Recent advances in oral anticancer agents for colon cancer

A Multifunctional Nanotherapy for Targeted Treatment of Colon Cancer by Simultaneously Regulating Tumor Microenvironment

Colitis-associated colon cancer (CAC) is a widely recognized cancer, while treatment with the existing chemotherapeutic drugs affords limited clinical benefits. Herein we proposed a site-specific, combination nanotherapy strategy for targeted treatment of CAC by the oral route. Methods: A reactive oxygen species (ROS)-responsive and hydrogen peroxide-eliminating material OCD was synthesized, which was further produced into a functional nanoparticle (OCD NP). The antioxidative stress and anti-inflammatory effects of OCD NP were examined by in vitro and in vivo experiments. By packaging an anticancer drug camptothecin-11 (CPT-11) into OCD NP, a ROS-responsive nanotherapy CPT-11/OCD NP was obtained, and its antitumor activity was evaluated by both in vitro and in vivo studies. Preliminary safety studies were also performed for CPT-11/OCD NP in mice. Results: OCD NP significantly attenuated oxidative stress and inhibited inflammatory response in different cells and mice with induced colitis. CPT-11/OCD NP could selectively release drug molecules under intestinal pH conditions and at high levels of ROS. In C26 murine colon carcinoma cells, this nanotherapy showed significantly higher antitumor activity compared to free CPT-11 and a non-responsive CPT-11 nanotherapy. Correspondingly, oral delivery of CPT-11/OCD NP notably inhibited tumorigenesis and tumor growth in mice with induced CAC. By combination therapy with the nanovehicle OCD NP in the inflammatory phase, more desirable therapeutic effects were achieved. Furthermore, CPT-11/OCD NP displayed excellent safety profile for oral administration at a dose that is 87.3-fold higher than that employed in therapeutic studies. Conclusions: Anticancer nanotherapies derived from intrinsic anti-inflammatory nanocarriers are promising for targeted combination treatment of inflammation-associated tumors by simultaneously shaping pro-inflammatory microenvironment toward a relatively normal niche sensitive to chemotherapy.

New Trends in the Therapeutic Approach to Metastatic Colorectal Cancer

Important developments in chemotherapy for metastatic colorectal cancer over the last years are reviewed, with an emphasis on the most recently published data from clinical trials. The systematic review of current literature was conducted involving Pubmed Central^® research and full articles were obtained and analyzed when appropriate. Fluorouracil still constitutes the backbone of metastatic colorectal cancer treatment; fluorouracil combination plus either irinotecan (FOLFIRI), oxaliplatin (FOLFOX) or capecitabine (CAPOX or XELOX) are chemotherapy protocols established as treatments producing similar outcomes. Actual treatment involves these chemotherapy protocols in combination with new molecular targeted drugs: bevacizumab and aflibercept (anti-vascular endothelial growth factor monoclonal antibody) and cetuximab and panitumumab (anti-epidermal growth factor receptor monoclonal antibody for patients with wild type KRAS) which confer significant survival benefits in select patients as first- or second-line therapies. The factors affecting the decisions for one treatment over other are related to the patient and toxicity drug. Finally, metastatic colorectal cancer patients progressing after all standard therapies (maintaining a good ECOG performance status) could be candidates for further therapies such as regorafenib and TAS-102. Regarding the future, promising therapies are under development for the metastatic colorectal cancer treatment and several agents are currently being evaluated in different clinical trials.

pH-operated hybrid silica nanoparticles with multiple H-bond stoppers for colon cancer therapy

Controlled delivery of a chemotherapeutic drug from pH-sensitive hybrid silica nanocarriers efficiently targets colon carcinoma cells. The drug, blocked by cyanuric acid as stopper, is autonomously released inside the cancer cells.