Treatment of Colorectal Cancer
Gastric cancer (GC) and colorectal cancer (CRC) are major malignant diseases of alimentary tract. While GC is the most common cancer in the Asian-Pacific region, CRC is ranked as the fourth most common malignancy world-wide, with about 1.2 million new cases and 609,051 deaths annually. Surgical resection with or without adjuvant chemo- and/or radiation therapy remains the key modality for GC and CRC, but unfortunately shows limited clinical benefits due to high rate of tumor metastasis. Although current adjuvant chemo-radiation therapy has been shown to extend patient survival in the presence of recurrent lesions, severe side effects usually limit the efficacy of this anti-cancer modality. To further improve the overall survival for CRC patients, it is critical to explore novel approaches to control tumor metastasis with or without the use of traditional chemo-and/or radiotherapy.
The dendritic cells (DCs) play a crucial role in the induction of antigen-specific T-cell responses to provide active immunotherapy. Clinical studies using specifically designed DC-targeted cancer cell vaccines demonstrated different clinical benefits. Patients with lymphoma, metastatic melanoma, colon cancer, and non-small cell lung cancer showed that vaccination with tumor antigen-pulsed DCs, either isolated directly from blood or generated ex vivo from blood precursors, elicited antigen specific immune reaction and, in some cases, significant tumor responses
The active immunotherapy using tumor-specific DC vaccine has the potential benefit to significantly enhance tumor-specific effector and memory T cells.
Safety and feasibility were confirmed for the DC vaccine with autologous tumor lysate in a phase 2 clinical study and for clinical use in combination with standard drug therapy. An immunological response was potentially associated with the antitumor effect of the DC vaccine.