Transformation of epidermal growth factor receptor mutated lung adenocarcinoma to small-cell carcinoma long after the cessation of tyrosine kinase inhibitor treatment: A case series and literature review.

Histological transformation to small-cell lung cancer (SCLC) is a well-known mechanism of acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), and almost all patients receive EGFR-TKIs at the time of transformation. We herein report three cases of EGFR-mutated lung adenocarcinoma that transformed into SCLC long after the cessation of EGFR-TKIs. Rapid tumor progression and elevated SCLC marker levels were observed at the time of transformation. Our case highlights the importance of considering SCLC transformation throughout the clinical course. Careful observation of the tumor behavior and SCLC markers should be performed to avoid diagnostic delays.

Robot-assisted thoracoscopic resection of a posterior mediastinal tumor with immunoglobulin G4-related disease: a case report.

BACKGROUND: Immunoglobulin (Ig)G4-related disease affects nearly every organ, and its clinical course varies depending on the involved organ; however, its occurrence in the mediastinum is rarely reported. CASE PRESENTATION: A 58-year-old woman presented with a posterior mediastinal tumor along the thoracic spine on imaging. Based on her elevated serum IgG4 level of 349.7 mg/dL, IgG4-related disease was suspected. Since the tumor was growing and malignancy could not be excluded, surgical resection was performed for definitive diagnosis. Robot-assisted thoracoscopic surgery was performed via the left semipronation and right thoracic approaches. The irregularly-shaped tumor was located on the level of the seventh to ninth thoracic vertebra, along the sympathetic nerve. A malignancy was not excluded based on the appearance of the tumor. The tumor had poor mobility. The sympathetic nerves, intercostal arteries, and veins were also excised. In this case, the articulated forceps, used during the robotic surgery, were useful in achieving complete tumor resection along the vertebral body. The pathological examination revealed IgG4-positive plasma infiltration, which fulfilled the criteria for IgG4-related diseases. The postoperative course was uneventful, and the patient underwent follow-up on an outpatient basis without additional medications. CONCLUSION: The clinical presentation of IgG4-related disease varies, based on the involved organs. This case was rare because the mediastinum was involved, and it emphasized the effectiveness of surgical resection.

Toxoplasmic encephalitis with high 201Tl uptake and retention mimicking malignant lymphoma in a patient with human immunodeficiency virus infection.

Various opportunistic infections develop during immunodeficiency due to human immunodeficiency virus (HIV) infection. The treatment options for malignant lymphoma (ML) and toxoplasmic encephalitis (TE) are completely different; therefore, their discrimination is critical. A 25-year-old female of foreign nationality had been experiencing headaches for several weeks and suddenly developed convulsions. Brain computed tomography revealed multiple intracranial lesions; therefore, the patient was referred to the neurosurgery department. Brain magnetic resonance imaging (MRI) revealed multiple masses with surrounding edema, accompanied by enhanced contrast. The largest mass (2 cm) in the left occipital lobe exhibited ringed contrast enhancement. Her blood test results showed a CD4 count of 40/µL, positive HIV Ag/Ab, HIV-RNA level of 56 × 104 copies/mL, positive anti-Toxoplasma IgG (63 IU/mL), and negative anti-Toxoplasma IgM. 201Tl- single photon emission computed tomography (201Tl-SPECT) revealed abnormal accumulation only in the tumor in the left occipital lobe (early T/N ratio, 3.034; delayed T/N ratio, 2.738; retention index, 0.9), which was suspected to be a ML. Both tumors, with or without high accumulation of 201Tl, were subjected to craniotomy biopsy. Pathological examination revealed infiltration of small lymphocytes with a necrotic background. The patient was diagnosed with TE based on a positive result of a tissue polymerase chain reaction test for Toxoplasma gondii. Two weeks after sulfamethoxazole and trimethoprim combination therapy, MRI imaging showed dramatic improvement in multiple brain tumors. This case is atypical because ML was ruled out despite high 201Tl-SPECT uptake and retention. Careful diagnosis through pathological examination and DNA testing is important.

Long-Term Outcomes of S-1 Combined With Low-Dose Docetaxel as Neoadjuvant Chemotherapy (N-1 Study, Phase II Trial) in Patients With Operable Breast Cancer.

BACKGROUND: We previously reported that S-1 and low-dose docetaxel (DOC) (N-1 study, phase II trial) could be a well-tolerated and effective neoadjuvant chemotherapies (NACs) for patients with operable breast cancer. Herein, we analyzed the long-term outcomes and developed clinicopathological and molecular predictors of pathological complete response (pCR). PATIENTS AND METHODS: Eighty-three patients received S-1 (40 mg/m2 orally on days 1-14) and DOC (40 mg/m2 intravenously on day 1) every 3 weeks for 4 to 8 cycles. Disease-free survival (DFS) and overall survival (OS) were analyzed for each population with a pCR status. To assess the relationship between pCR and clinicopathological factors such as tumor-infiltrating lymphocytes (TILs, 1+ <10%, 2+ 10%-50%, and 3+ >50%) and nuclear grade (NG), microarray was used to compare the microRNA profiles of the pCR and non-pCR groups using core needle biopsy specimens. RESULTS: With a median follow-up duration of 99.0 (range, 9.0-129.0) months, the 5-year DFS and OS rates were 80.7% and 90.9%, respectively. The 5-year OS rate of the pCR group was significantly better than that of the non-pCR group (100% vs. 86.2%, p = .0176). Specifically, in triple-negative patients, the difference was significant (100% vs. 60.0%, p = .0224). Multivariate analysis revealed that high TILs (≥2-3+) and NG 2-3 independently predicted pCR. Microarray data revealed that 3 miRNAs (miR-215-5p, miR-196a-5p, and miR-196b-5p) were significantly upregulated in the pCR group. CONCLUSION: Our NAC regimen achieved favorable long-term outcomes and significantly improved OS in the pCR group. High TILs, NG 2-3, and some miRNAs may be predictors of pCR.

Gastric fundic gland polyposis and cancer development after eradication of Helicobacter pylori in patient with gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS).

A 44-year-old woman with gastric cancer (GC) and fundic gland polyposis (FGPs) was referred to our hospital for further diagnosis and treatment. She successfully underwent eradication therapy for Helicobacter pylori (HP) 6 years ago, but did not exhibit FGPs at that time. When she underwent an esophagogastroduodenoscopy 2, 4, and 5 years after the eradication of HP, her imaging results revealed the existence of FGPs which gradually increased in her gastric fundus and body. Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) was suspected and a mutational analysis was performed, revealing an APC promoter 1B variant c.-191T > C. A robotic total gastrectomy with lymphadenectomy was performed. Histopathological analysis of the surgical specimens revealed GC with no lymph node metastasis. GAPPS is characterized by GC and FGPs. However, our case shows different gastric phenotypes that are dependent on the status of HP infection.

MR Imaging Findings of Uterine Adenomatoid Tumors.

PURPOSE: Adenomatoid tumor is a rare benign genital tract neoplasm of mesothelial origin. Uterine adenomatoid tumors occur in the outer myometrium and may mimic leiomyomas. Because hormonal treatment is not applicable to adenomatoid tumors and laparoscopic enucleation is not easy as myomectomy, it is important to differentiate adenomatoid tumors from leiomyomas for the adequate treatment. The purpose of this study is to evaluate the MRI findings of adenomatoid tumor for the differentiation from leiomyoma. METHODS: MRI findings of surgically proven 10 uterine adenomatoid tumors in 9 women were retrospectively evaluated with correlation to histopathological findings. RESULTS: All 10 tumors appeared as solid myometrial masses and showed heterogeneous signal intensity with admixture of partially ill-defined slight high-intensity areas containing abundant tubular tumor cells and well-defined myoma-like low-intensity areas reflecting smooth muscle hypertrophy on T2WI including 4 lesions with peripheral ring-like high intensity. High-intensity areas on T2WI tended to show high intensity on diffusion-weighted imaging (DWI) with relatively high apparent diffusion coefficient (ADC), suggesting T2 shine-through effect due to abundant tubules. Intra-tumoral hemorrhage revealed on MRI was rare. Early intense contrast-enhanced areas on dynamic contrast-enhanced study were observed dominantly within the high-intensity areas but rarely within the low-intensity areas on T2WI. CONCLUSION: The outer myometrial mass with the admixture of well-defined low- and ill-defined high-intensity areas on T2WI may be suggestive of adenomatoid tumor. Peripheral ring-like high intensity on T2WI and DWI may also be suggestive. Dynamic contrast-enhanced MR study may be helpful for the differentiation from leiomyoma.

Early Prediction of Radiotherapeutic Efficacy in a Mouse Model of Non-Small Cell Lung Carcinoma Using 18F-FLT and 18F-FDG PET/CT.

This study investigated the usefulness of [18F]-3'-deoxy-3'-fluorothymidine (18F-FLT) and [18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging for predicting the therapeutic efficacy of non-small cell lung cancer (NSCLC) irradiation at an early stage after radiation treatment. Mice were xenografted with the human lung adenocarcinoma line A549 or large cell lung cancer line FT821. Tumour uptake of 18F-FLT and 18F-FDG was imaged using PET/CT before and 1 week after irradiation. In A549 tumours, 18F-FLT uptake was significantly decreased, and 18F-FDG uptake was unchanged post-irradiation compared with pre-irradiation. In FT821 tumours, uptake of both 18F-FLT and 18F-FDG uptake was substantially decreased post-irradiation compared with pre-irradiation. In both xenografts, tumour volumes in the irradiated groups were significantly decreased compared with those in the control group. 18F-FLT is expected to contribute to individual NSCLC therapy because it accurately evaluates the decrease in tumour activity that cannot be captured by 18F-FDG. 18F-FDG may be useful for evaluating surviving cells without being affected by the inflammatory reaction at an extremely early stage, approximately 1 week after irradiation. Combined use of 18F-FLT and 18F-FDG PET/CT imaging may increase the accurate prediction of radiotherapy efficacy, which may lead to improved patient outcomes and minimally invasive personalised therapy. J. Med. Invest. 70 : 361-368, August, 2023.

Insulin receptor expression to predict resistance to axitinib and elucidation of the underlying molecular mechanism in metastatic renal cell carcinoma.

BACKGROUND: The study aimed to examine the significance of insulin receptor (INSR) expression in predicting resistance to axitinib in clear cell renal cell carcinoma (ccRCC). METHODS: Clinicopathological data were collected from 36 consecutive patients with metastatic RCC who received axitinib. Thirty-three primary tumours were obtained for immunohistochemistry. Patient-derived xenograft (PDX) models were created by transplanting primary tumours into immunodeficient mice, establishing axitinib-resistant PDX models. RCC cell lines were co-cultured with human renal glomerular endothelial cells (HGECs) treated with siRNA of INSR (HGEC-siINSR). Gene expression alteration was analysed using microarray. RESULTS: The patients with low INSR expression who received axitinib had a poorer outcome. Multivariate analysis showed that INSR expression was the independent predictor of progression-free survival. INSR expression decreased in axitinib-resistant PDX tumours. RCC cell lines showed upregulated interferon responses and highly increased interferon-ß levels by co-culturing with HGEC-siINSR. HGECs showed decreased INSR and increased interferon-ß after axitinib administration. RCC cell lines co-cultured with HGEC-siINSR showed high programmed death-ligand 1 (PD-L1) expression, which increased after interferon-ß administration. CONCLUSIONS: Decreased INSR in RCC could be a biomarker to predict axitinib resistance. Regarding the resistant mechanism, vascular endothelial cells with decreased INSR in RCC may secrete interferon-ß and induce PD-L1.

Dynamic contrast-enhanced MR imaging of uterine endometrial carcinoma with/without squamous differentiation.

PURPOSE: Endometrial carcinoma with strong enhancement on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is suggestive of high-grade type II endometrial carcinoma. However, low-grade type I endometrial carcinoma may also sometimes show strong enhancement. We hypothesized that squamous differentiation would contribute to the strong enhancement at the early phase on DCE-MRI-like uterine cervical squamous cell carcinoma and compared the DCE-MRI findings of endometrial carcinoma with and without squamous differentiation. METHODS: DCE-MRI of endometrial carcinoma including 41 low-grade type I endometrial carcinomas without squamous differentiation (LG), 39 low-grade type I endometrial carcinomas with squamous differentiation (LGSD), and 20 high-grade type II endometrial carcinomas (HG) was retrospectively evaluated. RESULTS: Significant difference in the time-intensity curves was found between LG and HG and LG and LGSD, whereas no significant difference was seen between HG and LGSD. Curve type 3 (initial signal rise which is steeper than that of the myometrium) was more frequent in HG (60%) and LGSD (77%) than in LG (34%). CONCLUSION: It should be recognized as a pitfall that high-grade type II endometrial carcinoma and low-grade type I endometrial carcinoma with squamous differentiation may show similar early strong enhancement on DCE-MRI.

Histological and immunohistochemical analysis of epithelial cells in epidermoid cysts in intrapancreatic accessory spleen.

BACKGROUND: Epidermoid cysts in intrapancreatic accessory spleen (ECIPAS) are a rare lesion. Its pathogenesis, including the origin of cystic epithelium, is not well established. We aimed to elucidate new aspects of the pathological features of ECIPAS to clarify its pathogenesis. METHODS: Six cases of ECIPAS were included in this study. As well as histopathological analysis, to elucidate the features and nature of cystic epithelial cells, immunohistochemical analysis including Pbx1 and Tlx1 and imaging mass spectrometry was performed. RESULTS: Histologically, the cysts were covered by either monolayered or multilayered epithelium. Immunohistochemistry revealed that the epithelial cells in multilayered epithelium exhibited different attributes between the basal and superficial layers. Few epithelial cells had abundant clear cytoplasm and were immunohistochemically positive for adipophilin, suggesting lipid-excreting function. The intracystic fluid contained cholesterol clefts and foamy macrophages, and imaging mass spectrometry revealed the accumulation of lipids. Immunohistochemical analysis indicated that the epithelial cells were positive for Pbx1 in some cases. CONCLUSION: Novel histological features of epithelial cells of ECIPAS were indicated. Although more cases need to be evaluated, we propose that the cause of ECIPAS may be different from that of pancreatic ductal origin. J. Med. Invest. 70 : 251-259, February, 2023.

Squamous cell carcinoma invading peripheral cerebral blood vessels and causing repeated cerebral hemorrhage : A case report.

Squamous cell carcinoma (SCC) is known to have less brain metastasis, but the reasons are not well established. Herein, we report the case of an 82-year-old man with recurrent cerebral hemorrhage of unknown cause ; upon brain biopsy, SCC was diagnosed infiltrating peripheral blood vessels of the brain and that it was state of micro-metastasis. It is possible that the blood-brain barrier blocked the infiltration of SCC into the brain parenchyma, and it did not form a mass in the brain parenchyma. In addition, because it did not form a mass, it could not be diagnosed as a metastatic brain tumor by contrast-enhanced magnetic resonance imaging or contrast-enhanced computed tomography. Among cases of recurrent cerebral hemorrhage of unknown cause in a short period, there may be cases of vascular infiltration without crossing the blood-brain barrier. Thus, if similar cases of recurrent cerebral hemorrhage of unknown cause is observed, it is necessary to distinguish metastatic brain tumors even if there is no evidence of suspected tumor on contrast-enhanced magnetic resonance imaging scan. J. Med. Invest. 70 : 276-280, February, 2023.

Imaging features of a myoepithelial carcinoma of the nasal cavity: A case report and literature review.

Myoepithelial carcinoma of the nasal cavity is extremely rare. We report the case of a 66-year-old man with myoepithelial carcinoma of the nasal cavity. Computed tomography (CT) and magnetic resonance imaging revealed a lobulated soft tissue mass with central necrosis and hemorrhage, as well as an invasion of the skull base and left orbit. The patient presented with continuous nasal congestion and heavy head and had no elevated level of squamous cell carcinoma-related antigen. CT, magnetic resonance imaging, or 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT revealed no evidence of a metastatic lesion. 18F-FDG accumulation in the tumor was inhomogeneous and moderate. Histopathological examination of the resected specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was a myoepithelial carcinoma of the left nasal cavity. This case shows that nasal myoepithelial carcinoma might appear as a well-defined lobulated mass with hemorrhagic necrosis and intense contrast enhancement in the solid component. We conjecture that hemorrhagic necrosis and intense enhancement values may be potential markers of nasal myoepithelial carcinoma.

ZFTA::RELA fusion in a distinct liposarcoma morphologically overlapping with chondroid lipoma.

Chondroid lipoma is a rare benign adipose tumor characterized by a recurrent ZFTA::MRTFB fusion. Herein, we report an unusual liposarcoma that partly exhibited overlapping features with those of chondroid lipoma and harbored a ZFTA::RELA fusion. A 59-year-old man presented with a shoulder mass that had existed for approximately 8 years and with increasing pain due to a pelvic mass. The 5.8-cm resected shoulder tumor partly consisted of nests and strands of variably lipogenic epithelioid cells within a hyalinized or focally chondromyxoid stroma, indistinguishable from chondroid lipoma. The histological pattern gradually transitioned to highly cellular, stroma-poor, diffuse sheets of cells with greater nuclear atypia and mitotic activity. Vascular invasion and necrosis were present. The metastatic pelvic tumor revealed a similar histology. Despite multimodal treatment, the patient developed multiple bone metastases and succumbed to the disease 14 months after presentation. Targeted RNA sequencing identified an in-frame ZFTA (exon 3)::RELA (exon 2) fusion, which was confirmed by reverse transcription-polymerase chain reaction, Sanger sequencing, and break-apart fluorescent in situ hybridization assays. The tumor showed a different histology from that of ependymoma, no brain involvement, and no match with any sarcoma types or ZFTA::RELA-positive ependymomas according to DNA methylation analysis. p65 and L1CAM were diffusely expressed, and a CDKN2A/B deletion was present. This is the first report of an extra-central nervous system tumor with a ZFTA::RELA fusion. The tumor partly displayed an overlapping histology with that of chondroid lipoma, suggesting that it may represent a hitherto undescribed malignant chondroid lipoma with an alternative ZFTA fusion.

Combination chemotherapy of doxorubicin and ifosfamide with proton beam therapy for myoepithelial carcinoma originating in the paraspinal region: A case report and literature review.

Soft tissue myoepithelial carcinoma (MEC) is an extremely rare mesenchymal tumor that has a poor prognosis unless complete surgical resection is achieved. The present study reported a case of a 38-year-old woman with a tumor in the left paraspinal region at L2 to L3 with vertebral destruction. MEC was diagnosed based on molecular pathological examination of a biopsy specimen. Because curative surgery was expected to be difficult, a combination of chemotherapy with doxorubicin and ifosfamide and proton beam therapy as local therapy was performed, resulting in long-term survival for at least 7.8 years. To the best of our knowledge, this is the first case of soft tissue MEC for which classical cytotoxic chemotherapy and proton beam therapy were effective. Although surgical resection with negative margins is the mainstay of treatment for MEC, adequate doxorubicin-based systemic therapy and high-dose radiation therapy may be a feasible alternative in patients with unresectable or advanced MEC. Future studies on the relationship between molecular pathological features, including biomarkers, and the selection of therapeutic agents are warranted.

[Gastric cancer genome profiling reveals HER2 false-negative status and informs a successful trastuzumab treatment strategy].

Intratumoral HER2 heterogeneity is a well-described gastric cancer feature and may explain many false-negative results related to this oncogene. An 81-year-old man was diagnosed at our hospital with stage IV gastric cancer with multiple lymph node metastases. Immunohistochemistry (IHC) analysis indicated that the primary tumor was HER2-negative. After a chemotherapy course, we submitted a pretreatment biopsy specimen for comprehensive cancer genome profiling (CGP) to determine the last-line therapy. This revealed HER2 amplification. The specimen was reevaluated using fluorescence in situ hybridization and IHC with deeper-cut specimens, which confirmed that the tumor was indeed HER2-positive. Therefore, the patient was treated with chemotherapy plus trastuzumab, which elicited tumor shrinkage and conferred long-term survival. Our current data underscore the CGP importance, which can provide more accurate tumor profilings and inform subsequent treatment decisions.

Nationwide retrospective observational study of idiopathic dendriform pulmonary ossification: clinical features with a progressive phenotype.

BACKGROUND: Diffuse pulmonary ossification is a specific lung condition that is accompanied by underlying diseases. However, idiopathic dendriform pulmonary ossification (IDPO) is extremely rare, and the clinical features remain unclear. In this study, we aimed to report the clinical characteristics of IDPO. METHODS: We conducted a nationwide survey of patients with IDPO from 2017 to 2019 in Japan and evaluated the clinical, radiological, and histopathological findings of patients diagnosed with IDPO. RESULTS: Twenty-two cases of IDPO were identified. Most subjects (82%) were male, aged 22-56 years (mean (SD), 37.9 (9.1)) at diagnosis. Nearly 80% of the subjects were asymptomatic, and the condition was discovered during a medical check-up. However, 36% of the subjects showed a decline in forced vital capacity (%FVC) predicted <80% at diagnosis. The typical radiological features of high-resolution CT (HRCT) are calcified branching structures that are predominantly distributed in the lower lung fields without any other conspicuous finding. Histopathological analysis also showed dendriform ossified lesions from the intraluminal areas to interstitial areas. Notably, during the follow-up period of 20 years, disease progression was found in 88% on HRCT and more than 50% on pulmonary function tests (FVC and/or forced expiratory volume in 1 s). Two cases with rapid decline of 10% /year in %FVC predicted were observed.)) at diagnosis. Nearly 80% of the subjects were asymptomatic, and the condition was discovered during a medical check-up. However, 36% of the subjects showed a decline in forced vital capacity (%FVC) predicted <80% at diagnosis. The typical radiological features of high-resolution CT (HRCT) are calcified branching structures that are predominantly distributed in the lower lung fields without any other conspicuous finding. Histopathological analysis also showed dendriform ossified lesions from the intraluminal areas to interstitial areas. Notably, during the follow-up period of 20 years, disease progression was found in 88% on HRCT and more than 50% on pulmonary function tests (FVC and/or forced expiratory volume in 1 s). Two cases with rapid decline of 10% /year in %FVC predicted were observed. CONCLUSIONS: IDPO develops at a young age with gradually progressive phenotype. Further research and long-term (>20 years) follow-up are required to clarify the pathogenesis and clinical findings in IDPO.

Magnetic resonance imaging characteristics of polypoid endometriosis and review of the literature.

AIM: Polypoid endometriosis is a rare variant of endometriosis and may mimic malignancy. The purpose of this study is to evaluate magnetic resonance (MR) imaging characteristics of polypoid endometriosis for the differential diagnosis with malignancy. METHODS: MR imaging findings of four histologically proven polypoid endometriosis were retrospectively evaluated with the review of the literature. RESULTS: All polypoid endometriosis exhibited high signal intensity on T2-weighted images reflecting abundant dilated endometrial glands. Peritoneal lesions were surrounded by low signal intensity rim represented the "black rim sign" reflecting endometriotic fibrous adhesion. Two cases arising from endometriotic cysts showed transmural extension (peritoneal extension and myometrial infiltration). Endometriotic hemorrhagic foci were demonstrated in four lesions as high signal intensity on T1-weighted images and/or susceptibility-induced signal voids on susceptibility-weighted MR sequence. Diffusion-weighted images showed high signal intensity with relatively high apparent diffusion coefficient (ADC) due to T2 shine-through effect but no diffusion restriction, and dynamic contrast-enhanced (DCE) MR imaging showed gradually increasing contrast-enhancement pattern like benign pathologies. CONCLUSIONS: Polypoid endometriosis may mimic malignancy; however, black rim sign may be a characteristic MR imaging finding for the peritoneal lesions, and no diffusion restriction and gradually increasing contrast-enhancement pattern may reflect its benign nature.

Cancer risk and genotype-phenotype correlation in Japanese patients with Cowden syndrome.

BACKGROUND: Cowden syndrome (CS) is an autosomal-dominant hereditary disorder caused by a germline PTEN variant and characterized by multiple hamartomas and a high risk of cancers. However, no detailed data on CS in Asian patients nor genotype-phenotype correlation have been reported. METHODS: We performed the first Japanese nationwide questionnaire survey on CS and obtained questionnaire response data on 49 CS patients. RESULTS: Patients included 26 females (median age 48 years). The incidence of breast, thyroid, endometrium, and colorectal cancer was 32.7%, 12.2%, 19.2% (among females), and 6.1%, respectively. The incidence of any cancers was relatively high among all patients (46.9%, 23/49), and particularly female patients (73.1%, 19/26), compared with previous reports from Western countries. Gastrointestinal (GI) polyps were more frequently found throughout the GI tract compared with previous studies. PTEN variants were detected in 95.6% (22/23) of patients; 12 in the N-terminal region (11 in phosphatase domain) and 10 in the C-terminal (C2 domain) region. The incidence of cancer in the C2 domain group was significantly higher than in the N-terminal region (phosphatase) group. All female patients with C2 domain variant had breast cancer. CONCLUSION: Our data suggest that Japanese patients with CS, particularly female patients and patients with C2 domain variant may have a high risk of cancers.

Radiation therapy induces an abscopal effect and upregulates programmed death-ligand 1 expression in a patient with non-small cell lung cancer.

Radiation therapy (RT) activates the antigen presentation of dendritic cells and priming of cancer-specific cytotoxic CD8+ T cells, occasionally resulting in a systemic immune response to the tumor outside of the treatment field. The phenomenon of tumor regression at the site distant from irradiated fields is known as the abscopal effect. Several case reports have indicated a potential role of RT in overcoming primary and acquired resistance against immune checkpoint inhibitors in non-small cell lung cancer (NSCLC) and melanoma patients. We herein report an NSCLC patient who developed acquired resistance to an RT-induced abscopal effect and subsequently experienced reactivation of the systemic antitumor immune response by pembrolizumab, an antiprogrammed death 1 antibody. In this case, RT not only induced an abscopal effect but also upregulated the programmed death-ligand 1 expression outside of the irradiated field when the patient developed resistance to the abscopal effect. This case can facilitate our understanding of the mechanism underlying the RT-induced systemic immune response against cancer cells and adaptive resistance mechanism of cancer cells from immune surveillance. These findings highlight the promising results of current clinical trials combining RT and immune checkpoint inhibitors. Ongoing clinical trials will further establish evidence supporting combination therapy with RT and immune checkpoint inhibitors.

ypN0 in Patients With Definitive cN-positive Status After Preoperative Treatment Is a Prognostic Factor in Esophageal Cancer.

BACKGROUND: Histopathological tumor regression grade is applied not to lymph nodes but primary tumors modified by preoperative treatments. This study focused on patients whose pathological examination at the time of surgery showed no residual tumor after chemo(radio)therapy in the primary lesion (ypT0) or lymph nodes (ypN0). PATIENTS AND METHODS: A total of 87 patients with clinical stage II/III thoracic esophageal cancer underwent esophagectomy following preoperative treatments to evaluate significances between pathological response and clinical outcomes; 51 patients with clinically definitive lymph node metastasis (cN+) were analyzed as a subgroup. RESULTS: ypT0 rates were 20.7% and 23.5%, and ypN0 rates were 47.1% and 27.5% in the whole cohort and in the cN+ subgroup, respectively. Disease-free survival, from surgery to relapse or death, was significantly influenced by ypN status (p=0.035) but not by ypT status in the 51 patients with definitive cN+ disease. Preoperative chemoradiation was an independent favorable factor for achievement of ypN0 in the 51 patients (odds ratio=0.09; p=0.007). CONCLUSION: ypN status was a predictive factor for DFS in patients treated with docetaxel plus low-dose 5-fluorouracil and cisplatin combined chemotherapy, superior to ypT status, especially in patients with definitive cN+ disease.