Our study clarified the anatomic variety of the vessels in right-sided colon cancer. Preoperative 3D-CT is useful for understanding the anatomy to ensure a safe, precise operation.

Aim We aimed to clarify the use of adjuvant chemotherapy and the prognosis of elderly colorectal cancer patients compared with non‐elderly patients, and the usefulness of sarcopenia as an indicator for the introduction and completion of adjuvant chemotherapy. Methods Between 2013 and 2021, 215 patients with pStage III disease were included. We investigated perioperative clinicopathological factors, adjuvant chemotherapy details, and prognosis. Preoperative sarcopenia status was evaluated using computed tomography images. Elderly patients were defined as those aged ≥70 years. Results We included 121 (56.3%) and 94 (43.7%) non‐elderly and elderly patients, respectively. Among the elderly patients, 47 had sarcopenia. There were no significant differences in the incompletion rate of adjuvant chemotherapy between elderly and non‐elderly patients (27.1%/16.2%, P = 0.119). The most common reason for the discontinuation of adjuvant chemotherapy was side effects, regardless of age. The respective 3‐year‐disease free survival of patients with no/completed/incomplete adjuvant chemotherapy were 65.5%, 80.2%, and 57.7% for non‐elderly patients (P = 0.045) and 73.4%, 70.6%, and 71.6% for elderly patients (P = 0.924). The number of elderly patients with sarcopenia was significantly higher in patients without adjuvant chemotherapy (P = 0.004) and those with incomplete adjuvant chemotherapy (P = 0.004). The 3‐year‐disease free survival of elderly sarcopenic patients without and with adjuvant chemotherapy were 78.3% and 59.2%, respectively (P = 0.833). Conclusion Elderly patients did not show a benefit of adjuvant chemotherapy regardless of whether they had completed adjuvant chemotherapy, unlike non‐elderly patients. Moreover, the evaluation of preoperative sarcopenia in elderly colorectal cancer patients may be useful in determining the indication for adjuvant chemotherapy.

Abstract. Epidermal growth factor receptor (EGFR) gene mutations have been reported to be clinically significant in non-small cell lung cancer (NSCLC). However, because most previous studies focused only on adenocarcinomas, EGFR mutations in other histotypes are poorly investigated. We evaluated the frequency of EGFR gene mutations in squamous cell carcinoma (SCC) and its clinicopathological features. In total, 89 frozen tumor specimens that had been first diagnosed as SCCs, were examined for EGFR mutations in exons 19 and 21 using direct sequencing, PNA-enriched sequencing and SmartAmp2. Additionally, pathological investigation, including immunostaining for p63 and TTF-1, alcian blue staining and EGFR mutation-specific immunohistochemistry in mutation-positive samples was also performed. The frequency of EGFR mutations was 5.6% (5/89); all mutations were deletions in EGFR exon 19. Immunohistological investigation of these samples revealed that two of five were positive for p63 and TTF-1 staining, and showed production of mucin, as evidenced by alcian blue staining. Consequently, three of the samples were considered to be true SCC at final pathological diagnosis, while the remaining two samples were revised to adenosquamous carcinoma and adenocarcinoma. The final frequency of the EGFR mutations in true SCC was 3.4% (3/87). In conclusion, EGFR mutations were found in a small, but significant, number of SCC tumor samples and thus EGFR mutational analysis was useful in the accurate diagnosis of SCC. Our data demonstrate that EGFR mutational analysis should be performed not only in adenocarcinoma, but also in SCC to allow accurate diagnosis and treatment.

Background/Aim: L-type amino acid transporter 1 (LAT1) is highly expressed in various human cancers. However, the clinicopathological significance of LAT1 and 4F2 cell surface antigen (4F2hc) in patients with colorectal cancer (CRC) is unknown. The aim of this study was to clarify the prognostic significance of LAT1 expression in CRC patients who underwent surgical resection. Materials and Methods: Samples from one hundred and forty-seven patients were examined by immunohistochemistry. The expression of LAT1 and 4F2hc, and the Ki-67 labeling index were assessed using resected tumor specimens. Results: The positive expression of LAT1 and 4F2c was 80% (118/147) and 58% (86/147) (p<0.01), respectively. The expression of LAT1 was identified as an independent significant marker linked to worse prognosis in patients with CRC, and was correlated with tumor cell proliferation, tumor aggressiveness, and metastasis. Moreover, LAT1 was closely associated with the expression of 4F2hc and phosphorylation of the mTOR pathway. Conclusion: LAT1 is a significant molecular marker used to predict prognosis after surgical resection of CRC patients.Colorectal cancer (CRC) is one of the major neoplasms that cause cancer-related deaths worldwide. When the initial diagnosis of CRC is made in the advanced stage of the disease, systemic chemotherapy is a suitable treatment in addition to palliative surgery when necessary. Despite recent translational research efforts, there is still no established biomarker to predict prognosis after any treatment.We investigated the clinicopathological significance of L-type amino acid transporter 1 (LAT1) expression within tumor specimens from patients with human neoplasms and confirmed that LAT1 is highly expressed in many types of cancers (1-9). We found that the increased expression of LAT1 is a clear negative marker predicting worse outcomes in some human cancers (2,(4)(5)(6)(7). Although LAT1 works as a membrane transporter of neutral amino acids, 4F2hc (CD98) is required for its function (10). The L-type amino acid transporter consists of several subtypes, such as LAT1, LAT2, LAT3, and LAT4 (1, 3, 10). Recent studies have indicated that LAT1 can be used as a specific marker for malignant lesions, LAT2 is expressed in normal tissues, LAT3 is observed in hormone-producing tumors such as prostate cancer, and the role of LAT4 in tumor growth and progression is unknown (11). It has been established that LAT1 is an important molecule in targeted therapy, and the inhibition of LAT1 contributes to the suppression of tumor growth via the mammalian target of rapamycin (mTOR) pathway (8, 9). The protein expression of LAT1 has been clinically proven to be different according to the histological subtype, and its overexpression is closely linked to tumor proliferation, angiogenesis, and metastasis (2-9). Little is known about the prognostic significance of LAT1 expression in patients with CRC; however, Hayase et al. recently reported that LAT1 was highly expressed in 72.4% of CRC patients, and its up-2535

<b><i>Introduction:</i></b> Programmed death-ligand 1 (PD-L1) expression is a prognostic marker for gastric cancer that correlates with tumor diameter and depth of penetration. But the role of PD-L1 and mechanism(s) employed in the initial phase of invasion in early gastric cancer is yet to be understood. <b><i>Objective:</i></b> This study aims to elucidate the role of PD-L1 during the progression of gastric cancer, specifically invading the submucosa beyond the lamina muscularis mucosa. <b><i>Methods:</i></b> Using 107 patients with pathological submucosal gastric cancer, we determined the expression of PD-L1 based on the staining of the cell membrane or cytoplasm of tumor cells in the central and invasive front of the tumor. Samples were categorized into 3 groups based on the intensity of PD-L1 expression. CD8⁺ lymphocytes expressing PD-1 and CD163⁺ macrophages were used to determine the number of cell nuclei at the invasive front, similar to PD-L1. CMTM6 levels were determined and used to stratify samples into 3 groups. <b><i>Results:</i></b> PD-L1 expression was higher in the invasive front (26.2%) than in the central portion of the tumors (7.4%; <i>p</i> &#x3c; 0.001). Moreover, lymphatic and vascular invasion were more frequently observed in samples with high levels of PD-L1 (lymphatic invasion: 60.7 vs. 35.4%, <i>p</i> = 0.0026, and vascular invasion: 39.3 vs. 16.5%, <i>p</i> = 0.0018). There was no correlation between PD-L1 expression and the levels of PD-1, CD8, CD163, and CMTM6. <b><i>Conclusions:</i></b> PD-L1-expressing cancer cells at the invasive front of gastric cancer influence the initial stages of tumor invasion and lymphovascular permeation in early-stage gastric cancers. Immune checkpoint signaling may be the driving force in the invasive front during the invasion of the submucosa beyond the lamina muscularis mucosa.