Durable Complete Response of Colorectal Cancer Metastasis after Biochemotherapy

Resection of the metastatic site is indicated but not always possible in patients with metastatic colorectal cancer (mCRC) who achieve a partial or complete response (CR) to induction systemic treatment. CR after systemic treatment alone is uncommon, and even patients with radiologic CR after induction chemotherapy harbour persistent macroscopic or microscopic residual disease in more than 80% of cases. Occasionally, some metastatic lesions disappear radiologically but others persist after induction systemic treatment. The indication and extent of metastasectomy in these situations is controversial, especially regarding sites with completely regressed metastases.

This case report describes a patient with mCRC who achieved a long-term response after biochemotherapy and incomplete metastasectomy. One of the known liver lesions could not be removed due to its disappearance after induction biochemotherapy with FOLFOX and bevacizumab. Further adjuvant chemotherapy using the FOLFOX regimen was administered postoperatively. The patient has been meticulously followed by radiology including repeated positron emission tomography/computed tomography and magnetic resonance scans, clinical examination and tumour markers. No recurrence of cancer has been detected after a follow-up of 5 years.

CR to systemic treatment is uncommon, but this case report demonstrates that it can be durable in patients with colorectal cancer and liver metastases. This case report indicates that some patients with mCRC can be cured with systemic therapy only, challenging the prevailing paradigm of mCRC therapy.Key words: colorectal cancer - metastasis - chemotherapy - molecular targeted therapy - diagnostic imaging.