitinib].

A 57-year-old man was referred to our department for further examination for chest abnormal shadow in the right upper lobe. Positron emission tomography (PET)-computed tomography (CT) showed abnormal accumulation of fluorodeoxyglucose (FDG). Because of lung cancer could not be denied, he underwent right upper lobectomy and the nodule was diagnosed as adenocarcinoma by pathology. A chest CT performed one and a half years after surgery showed multiple lung nodules and was diagnosed as recurrence. Since the deletion mutation of exon19 was confirmed in the epidermal growth factor receptor( EGFR) gene mutation analysis, gefitinib( 250 mg/day) daily administration was started. Multiple lung nodules were almost banished promptly, but severe skin rash developed, so gefitinib administration was reduced to 250 mg/every second day and the skin rush disappeared. In spite of reduced dose antitumor effect was maintained for two years without recurrence of skin rash.

Clinicopathological features of PD-L1 protein expression, EBV positivity, and MSI status in patients with advanced gastric and esophagogastric junction adenocarcinoma in Japan.

This real-world study examined the prevalence of programmed death ligand-1 (PD-L1) expression and assessed the frequency of microsatellite instability-high (MSI-H) status and Epstein-Barr virus (EBV) positivity in Japanese patients with advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma. This multicenter (5 sites), retrospective, observational study (November 2018-March 2019) evaluated Japanese patients with advanced gastric and GEJ adenocarcinoma after surgical resection (Stage II/III at initial diagnosis) or unresectable advanced cancer (Stage IV). The primary objectives were prevalence of PD-L1 expression (combined positive score [CPS] ≥1), MSI status, and EBV positivity. Tumor specimens of 389/391 patients were analyzed (male, 67.1%; mean age, 67.6 ± 12.2 years); 241/389 (62%) were PD-L1 positive, 24/379 (6.3%) had MSI-H tumors, and 13/389 (3.3%) were EBV positive. PD-L1 expression was higher in tumor-infiltrating immune cells than in tumor cells for lower CPS cutoffs. Among patients with MSI-H tumors and EBV-positive tumors, 19/24 (79.2%) and 9/13 (69.2%), respectively, were PD-L1 positive. A greater proportion of patients with MSI-H tumors (83.3% [20/24]) were PD-L1 positive than those with MSI-low/stable tumors (60.8% [216/355]; p = .0297); similarly, an association was observed between history of H pylori infection and PD-L1 expression. A higher proportion of patients with MSI-H tumors demonstrated PD-L1 expression with a CPS ≥10 (66.7% [16/24]) vs those with MSI-low/stable tumors (24.8% [88/355]; p < .0001). The prevalence of PD-L1 positivity among Japanese patients was comparable to that in previous pembrolizumab clinical trials and studies in gastric cancer. Particularly, higher PD-L1 expression was observed in MSI-H tumors.

Preoperative Chemoradiotherapy plus Nivolumab before Surgery in Patients with Microsatellite Stable and Microsatellite Instability-High Locally Advanced Rectal Cancer.

PURPOSE: Preoperative chemoradiotherapy (CRT) and surgical resection are the standard treatment for locally advanced rectal cancer (LARC). Combining immune checkpoint inhibitors with radiation suggests a promising approach for enhancing efficacy. We investigated the efficacy of CRT followed by nivolumab and surgery in patients with LARC. PATIENTS AND METHODS: In phase I, we investigated the feasibility of sequentially combined CRT, 5 cycles of nivolumab, and radical surgery. In phase II, patients with microsatellite stable (MSS) and microsatellite instability-high (MSI-H) LARC were evaluated. RESULTS: Three patients in phase I received full courses of CRT and nivolumab without dose modification; the schedule was recommended for phase II. A pathologic complete response (pCR) was centrally confirmed in 30% [11/37; 90% confidence interval (CI), 18%-44%] and 60% (3/5) of the MSS and exploratory MSI-H cohorts, respectively. While immune-related severe adverse events were observed in 3 patients, no treatment-related deaths were observed. In 38 patients with MSS who underwent surgery, pCR rates of 75% (6/8) and 17% (5/30; P = 0.004, Fisher exact test) were observed in those with programmed cell death ligand 1 (PD-L1) tumor proportion score ≥1% and <1%, respectively; IHC staining was performed using pre-CRT samples. In 24 patients with MSS, pre-CRT samples were analyzed by flow cytometry; pCR rates of 78% (7/9) and 13% (2/15; P = 0.003, Fisher exact test) were observed for CD8+ T cell/effector regulatory T cell (CD8/eTreg) ratios of ≥2.5 and <2.5, respectively, in tumor-infiltrating lymphocytes. CONCLUSIONS: CRT followed by consolidation nivolumab could increase pCR. PD-L1 expression and an elevated CD8/eTreg ratio were positive predictors in patients with MSS LARC.

Cytology Reporting System for Lung Cancer from the Japan Lung Cancer Society and the Japanese Society of Clinical Cytology: An Extensive Study Containing More Benign Lesions.

INTRODUCTION: The Japan Lung Cancer Society (JLCS) and the Japanese Society of Clinical Cytology (JSCC) have proposed a new four-tiered cytology reporting system for lung carcinoma (JLCS-JSCC system). Prior to the proposal, the Papanicolaou Society of Cytopathology (PSC) had proposed a revised reporting system (PSC system), which comprises the "neoplastic, benign neoplasm, and low-grade carcinoma" category (N-B-LG category), in addition to the 4 categories of the JLCS-JSCC system. This study aimed to evaluate the interobserver agreement of the JLCS-JSCC system with an additional dataset with more benign lesions in comparison with the PSC system. METHODS: We analyzed 167 cytological samples, which included 17 benign lesions, obtained from the respiratory system. Seven observers classified these cases into each category by reviewing one Papanicolaou-stained slide per case according to the JLCS-JSCC system and PSC system. RESULTS: The interobserver agreement was moderate in the JLCS-JSCC (k = 0.499) and PSC (k = 0.485) systems. Of the 167 samples, 17 samples were benign lesions: 7 pulmonary hamartomas, 5 sclerosing pneumocytomas, 2 squamous papillomas, one solitary fibrous tumor, one meningioma, and one lymphocytic proliferation. There were diverse sample types as follows: 11 touch smears, 3 brushing smears, 2 aspirations, and one sputum sample. Fourteen samples (82.3%) were categorized into "negative" or "atypical" by more than half of the observers in the JLCS-JSCC system. Conversely, 3 samples were categorized as "suspicious" or "malignant" by more than half of the observers in the JLCS-JSCC system. On the other hand, 11 samples (64.7%) were categorized into the N-B-LG category by more than half of the observers in the PSC system. CONCLUSIONS: The concordance rate in the JLCS-JSCC system was slightly higher than that in the PSC system; however, the interobserver agreement was moderate in both the JLCS-JSCC and PSC systems. These results indicate that both the JLCS-JSCC and PSC systems are clinically useful. Therefore, both systems are expected to have clinical applications. It may be important to integrate the 2 systems and construct a universal system that can be used more widely in clinical practice.

Endoscopic submucosal dissection of cervical esophageal cancer with hypopharyngeal invasion using a curved laryngoscope.

Video 1Video describing the clinical course of this case, the endoscopic treatment method, and the histopathologic results.

[Rheumatoid Lung Nodule could be Diagnosed by Pulmonary Biopsy:Report of a Case].

A 60-year-old woman was referred to our department for further examination for chest abnormal shadow in the right upper lobe. She had a past history of rheumatoid arthritis. Positron emission tomography-computed tomography (PET-CT) showed mild abnormal accumulation of fluorodeoxyglucose (FDG). Because of lung cancer could not be denied, she underwent partial resection of the right upper lobe and the nodule was diagnosed as a rheumatoid nodule by pathology.

Maintenance Therapy With Bortezomib and Dexamethasone for Transplant-ineligible Patients With Multiple Myeloma.

Background/Aim: Here, we investigated whether bortezomib as a maintenance therapy affected outcomes in transplant-ineligible patients with multiple myeloma (MM). Patients and Methods: Following induction therapy with bortezomib, maintenance therapy with bortezomib (1.3 mg/m 2 ) and dexamethasone (20 mg) was administered once or twice every 4 weeks until disease progression. The endpoints of this study were time to next treatment and overall survival. Results: Seventy-six newly diagnosed, transplant-ineligible patients were treated with a bortezomib-based regimen; 28 discontinued induction therapy, 27 did not receive maintenance therapy after induction therapy (the non-maintenance group), and 21 did (the maintenance group). In the three groups, the median times to the next required treatment were 3, 14, and 37 months, respectively. The 3-year overall survival rates were 55%, 69%, and 85%, respectively. There were no significant differences in patient characteristics between the non-maintenance and maintenance groups, except for poorer estimated glomerular filtration rates in the maintenance group. Conclusion: Bortezomib maintenance therapy may be a useful option for transplant-ineligible patients with MM.

A Case of Synchronous Occurrence of Intracranial Germinoma and Systemic Sarcoidosis.

Although the synchronous occurrence of testicular seminoma and systemic sarcoidosis has been reported, that of intracranial germinoma and systemic sarcoidosis is unknown. A 26-year-old man presented with symptoms of panhypopituitarism and consciousness disturbance. Imaging demonstrated a large nodule in the upper right lung field and swelling of multiple bilateral pulmonary and mediastinal lymph nodes in addition to the bifocal pineal and suprasellar tumors with obstructive hydrocephalus. The pathological diagnosis of the intracranial bifocal tumors was pure germinoma, whereas that of the mediastinal lymph nodes was epithelioid granuloma. Three courses of chemotherapy using carboplatin and etoposide were administered, followed by whole ventricle irradiation. The intracranial tumors completely disappeared, but the lung nodule and mediastinal lymph nodes progressed. Whole-body fluorine-18-fluorodeoxyglucose positron emission tomography demonstrated accumulation in the mediastinal lymphadenopathy, lung masses, and multiple lymph nodes of the whole body. Transbronchial lung biopsy revealed epithelioid granuloma with multinucleated giant cells. In conjunction with the high blood concentration of angiotensin-converting enzyme and soluble interleukin-2 receptor, these findings established a diagnosis of sarcoidosis. This is the first report of synchronous occurrence of intracranial germinoma and sarcoidosis. Such coexistence is extremely rare, but we should mind that sarcoidosis can occur with intracranial germinoma.

Prognostic values of L-type amino acid transporter 1 and CD98hc expression in breast cancer.

AIMS: L-type amino acid transporter 1 (LAT1) is a major Na+-independent neutral amino acid transporter, forming a complex with CD98hc. The aim of this study is to investigate the significance of LAT1 and CD98hc in invasive breast cancer. METHODS: LAT1 and CD98hc expression was immunohistochemically assessed in 280 invasive breast cancers and analysed for association with clinicopathological features. RESULTS: High levels of LAT1 and CD98hc were observed in triple-negative breast cancers (TNBCs) possessing negative immunoreactivity with oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, compared with non-TNBCs (NTNBCs), and were associated with lymph-node metastasis and higher nuclear grade. The high-LAT1-expression group showed a poor prognosis in NTNBC and TNBC, however, high-CD98hc-expression group showed a poor prognosis only in NTNBC. LAT1 and CD98hc expression could be the prognostic factors in univariate analyses, but not in multivariate analyses. Further, we found that invasive tumour components showed higher LAT1 and CD98hc expression than non-invasive tumour components. CONCLUSIONS: LAT1 and CD98hc may possess prognostic values in invasive breast cancer. LAT1 may be linked with cancer cell activities and disease progression in breast cancer.

Method for preservation of DNA stability of liquid-based cytology specimens from a lung adenocarcinoma cell line.

Liquid-based cytology (LBC) specimens of lung adenocarcinoma have the potential to be widely used for genetic analysis. However, formaldehyde contained in some LBC preservation solutions can cause DNA fragmentation during specimen storage, rendering the samples unsuitable for molecular analysis. To investigate a novel preservation technique for improved DNA stability, which was evaluated by mutation analysis of epidermal growth factor receptor (EGFR) gene in human lung adenocarcinoma cell lines. Cells were fixed in CytoRich Red preservation solution. After 30 min of fixation, cells were either stored using the conventional method (suspended in preservation solution) or washed in phosphate-buffered saline and stored as a cell pellet (newly proposed method). The effect of storage was evaluated after 5, 7, and 9 days of storage at ambient temperature. The cell pellet group was also tested after 14 and 28 days. Specifically, we evaluated the DNA stability, DNA yield, and sample suitability for polymerase chain reaction (PCR), and EGFR mutation detection. The DNA yields and degree of stability from the cell pellet group were higher than those from the suspension group at every time point examined. PCR amplification from the cell pellet group was successful up to day 28. Mutation detection using the Cycleave PCR method indicated that the Ct values of the cell pellet group were significantly lower than those of the suspension group. Storing LBC specimens as a cell pellet post-fixation can maintain the DNA quality for a longer period than the conventional method, making it a promising strategy for molecular analysis.