An algorithm-based technique for counting mitochondria in cells using immunohistochemical staining of formalin-fixed and paraffin-embedded sections.

PURPOSE: Visualizing mitochondria in cancer cells from human pathological specimens may improve our understanding of cancer biology. However, using immunohistochemistry to evaluate mitochondria remains difficult because almost all cells contain mitochondria and the number of mitochondria per cell may have important effects on mitochondrial function. Herein, we established an objective system (Mito-score) for evaluating mitochondria using machine-based processing of hue, saturation, and value color spaces. METHODS: The Mito-score was defined as the number of COX4 (mitochondrial inner membrane) immunohistochemistry-positive pixels divided by the number of nuclei per cell. The system was validated using four lung cancer cell lines, normal tissues, and lung cancer tissues (199 cases). RESULTS: The Mito-score correlated with MitoTracker, a fluorescent dye used to selectively label and visualize mitochondria within cells under a microscope (R2 = 0.68) and with the number of mitochondria counted using electron microscopy (R2 = 0.79). Histologically, the Mito-score of small cell carcinoma (57.25) was significantly lower than that of adenocarcinoma (147.5, p < 0.0001), squamous cell carcinoma (120.6, p = 0.0004), and large cell neuroendocrine carcinoma (111.8, p = 0.002). CONCLUSION: The Mito-score method enables the analysis of the mitochondrial status of human formalin-fixed paraffin-embedded specimens and may provide insights into the metabolic status of cancer.

Lessons learned from contamination with endotoxin originated from the supplement in the cell culture medium.

Introduction: Endotoxin is a typical pyrogen derived from the outer membrane of Gram-negative bacteria. In fabricating cell-based medicinal products, it is necessary to control endotoxin in the process and the products. In the quality control tests of our clinical study, endotoxin concentration in the culture supernatant of autologous oral mucosal epithelial cell sheets exceeded the criterion value. Therefore, endotoxin measurements were conducted to clarify the cause of the endotoxin contamination. Methods: The reagents used to prepare the culture medium, the unused culture medium, and the culture supernatants were diluted with pure water. Endotoxin concentrations in the diluted samples were measured. Results: Endotoxin was detected in both the unused culture medium and the culture supernatant of the epithelial cell sheets at higher concentrations than the criterion value. Therefore, endotoxin concentrations in the reagents used to prepare the culture medium were measured and were found to be below the criterion value, except for cholera toxin. On the other hand, three lots of cholera toxin products were used for the measurement, and the endotoxin concentrations were higher than the criterion value. The results indicate that the endotoxin contamination is caused by the cholera toxin product. Conclusions: To prevent endotoxin contamination in cell-based medicinal products, endotoxin concentrations in reagents used for the fabrication should be measured in the facility conducting clinical research or confirmed by an adequate certificate of analysis from the manufacturers of the reagents.

Molecular subtypes of lung adenocarcinoma present distinct immune tumor microenvironments.

Overcoming resistance to immune checkpoint inhibitors is an important issue in patients with non-small-cell lung cancer (NSCLC). Transcriptome analysis shows that adenocarcinoma can be divided into three molecular subtypes: terminal respiratory unit (TRU), proximal proliferative (PP), and proximal inflammatory (PI), and squamous cell carcinoma (LUSQ) into four. However, the immunological characteristics of these subtypes are not fully understood. In this study, we investigated the immune landscape of NSCLC tissues in molecular subtypes using a multi-omics dataset, including tumor-infiltrating leukocytes (TILs) analyzed using flow cytometry, RNA sequences, whole exome sequences, metabolomic analysis, and clinicopathologic findings. In the PI subtype, the number of TILs increased and the immune response in the tumor microenvironment (TME) was activated, as indicated by high levels of tertiary lymphoid structures, and high cytotoxic marker levels. Patient prognosis was worse in the PP subtype than in other adenocarcinoma subtypes. Glucose transporter 1 (GLUT1) expression levels were upregulated and lactate accumulated in the TME of the PP subtype. This could lead to the formation of an immunosuppressive TME, including the inactivation of antigen-presenting cells. The TRU subtype had low biological malignancy and "cold" tumor-immune phenotypes. Squamous cell carcinoma (LUSQ) did not show distinct immunological characteristics in its respective subtypes. Elucidation of the immune characteristics of molecular subtypes could lead to the development of personalized immune therapy for lung cancer. Immune checkpoint inhibitors could be an effective treatment for the PI subtype. Glycolysis is a potential target for converting an immunosuppressive TME into an antitumorigenic TME in the PP subtype.

Baseline ctDNA gene alterations as a biomarker of survival after panitumumab and chemotherapy in metastatic colorectal cancer.

Certain genetic alterations and right-sided primary tumor location are associated with resistance to anti-epidermal growth factor (EGFR) treatment in metastatic colorectal cancer (mCRC). The phase 3 PARADIGM trial (n = 802) demonstrated longer overall survival with first-line anti-EGFR (panitumumab) versus antivascular endothelial growth factor (bevacizumab) plus modified FOLFOX6 in patients with RAS wild-type mCRC with left-sided primary tumors. This prespecified exploratory biomarker analysis of PARADIGM (n = 733) evaluated the association between circulating tumor DNA (ctDNA) gene alterations and efficacy outcomes, focusing on a broad panel of gene alterations associated with resistance to EGFR inhibition, including KRAS, NRAS, PTEN and extracellular domain EGFR mutations, HER2 and MET amplifications, and ALK, RET and NTRK1 fusions. Overall survival was prolonged with panitumumab plus modified FOLFOX6 versus bevacizumab plus modified FOLFOX6 in patients with ctDNA that lacked gene alterations in the panel (that is, negative hyperselected; median in the overall population: 40.7 versus 34.4 months; hazard ratio, 0.76; 95% confidence interval, 0.62-0.92) but was similar or inferior with panitumumab in patients with ctDNA that contained any gene alteration in the panel (19.2 versus 22.2 months; hazard ratio, 1.13; 95% confidence interval, 0.83-1.53), regardless of tumor sidedness. Negative hyperselection using ctDNA may guide optimal treatment selection in patients with mCRC. ClinicalTrials.gov registrations: NCT02394834 and NCT02394795 .

Neutrophil-to-lymphocyte ratio is a prognostic factor reflecting immune condition of tumor microenvironment in squamous cell lung cancer.

Inflammatory factors in the peripheral blood, such as the C-reactive protein level and neutrophil-to-lymphocyte ratio (NLR), are prognostic markers in multiple types of cancer, including non-small cell lung cancer (NSCLC). However, the association between inflammatory factors and prognosis based on histological types has not been adequately reported. In addition, the relationship between these factors and the immune condition of the tumor microenvironment (TME) is unclear. In this single center, retrospective study, we first investigated the relationship between preoperative inflammatory markers and clinical outcomes in 176 patients with NSCLC who underwent surgery. Lung adenocarcinoma (LUAD) showed no significant prognostic marker, whereas for lung squamous cell carcinoma (LUSC), a multivariate analysis showed that a high NLR was significantly associated with postoperative recurrence. In LUSC patients, the median time of postoperative recurrence-free survival in patients with a low NLR was longer than that in patients with a high NLR. We then compared the tumor-infiltrating lymphocyte (TIL) profile with inflammatory markers in peripheral blood and found that the NLR was negatively correlated with the frequencies of T cells and B cells in LUSC tissues. Thus, the NLR is a useful predictive biomarker for postoperative recurrence and may reflect the immune condition of the TME in LUSC.

Association between continuous cessation or reduction of drinking alcohol and improvement of multiple dysplastic lesions in patients with esophageal squamous cell carcinoma after endoscopic resection.

BACKGROUND: Multiple development of squamous cell carcinoma (SCC) in the upper aerodigestive tract has been explained by the 'field cancerization phenomenon' associated with alcohol drinking. Squamous dysplastic lesion is clinically visualised as a Lugol-voiding lesion (LVL) by chromoendoscopy. Whether cessation or reduction of alcohol drinking improves multiple LVL and reduces the risk of field cancerization has not been elucidated. METHODS: We analysed 330 patients with newly diagnosed superficial esophageal SCC (ESCC) enrolled in the cohort study. The grade of LVL was assessed in all patients every 6 months. We instructed the patients to stop smoking and drinking and recorded their drinking and smoking status every 6 months. RESULTS: Among 330 patients, we excluded 98 with no LVL or no drinking habit. Of the remaining 232 patients, 158 continuously ceased or reduced their drinking habit. Patients who ceased or reduced their drinking habit significantly showed improvement in the grade of LVL. Multivariate analysis showed that continuous cessation or reduction of drinking habit improved the grade of LVL (hazard ratio [HR] = 8.5, 95% confidence interval [CI] 1.7-153.8, p = 0.0053). Higher grade of LVL carried a high risk of multiple ESCC and head and neck SCC (HNSCC) (HR = 3.7, 95% CI 2.2-6.4, p < 0.0001). Improvement in LVL significantly decreased the risk of multiple ESCC and HNSCC (HR = 0.2, 95% CI 0.04-0.7, p = 0.009). CONCLUSIONS: This is the first report indicating that field cancerization was reversible and cessation or reduction of drinking alcohol could prevent multiple squamous dysplastic lesion and multiple ESCC and HNSCC development. CLINICAL TRIALS REGISTRY NUMBER: UMIN000001676.

Metabolic Hallmarks for Purine Nucleotide Biosynthesis in Small Cell Lung Carcinoma.

Small cell lung cancer (SCLC) has a poor prognosis, emphasizing the necessity for developing new therapies. The de novo synthesis pathway of purine nucleotides, which is involved in the malignant growth of SCLC, has emerged as a novel therapeutic target. Purine nucleotides are supplied by two pathways: de novo and salvage. However, the role of the salvage pathway in SCLC and the differences in utilization and crosstalk between the two pathways remain largely unclear. Here, we found that deletion of the HPRT1 gene, which codes for the rate-limiting enzyme of the purine salvage pathway, significantly suppressed tumor growth in vivo in several SCLC cells. We also demonstrated that HPRT1 expression confers resistance to lemetrexol (LMX), an inhibitor of the purine de novo pathway. Interestingly, HPRT1-knockout had less effect on SCLC SBC-5 cells, which are more sensitive to LMX than other SCLC cell lines, suggesting that a preference for either the purine de novo or salvage pathway occurs in SCLC. Furthermore, metabolome analysis of HPRT1-knockout cells revealed increased intermediates in the pentose phosphate pathway and elevated metabolic flux in the purine de novo pathway, indicating compensated metabolism between the de novo and salvage pathways in purine nucleotide biosynthesis. These results suggest that HPRT1 has therapeutic implications in SCLC and provide fundamental insights into the regulation of purine nucleotide biosynthesis. IMPLICATIONS: SCLC tumors preferentially utilize either the de novo or salvage pathway in purine nucleotide biosynthesis, and HPRT1 has therapeutic implications in SCLC.

Fibroblast inhibition by tocilizumab enabled gemcitabine/nab-paclitaxel rechallenge for pancreatic cancer.

Interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) pathway inhibition may overcome chemoresistance of metastatic pancreatic cancer (MPC). We sought to determine the safety and recommended dose of tocilizumab (TCZ), an IL-6 receptor monoclonal antibody, and biological correlates of tumor shrinkage in patients with gemcitabine (GEM)/nanoparticle albumin-bound paclitaxel (nab-PTX)-refractory MPC. This phase 1 study enrolled 10 patients with MPC who had progressed after GEM/nab-PTX. Patients initially received TCZ 8 mg/kg on Day 1 and nab-PTX 100 mg/m2 + GEM 750 mg/m2 on Days 2, 9, and 16. Before and at the end of Cycle 1, biopsy of liver metastases was performed 3-5 h after levofloxacin (LVFX) administration to measure LVFX infiltration into tumor tissue. No dose-limited toxicities occurred, and the recommended dosage of TCZ was determined to be 8 mg/kg. Treatment-emergent adverse events occurred in 80% of patients, of which decreased neutrophil count was the most common. Tumor reduction during Cycle 1 was observed in four patients, who were defined as responders. In paired-biopsy samples, responder-related biological activities were an increase of cleaved PARP expression of tumor nuclei (p = 0.01), a decrease of proliferative cancer-associated fibroblasts (CAFs) (p = 0.08), and an increase of LVFX infiltration in the tumor (p = 0.04). A decrease of phosphorylated STAT3 expression (p = 0.02) favored an increase in LVFX infiltration. In conclusion, TCZ + GEM/nab-PTX-rechallenge had a manageable safety profile and showed preliminary activity via inhibition of CAF and improved intratumoral drug infiltration in MPC.

Assessment of Elastic Laminal Invasion Contributes to an Objective pT3 Subclassification in Colon Cancer.

The extent of tumor spread influences on the clinical outcome, and which determine T stage of colorectal cancer. However, pathologic discrimination between pT3 and pT4a in the eighth edition of the American Joint Committee on Cancer (AJCC)-TNM stage is subjective, and more objective discrimination method for deeply invasive advanced colon cancer is mandatory for standardized patient management. Peritoneal elastic laminal invasion (ELI) detected using elastic staining may increase the objective discrimination of deeply invasive advanced colon cancer. In this study, we constructed ELI study group to investigate feasibility, objectivity, and prognostic utility of ELI. Furthermore, pT classification using ELI was investigated based on these data. At first, concordance study investigated objectivity using 60 pT3 and pT4a colon cancers. Simultaneously, a multi-institutional retrospective study was performed to assess ELI's prognostic utility in 1202 colon cancer cases from 6 institutions. In the concordance study, objectivity, represented by κ, was higher in the ELI assessment than in pT classification. In the multi-institutional retrospective study, elastic staining revealed that ELI was a strong prognostic factor. The clinical outcome of pT3 cases with ELI was significantly and consistently worse than that of those without ELI. pT classification into pT3 without ELI, pT3 with ELI, and pT4a was an independent prognostic factor. In this study, we revealed that ELI is an objective method for discriminating deeply invasive advanced colon cancer. Based on its feasibility, objectivity, and prognostic utility, ELI can subdivide pT3 lesions into pT3a (without ELI) and pT3b (with ELI).

Tumor-infiltrating Leukocyte Profiling Defines Three Immune Subtypes of NSCLC with Distinct Signaling Pathways and Genetic Alterations.

Resistance to immune checkpoint blockade remains challenging in patients with non-small cell lung cancer (NSCLC). Tumor-infiltrating leukocyte (TIL) quantity, composition, and activation status profoundly influence responsiveness to cancer immunotherapy. This study examined the immune landscape in the NSCLC tumor microenvironment by analyzing TIL profiles of 281 fresh resected NSCLC tissues. Unsupervised clustering based on numbers and percentages of 30 TIL types classified adenocarcinoma (LUAD) and squamous cell carcinoma (LUSQ) into the cold, myeloid cell-dominant, and CD8+ T cell-dominant subtypes. These were significantly correlated with patient prognosis; the myeloid cell subtype had worse outcomes than the others. Integrated genomic and transcriptomic analyses, including RNA sequencing, whole-exome sequencing, T-cell receptor repertoire, and metabolomics of tumor tissue, revealed that immune reaction-related signaling pathways were inactivated, while the glycolysis and K-ras signaling pathways activated in LUAD and LUSQ myeloid cell subtypes. Cases with ALK and ROS1 fusion genes were enriched in the LUAD myeloid subtype, and the frequency of TERT copy-number variations was higher in LUSQ myeloid subtype than in the others. These classifications of NSCLC based on TIL status may be useful for developing personalized immune therapies for NSCLC. Significance: The precise TIL profiling classified NSCLC into novel three immune subtypes that correlates with patient outcome, identifying subtype-specific molecular pathways and genomic alterations that should play important roles in constructing subtype-specific immune tumor microenvironments. These classifications of NSCLC based on TIL status are useful for developing personalized immune therapies for NSCLC.

Panitumumab vs Bevacizumab Added to Standard First-line Chemotherapy and Overall Survival Among Patients With RAS Wild-type, Left-Sided Metastatic Colorectal Cancer: A Randomized Clinical Trial.

Importance: For patients with RAS wild-type metastatic colorectal cancer, adding anti-epidermal growth factor receptor (anti-EGFR) or anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies to first-line doublet chemotherapy is routine, but the optimal targeted therapy has not been defined. Objective: To evaluate the effect of adding panitumumab (an anti-EGFR monoclonal antibody) vs bevacizumab (an anti-VEGF monoclonal antibody) to standard first-line chemotherapy for treatment of RAS wild-type, left-sided, metastatic colorectal cancer. Design, Setting, and Participants: Randomized, open-label, phase 3 clinical trial at 197 sites in Japan in May 2015-January 2022 among 823 patients with chemotherapy-naive RAS wild-type, unresectable metastatic colorectal cancer (final follow-up, January 14, 2022). Interventions: Panitumumab (n = 411) or bevacizumab (n = 412) plus modified fluorouracil, l-leucovorin, and oxaliplatin (mFOLFOX6) every 14 days. Main Outcomes and Measures: The primary end point, overall survival, was tested first in participants with left-sided tumors, then in the overall population. Secondary end points were progression-free survival, response rate, duration of response, and curative (defined as R0 status) resection rate. Results: In the as-treated population (n = 802; median age, 66 years; 282 [35.2%] women), 604 (75.3%) had left-sided tumors. Median follow-up was 61 months. Median overall survival was 37.9 months with panitumumab vs 34.3 months with bevacizumab in participants with left-sided tumors (hazard ratio [HR] for death, 0.82; 95.798% CI, 0.68-0.99; P = .03) and 36.2 vs 31.3 months, respectively, in the overall population (HR, 0.84; 95% CI, 0.72-0.98; P = .03). Median progression-free survival for panitumumab vs bevacizumab was 13.1 vs 11.9 months, respectively, for those with left-sided tumors (HR, 1.00; 95% CI, 0.83-1.20) and 12.2 vs 11.4 months overall (HR, 1.05; 95% CI, 0.90-1.24). Response rates with panitumumab vs bevacizumab were 80.2% vs 68.6%, respectively, for left-sided tumors (difference, 11.2%; 95% CI, 4.4%-17.9%) and 74.9% vs 67.3% overall (difference, 7.7%; 95% CI, 1.5%-13.8%). Median duration of response with panitumumab vs bevacizumab was 13.1 vs 11.2 months for left-sided tumors (HR, 0.86; 95% CI, 0.70-1.10) and 11.9 vs 10.7 months overall (HR, 0.89; 95% CI, 0.74-1.06). Curative resection rates with panitumumab vs bevacizumab were 18.3% vs 11.6% for left-sided tumors; (difference, 6.6%; 95% CI, 1.0%-12.3%) and 16.5% vs 10.9% overall (difference, 5.6%; 95% CI, 1.0%-10.3%). Common treatment-emergent adverse events were acneiform rash (panitumumab: 74.8%; bevacizumab: 3.2%), peripheral sensory neuropathy (panitumumab: 70.8%; bevacizumab: 73.7%), and stomatitis (panitumumab: 61.6%; bevacizumab: 40.5%). Conclusions and Relevance: Among patients with RAS wild-type metastatic colorectal cancer, adding panitumumab, compared with bevacizumab, to standard first-line chemotherapy significantly improved overall survival in those with left-sided tumors and in the overall population. Trial Registration: ClinicalTrials.gov Identifier: NCT02394795.

Impact of Programmed Death-Ligand 1 Expression on Mismatch Repair Deficiency and Epstein-Barr Virus Status on Survival Outcomes in Patients with Stage II/III Gastric Cancer After Surgery.

BACKGROUND: The aim of this study was to investigate the prognostic impact of mismatch repair (MMR) status, programmed death-ligand 1 (PD-L1) expression, and Epstein-Barr virus (EBV) status in stage II/III gastric cancer after surgery. METHODS: This study included 679 patients diagnosed with pathological stage II/III gastric cancer who underwent curative gastrectomy followed by adjuvant chemotherapy (AC) or observation between 2007 and 2015. Clinical outcomes were retrospectively reviewed and compared with stratification by AC and other clinicopathological factors. RESULTS: Patients were divided into AC (n = 484) or surgery alone (SA; n = 195) groups and were further stratified by MMR and EBV status: MMR-deficient (DMMR) and MMR-proficient (PMMR) groups. Comparing the AC-DMMR group versus the AC-PMMR group, 5-year overall survival was 92.0% versus 74.0% (log-rank p < 0.01), and comparing the SA-DMMR group versus the SA-PMMR group, 5-year overall survival was 71.1% versus 73.7% (log-rank p = 0.89). DMMR (hazard ratio 0.25, 95% confidence interval 0.07-0.81) was identified as an independent prognostic factor in the AC group but not in the SA group. In the subgroup analysis, PD-L1-negative patients among the EBV-positive patients or in the DMMR group had a poor prognosis in both the AC and SA groups. The prognosis of the PMMR and EBV-negative patients was similar regardless of PD-L1 expression. CONCLUSIONS: DMMR was associated with a favorable prognosis in stage II/III gastric cancer after surgery and adjuvant therapy. PD-L1 expression may affect the prognosis of DMMR and EBV-positive gastric cancer.

Requirement of image standardization for AI-based macroscopic diagnosis for surgical specimens of gastric cancer.

PURPOSE: The pathological diagnosis of surgically resected gastric cancer involves both a macroscopic diagnosis by gross observation and a microscopic diagnosis by microscopy. Macroscopic diagnosis determines the location and stage of the disease and the involvement of other organs and surgical margin. Lesion recognition is, thus, an important diagnostic step that requires a skilled pathologist. Nonetheless, artificial intelligence (AI) technologies could allow even inexperienced doctors and laboratory technicians to examine surgically resected specimens without the need for pathologists. However, organ imaging conditions vary across hospitals, and an AI algorithm created in one setting may not work properly in another. Thus, we identified and standardized factors affecting the quality of pathological macroscopic images, which could further affect lesion identification using AI. METHODS: We examined necessary image standardization for developing cancer detection AI for surgically resected gastric cancer by changing the following imaging conditions: focus, resolution, brightness, and contrast. RESULTS: Regarding focus, brightness, and contrast, the farther away the test data were from the training macro-image, the less likely the inference was to be correct. Little change was observed for resolution, even with differing conditions for the training and test data. Regarding focus, brightness, and contrast, there were conditions appropriate for AI. Contrast, in particular, was far from the conditions appropriate for humans. CONCLUSION: Standardizing focus, brightness, and contrast is important in the development of AI methodologies for lesion detection in surgically resected gastric cancer. This standardization is essential for AI to be implemented across hospitals.

Methods for preparing tissue microarray slides using xenografts with different levels of HER2 expression to standardize HER2 detection.

Gene amplification and protein overexpression of human epidermal growth factor receptor type 2 (HER2) are specific targets for HER2-targeting drugs in breast, gastric, salivary gland, and colorectal cancers. The histopathological determination of HER2 status is crucial for treatment, highlighting the importance of improving HER2 detection accuracy in clinical practice. We prepared tissue microarray (TMA) slides for use as control slides for the standardization of gastric HER2 testing. Four human gastric cancer cell lines with HER2 scores of 3+, 2+, 1+, and 0 were xenografted in NOG mice. The TMA slides were constructed using samples from three different areas in these tumors. Staining properties were determined using six clinical kits for HER2. In TMA, HER2-positive tumors with HER2 scores of 3+ and 2+ showed good staining with all diagnostic kits, and the tissue images were similar to those of clinical samples. Xenograft tumor slides could potentially be used as external controls to standardize staining conditions for a variety of kits and may improve the accuracy of HER2 detection in clinical practice.

Serum microRNAs as new criteria for referral to early palliative care services in treatment-naïve advanced cancer patients.

A major obstacle to the implementation of early palliative care (EPC) is the lack of objective criteria for referral to EPC. Circulating microRNAs (miRNAs) have been recognized as promising biomarkers. The present study investigated objective definitions for referral to EPC using microRNA. A total of 178 serum samples were obtained from patients with lung, gastrointestinal, colorectal, bile duct, pancreas and bladder cancers who were treatment-naïve and received chemotherapy between January 2011 and December 2013 at National Cancer Center Hospital East. We investigated expression levels of miRNAs using microarrays. The primary outcome was prediction of admission to a palliative care unit ≤6 months after first visit. Diagnostic models using clinical characteristics, miRNAs and combinations of both were constructed. The miRNA models were constructed using 6 miRNA levels. The best areas under the receiver operating characteristic curve (AUCs) of the clinical model was 0.741, while the average AUCs of miRNA-based models and combination models were 0.769 and 0.806, respectively. Combination models showed higher AUCs than the clinical model (p < 0.023). The present combination models might offer new objective definitions for referral to EPC and thus contribute to real-world implementation of EPC.

Japanese multicenter prospective study investigating laparoscopic surgery for locally advanced rectal cancer with evaluation of CRM and TME quality (PRODUCT trial).

Aim: In Japan, we have not been able to validate the results of laparoscopic surgery for locally advanced rectal cancer using the universal index "circumferential resection margin (CRM)." Previously, we established a semi-opened circular specimen processing method and validated its feasibility. In the PRODUCT trial, we aimed to assess CRM in patients with locally advanced rectal cancer who underwent laparoscopic rectal resection. Methods: This was a multicenter, prospective, observational study. Eligible patients had histologically confirmed rectal adenocarcinoma located at or below 12 cm above the anal verge with clinical stage II or III and were scheduled for laparoscopic or robotic surgery. The primary endpoint was pathological CRM. CRM ≤1 mm was defined as positive. Results: A total of 303 patients operated on between August 2018 and January 2020 were included in the primary analysis. The number of patients with clinical stage II and III was 139 and 164, respectively. Upfront surgery was performed for 213 patients and neoadjuvant therapy for 90 patients. The median CRM was 4.0 mm (IQR, 2.1-8.0 mm), and CRM was positive in 26 cases (8.6%). Univariate and multivariate analyses demonstrated that a predicted CRM from the mesorectal fascia of ≤1 mm on MRI was the significant factor for positive CRM (P = .0012 and P = .0045, respectively). Conclusion: This study showed the quality of laparoscopic rectal resection based on the CRM in Japan. Preoperative MRI is recommended for locally advanced rectal cancer to prevent CRM positivity.

Different types of reactions to E7386 among colorectal cancer patient-derived organoids and corresponding CAFs.

Colorectal cancer (CRC) harbors genetic alterations in a component of the Wnt signaling pathway in ~90% of cases. In addition, the Wnt signaling pathway has been previously suggested to serve a notable role in the pathophysiology of CRC cells and cancer-associated fibroblasts (CAFs). In the present study, the possible effects of E7386, a selective inhibitor of the interaction between ß-catenin and the cAMP response element-binding protein-binding protein, were evaluated using organoids and the corresponding CAFs derived from patients with CRC. E7386 at 100 nM was revealed to decrease the viability of CRC organoids and CAFs. Analysis of the gene expression profiles revealed marked changes in the expression levels of different types of cancer-associated genes associated with E7386 concentrations in the organoids and/or CAFs, such as those regulating glucose and amino acid metabolism [phosphoenolpyruvate carboxykinase 2, asparagine synthetase (glutamine-hydrolyzing), phosphoserine aminotransferase 1 and phosphoglycerate dehydrogenase], stimulation of natural killer cell-mediated cytotoxicity (UL16-binding protein 1) and modification of the Wnt/ß-catenin signaling pathway (indicated by very low density lipoprotein receptor). Results of the hydrophilic metabolome analysis in the organoids were consistent with those of the transcriptomic analysis. In vivo experiments used corresponding xenograft models, although changes in volume of tumor tissues could not be observed at 50 mg/kg body weight twice a day for 14 days, results on the protein expression levels partially supported those in the in vitro experiments. In conclusion, different types of reactions, such as alterations in the glucose and amino acid metabolic pathways, stimulation of stress responses and NK-cell mediated cytotoxicity and components in the Wnt/ß-catenin signaling pathway, to E7386 in the CRC organoids and corresponding CAFs were observed under conditions with decreased cell viability. However, further mechanistic studies to clarify the relationships with Wnt/ß-catenin signaling pathway and these reactions using preclinical models and biomarker studies using clinical human samples are required for verification of the present preclinical biomarkers.

Prospective analysis of the expression status of FGFR2 and HER2 in colorectal and gastric cancer populations: DS-Screen Study.

PURPOSE: Fibroblast growth factor receptor 2 (FGFR2) and human epidermal growth factor receptor 2 (HER2) proteins are both molecular targets for cancer therapy. The objective of this study was to evaluate the expression status of FGFR2 and HER2 in patients with gastric cancer (GC) or colorectal cancer (CRC). METHODS: Archived tumor tissue samples from patients with histologically-confirmed GC or CRC suitable for chemotherapy were analyzed for FGFR2 and HER2 expression using immunohistochemistry and fluorescence in situ hybridization (HER2 in CRC only). RESULTS: A total of 176 GC patients and 389 CRC patients were enrolled. Among patients with GC, 25.6% were FGFR2-positive and 26.1% were HER2-positive. Among patients with CRC, 2.9% were FGFR2-positive and 16.2% were HER2-positive. No clear relationship was found between FGFR2 and HER2 status in either GC or CRC. In GC, FGFR2 and HER2 statuses did not differ between different primary cancer locations, whereas there were some differences between histological types. Based on FGFR2- and/or HER2-positive status, 117 patients were identified as potentially suitable for inclusion in clinical trials of therapeutic agents targeting the relevant protein (GC = 45, CRC = 72; FGFR = 56, HER2 = 62), of whom 7 were eventually enrolled into such clinical trials. CONCLUSIONS: This study indicated the prevalence of FGFR2 and HER2 in GC and CRC in the Japanese population. The screening performed in this study could be useful for identifying eligible patients for future clinical trials of agents targeting these proteins. TRIAL REGISTRATION: Clinical trial registration Japic CTI No.: JapicCTI-163380.  https://www. CLINICALTRIALS: jp/cti-user/trial/ShowDirect.jsp?directLink=RNlzx1PPCuT.PrVNPxPRwA .