Background: RAS/BRAF^V600E mutations are the most remarkable oncogenic driver mutations in colorectal cancer (CRC) and play an important role in treatment selection. No data are available regarding the clinical and prognostic features of patients with detailed RAS/BRAF^V600E-mutant metastatic CRC (mCRC) in Japan. Methods: A total of 152 chemotherapy-naïve patients with mCRC were included in this study between August 2018 and July 2019. Tumor samples were collected, and RAS/BRAF^V600E status was investigated. RAS/BRAF^V600E status was examined using a MEBGEN RASKET-B kit and polymerase chain reaction reverse sequence-specific oligonucleotide method. Results: RAS/BRAF^V600E mutations were detected in 54% of cases (KRAS codon 12, 26%; KRAS codon 13, 17%; KRAS non-Exon2, 5%; NRAS, 5%; and BRAF^V600E, 7%). BRAF^V600E-mutant CRC mainly existed in the right colon, whereas KRAS non-Exon2 and NRAS-mutant CRC was predominantly present in the left colon. KRAS non-Exon2 and NRAS-mutant CRC were associated with shorter survival time than RAS wild-type CRC (hazard ratio [HR], 2.26; 95% confidence interval [CI], 0.64–8.03; p = 0.19; HR, 2.42; 95% CI, 0.68–8.61; p = 0.16) and significantly shorter overall survival than KRAS Exon2-mutant CRC (HR, 3.88; 95% CI, 0.92–16.3; p = 0.04; HR, 4.80; 95% CI, 1.14–20.2; p = 0.02). Conclusions: In our multicenter study, the findings elucidated the clinical and prognostic features of patients with detailed RAS/BRAF^V600E-mutant mCRC in Japan.

Trastuzumab deruxtecan (T-DXd) has shown promising efficacy against HER2-positive advanced gastric cancer (AGC). However, data on its real-world efficacy in AGC patients are insufficient, and the predictive marker of T-DXd is unclear. In this multi-center retrospective study, we collected clinical information of 18 patients with HER2-positive AGC who received T-DXd after intolerant or refractory responses to at least two prior regimens and analyzed predictive factors. The median age was 71 years (range: 51–85), 13 men were included, and ECOG performance status (PS): 0/1/2/3 was 9/6/2/1. A total of 11 patients (61%) received prior immune checkpoint inhibitors (ICIs), 14 patients were HER2 3+, and 4 patients were HER2 2+/FISH positive. The median trastuzumab (Tmab)-free interval was 7.7 months (range: 2.8–28.6). The overall response rate was 41%, and the disease control rate was 76%. Median progression-free survival (PFS) was 3.9 months (95% CI: 2.6–6.5), and median overall survival (OS) was 6.1 months (95% CI: 3.7–9.4). PFS (6.5 vs. 2.9 months, p = 0.0292) and OS (9.2 vs. 3.7 months, p = 0.0819) were longer in patients who received prior ICIs than in those who had not. PFS (6.5 vs. 3.4 months, p = 0.0249) and OS (9.4 vs. 5.7 months, p = 0.0426) were longer in patients with an 8 month or longer Tmab-free interval. In patients with ascites, PFS (6.5 vs. 2.75 months, p = 0.0139) and OS (9.4 vs. 3.9 months, p = 0.0460) were shorter. T-DXd showed promising efficacy in HER2-positive AGC patients in a real-world setting. Pre-administration of ICIs and a sufficient Tmab-free interval may be predictive factors of T-DXd efficacy.

Introduction: Extensive small cell lung cancer (ES‐SCLC) are currently managed using first‐line chemotherapy options, including atezolizumab (Atezo) plus etoposide and carboplatin (CE) or durvalumab (Durva) plus etoposide with either cisplatin (PE) or carboplatin (CE). However, a definitive distinction in therapeutic effects between Atezo and Durva in these regimens remains unestablished.Methods: We analyzed data from 100 patients diagnosed with ES‐SCLC who received immune checkpoint inhibitors (ICIs) as first‐line chemotherapy. Among them, 70 were administered Atezo + CE, 12 received Durva + PE, and 18 received Durva + CE. We assessed the efficacy of the two ICIs across various factors.Results: The progression‐free survival (PFS) and overall survival (OS) did not significantly differ between Atezo + CE and Durva + CE/PE as first‐line chemotherapy treatments for SCLC. We observed no significant differences in age, sex, performance status (PS), liver metastasis, bone metastasis, or platinum‐based agent usage between the treatment cohorts. However, a marked improvement in PFS and OS was observed in the solitary patient with brain metastasis treated with Atezo + CE.Conclusion: The primary distinction between these treatments was observed in the management of patients with brain metastasis. The literature lacks comparative studies on the effects of first‐line ICI treatment on the central nervous system, rendering our findings significant in clinical practice. Despite the retrospective nature of this study and the potential for various biases, we recommend the preferential use of Atezo + CE in patients with brain metastasis to potentially enhance prognosis.

Background: Immuno-oncology (IO) drugs are essential for treating various cancer types; however, safety concerns persist in older patients. Although the incidence of immune-related adverse events (irAEs) is similar among age groups, higher rates of hospitalization or discontinuation of IO therapy have been reported in older patients. Limited research exists on IO drug safety and risk factors in older adults. Our investigation aimed to assess the incidence of irAEs and identify the potential risk factors associated with their development. Methods: This retrospective analysis reviewed the clinical data extracted from the medical records of patients aged > 80 years who underwent IO treatment at our institution. Univariate and multivariate analyses were performed to assess the incidence of irAEs. Results: Our study included 181 patients (median age: 82 years, range: 80–94), mostly men (73%), with a performance status of 0–1 in 87% of the cases; 64% received IO monotherapy. irAEs occurred in 35% of patients, contributing to IO therapy discontinuation in 19%. Our analysis highlighted increased body mass index, eosinophil counts, and albumin levels in patients with irAEs. Eosinophil count emerged as a significant risk factor for any grade irAEs, particularly Grade 3 or higher, with a cutoff of 118 (/μL). The group with eosinophil counts > 118 had a higher frequency of irAEs, and Grade 3 or higher events than the group with counts ≤ 118. Conclusion: IO therapy is a safe treatment option for patients > 80 years old. Furthermore, patients with elevated eosinophil counts at treatment initiation should be cautiously managed.

Original Article Impact of immune-related adverse events on clinical outcomes in patients with advanced non-small cell lung cancer with low PD-L1 expression, focusing on pneumonitis: a multicenter retrospective study in Japan Shiho Goda, Tadaaki Yamada, Kenji Morimoto, Tae Hata, Yasuhiro Goto, Akihiko Amano, Yoshiki Negi, Satoshi Watanabe, Naoki Furuya, Tomohiro Oba, Tatsuki Ikoma, Akira Nakao, Keiko Tanimura, Hirokazu Taniguchi, Akihiro Yoshimura, Tomoya Fukui, Daiki Murata, Kyoichi Kaira, Shinsuke Shiotsu, Asuka Okada, Makoto Hibino, Yusuke Chihara, Takashi Kijima, Koichi Takayama