Pathological Complete Response and Successful Conversion Surgery After Nivolumab Therapy for Stage IV Oesophagogastric Junction Cancer

A Case of Pathologically Complete Response After Nivolumab Combined with Chemotherapy in a Gastric Cancer Patient with Virchow's Lymph Node Metastasis

Gastric cancer with Virchow's lymph node metastasis (LNM) is not indicated for initial curative surgery. Although there have been some case reports of curative resections after pre-operative treatment, including immune checkpoint inhibitors (ICIs), there is no consensus regarding the optimal timing of surgery. We describe a rare case of initially unresectable gastric cancer treated preoperatively with nivolumab combined chemotherapy, which achieved a pathologically complete response. An 82-year-old man was referred for gastric cancer treatment. Contrast-enhanced computed tomography revealed stomach wall thickening and swollen left supraclavicular LN. This gastric cancer was assessed as unresectable due to the presence of Virchow's LNM; therefore, chemotherapy and ICI using S-1 plus oxaliplatin plus nivolumab were administered. After three courses of treatment, the primary tumor and Virchow's LN showed a marked reduction in size. The patient underwent Virchow's LNM resection as a preliminary step to determine indications for curative surgery. A pathological examination revealed no viable cancer cells were found inside the resected LN. The patient underwent distal gastrectomy. Pathological examination revealed complete degeneration of the primary tumor and regional LN without residual carcinoma. The patient did not receive adjuvant chemotherapy and survived with no evidence of recurrence for one year after the initial treatment.

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 conversion surgery following chemotherapy with an immune checkpoint inhibitor in an older adult patient with stage IVB esophageal squamous cell carcinoma: a case report

BACKGROUND

Chemotherapy and chemoradiotherapy are common treatments for esophageal squamous cell carcinoma with distant metastasis; however, the prognosis remains poor, and complete remission is difficult to achieve. Here, we report a case of an older adult patient with esophageal squamous cell carcinoma who underwent surgery following combined treatment of immunotherapy and chemotherapy and achieved pathological complete response.

CASE PRESENTATION

An 80-year-old woman presenting with difficulty swallowing was referred to our hospital. She was diagnosed with esophageal squamous cell carcinoma with distant metastasis of the lymph node at the dorsal side of the IVC and the left supraclavicular lymph node. She was treated with pembrolizumab, cisplatin, and 5-fluorouracil. After four pharmacotherapy courses, primary tumor and metastatic lymph node shrinkage was observed. The patient underwent thoracoscopic subtotal esophagectomy and regional lymph node dissection. The lymph node at the dorsal side of the IVC was not resected, and the left supraclavicular lymph node was removed. Histological examination revealed complete response with no residual tumor or lymph node metastasis. The patient had no recurrence 10 months postoperatively without adjuvant chemotherapy.

CONCLUSIONS

Conversion surgery following preoperative therapy, including immunotherapy, may be an effective treatment strategy for improving survival in patients with esophageal squamous cell carcinoma even among older adult patients.

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.