Opportunities for nanotheranosis in lung cancer and pulmonary metastasis

Malignancies of the lungs, both primary and metastatic, are the leading cause of death worldwide. Over 1.5 million new cases of primary lung cancer are diagnosed annually worldwide with a dismal 5-year survival rate of approximately 15 %, which remains unchanged despite major efforts and medical advances. As expected, survival for patients with lung metastases is even worse at about 5 %. Early detection and staging are fundamental in improving survival rates and selecting the most effective treatment strategies. Recently, nanoparticles have been developed for imaging and treating various cancers, including pulmonary malignancies. In this work, three different examples of nanoparticle configurations for cancer theranosis are presented, namely conventional spherical polymeric nanoparticles with a diameter of ~150 nm; and discoidal mesoporous silicon nanoconstructs and discoidal polymeric nanoconstructs with a diameter of ~1,000 nm and a height of 400 and 500 nm, respectively. The spherical nanoparticles accumulate in tumors by means of the well-known enhanced permeation and retention effect, whereas sub-micrometer discoidal nanoconstructs are rationally designed to adhere firmly to the tortuous tumor vasculature. All three nanoparticles are characterized for their in vivo performance in terms of magnetic resonance, positron-emission tomography (PET), and optical imaging. Preliminary data on the in vivo and ex vivo PET/CT imaging of breast cancer metastasis in the lungs using discoidal nanoconstructs is presented. In conclusion, opportunities for nanoparticle-based theranosis in primary lung cancer and pulmonary metastasis are presented and discussed.