Factors affecting responsiveness of vadadustat in patients with anemia associated with chronic kidney disease: a post-hoc subgroup analysis of Japanese phase 3 randomized studies.

BACKGROUND: Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor developed for treating anemia in chronic kidney disease (CKD). The purpose of this post-hoc analysis was to investigate the factors affecting the responsiveness to vadadustat in anemia patients with nondialysis-dependent (NDD) or hemodialysis-dependent (HDD) CKD in two Japanese phase 3 studies. METHODS: Of 151 and 162 patients enrolled in NDD-CKD and HDD-CKD studies, 136 and 140 patients, respectively, were included and divided into subgroups for the analysis. To assess vadadustat responsiveness, the resistance index was defined as the mean body weight-adjusted dose of vadadustat (mg/kg) at weeks 20-24 divided by the mean hemoglobin (g/dL) at weeks 20-24. Multivariate analysis was performed to identify the variables affecting the resistance index. RESULTS: Independent factors identified as determinants for better response to vadadustat were as follows: high baseline hemoglobin, low baseline eGFR, high week-20-24 ferritin, and CKD not caused by autoimmune disease/glomerulonephritis/vasculitis in NDD-CKD; and male sex, high baseline C-reactive protein, and low baseline erythropoiesis-stimulating agent resistance index (ERI) in HDD-CKD. CONCLUSIONS: In this post-hoc analysis, several factors were identified as affecting the response to vadadustat. These results may provide useful information leading to an appropriate dose modification for vadadustat. CLINICAL TRIAL REGISTRATION: NCT03329196 (MT-6548-J01) and NCT03439137 (MT-6548-J03).

Cyclin-dependent kinase (CDK) 4/6 inhibition in non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutations.

BACKGROUND: Lung cancer is the leading cause of cancer death worldwide, and EGFR mutation is the most common genetic alteration among Asian patients with lung adenocarcinoma. While osimertinib has been shown to be effective in lung cancer patients with EGFR mutation, the majority of patients eventually develop acquired resistance to treatment. We explored the significance of the cyclin D1 expression in patients with EGFR mutation and the potential efficacy of adding abemaciclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, simultaneously with osimertinib in vitro. MATERIALS AND METHODS: Immunohistochemical staining, using an anti-cyclin D1 antibody, of specimens from 83 patients with EGFR mutation (male, n = 27; pStage 0-I, n = 71) who were treated by surgical resection between 2017 and 2020, and the relationship between the cyclin D1 expression and clinicopathological factors was analyzed. Additionally, the combined effect of osimertinib and abemaciclib in lung cancer cell lines were analyzed using a growth inhibition test, and the signaling pathway underlying the combined effect was investigated. RESULTS: Cyclin D1 was negative in 18.1% of patients with EGFR mutation, and cyclin D1 negativity was associated with pStage ≥ II (p = 0.02), lymph node metastasis (p = 0.001), and lymphatic invasion (p = 0.01). The cyclin D1-negative group had significantly shorter recurrence-free survival (p = 0.02), although this difference disappeared when limited to pN0 patients. In EGFR mutated cell lines, the combination of osimertinib and abemaciclib demonstrated synergistic effects, which were thought to be mediated by the inhibition of AKT phosphorylation. CONCLUSION: Combination therapy with CDK4/6 inhibitors and EGFR-TKIs may be a promising approach.

Enhanced Ca2+ binding to EF-hands through phosphorylation of conserved serine residues activates MpRBOHB and chitin-triggered ROS production.

NADPH oxidases/RBOHs catalyze apoplastic ROS production and act as key signaling nodes, integrating multiple signal transduction pathways regulating plant development and stress responses. Although RBOHs have been suggested to be activated by Ca2+ binding and phosphorylation by various protein kinases, a mechanism linking Ca2+ binding and phosphorylation in the activity regulation remained elusive. Chitin-triggered ROS production required cytosolic Ca2+ elevation and Ca2+ binding to MpRBOHB in a liverwort Marchantia polymorpha. Heterologous expression analysis of truncated variants revealed that a segment of the N-terminal cytosolic region highly conserved among land plant RBOHs encompassing the two EF-hand motifs is essential for the activation of MpRBOHB. Within the conserved regulatory domain, we have identified two Ser residues whose phosphorylation is critical for the activation in planta. Isothermal titration calorimetry analyses revealed that phosphorylation of the two Ser residues increased the Ca2+ binding affinity of MpRBOHB, while Ca2+ binding is indispensable for the activation, even if the two Ser residues are phosphorylated. Our findings shed light on a mechanism through which phosphorylation potentiates the Ca2+ -dependent activation of MpRBOHB, emphasizing the pivotal role of Ca2+ binding in mediating the Ca2+ and phosphorylation-driven activation of MpRBOHB, which is likely to represent a fundamental mechanism conserved among land plant RBOHs.

Acute ischemic colitis with hematochezia related to baloxavir marboxil treatment for influenza A.

Oseltamivir, an established oral anti-influenza medication, increases the risk of ischemic colitis. Baloxavir marboxil is a novel oral anti-influenza medication, and few studies have evaluated its potential side effects, including ischemic colitis. Moreover, as influenza A can also induce ischemic colitis, drug-induced colitis associated with anti-influenza medication is not clearly understood. In this report, we describe the case of a 62-year-old Japanese woman who developed acute ischemic colitis after taking baloxavir for influenza A. The day after taking baloxavir (day 2), the patient experienced abdominal pain, diarrhea, and nausea. On day 3, she had developed hematochezia and decided to visit our hospital. Upon presentation, inflammation of the descending and sigmoid colon was detected by abdominal echography and computed tomography. Fluid replacement therapy and dietary restrictions were initiated. On day 4, the inflammation of the descending colon and marked intestinal edema were confirmed by colonoscopy. She was clinically diagnosed with ischemic colitis, from which she recovered completely by day 9. This case suggests that patients taking baloxavir may be at risk of developing ischemic colitis with hematochezia and underscores the need to further study the induction of this condition by commonly used oral anti-influenza agents.

Acquired resistance to an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in an uncommon G719S EGFR mutation.

Background Acquired resistance (AR) to an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is a common event, and several underlying mechanisms, including T790 M, MET amplification and PTEN downregulation, have been reported for the common EGFR mutations. EGFR G719X is an uncommon mutation that has been reported to show sensitivity to EGFR-TKIs. However, no established cell lines harboring the EGFR G719X have been reported in the literature. Materials and Methods G719S-GR cells were established from malignant pleural effusion of a patient whose tumor developed AR from gefitinib treatment. G719S-GR cells were then genotyped and tested for drug sensitivities. Multiplex ligation-dependent probe amplification (MLPA) was used to compare the clinical tumor samples with G719S-GR. Results G719S-GR cells were resistant to EGFR-TKIs with an LC50 of around 10 µM. A genomic analysis showed that G719S-GR cells harbor the EGFR G719S mutation as well as the amplification of EGFR locus. The homozygous deletion of CDKN2A and the loss of PTEN and TSC1 were also detected. On comparing the copy number of tumor suppressor genes using MLPA, G719S-GR cells were found to lack one copy of PTEN, which was not observed in a tumor obtained before gefitinib treatment. Loss of PTEN may result in AKT activation. The mTORC1/2 inhibitor Torin-1 was able to inhibit the downstream signaling when combined with osimertinib. Discussion The newly established G719S-GR cell line may be useful for investigating the mechanism underlying the development of AR in the G719X mutation; the loss of PTEN may be one such mechanism.

EGFR-mutated lung adenocarcinoma with choroidal oligometastasis during treatment with gefitinib: a case report.

The patient was a 74-year-old woman who was diagnosed with lung adenocarcinoma, clinical Stage IIIA. Induction chemoradiation was performed followed by right upper lobectomy and lymph node dissection. Because of positive pleural effusion cytology, which was proven after surgery, the patient was diagnosed with pathological Stage IVA with EGFR L858R mutation. At 17 months after the administration of gefitinib, left choroidal metastasis appeared. Stereotactic irradiation and ruthenium small-beam radiation were effective; however, the metastatic lesion showed regrowth 7 months after these treatments. Because the patient's choroidal oligometastasis was resistant to conservative therapy, left ophthalmectomy was performed. EGFR mutations (L858R and E709K) were detected in the resected choroidal tumor. The patient continued to take gefitinib. However, a neoplastic lesion developed on the optic nerve adjacent to the resected posterior eye segment. The lesion was treated with stereotactic radiation, gefitinib was switched to afatinib 30 mg, and the patient remains alive and disease free for 11 months.

Significance of programmed death-ligand 1 expression in resected lung cancer and its relationship with EGFR mutation.

BACKGROUND: Several studies have reported that the high expression of programmed death-ligand 1 (PD-L1) within tumor cells predicts a poor prognosis. However, the relationship between the PD-L1 expression and lymph node metastasis or driver mutations in lung cancer remains poorly understood. METHODS: A total of 356 consecutive patients who underwent surgical resection for primary lung cancer were included in the study. There were 268 adenocarcinomas including 100 EGFR mutations, 67 squamous cell carcinomas (Sq), and 21 other histologies. The high expression of PD-L1 was defined as a tumor proportion score (TPS) of ≥50. The relationship between the PD-L1 expression and clinicopathological factors and recurrence-free survival (RFS) was analyzed. RESULTS: The PD-L1 expression was high in 75 patients. It was significantly related to smoking history, Sq histology, driver mutation negative, elevated serum carcinoembryonic antigen levels, and lymph node metastasis. Among patients with driver mutations, a high PD-L1 TPS was found in patients with EGFR G719X mutation. A significant difference in RFS was observed in adenocarcinoma patients. A multivariate analysis of adenocarcinoma cases revealed that tumor size and lymph node metastasis were independent prognostic factors for poor RFS, while the PD-L1 expression was not. A logistic regression analysis revealed that the absence of driver mutations, lymph node metastasis, and a history of smoking were significantly associated with the high expression of PD-L1. CONCLUSION: Lymph node metastasis was positively related with the high expression of PD-L1, resulting in poor RFS. A high PD-L1 TPS was observed in patients with the EGFR G719X mutation.

Osimertinib as first-line treatment for recurrent lung cancer patients with EGFR mutation.

Background: Although osimertinib was approved as adjuvant therapy for lung cancer patients with EGFR mutation in various countries, there is still some ongoing debate as osimertinib has been approved based on disease-free survival (DFS) rather than overall survival (OS). We curated a case series in which we documented patterns of recurrence and efficacy and safety of osimertinib after recurrence. Methods: Patients who received osimertinib as first-line treatment for postoperative recurrence between September 2018 and January 2023 were included. Clinicopathological factors, duration of osimertinib treatment (DoT), and adverse events were collected and analyzed. Results: Twenty patients received osimertinib [male, n=6; median age, 75 years (range, 55-85 years)]. The EGFR mutation type was L858R in 11 patients and exon 19 deletion in eight patients. The performance status (PS) was 0 or 1 in all but two patients, who had symptomatic brain metastasis and were therefore PS 3. The first site of postoperative recurrence was locoregional in five patients and distant in 15 patients, including seven with brain metastasis. As of February 2023, 10 patients were still on osimertinib, including three with brain metastasis. Patients with brain metastasis or poor PS had a considerably shorter DoT than their counterparts. Three patients with symptomatic brain metastasis or leptomeningeal metastasis initially responded to osimertinib, but all died of disease progression. Five patients discontinued osimertinib due to serious adverse effects (pneumonitis, drug eruption, and heart failure). Conclusions: Although osimertinib exerts great disease control, even in patients with brain metastasis or poor PS, their presence was associated with a poor prognosis, even with osimertinib treatment. Therefore, adjuvant osimertinib is recommended unless contraindicated.

Giant benign intrathoracic schwannoma: a decade-long progression towards fatality.

BACKGROUND: Intrathoracic neurogenic tumors arise from sympathetic nerve trunks and intercostal nerves; more than 90% are benign. Schwannomas are the most common histological variety, but fatalities due to giant schwannomas are rare. CASE PRESENTATION: We report a case of a 65-year-old woman who presented with chest pain and cough. Computed tomography (CT) revealed a large left chest wall mass of 130-mm in size, and the patient was referred to our department. Tumor biopsy was performed under local anesthesia, and a diagnosis of schwannoma was made. Ten years previously, a 30-mm tumor had been noted in the left third intercostal space by a previous doctor, but follow-up had been interrupted owing to depressive disorder. Although we planned to perform intercostal artery embolization followed by chest wall tumor resection, the patient did not consent to surgery due to uncontrolled depression. After four months, she developed respiratory failure caused by compression due to an enlarged tumor and died. Autopsy also revealed a benign schwannoma with no malignant findings. CONCLUSIONS: Although schwannomas are benign tumors, there are some very rare cases in which they can become huge and life-threatening. Therefore, a benign tumor should not be neglected, and if surgery is not possible at the time of diagnosis, a regular follow up is necessary, in order not to miss the right timing for surgery.

Tracheal injury from dog bite in a child.

BACKGROUND: Dog bites associated with the head and neck area in children are a common problem. Most of the lacerations are found in the upper lip and the nose region, and tracheal injury is rare [1]. Tracheal injury requires prompt and accurate diagnosis and treatment to rescue the patient. Especially in children, securing the airway is often more difficult than in adults because of their short neck and narrow trachea. In this report, we experienced a pediatric case of multiple dog bites with tracheal injuries in the neck. CASE PRESENTATION: We report the case of a 3-year-old girl who presented with multiple dog bites. There were multiple wounds on the head, face, neck, and anterior chest, and air leakage was observed from the cervical wound at the time of transfer. It was difficult to perform oral endotracheal intubation, therefore, we extended the neck wound, probed the trachea with finger, and inserted a tracheal tube directly from the cervical wound in the emergency room. Tracheoplasty and another wound cleansing were performed in the operating room. The patient was discharged on the 18th day after surgery, without further complications. CONCLUSION: Tracheal injury from a dog bite is rare. It is important to prompt and accurate diagnosis and treatment. Children should be especially careful because of their short necks and narrow tracheas.

Autotaxin regulates vascular development via multiple lysophosphatidic acid (LPA) receptors in zebrafish.

Autotaxin (ATX) is a multifunctional ecto-type phosphodiesterase that converts lysophospholipids, such as lysophosphatidylcholine, to lysophosphatidic acid (LPA) by its lysophospholipase D activity. LPA is a lipid mediator with diverse biological functions, most of which are mediated by G protein-coupled receptors specific to LPA (LPA1-6). Recent studies on ATX knock-out mice revealed that ATX has an essential role in embryonic blood vessel formation. However, the underlying molecular mechanisms remain to be solved. A data base search revealed that ATX and LPA receptors are conserved in wide range of vertebrates from fishes to mammals. Here we analyzed zebrafish ATX (zATX) and LPA receptors both biochemically and functionally. zATX, like mammalian ATX, showed lysophospholipase D activity to produce LPA. In addition, all zebrafish LPA receptors except for LPA5a and LPA5b were found to respond to LPA. Knockdown of zATX in zebrafish embryos by injecting morpholino antisense oligonucleotides (MOs) specific to zATX caused abnormal blood vessel formation, which has not been observed in other morphant embryos or mutants with vascular defects reported previously. In ATX morphant embryos, the segmental arteries sprouted normally from the dorsal aorta but stalled in midcourse, resulting in aberrant vascular connection around the horizontal myoseptum. Similar vascular defects were not observed in embryos in which each single LPA receptor was attenuated by using MOs. Interestingly, similar vascular defects were observed when both LPA1 and LPA4 functions were attenuated by using MOs and/or a selective LPA receptor antagonist, Ki16425. These results demonstrate that the ATX-LPA-LPAR axis is a critical regulator of embryonic vascular development that is conserved in vertebrates.

Clinical significance of part-solid lung cancer in the eighth edition TNM staging system.

OBJECTIVES: The ground-glass component of part-solid tumour (PST) was eliminated as a clinical T (cT) descriptor in the eighth edition of the tumour, node and metastasis (TNM) staging system. We aimed to validate the new cT descriptor and investigate the prognostic impact of PST in the new staging system. METHODS: Non-small-cell lung cancer (NSCLC) patients (n = 1061) who underwent lung resection and were available for the assessment of thin-section computed tomography images were retrospectively reviewed. Tumours with a solid component (SC) size-to-whole tumour size (STR) ratio of 0, those with 0 < STR < 1 and those with an STR of 1 were defined as pure ground-glass tumours, PSTs and solid tumours (STs), respectively. RESULTS: Tumours with an SC diameter of >30 mm were less frequently observed among PSTs than among STs (4.83% vs 32.6%, P < 0.001). The postoperative 5-year survival of NSCLC patients with ground-glass tumour, PST and ST was 97.6%, 89.0% and 76.3%, respectively. In the survival analysis of patients with an SC diameter ≤30 mm, significant differences were observed among PST and ST (5-year survival, 90.7% vs 74.6%, P < 0.001). The multivariable analysis showed that age <70 years old, female sex, procedures with a lobectomy or more, SC size, pN0 disease and PST were independent predictors of a better survival among all PST and ST patients. CONCLUSIONS: Among patients with cT1 tumours, those with PST showed a significantly better survival than did those with ST. Small-sized PST tumours may not be suitable for the new cT descriptor.

Prognostic significance of HE4 expression in pulmonary adenocarcinoma.

We investigated the possibility of human epididymis 4(HE4) to predict survival for patients with pulmonary adenocarcinoma. One hundred and thirty-seven patients with pulmonary adenocarcinoma underwent surgery in our institute from 2000 to 2008. We used immunohistochemical analysis to determine the expression of HE4 and compared with the clinicopathological factors and survival. Serum levels of HE4 in lung adenocarcinoma were investigated by enzyme immunometric assay. Fifty-seven of 137 cases (41.6%) were HE4 positive. It was found that there was no correlation between HE4 expression by immunohistochemistry and clinicopathological factors, however, adenocarcinoma subtype was significantly associated with HE4 expression. Sera in lung adenocarcinoma were significantly higher than in healthy control. Five-year disease-free survival in the HE4-positive group (44.6%) was significantly different from that in the negative group (82.3%, p = 0.001) by immunohistochemistry. The five-year overall survival rate was 60.1% in the HE4-positive group, as compared with 90.8% in the HE4-negative group (p = 0.001). In multivariate Cox regression analysis, positive HE4 protein expression was a worse prognosis factor of disease-free and overall survival (HR = 3.7, 95%CI = [1.7-8.4], p = 0.001; HR = 5.5, 95%CI = [1.8-17.2], p = 0.003, respectively), in addition to nodal status as a powerful value. When HE4 expression in adenocarcinoma cases except the BAC were analyzed, nodal status and HE4 expression were independent prognostic factors in disease-free and overall survivals. These data showed that HE4 expression is associated with a worse prognosis and is a possible prognostic factor of lung adenocarcinoma.

Ciliated muconodular papillary tumor of the lung: a case report and literature review.

Ciliated muconodular papillary tumor (CMPT) of the lung is characterized as a peripheral low-grade malignant tumor with ciliated columnar cells and goblet cells with basaloid cell proliferation. Herein, we report on a case of CMPT with a radiologically abnormal shadow which was reminiscent of adenocarcinoma. The patient underwent right S6 + S8a segmentectomy because an intraoperative biopsy suggested CMPT, the malignancy of which was difficult to distinguish; however, the tumor was small and located in the peripheral lung. Many details of this tumor remain unclear, as CMPT is a rare tumor with few reports. CMPT has therefore not yet been classified by the WHO. In this report, we will consider the characteristics of CMPT and treatment based on our case and previous case reports.

The Sperm-surface glycoprotein, SGP, is necessary for fertilization in the frog, Xenopus laevis.

To identify a molecule involved in sperm-egg plasma membrane binding at fertilization, a monoclonal antibody against a sperm-surface glycoprotein (SGP) was obtained by immunizing mice with a sperm membrane fraction of the frog, Xenopus laevis, followed by screening of the culture supernatants based on their inhibitory activity against fertilization. The fertilization of both jellied and denuded eggs was effectively inhibited by pretreatment of sperm with intact anti-SGP antibody as well as its Fab fragment, indicating that the antibody recognizes a molecule on the sperm's surface that is necessary for fertilization. On Western blots, the anti-SGP antibody recognized large molecules, with molecular masses of 65-150 kDa and minor smaller molecules with masses of 20-28 kDa in the sperm membrane vesicles. SGP was distributed over nearly the entire surface of the sperm, probably as an integral membrane protein in close association with microfilaments. More membrane vesicles containing SGP bound to the surface were found in the animal hemisphere compared with the vegetal hemisphere in unfertilized eggs, but the vesicle-binding was not observed in fertilized eggs. These results indicate that SGP mediates sperm-egg membrane binding and is responsible for the establishment of fertilization in Xenopus.

Detection of the Onset of the Epidemic Period of Respiratory Syncytial Virus Infection in Japan.

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in young children worldwide. An annual epidemic of RSV infection generally begins around autumn, reaching a peak at the end of year in Japan, but in 2017 it started in early July and peaked in September. As the onset timing of RSV season varies, it is important to detect the beginning of an epidemic, to enable the implementation of preventive measures. However, there are currently no specified criteria or methods to determine the onset of RSV season in a timely manner. Therefore, we developed a model to detect the epidemic onset, based on data from the Infectious Diseases Weekly Report from 2012 to 2017. The 47 prefectures of Japan span 11 climate zones, which affect the timing of epidemic onset. Therefore, the onset of RSV season was assessed separately in each prefecture. Non-linear regression analysis was performed to generate a mathematical model of the annual epidemic cycle for each prefecture. A search index was used to determine the onset of RSV season, which was estimated using the number of RSV reports per week within an epidemic period (RSV-reports/w) and the number of reported cases included within an epidemic period relative to the total number of RSV reports (capture rate). A number of RSV-reports/w, which was used as a threshold (a number at onset line) to determine the condition of the onset of RSV season, was then estimated based on the search index. The mean number at the onset of RSV season for 47 prefectures was 29.7 reports/week (median 21.0, range 6.0-121.0 reports/ week). The model also showed that the onset of RSV season in 2017 was more than 1 month earlier than the previous year. In conclusion, the model detected epidemic cycles and their onset conditions in all prefectures, despite the 11 climate zones of Japan. The results are expected to contribute to infant medical care by allowing medical personnel to take preventive measures promptly at the beginning of the epidemic RSV season.

Elevated red cell distribution width to platelet count ratio predicts poor prognosis in patients with breast cancer.

Red cell distribution width (RDW) to platelet ratio (RPR) is a prognosticator in acute pancreatitis and myocardial infarction; however, the prognostic values of RDW and RPR in breast cancer have not been studied. This retrospective analysis of 299 breast cancer patients investigated the association between RDW and RPR and clinicopathological characteristics and prognosis, compared to platelet distribution width to platelet count ratio (PDW/P) which is a known independent prognostic factor in patients with breast cancer. We found a significant correlation between RPR, and age and HER2 status. An elevated RPR significantly correlated with age and HER2 status. After a median follow-up duration of 48 months, tumour size, nuclear grade, PDW/P, and RPR were recgnized to be significantly associated with lower disease-free survival rates (tumour size: p < 0.01; nuclear grade, PDW/P, and RPR: p < 0.05) in univariate analysis. Tumour size and RPR were significant prognostic factors for lower disease-free survival rates, with hazard ratios of 4.31 (95% confidence interval: 1.76-10.53) (p < 0.01)] and 2.79 [95% confidence interval: 1.01-87.69) (p < 0.05)], respectively, in a multivariate analysis using the Cox proportional hazards model. This is the first study showing that an elevated RPR could independently predict poor prognosis in patients with breast carcinoma. Thus, RPR could be a novel biomarker for prognostic estimation.

Monooxygenase-catalyzed regioselective hydroxylation for the synthesis of hydroxyequols.

Monooxygenases exhibiting high activity and differing regioselectivity for the dietary isoflavone metabolite equol were discovered among enzymes in the HpaBC family by a genome mining approach. These enzymes enabled the one-step product-selective synthesis of 3'- and 6-hydroxyequols from equol and molecular oxygen.

Erlotinib and bevacizumab combination therapy for afatinib-refractory leptomeningeal carcinomatosis from EGFR-mutated lung cancer.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors remains the main hurdle in treating EGFR-mutated lung cancer. Besides, when leptomeningeal carcinomatosis occurs during treatment, it often leads to treatment failure. We herein report a case of lung adenocarcinoma involving a patient with an EGFR exon 19 deletion mutation who developed leptomeningeal carcinomatosis after afatinib treatment for post-operative recurrence. He received right lower lobectomy, followed by four cycles of cisplatin and pemetrexed treatment. Follow-up CT/MRI revealed multiple pulmonary metastases and brain metastases at 7 months after surgery, and afatinib (40 mg/day) was administered after stereotactic radiotherapy for brain metastasis. At 28 months after surgery, follow-up MRI revealed asymptomatic leptomeningeal carcinomatosis, which was cytologically proven from the cerebrospinal fluid. Because EGFR T790M was not detected in plasma cell-free DNA or cerebrospinal fluid, erlotinib and bevacizumab combination treatment was administered. He remained asymptomatic and was radiographically clear of LM at 2 months after treatment. In comparison to other EGFR-TKIs, erlotinib shows penetrance into the cerebrospinal fluid. Furthermore, the addition of bevacizumab might enhance the treatment effect, because it is known to relieve brain edema from metastatic brain tumors by normalizing immature vascularity and improving drug penetrance into the cerebrospinal fluid by reducing interstitial fluid pressure.

Intratumoral heterogeneity of copy number variation in lung cancer harboring L858R via immunohistochemical heterogeneous staining.

BACKGROUND: Although intratumoral heterogeneity is commonly observed in several cancers, few studies have shown its presence in EGFR-mutated lung cancer. We performed immunohistochemistry to analyze the intratumoral heterogeneity in EGFR-mutated (L858R) lung cancer and performed targeted sequencing in specific cases. We discuss the effects of intratumoral heterogeneity and acquired resistance to EGFR-TKI. METHODS: Twenty resected primary lung cancers known to harbor EGFR L858R were analyzed. IHC was performed using an L858R mutant-specific rabbit monoclonal antibody and the samples were scored by staining intensity (0-3) and proportion. For cases with heterogeneous L858R protein expression, the nucleic acids were extracted from each differently stained lesion, and targeted sequencing was performed. Single nucleotide variations (SNVs) and copy number variations (CNVs) were then analyzed. The cell proliferation and apoptosis were also evaluated by the ki-67 labeling index and TUNEL staining. RESULTS: Among 20 cases, 3 showed heterogeneous staining. Genetic analyses for cases with heterogeneous staining revealed an increase in the copy number of EGFR in the IHC-positive part compared to the negative part, and an increase in the copy number of CCNE1 was observed in the IHC-positive part compared to the negative part in one case (case 1). In another case (case 2), an increase in the copy number of EGFR was observed in the IHC-positive part compared to the negative part, and an increase in the copy number of MDM2 was observed in the IHC-positive part compared to the negative part. In three cases, no SNV changes were observed. An increase in the ki-67 labeling index in the L858R-positive part in case 1 and increased apoptosis in the L858R-positive part in case 2 were observed, suggesting the functional significance of CNV changes. CONCLUSION: These cases exhibiting L858R IHC intratumoral heterogeneity suggest a heterogeneous effect on the cell activity due to CNV heterogeneity.