BRAF K601E-mutated metastatic colorectal cancer in response to combination therapy with encorafenib, binimetinib, and cetuximab: A case report.

BACKGROUND: BRAF mutation has been recognized as a negative prognostic marker for metastatic colorectal cancer (mCRC), but these data are from common BRAF V600E-mutated mCRC. Combination therapy of BRAF inhibitor and anti-epidermal growth factor receptor (EGFR) antibody has been approved for BRAF V600E-mutated mCRC. However, BRAF non-V600 mutations are rare mutations, and their clinical behavior is not understood. Moreover, the BRAF K601E mutation is extremely rare in mCRC, and there have been no reports on its specific treatment. CASE SUMMARY: Herein, we report the case of a 59-year-old female with super aggressive mCRC with multiple metastases, which extended to whole body including mediastinal to abdominal lymph nodes, bones, pleura, and peritoneum. The companion diagnostics of tumor tissues showed RAS/BRAF wild-type without microsatellite instability. She received chemotherapy with mFOLFOX6 (oxaliplatin plus infusional 5-fluorouracil [5-FU] and leucovorin) plus panitumumab, following FOLFIRI (irinotecan plus infusional 5-FU and leucovorin) plus ramucirumab. For the next regimen selection, a comprehensive genomic profiling panel was performed and revealed a BRAF K601E mutation, which was not covered in the initial companion diagnostics. After disease progression, a combination of encorafenib, binimetinib, and cetuximab was selected as third-line chemotherapy. The serum levels of tumor markers were immediately decreased accompanied by improvements in pleural effusion and ascites. However, the disease progressed again, and best supportive care was done instead. CONCLUSION: This case offers novel insights into the clinical behaviors of BRAF non-V600E-mCRC, potentially advancing personalized therapy for rare and aggressive cases.

Clinical Impact of Proton Pump Inhibitor and Potassium-Competitive Acid Blocker for Predicting the Curability of Endoscopic Resection in Ulcerative Early Gastric Cancer.

INTRODUCTION: Endoscopic diagnosis is essential for predicting the curability of early gastric cancer (EGC; R0 resection) before treatment, but the relationship between ulcerative lesions and clinical outcomes remains unclear. We aimed to investigate the effect of proton pump inhibitor (PPI) or potassium-competitive acid blocker (P-CAB) on the morphological changes of ulcerative EGCs and its relevance to the clinical outcomes. METHODS: Altogether, 143 patients with differentiated ulcerative EGC that were resected by endoscopic submucosal dissection were retrospectively identified and divided into the following two cohorts depending on their PPI/P-CAB administration status: PPI/P-CAB (n = 76) and non-PPI/P-CAB (n = 67) cohorts. Furthermore, in each cohort, the patients were further divided into the improved and unimproved subgroups based on the ulcerative changes. RESULTS: In the PPI/P-CAB cohort, the deep submucosal invasion and lymphovascular invasion rates were significantly higher in the unimproved subgroup than in the improved subgroup, resulting in a significantly lower R0 resection rate. Contrarily, no significant differences were found between the two subgroups in the non-PPI/P-CAB cohort. The significance of PPI/P-CAB administration was observed only in the ulcerative EGCs with open-type atrophy (R0 resection rate; improved vs. unimproved, 90.9% vs. 48.0%, p = 0.001). When the finding of improved ulcer with PPI/P-CAB administration was used as the indication of endoscopic resection in ulcerative EGCs with open-type atrophy, high sensitivity (78.9%) and accuracy (76.3%) rates for the curability were observed, which were higher than those of conventional endoscopic diagnosis alone (p = 0.021). CONCLUSION: PPI or P-CAB administration might contribute to the potential selection of ulcerative EGCs, enabling endoscopic curative resection.

A multicenter case-control study of self-expanding metallic stent versus trans-anal colorectal tube for stage II/III non-right-sided obstructive colon cancer.

BACKGROUND: Self-expanding metallic stent (SEMS) and trans-anal colorectal tube (TCT) are alternative treatments to conventional emergency surgery for non-right-sided obstructive colon cancer (NROCC). However, the one with better short- and long-term outcomes remains controversial. Thus, this multicenter case-control study aimed to analyze and compare SEMS and TCT for NROCC. METHODS: Patients with stage II/III NROCC who underwent surgery between January 2010 and December 2019 at either of the eight selected Japanese affiliate hospitals were, retrospectively, reviewed. Baseline characteristics between the SEMS and TCT groups were adjusted by propensity score (PS) matching. RESULTS: Among 239 reviewed patients (SEMS: 76, TCT: 163), 180 were finally included in two well-balanced cohorts through PS: SEMS group (65 patients) and TCT group (115 patients). Technical success, clinical success, morbidity, and short-term mortality were not significantly different between the two groups. SEMS placement achieved significantly higher rates for primary resection/anastomosis without stoma (SEMS: 90.8% vs. TCT: 77.4%, p < 0.001) and laparoscopic surgery (SEMS: 64.6% vs. TCT: 43.5%, p < 0.001) than TCT placement. However, 5-year overall survival (SEMS: 83.7% vs. TCT: 86.4%; p = 0.822) and 5-year relapse-free survival (SEMS: 64.7% vs. TCT: 66.4%; p = 0.854) showed no significant differences between these groups. CONCLUSIONS: Both SEMS and TCT revealed similar long-term outcomes, but SEMS placement was better in achieving primary resection/anastomosis and laparoscopic surgery in patients with stage II/III NROCC.

Perivascular Epithelial Cell Tumor of the Pancreas Diagnosed Preoperatively by Endoscopic Ultrasound-guided Fine-needle Aspiration.

We herein report a 49-year-old woman with a perivascular epithelial cell tumor (PEComa) of the pancreas. Imaging studies demonstrated a relatively well-demarcated mass, measuring approximately 40 mm in diameter, located in the pancreatic tail. It was heterogeneously enhanced almost to the same degree as the surrounding pancreatic tissue in both the arterial and portal venous phases. We performed endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) using the Acquire® 22-gauge needle and preoperatively obtained a definitive diagnosis with a sufficient sample. Clinicians should consider pancreatic PEComa in their differential diagnosis of patients with a pancreatic mass.

Acute Acalculous Cholecystitis Caused by Giardia lamblia.

We report a case of a 70-year-old man with acute acalculous cholecystitis caused by Giardia lamblia. Contrast-enhanced computed tomography (CT) showed distention of the gallbladder due to a pericholecystic abscess without gallstones. Magnetic resonance cholangiopancreatography and drip infusion cholecystocholangiography-CT demonstrated a stricture of the hilar bile duct and cystic duct obstruction. We conducted transpapillary bile duct brush cytology and a biopsy of the hilar bile duct stricture; numerous active trophozoites of Giardia lamblia were observed without malignant findings. We considered this bile duct lesion to be biliary giardiasis. Biliary giardiasis should be taken into consideration when diagnosing acute acalculous cholecystitis.