Significance of radiation therapy in the myxoid round-cell liposarcoma treatment regimen.

BACKGROUND AND PURPOSE: Because myxoid liposarcomas are more radiosensitive than other soft tissue sarcomas, there have been several reports of 50 Gy preoperative radiation therapy combined with surgery, but the wound complication rate is reportedly high. We have performed preoperative irradiation at a reduced dose of 40 Gy and definitive radiation therapy for unresectable cases. This study aimed to report the tumor reduction rate and oncological results with a reduced dose of preoperative irradiation and the outcome of definitive irradiation for unresectable cases. MATERIALS AND METHODS: Forty-one patients with myxoid liposarcoma treated in our institution between 2002 and 2021 were included. We examined the tumor volume shrinkage rate with preoperative radiation, compared complications and oncological outcomes between preoperative radiation and surgery-only cases, and investigated the prognosis and tumor shrinkage of definitive radiation cases. RESULTS: The total dose irradiated was 40 Gy except in two cases. The mean tumor volume reduction rate was 52.0%. A decreased dose of preoperative radiation did not worsen clinical outcomes with fewer complications. The total dose of definitive radiation was approximately 60 Gy. The mean tumor volume reduction rate was 55.0%. The tumor shrinkage maintenance rate was 100% in a median follow-up period of 50.5 months. CONCLUSION: Preoperative radiation therapy for myxoid liposarcoma near vital organs is a good approach because even with a reduced dose of 40 Gy, significant tumor reduction and excellent results were achieved. Definitive radiation therapy is the recommended treatment for older patients with serious comorbidities or inoperable patients.

Perioperative Adriamycin plus ifosfamide vs. gemcitabine plus docetaxel for high-risk soft tissue sarcomas: randomised, phase II/III study JCOG1306.

BACKGROUND: This randomised phase II/III trial aimed to determine whether perioperative chemotherapy with gemcitabine plus docetaxel (GD) is non-inferior to the standard Adriamycin plus ifosfamide (AI) in terms of overall survival (OS) in patients with soft tissue sarcoma (STS). METHODS: Patients with localised high-risk STS in the extremities or trunk were randomised to receive AI or GD. The treatments were repeated for three preoperative and two postoperative courses. The primary endpoint was OS. RESULTS: Among 143 enrolled patients who received AI (70 patients) compared to GD (73 patients), the estimated 3-year OS was 91.4% for AI and 79.2% for GD (hazard ratio 2.55, 95% confidence interval: 0.80-8.14, P = 0.78), exceeding the prespecified non-inferiority margin in the second interim analysis. The estimated 3-year progression-free survival was 79.1% for AI and 59.1% for GD. The most common Grade 3-4 adverse events in the preoperative period were neutropenia (88.4%), anaemia (49.3%), and febrile neutropenia (36.2%) for AI and neutropenia (79.5%) and febrile neutropenia (17.8%) for GD. CONCLUSIONS: Although GD had relatively mild toxicity, the regimen-as administered in this study-should not be considered a standard treatment of perioperative chemotherapy for high-risk STS in the extremities and trunk. CLINICAL TRIAL REGISTRATION: jRCTs031180003.

Standardization of evaluation method and prognostic significance of histological response to preoperative chemotherapy in high-grade non-round cell soft tissue sarcomas.

BACKGROUND: Preoperative chemotherapy is widely applied to high-grade localized soft tissue sarcomas (STSs); however, the prognostic significance of histological response to chemotherapy remains controversial. This study aimed to standardize evaluation method of histological response to chemotherapy with high agreement score among pathologists, and to establish a cut-off value closely related to prognosis. METHODS: Using data and specimens from the patients who had registered in the Japan Clinical Oncology Group study, JCOG0304, a phase II trial evaluating the efficacy of perioperative chemotherapy with doxorubicin (DOX) and ifosfamide (IFO), we evaluated histological response to preoperative chemotherapy at the central review board. RESULTS: A total of 64 patients were eligible for this study. The percentage of viable tumor area ranged from 0.1% to 97.0%, with median value of 35.7%. Regarding concordance proportion between pathologists, the weighted kappa coefficient (κ) score in all patients was 0.71, indicating that the established evaluation method achieved substantial agreement score. When the cut-off value of the percentage of the residual tumor area was set as 25%, the p-value for the difference in overall survival showed the minimum value. Hazard ratio of the non-responder with percentage of the residual tumor < 25%, to the responder was 4.029 (95% confidence interval 0.893-18.188, p = 0.070). CONCLUSION: The standardized evaluation method of pathological response to preoperative chemotherapy showed a substantial agreement in the weighted κ score. The evaluation method established here was useful for estimating of the prognosis in STS patients who were administered perioperative chemotherapy with DOX and IFO. TRIAL REGISTRATION: UMIN Clinical Trials Registry C000000096. Registered 30 August, 2005 (retrospectively registered).

Osteosclerotic change as a therapeutic response to gefitinib in symptomatic non-small cell lung cancer bone metastasis.

BACKGROUND: Despite improvement in the overall survival of patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation, the effects of EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment on bone metastasis remain unclear. This study investigated radiological responses to gefitinib regarding bone metastasis in patients. METHODS: We treated 260 patients with NSCLC and symptomatic bone metastasis. Thirty-seven patients harboring EGFR mutation were treated with gefitinib for more than 30 days and followed up for more than 3 months (GEF group). We performed a retrospective observational study by selecting 36 cases without EGFR-TKI treatment, at least 3 months of follow-up, and at least two radiological evaluations as the control group. We assessed the best overall radiological response, interval from treatment initiation to appearance of a radiological response, and the local response maintenance rate. RESULTS: The best effect in the GEF group was 98% partial response or better, which was significantly higher than the 57% observed in the control group (p < 0.001). The GEF and control groups maintained 83% and 42% local response maintenance rates at one year, respectively (p < 0.001). In the GEF with radiotherapy group, the local response maintenance rate was maintained at 92% at 1 year, while in the GEF without RT group, there was a decrease in the local response maintenance rate from 270 days. CONCLUSION: Gefitinib treatment for bone metastases in patients harboring EGFR mutation resulted in a beneficial osteosclerotic change in most patients. Combined gefitinib and radiotherapy provide long-lasting local control of bone metastases.

Direct femoral head approach without surgical dislocation for femoral head chondroblastoma: a report of two cases.

BACKGROUND: Chondroblastomas are rare, benign, locally aggressive lesions that appear in the epiphysis. Surgery for femoral head chondroblastoma (FHCB) is difficult. Conventional treatment with curettage via a drilled tunnel along the femoral neck can damage the growth plate and is associated with high local recurrence rates. The trapdoor procedure, which directly facilitates lesion access from the femoral head articular surface, can reduce local recurrence and avoid growth plate damage, although it requires surgical dislocation. Little is known about the long-term results of this direct articular surface approach, and there are no case reports on trapdoor procedures without dislocation. CASE PRESENTATION: We report two cases (patients aged 12 and 15 years) of FHCB presented with coxalgia treated using the trapdoor procedure without surgical dislocation. Both surgeries were performed with patients in the semi-lateral position. The hip joint was exposed via an anterior approach, and a capsulotomy was performed at the superior rim of the acetabulum, followed by the external rotation of the hip joint. With a fine osteotome, a rectangular flap (trapdoor) was opened on the cartilage surface in the lateral non-weight-bearing area, and curettage of the lesion followed by bone and/or bone substitute grafting was performed. Subsequently, the trapdoor was replaced in its original position. There has been no local recurrence or femoral head aseptic necrosis after more than 6 and 12 years for patients 1 and 2, respectively. Both patients had musculoskeletal tumor society scores of 100% at follow-up and are enjoying a normal active life. CONCLUSIONS: This direct femoral head approach without dislocation may be a simple treatment alternative for FHCB.

A phase II study of palliative radiotherapy combined with zoledronic acid hydrate for metastatic bone tumour from renal cell carcinoma.

PURPOSE: Palliative radiotherapy is the standard of care for bone metastases. However, skeletal-related events, defined as a pathologic fracture, paraplegia, surgery or radiotherapy for local recurrence, or severe pain in previously irradiated bone with radio-resistant histology type still present high incidence. The primary objective of this study was to determine whether zoledronic acid hydrate and palliative radiotherapy could prevent local skeletal-related events. METHODS: Eligible patients with bone metastases from renal cell carcinoma were treated with zoledronic acid hydrate every 3 or 4 weeks and concurrent palliative radiotherapy of 30 Gy in 3 Gy fractions. The criteria for radiotherapy were established by the treating physician, but patients with complicated bone metastases (impending pathological fracture or spinal cord compression) which needed immediate surgery were excluded. The primary endpoint was the local skeletal-related event-free survival rate at 1 year. RESULTS: Twenty-seven patients were included in the study. The median age was 65 (range, 50-84) years. Radiotherapy dose was 30 Gy for all patients except 1 whose radiotherapy was terminated due to brain metastasis progression at 18 Gy. Zoledronic acid hydrate was administered in a median of 12 (range, 0-34) times. The median follow-up period was 12 months and 19 months in patients who were still alive. Of 27 patients in the efficacy analysis, the 1-year local skeletal-related event-free rate was 77.6% (80% confidence interval, 66.2-89.0). Common grade 3 toxicities were hypocalcemia (1 [4%]), sGPT level increase (1 [4%]) and sGOT level increase (1 [4%]). There was no grade 4 or 5 toxicity. CONCLUSION: Zoledronic acid hydrate administration and palliative radiotherapy were a well-tolerated and promising treatment reducing skeletal-related events for bone metastases from renal cell carcinoma.

Japanese version of The Cancer Genome Atlas, JCGA, established using fresh frozen tumors obtained from 5143 cancer patients.

This study aimed to establish the Japanese Cancer Genome Atlas (JCGA) using data from fresh frozen tumor tissues obtained from 5143 Japanese cancer patients, including those with colorectal cancer (31.6%), lung cancer (16.5%), gastric cancer (10.8%) and other cancers (41.1%). The results are part of a single-center study called "High-tech Omics-based Patient Evaluation" or "Project HOPE" conducted at the Shizuoka Cancer Center, Japan. All DNA samples and most RNA samples were analyzed using whole-exome sequencing, cancer gene panel sequencing, fusion gene panel sequencing and microarray gene expression profiling, and the results were annotated using an analysis pipeline termed "Shizuoka Multi-omics Analysis Protocol" developed in-house. Somatic driver alterations were identified in 72.2% of samples in 362 genes (average, 2.3 driver events per sample). Actionable information on drugs that is applicable in the current clinical setting was associated with 11.3% of samples. When including those drugs that are used for investigative purposes, actionable information was assigned to 55.0% of samples. Germline analysis revealed pathogenic mutations in hereditary cancer genes in 9.2% of samples, among which 12.2% were confirmed as pathogenic mutations by confirmatory test. Pathogenic mutations associated with non-cancerous hereditary diseases were detected in 0.4% of samples. Tumor mutation burden (TMB) analysis revealed 5.4% of samples as having the hypermutator phenotype (TMB ≥ 20). Clonal hematopoiesis was observed in 8.4% of samples. Thus, the JCGA dataset and the analytical procedures constitute a fundamental resource for genomic medicine for Japanese cancer patients.

Ten-year follow-up results of perioperative chemotherapy with doxorubicin and ifosfamide for high-grade soft-tissue sarcoma of the extremities: Japan Clinical Oncology Group study JCOG0304.

BACKGROUND: Soft-tissue sarcomas (STS) are rare malignant tumors those are resistant to chemotherapy. We have previously reported the 3-year follow-up result on the efficacy of perioperative chemotherapy with doxorubicin (DXR) and ifosfamide (IFM) for high-risk STS of the extremities (JCOG0304). In the present study, we analyzed the 10-year follow-up results of JCOG0304. METHODS: Patients with operable, high-risk STS (T2bN0M0, AJCC 6th edition) of the extremities were treated with 3 courses of preoperative and 2 courses of postoperative chemotherapy, which consisted of 60 mg/m2 of DXR plus 10 g/m2 of IFM over a 3-week interval. The primary study endpoint was progression-free survival (PFS) estimated by Kaplan-Meier methods. Prognostic factors were evaluated by univariable and multivariable Cox proportional hazards model. RESULTS: A total of 72 patients were enrolled between March 2004 and September 2008, with 70 of these patients being eligible. The median follow-up period was 10.0 years for all eligible patients. Local recurrence and distant metastasis were observed in 5 and 19 patients, respectively. The 10-year PFS was 65.7% (95% CI: 53.4-75.5%) with no PFS events being detected during the last 5 years of follow-up. The 10-year overall survival was 78.1% (95% CI: 66.3-86.2%). Secondary malignancy was detected in 6 patients. The subgroup analysis demonstrated that there was significant difference in survival with regard to primary tumor size. CONCLUSIONS: Only a few long-term results of clinical trials for perioperative chemotherapy treatment of STS have been reported. Our results demonstrate that the 10-year outcome of JCOG0304 for patients with operable, high-risk STS of the extremities was stable and remained favorable during the last 5 years of follow-up. TRIAL REGISTRATION: This trial was registered at the UMIN Clinical Trials Registry as C000000096 on August 30, 2005.

Pro-gastrin-releasing peptide as a marker for the Ewing sarcoma family of tumors.

BACKGROUND: Pro-gastrin-releasing peptide (ProGRP) is an established tumor marker of small cell lung cancer. The purpose of this study was to determine if ProGRP could serve as a tumor marker for the Ewing sarcoma family of tumors (ESFTs). METHODS: Sixteen patients with ESFTs (mean age 32 years) were included in this study. As a control group, 42 patients with other tumor types that clinically or pathologically mimic ESFTs were also analyzed. Pre-treatment serum ProGRP and neuron-specific enolase (NSE) levels, the relationships between these levels, and tumor volume were investigated. In addition, serial changes in the serum or plasma ProGRP (6 patients) and NSE levels (5 patients) were measured over the course of treatment. RESULTS: Pre-treatment serum ProGRP levels were higher than the normal range in 8 of 16 patients; for these eight patients, ProGRP levels positively correlated with tumor volume (R = 0.99). In the control group, ProGRP levels were within the normal range, except for the two patients. Changes in ProGRP levels during treatment were consistent with tumor volume. Serum NSE levels were elevated in 14 of 16 patients with ESFTs and 8 of 42 patients with other tumor types. The range of NSE elevation was much smaller compared to that of ProGRP. Our data indicate that ProGRP is superior to NSE in terms of specificity. CONCLUSIONS: Serum ProGRP levels were elevated in half of the patients with ESFTs and reflected therapeutic response. ProGRP is a reliable tumor marker for the diagnosis of ESFTs and evaluation of treatment response.

Posterior reversible encephalopathy syndrome (PRES) induced by pazopanib, a multi-targeting tyrosine kinase inhibitor, in a patient with soft-tissue sarcoma: case report and review of the literature.

Posterior reversible encephalopathy syndrome (PRES) is a clinical entity characterized by acute neurological symptoms such as severe headache, seizures, and visual disturbance, and by typical reversible lesion on brain magnetic resonance (MR) images. Since PRES is thought to be caused by vascular endothelial injury due to cytotoxic agents or acute systemic hypertension, the number of reports on PRES associated with angiogenesis inhibitors has been increasing. Although five cases that developed PRES due to pazopanib for renal cell carcinoma have already been reported, none of PRES due to pazopanib for soft-tissue sarcoma has been reported thus far. We describe a case of a 49-year-old woman with retroperitoneal soft-tissue sarcoma who developed PRES during pazopanib administration. Pazopanib at 800 mg/day was administered as her third-line treatment at relapse. After 38 days of pazopanib, she was admitted to our hospital with severe headache, vomiting, and systemic hypertension. The next day, she developed consciousness deterioration and visual disturbance together with exacerbated systemic hypertension. Brain MR images revealed hyper-intense signals on FLAIR sequences in the bilateral occipital lobes and the left thalamus. Intravenous nicardipine injection was immediately started to control her blood pressure and pazopanib was discontinued. Her symptoms gradually improved and disappeared on the fifth hospital day. After 2 weeks, hyper-intense signals on a FLAIR sequence disappeared completely. She restarted a low dose of pazopanib under good blood pressure control and experienced no subsequent recurrence of PRES.

Radiotherapy combined with zoledronate can reduce skeletal-related events in renal cell carcinoma patients with bone metastasis.

BACKGROUND: Skeletal-related events (SRE) are common in patients with renal cell carcinoma (RCC) that includes bone metastasis. The purpose of this study was to clarify the effectiveness of zoledronate with and without sunitinib, combined with radiotherapy, for the treatment of bone metastasis from RCC. METHODS: We retrospectively analyzed 62 RCC patients with bone metastasis, who had been treated with radiotherapy at our institution. We divided the study cohort into two groups: patients treated with radiotherapy alone (RT; n = 27) and those treated with radiotherapy combined with zoledronate (RT + Z; n = 35). We investigated the overall survival and post-irradiation (PI)-SRE-free rate for each group, as well as the effect of sunitinib in the RT + Z treatment group. In addition, we determined treatment effectiveness by imaging assessments and relative response rates. RESULTS: There was no significant difference in the survival rates between the RT and RT + Z treatment groups (p = 0.11). However, the PI-SRE-free rate in the RT + Z group was significantly higher than that in the RT group (p = 0.02). The PI-SRE-free rate was significantly higher in patients who were treated with sunitinib after radiotherapy than in those who were treated without sunitinib (p = 0.03). However, there was no significant difference in the relative response rates, as assessed by imaging, in each group. CONCLUSION: Radiotherapy combined with zoledronate is an effective treatment for RCC with bone metastasis to prevent PI-SRE. Sunitinib may reduce PI-SRE if used after radiotherapy and combined with zoledronate.

Asymmetrical vertebral collapse from spinal metastasis in lower thoracic and lumbar spine.

OBJECTIVE: The purpose of this study was to investigate the differences between spinal metastasis and osteoporotic compression fractures on plain X-ray images, focusing on asymmetrical vertebral collapse and fracture level. MATERIALS AND METHODS: This study included 180 patients with pathological collapse from spinal metastasis (188 vertebrae) who were treated at our institution and 70 patients (92 vertebrae) with osteoporotic compression fractures. Anteroposterior X-ray images of the lower thoracic and lumbar spine were evaluated for asymmetrical collapse deformity. RESULTS: Asymmetrical collapse was found in 134 vertebrae (71.3%) with metastasis, and in 20 osteoporotic vertebrae (21.7%); this difference was significant (p < 0.0001). The asymmetrical collapse angle in spinal metastasis patients ranged from 0 to 18°, with a mean of 7.0 and a standard deviation (SD) of 4.5. In contrast, the asymmetrical collapse angle in patients with osteoporotic fractures ranged from 0 to 13°, with a mean of 3.1 and a SD of 2.8. The difference in collapse angle between the two groups was statistically significant (p < 0.001). The cutoff value to suspect spinal metastasis was determined to be 5° or more (sensitivity 0.67, specificity 0.74). Fracture at Th10 or below L3 was found in 20.2% of spinal metastasis patients; only 3% of osteoporotic fractures occurred at these levels. CONCLUSION: Asymmetrical collapse with an angle of 5° or more and fractures at atypical levels on plain radiographs can be useful clues to spinal metastasis.

Factors associated with the decision of operative procedure for proximal femoral bone metastasis: Questionnaire survey to institutions participating the Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group.

BACKGROUND: Pathological fracture of the proximal femur is a main cause of cancer patients losing their ability to walk. Although both osteosynthetic devices (predominantly intramedullary nails) and prosthetic replacement have been widely performed for treatment, controversies exist regarding which procedure should be used for the various conditions. In order to decide the eligibility criteria of a planned randomized prospective study about the treatment of pathological fractures of the proximal femur, we assessed the factors affecting the selection of operative procedures using questionnaires sent to the members of the Bone and Soft Tissue Tumor Study Group (BSTTSG) of the Japan Clinical Oncology Group (JCOG). METHODS: Questionnaire surveys to evaluate (1) the priority levels of the factors, (2) the equipoise range of each factor in situations where either procedure could be applied, (3) risk and benefit of each procedure, and (4) the degree of bone destruction affecting the selection of operative procedures, were sent to 26 institutions. RESULTS: Over 80% of the institutions answered. Orthopaedic surgeons of BSTTSG decided on the procedure according to the following factors in descending order: life expectancy, performance status before fracture, the degree of bone destruction, walking ability before fracture, general complications, the number of bone metastases in other sites, and the visceral metastasis status. With regard to bone destruction, (1) the involvement of the head, neck, calcar, and intertrochanteric region, (2) transverse destruction >1/2, and (3) soft-tissue tumor extension, were the factors that led to the choice of prosthesis treatment. CONCLUSIONS: Using these identified factors, the inclusion criteria for the prospective randomized study of the surgical treatment of metastatic bone tumors of the proximal femur were optimized. The evaluation system about the bone destruction of metastases needs to be refined through the following prospective randomized study.

Clinical outcome for patients of solitary bone only metastasis.

BACKGROUND: Solitary bone only metastasis (SBOM) is a rare condition in which metastasis is limited to a single skeletal lesion originating from a previously treated or controllable primary lesion. The study objective was to evaluate the clinical features and survival regarding this rare condition and to clarify its treatment strategy. METHODS: A total of 1453 patients with bone metastasis registered in our hospital database were enrolled. To assess the primary and/or metastatic lesion we used plain X-ray images, CT, MRI and FDG-PET scans as well as bone scans. RESULTS: Among the patients, only 27 (1.8%) had SBOM. The primary cancers responsible for SBOM were lung in seven patients, breast in five, kidney in four, prostate in two, uterus in two and other types in seven. Treatment of SBOM involved resection in four patients, radiotherapy only in 17, radiotherapy in combination with zoledronate in six and chemotherapy with zoledronate in one. Local recurrence did not develop in the four cases treated with resection. However, in-field recurrence was found in 4 of 22 (18%) patients who underwent radiotherapy. All three patients who received >40 Gy did not develop in-field recurrence. The overall and event free survival rates at 5 years were 63% and 41%, respectively. CONCLUSIONS: Solitary bone only metastasis should be treated with wide resection or long-course radiotherapy at doses 40-50 Gy to achieve long lasting local tumor control.

Impact of Mutations in Subunit Genes of the Mammalian SWI/SNF Complex on Immunological Tumor Microenvironment.

BACKGROUND/AIM: Recently, inactivating somatic mutations of SWI/SNF chromatin-remodeling genes in cancers have been reported. However, few studies have been performed regarding the immunological analysis of the tumor microenvironment (TME) in chromatin remodeling complex gene-mutated tumors. In the present study, we identified cancer patients harboring various mammalian SWI/SNF complex mutations and investigated the immunological features in those mutated cancers. PATIENTS AND METHODS: Cancer patients harboring any type of chromatin remodeling complex gene mutation were selected and clinicopathological features were compared between chromatin remodeling complex gene expression-low and expression-high groups. Specifically, expression levels of immune response-associated genes and cancer-associated genes were compared between the SMARCA4 expression-low and expression-high groups using volcano plot analysis. RESULTS: Among cancers harboring PBRM1, SAMRACA4 and ARID2 gene mutations, T-cell marker and mature B-cell marker genes were up-regulated in the tumor. Specifically, T-cell effector genes (CD8B, CD40LG), central memory marker genes (CD27, CCR7) and mature B-cell marker genes (CD20, CD38, CD79 and IRF4) were up-regulated, and cancer-associated genes including MYB, MYC and AURKB genes were down-regulated in the SMARCA4 expression-low group. Remarkably, heatmap of gene expression and immunohistochemistry (IHC) data demonstrated that the tertiary lymphoid structure (TLS) gene signature of mature B cells was up-regulated in SMACA4 gene-mutated stomach cancers. CONCLUSION: These results suggest that immune tumor microenvironment status, such as mature B cell recruitment featuring the TLS gene signature and immune activation mediated by cancer signal down-regulation, might contribute to the classification of SMARCA4 gene-mutated tumors as immune checkpoint blockade therapy-sensitive target tumors.

Evaluation of whole genome sequencing utility in identifying driver alterations in cancer genome.

In cancer genome analysis, identifying pathogenic alterations and assessing their effects on oncogenic processes is important. Although whole exome sequencing (WES) can effectively detect such changes, driver alterations could not be identified in 27.8% of the cases, according to a previous study. The objectives of the present study were to evaluate the utility of whole genome sequencing (WGS) and clarify its differences with WES in terms of driver alteration detection. For this purpose, WGS analysis was conducted on 177 driverless WES samples, selected from 5,480 fresh frozen samples derived from 5,140 Japanese patients with cancer. These samples were selected as primary tumor, both WES and transcriptome profiling were performed, estimated tumor content of ≥ 30%, and no driver alterations were identified by WES. WGS identified driver and likely driver alterations in 68.4 and 22.6% of the samples, respectively. The most frequent alteration type was oncogene amplification, followed by tumor suppressor gene deletion and small variants located outside the coding region. In the remaining 9.0% of samples, no such signals were identified; therefore, further investigations are required. The current study clearly demonstrated the role and utility of WGS in identifying genomic alterations that contribute to tumorigenesis.

Extraskeletal myxoid chondrosarcoma in the pelvis successfully treated with proton beam radiotherapy.

The standard treatment for extraskeletal myxoid chondrosarcoma is wide excision. However, extraskeletal myxoid chondrosarcoma is often located in the deep layers of the extremities and pelvis, so functional impairment due to wide resection is unavoidable in many cases. In addition, the efficacy of radiotherapy and chemotherapy has not been defined, so no treatment method is established for unresectable cases. Here we report a case involving a man in his late 60s with extraskeletal myxoid chondrosarcoma of the pelvis who responded to proton beam radiotherapy with intra-arterial chemotherapy and did not require surgery. The patient maintained a complete response for more than 7 years. The findings from this case suggest that definitive irradiation can be an alternative to wide resection for cases of extraskeletal myxoid chondrosarcoma in which severe disability cannot be avoided after resection or when the tumour is inoperable due to its size and location.

Generation of novel complete HLA class I monoallelic cell lines used in an MHC stabilization assay for neoantigen evaluation.

Immunogenic neoantigens derived from somatic mutations in cancer have been identified through clinical studies with the cloning of tumor-infiltrating T cells, and cancer driver gene mutation-derived epitopes have been reported; however, these are rare. At present, the validation of epitopes predicted in silico is difficult as human T-cell clonal diversity cannot be reproduced in vitro or in experimental animal models. To confirm the epitope peptides presented by human leukocyte antigen (HLA) class I molecules predicted in silico, biochemical methods such as major histocompatibility complex (MHC) stabilization assays and mass spectrometry-mediated identification have been developed based on HLA-A*02:01 monoallelic T2 cells and HLA-C*01:02 monoallelic LCL721.221 cells. Therefore, in the present study, to prevent confusion due to peptide cross-presentation among HLA molecules, HLA class I monoallelic B-cell clones were generated from the TISI cell line by knocking out HLA-ABC and TAP2, and knocking in HLA alleles. To explore cancer driver mutations as potential targets for immunotherapy, exome sequencing data from 5,143 patients with cancer enrolled in a comprehensive genome analysis project at the Shizuoka Cancer Center were used to identify somatic amino acid substituted mutations and the 50 most frequent mutations in five genes, TP53, EGFR, PIK3CA, KRAS and BRAF, were identified. Using NetMHC4.1, the present study predicted whether epitopes derived from these mutations are presented on major HLA-ABC alleles in Japanese individuals and synthesized 138 peptides for MHC stabilization assays. The authors also attempted to examine the candidate epitopes at physiological temperatures by using antibody clone G46-2.6, which can detect HLA-ABC, independent of ß2-microglobulin association. In the assays, although the peptide-induced HLA expression levels were associated with the predicted affinities, the respective HLA alleles exhibited varying degrees of responsiveness, and unexpectedly, p53-mutant epitopes with predicted weak affinities exhibited strong responses. These results suggested that MHC stabilization assays using completely monoallelic HLA-expressing B-cell lines are useful for evaluating the presentation of neoantigen epitopes.

Characterization of the Immunological Status of Hypermutated Solid Tumors in the Cancer Genome Analysis Project HOPE.

BACKGROUND: Many reports demonstrate that a high tumor mutation burden (TMB-H) is closely associated with good prognosis of cancer. However, specific studies investigating the association of various TMB statuses with overall survival in patients with solid tumors are scarce. PATIENTS AND METHODS: In the present study, we investigated the association of TMB status with overall survival in 5,072 patients with cancer from the HOPE project and clarified the specific mechanism responsible for the good prognosis of the TMB-H group. All tumors were classified into one of four groups based on TMB: ultralow (UL), low (L), intermediate (I) and high (H). RESULTS: The TMB-H group had a better prognosis than the TMB-I and TMB-L groups, but not than the TMB-UL group. Analyzing the expression of 293 immune response-associated genes, 17 genes were up-regulated in the TMB-H group compared to the TMB-I and TNB-L groups, and two genes [CD274 and interferon-γ (IFNG)] were identified as good prognostic factors. Analysis of immune cell populations inside tumors demonstrated that the frequencies of exhausted CD8+ T-cells, activated effector CD8+ T-cells and natural killer cells were significantly higher in the TMB-H group. The T-cell receptor repertoire numbers and the diversity evenness score (DE50) were lower in the TMB-H group than in TMB-UL group; however, no association of the DE50 value with the binding or elution affinity of epitope peptides from neoantigens was found. CONCLUSION: One possible mechanism for the good prognosis of the TMB-UL group compared to the TMB-H group might be that the TMB-UL group features a balance between immunosuppression and immunostimulation.