Background/Aims: Immune checkpoint blockade has recently been reported to be effective in treating microsatellite instability (MSI)-high tumors. Therefore, sufficient sampling of histological specimens is necessary in cases of unresectable pancreatic cancer (UR-PC). This multicenter study investigated the efficacy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) using a Franseen needle for MSI evaluation in patients with UR-PC. Methods: A total of 89 patients with UR-PC who underwent endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) or EUS-FNB using 22-G needles at three hospitals in Japan (2018–2021) were enrolled. Fifty-six of these patients (FNB 23 and FNA 33) were followed up or evaluated for MSI. Patient characteristics, UR-PC data, and procedural outcomes were compared between patients who underwent EUS-FNB and those who underwent EUS-FNA. Results: No significant difference in terms of sufficient tissue acquisition for histology was observed between patients who underwent EUS-FNB and those who underwent EUS-FNA. MSI evaluation was possible significantly more with tissue samples obtained using EUS-FNB than with tissue samples obtained using EUS-FNA (82.6% [19/23] vs. 45.5% [15/33], respectively; p<0.01). In the multivariate analysis, EUS-FNB was the only significant factor influencing the possibility of MSI evaluation. Conclusions EUS-FNB using a Franseen needle is desirable for ensuring sufficient tissue acquisition for MSI evaluation.

Introduction: Although stop-and-go method is recommended for the introduction of methadone by the Japanese guidelines, it may temporarily result in inadequate pain control and/or serious side effects. We report our experience that alleviation of symptoms was achieved by introducing low-dose methadone at an early stage on top of preceding opioids for a patient with refractory cancer pain. Case: Tapentadol and an analgesic adjuvant were given to a 70-year-old man to treat the patient’s old anal pain due to recurrence of rectal cancer at the rectal anastomosis. However, since the pain was poorly controlled, methadone 5 mg was given adjunctively once daily. After methadone medication, remarkable alleviation of pain and improvement in QOL were observed. Discussion: To achieve a safe pain management, adding a small amount of methadone at an early stage, as in this case, may possibly considered.