INTRODUCTION: Bioprosthetic valve failure after mitral valve replacement is a well-recognized phenomenon, with pannus overgrowth being one notable cause. The standard treatments include redo surgical mitral valve replacement and the less invasive transcatheter treatment, mitral valve-in-valve. However, the feasibility and safety of performing mitral valve-in-valve when pannus overgrowth has reduced the valvular opening to a mere pinhole remains uncertain.

CASE PRESENTATION: A 76-year-old woman, who had previously undergone mitral valve replacement, was admitted for congestive heart failure. Severe mitral stenosis and severe mitral regurgitation were diagnosed using transthoracic echocardiography. During redo mitral valve replacement, we observed that the prosthetic valve leaflets on the left atrial side were almost entirely covered with pannus tissue, leaving only a central pinhole for blood flow. Macroscopic and microscopic examination of the bioprosthesis revealed accordion-like leaflet deformation on the ventricular side.

CONCLUSIONS: Although the transcatheter valve-in-valve procedure is recognized as a less invasive treatment option for degenerated biological valves, in certain cases such as ours, open surgery becomes imperative as the most appropriate treatment.

INTRODUCTION: Intrahepatic cholangiocarcinoma (ICC) is a highly malignant cancer for which surgery is the only curative treatment. The prognosis of ICC is extremely poor, especially in cases of lymph node metastasis (LNM), owing to the high postoperative recurrence rate. Herein, we present a case of advanced ICC with a breast cancer susceptibility gene-2 (BRCA2) mutation, treated with preoperative chemotherapy, including cisplatin, followed by surgery, in which we achieved a pathologic complete response.

CASE PRESENTATION: A 52-year-old woman was referred to our hospital and was subsequently diagnosed with bilateral breast cancer. Computed tomography (CT) and magnetic resonance imaging incidentally detected a liver tumor in the hilar region and lymph node enlargement in the hepatoduodenal ligament. A 19 mm tumor was observed in the area surrounded by the right and left branches of the portal vein and an abnormal portal branch of segment 7. Positron emission tomography-CT showed fluorodeoxyglucose uptake in the liver tumor, hepatoduodenal ligament lymph nodes, and bilateral breasts. A tumor biopsy showed a papillary tumor, and ICC was suspected. As ICC with LNM has a poor prognosis, neoadjuvant chemotherapy was planned. Genetic testing using a blood sample revealed a BRCA2 mutation, indicating the patient would benefit from chemotherapy, particularly cisplatin. The patient received a chemotherapy regimen comprised of gemcitabine, cisplatin, and S-1 (GCS), and after 7 courses, her carbohydrate antigen 19-9 level decreased from 2433 to 15 U/mL. CT showed that the tumor had shrunk and the LNMs were indistinct. The patient was referred to our department for curative surgery, which included a left hepatectomy, caudate lobectomy, hepatoduodenal ligament lymph node dissection, bile duct resection, and choledocojejunostomy. The postoperative course was generally uneventful, and the patient was discharged on postoperative day 18. Pathological examination of the resected specimen revealed an absence of malignant cells. At 24 months postoperative, there was no evidence of recurrence.

CONCLUSIONS: We encountered a patient with advanced ICC with a BRCA2 mutation, which was successfully treated with preoperative GCS therapy followed by surgical resection, and a pathologic complete response was achieved. GCS therapy, therefore, appears promising as neoadjuvant chemotherapy for the treatment of ICC.

INTRODUCTION: Pembrolizumab has been introduced to solid cancers with microsatellite instability (MSI)-high cases; however, its clinical experience for cholangiocarcinoma remains very limited. Here, we present a case who successfully underwent conversion surgery following pembrolizumab treatment for MSI-high perihilar cholangiocarcinoma, which pathologically exhibited complete response.

CASE PRESENTATION: A 69-year-old male with Bismuth IV perihilar cholangiocarcinoma with bulky lymphadenopathy was referred, who initially required left hepatic trisectionectomy, caudate lobectomy, bile duct resection, and portal vein resection and reconstruction (H123458-B-PV). During the waiting period after preoperative portal vein embolization, the right hepatic artery was involved by rapid tumor progression, needing a modification of the initially scheduled surgical procedure to additional hepatic artery resection and reconstruction (H123458-B-PV-HA). We revised the surgical decision of resectable to locally unresectable disease. He received systemic chemotherapy with gemcitabine and cisplatin as first-line, showing the best effect of stable disease followed by slight tumor progression and re-elevation of tumor marker after 5 courses of treatment. Cancer multi-gene panel analysis using percutaneous biopsy specimen showed the nature of MSI-high. Therefore, he received pembrolizumab treatment as second-line therapy, leading to a drastic downsize >30% in tumor diameter and normalization of the tumor marker as well after only 2 cycles of administration. After confirmation of keeping tumor shrinkage during 22 courses of pembrolizumab treatment without any severe adverse events, we decided to perform conversion surgery and performed left trisectionectomy, caudate lobectomy, and bile duct resection with portal vein resection (H123458-B-PV). Although the right hepatic artery was extensively fibrotic, there was no evidence of malignancy by frozen section histologic diagnosis. The pathological findings showed pathological complete response with no residual tumor cells. The patient is under periodical checkup without adjuvant chemotherapy, and no tumor recurrence was observed at 4 months postoperatively.

CONCLUSIONS: We experienced clinical partial response but pathological complete response after second-line pembrolizumab treatment for unresectable locally advanced perihilar cholangiocarcinoma with a biologic nature of MSI-high. Conversion surgery may be considered as a promising option for such effective case, whereas there is a possibility to avoid resection in the MSI-high setting.

INTRODUCTION: Colorectal cancer is a prevalent malignancy that necessitates personalized chemotherapy, especially with the advent of molecular-targeted drugs and immune checkpoint inhibitors. In Japan, immune checkpoint inhibitors have been approved for unresectable advanced and recurrent colorectal cancer; however, their use in preoperative therapy for colorectal cancer has not yet been approved. Globally, neoadjuvant immunotherapy has demonstrated promising outcomes in colorectal cancer cases with high immunogenicity, including microsatellite instability-high and deficient mismatch repair.

CASE PRESENTATION: We report a case of a microsatellite instability-high, clinically unresectable, locally advanced ascending colon cancer treated with immune checkpoint inhibitors, which showed significant tumor shrinkage, facilitating standard surgery while avoiding adjunct organ resection. The patient, a 70-year-old male, experienced chronic abdominal pain and diarrhea. Lower gastrointestinal endoscopy and computed tomography confirmed a diagnosis of ascending colon cancer with suspected invasion into the descending duodenum. Although curative resection was technically feasible with pancreatoduodenectomy, neoadjuvant chemotherapy was selected to reduce tumor size, considering the patient’s overall condition. Companion diagnostics revealed microsatellite instability-high status and BRAF^V600E mutation, leading to the initiation of chemotherapy combined with an immune checkpoint inhibitor (pembrolizumab). Subsequently, prolonged pembrolizumab administration was challenging due to suspected immune-related adverse events, including diarrhea and pruritus. However, significant tumor reduction was observed during a follow-up computed tomography scan, facilitating surgery approximately 6 months after treatment initiation. The perioperative period was uneventful, and the patient was discharged on the eighth day after operation. The final pathological results revealed complete tumor disappearance (histological effect of chemotherapy: Grade 3).

CONCLUSIONS: This case highlights the potential of neoadjuvant immunotherapy in reducing surgical invasiveness in patients with colorectal cancer.

INTRODUCTION: Perioperative mortality is significantly higher in cases of heart failure with severe left ventricular ejection fraction (LVEF) reduction, making it challenging to decide whether to proceed with surgery for early-stage breast cancer, which is not immediately fatal. However, the prognosis of heart failure has improved and breast cancer is increasingly becoming a prognostic factor. Herein, we report the case of a breast cancer patient with severe heart failure due to dilated cardiomyopathy (DC), who was deemed fit to undergo surgery under general anesthesia after obtaining sufficient informed consent and achieving improvement in heart failure symptoms during endocrine therapy.

CASE PRESENTATION: A 64-year-old female with a history of DC and sustained ventricular tachycardia, who had received cardiac resynchronization therapy with defibrillator implantation, underwent breast cancer surgery. She had been repeatedly hospitalized for heart failure with an LVEF of 19% and New York Heart Association (NYHA) Class III status, and heart transplant surgery was considered. However, a screening computed tomography scan revealed right breast cancer, and neither heart transplantation nor breast cancer surgery was performed. Endocrine therapy was initiated and failed 48 months after administration. Although the LVEF remained low at 21%, the NYHA classification improved to Class II, and she had not been hospitalized for heart failure for an extended period since her breast cancer diagnosis. Therefore, breast cancer surgery was performed under general anesthesia and no postoperative complications were observed throughout the course of the surgery.

CONCLUSION: Given that the prognosis for heart failure may statistically be better than that for breast cancer, early breast cancer surgery should be performed in patients with stable heart failure symptoms.