Successful Conversion Surgery for Stage IV Gastric Cancer after Nivolumab Monotherapy as Third-Line Chemotherapy

Complete response of a metastatic microsatellite-stable gastric cancer after neoadjuvant chemoimmunotherapy: should we still operate? A case report and review of the literature

Gastric cancer often presents at an advanced stage in Western populations due to a lack of screening programs, leading to poor prognoses. Historically, palliative chemotherapy resulted in a median survival of 9.9 months. However, the introduction of the FLOT regimen and immunotherapy has significantly altered treatment outcomes. Oligometastatic gastric cancer, defined as metastasis limited to a single organ or a few sites, has emerged as a distinct subgroup with improved survival when treated with a combination of systemic and local therapies. We present the case of a 54-year-old male patient diagnosed with microsatellite-stable (MSS) oligometastatic gastric adenocarcinoma, including liver and peritoneal metastases, who achieved a complete pathological response following neoadjuvant chemoimmunotherapy with FOLFOX and nivolumab. Despite unfavorable prognostic factors, such as liver involvement and positive peritoneal cytology, the patient responded well to the treatment, allowing curative surgery. Postoperative histology confirmed complete regression of both the primary tumor and metastases, with no recurrence observed at the 1-year follow-up. This case shows the potential of combined chemoimmunotherapy to convert previously inoperable MSS gastric cancer to surgical candidates. Further research is needed to better define patient selection criteria and assess long-term outcomes for these patients.

Stage IV gastric cancer with microsatellite instability-high achieving long-term survival by gastrectomy after nivolumab as third-line therapy: a case report and literature review

BACKGROUND

The prognosis for stage IV gastric cancer remains poor; however, the advent of immune checkpoint inhibitors (ICIs) such as nivolumab has increased the number of patients with long-term survival. Patients with microsatellite instability (MSI)-high gastric cancer have been recognized as a highly effective population for ICIs. Herein, we report a patient with MSI-high advanced gastric cancer treated with gastrectomy after the administration of nivolumab as third-line therapy.

CASE PRESENTATION

A 73-year-old woman presented with a type 3 tumor in the lower part of the gastric body, which was diagnosed as gastric cancer through biopsy. Staging laparoscopy revealed that the tumor had invaded the pancreas and the posterior lobe of the transverse mesocolon, and disseminated nodules were found near the ligament of Treitz. After 4 courses of S-1 plus cisplatin therapy, laparoscopic gastrojejunal bypass was performed because of difficulty in oral intake. She received S-1 plus oxaliplatin therapy after a gastrojejunal bypass; however, her regional lymph nodes were enlarged. After six courses of paclitaxel plus ramucirumab as second-line chemotherapy, computed tomography (CT) showed exacerbation of peritoneal dissemination; thus, nivolumab was selected as the third-line therapy. The tumor was characterized by MSI-high. At 24 courses, CT and gastroscopy revealed a complete clinical response of the tumor; however, re-growth of the primary tumor was observed at 36 courses. The patient underwent distal gastrectomy with D1 + lymph node dissection, and received S-1 monotherapy as adjuvant therapy for 1 year. No recurrence was noted at 39 months after the surgery.

CONCLUSIONS

We report a patient with highly advanced gastric cancer with peritoneal dissemination, which worsened during second-line therapy and was successfully treated with gastrectomy after nivolumab administration as a third-line therapy. MSI-high gastric cancer is a target that should be actively considered for the administration of ICIs, such as nivolumab, and multidisciplinary treatment combined with chemotherapy and gastrectomy, including conversion surgery, can lead to patients' long-term survival.

Successful R0 resection after chemotherapy, including nivolumab, for gastric cancer with liver metastases: three case reports

BACKGROUND

Advances in chemotherapy have increased clinical experience with conversion surgery for inoperable advanced gastric cancer. This report describes three patients with unresectable gastric cancer accompanied by multiple liver metastases. In all three patients, nivolumab resolved the liver metastases and subsequent conversion surgery achieved a pathological complete response.

CASE PRESENTATION

In Case 1, a 68-year-old man with clinical Stage IVB gastric cancer and multiple liver metastases initiated first-line therapy with SOX plus nivolumab. The patient completed 13 cycles; however, only nivolumab was continued for 3 cycles because of adverse events. Distal gastrectomy and partial hepatic resection were performed because of a significant reduction in the size of the liver metastases as observed on magnetic resonance imaging (MRI). In Case 2, a 72-year-old man with clinical Stage IVB gastric cancer and multiple liver metastases initiated first-line therapy with SOX. Because of the subsequent emergence of new liver metastases, the patient transitioned to ramucirumab plus paclitaxel as second-line therapy. Third-line therapy with nivolumab was initiated because of side effects. MRI revealed necrosis within the liver metastasis, and the patient underwent proximal gastrectomy and partial hepatectomy. In Case 3, a 51-year-old woman with clinical Stage IVB gastric cancer accompanied by multiple metastases of the liver and para-aortic lymph nodes began first-line therapy with SOX plus nivolumab. The patient completed 10 cycles; however, only nivolumab was continued for 5 cycles because of adverse events. Computed tomography showed a significant decrease in the size of the para-aortic lymph nodes, while MRI indicated the presence of a singular liver metastasis. Distal gastrectomy and partial hepatic resection were subsequently performed. In all three cases, MRI revealed the presence of liver metastases; however, pathological examination showed no viable tumor cells.

CONCLUSIONS

We herein present three cases in which chemotherapy, including nivolumab, elicited a response in patients with multiple unresectable liver metastases, ultimately culminating in R0 resection through conversion surgery. Although MRI showed liver metastases, pathological analysis revealed no cancer, underscoring the beneficial impact of chemotherapy.

Pathological complete response with nivolumab for recurrence of liver metastasis after gastrectomy of gastric cancer

BACKGROUND

Advanced gastric cancer has an unfavorable prognosis and poor curability. Immune checkpoint inhibitors, such as nivolumab, have recently emerged as a potential solution for this aggressive disease. However, there is a lack of established evidence on the clinical efficacy of these agents, particularly in the perioperative period for advanced gastric cancer patients who are unresectable, recurrent, or preoperative. Despite the limited data available, there have been rare cases of dramatic therapeutic effects. In this study, we present a successful case of nivolumab treatment along with surgery.

CASE PRESENTATION

A 69-year-old female presented with pericardial discomfort and was diagnosed with advanced gastric cancer following upper gastrointestinal endoscopy. Laparoscopic distal gastrectomy with D2 lymph node dissection was performed, resulting in a final pathological diagnosis of Stage IIIA. The patient received postoperative adjuvant chemotherapy with oral S-1 therapy, but was found to have multiple liver metastases at 8 months postsurgery. Weekly paclitaxel and ramucirumab therapy was initiated, but the patient experienced adverse side effects, leading to the discontinuation of treatment. Nivolumab monotherapy was then administered for 18 cycles, resulting in a partial therapeutic response and PET-CT revealed a complete metabolic response. However, the patient developed a Grade 3 pemphigoid as an immune-related adverse event, leading to the cessation of nivolumab. The patient underwent laparoscopic partial hepatectomy. Postoperative pathology showed no residual tumor cells, indicating a complete response. At present, 25 months after surgery, the patient was alive without recurrence.

CONCLUSION

In this report, we present a case of gastric cancer with liver metastatic recurrence, in which a complete pathological response was achieved with nivolumab treatment. Although determining whether surgical intervention is necessary following successful drug treatment can be challenging, PET-CT imaging may be useful in decision-making regarding surgical treatment.

Successful management of multiple liver metastasis from gastric cancer with second conversion surgery: A case report

INTRODUCTION

Most conversion surgeries for patients with stageIV gastric cancer are performed on patients who have responded to first-line chemotherapy. Although conversion surgery after third-line chemotherapy with nivolumab has been reported, there are no cases wherein second conversion surgery was performed after third-line chemotherapy with nivolumab.

PRESENTATION OF CASE

A 72-year-old man presented with gastric cancer and an enlarged regional lymph node, and early esophageal cancer was identified after endoscopic submucosal dissection. After S-1 plus oxaliplatin as first-line chemotherapy, staging laparoscopy was performed, and liver metastasis was confirmed. The patient underwent a total gastrectomy with D2 lymphadenectomy, hepatic left lateral segmentectomy, and partial hepatectomy. One year after conversion surgery, new liver metastases appeared. He received nab-paclitaxel plus ramucirumab and nivolumab as the second and third-line chemotherapy, respectively. Liver metastases were significantly reduced following these courses of chemotherapy. The patient underwent partial hepatectomy as second conversion surgery. Although nivolumab was continued after the second conversion surgery, new para-aortic lymph node metastasis and bilateral hilar lymph node metastasis appeared. However no new metastasis appeared in the liver and he survived for 60 months after first-line chemotherapy.

DISCUSSION

A second conversion surgery with stageIV gastric cancer after third-line chemotherapy with nivolumab is rare. Multiple hepatectomy as conversion surgery may be an option to control liver metastases.

CONCLUSION

Multiple hepatectomy as conversion surgery may be effective in controlling liver metastases. However, when to perform conversion surgery and the adequate selection of the patient are the most difficult and important.

Successful second conversion surgery after trastuzumab deruxtecan for recurrent HER2-positive gastric cancer

A 65-year-old woman with HER2-positive gastric cancer with multiple liver metastases underwent first conversion surgery of gastrectomy with D2 lymph nodes dissection and three liver metastases after combination therapy with capecitabine, cisplatin, and trastuzumab. Two years later, she experienced multiple liver metastases that were refractory to combination therapy with paclitaxel albumin-bound nanoparticles and ramucirumab. She participated in the DESTINY-Gastric01 trial and received tri-weekly trastuzumab deruxtecan as third-line treatment for 26 cycles. The recurrent lesions markedly shrank, and this effect continued for 19 months. We then performed partial hepatectomy for the one remaining lesion. No adjuvant chemotherapy was given, and she remains alive without recurrence 18 months after the second conversion surgery. Trastuzumab deruxtecan may generate a notable tumor response and subsequent conversion surgery could be a treatment option for HER2-positive stage IV gastric cancer.

Conversion surgery for microsatellite instability-high gastric cancer with a complete pathological response to pembrolizumab: a case report

BACKGROUND

Immune checkpoint inhibitors are reportedly effective in treating microsatellite instability (MSI)-high gastric cancer. There are a few case reports of conversion surgery (CS) with nivolumab but none with pembrolizumab. Herein, we describe a patient with MSI-high gastric cancer who was successfully treated with pembrolizumab and underwent CS with a pathological complete response.

CASE PRESENTATION

A 69-year-old man was diagnosed with stage III gastric cancer (T3N2M0) based on contrast-enhanced computed tomography, which revealed a neoplastic lesion and enlarged perigastric lymph nodes in the gastric lesser curvature. The anterior superior lymph node of the common hepatic artery (CHA) was determined to be unresectable due to invasion of the pancreatic head and CHA. Histopathologically, the biopsied tissue showed moderately differentiated adenocarcinoma, then determined to be MSI-high. After three courses of mFOLFOX6 therapy, the patient was diagnosed with progressive disease. Since one course of paclitaxel plus ramucirumab therapy caused grade 3 fatigue, his second-line therapy was switched to pembrolizumab monotherapy. After three courses, the primary tumor and perigastric lymph nodes had shrunk, and it was determined as a partial response. The anterior superior lymph node of the CHA became resectable based on the improvement of infiltration of the pancreatic head and CHA due to shrinkage of the lymph node. Tumor markers remained low; hence, distal gastrectomy plus D2 lymphadenectomy was performed at the end of six courses. Anterior superior lymph node of the CHA was confirmed by intraoperative ultrasonography, and the resection was completed safely. The gross examination of the resected specimen revealed an ulcer scar at the primary tumor site. The histopathological examination showed no viable tumor cell remnants in the primary tumor, which had a grade 3 histological response, and resection margins were negative. The lymph nodes showed mucus retention only in the anterior superior lymph node of the CHA, indicating the presence of metastasis, but no viable tumor cells remained. The patient commenced 6 months of adjuvant pembrolizumab monotherapy 3 months after surgery. Twenty months after surgery, there was no evidence of recurrence.

CONCLUSIONS

Conversion surgery following pembrolizumab monotherapy has a potential utility for the treatment of MSI-high gastric cancer.