Lobaplatin hyperthermic intraperitoneal chemotherapy plus cytoreduction and rechallenge using cetuximab for wild-type RAS peritoneal metastatic colon cancer: a case report and literature review

Background Synchronous peritoneal metastasis of colorectal cancer usually predicts a bleak prognosis. Hyperthermic intraperitoneal chemotherapy (HIPEC) and cytoreductive surgery (CRS) have brought a glimmer of hope to the treatment of peritoneal cancer. Few cases treated with lobaplatin have been reported in the literature and the regimen is controversial. In this case, the comprehensive treatment scheme of lobaplatin-based HIPEC plus CRS and rechallenge using cetuximab plus systemic chemotherapy is effective, especially for the patients with left colon cancer (wild-type RAS). Case presentation A 49 year-old man with signet ring cell carcinoma of sigmoid colon with extensive abdominal metastasis (wild-type RAS) was hospitalized with prolonged abdominal pain, distention and abdominal mass. After receiving HIPEC with lobaplatin and XELOX regimen combined with cetuximab for eight cycles, the patient had been treated with the FOLFIRI regimen and cetuximab for 24 cycles, which discontinued due to myelosuppression. Because the disease recurred unfortunately 4 months later, the FOLFIRI + cetuximab regimen was initiated again and stopped after two cycles. Intestinal obstruction occurred 1 month later, so open total colectomy, CRS + HIPEC and ileorectal anastomosis were performed. Capecitabine adjuvant chemotherapy was administered, followed by the maintenance therapy with FOLFIRI + cetuximab regimen. After that, the patient has been in relatively stable condition. By August 2021, the overall survival is more than 45 months, which displays significant curative effect. Conclusion For peritoneal metastasis from left colon cancer, the management with CRS + lobaplatin HIPEC and rechallenge of systemic chemotherapy plus targeted medicine based on gene detection can dramatically improve prognosis and extend the overall survival.