Molecularly targeted approaches to the chemoprevention of lung cancer

Area of Science:

• Oncology
• Chemoprevention
• Translational Research

Background:

• Previous large trials for lung cancer primary prevention using beta-carotene, alpha-tocopherol, and retinyl palmitate yielded disappointing results.
• Epidemiological data initially suggested a role for these micronutrients in lung cancer prevention.
• This led to a shift towards biomarker-driven translational trials focusing on reversing premalignancy.

Purpose of the Study:

• To evaluate the efficacy of novel chemopreventive agents in reversing lung cancer premalignancy.
• To explore biomarker-driven strategies for lung cancer prevention.
• To investigate the role of retinoids and other molecular targets in lung carcinogenesis.

Main Methods:

• Conducting serial trials of retinoids, including 13-cis-retinoic acid (isotretinoin) and 9-cis-retinoic acid.
• Monitoring the reversal of premalignancy in active smokers.
• Targeting molecular markers such as cyclooxygenase-2, the ras-signaling pathway, and the tyrosine kinase/epidermal growth factor receptor pathway.

Main Results:

• Trials with 13-cis-retinoic acid did not show a significant difference in reversing premalignancy or preventing second primary tumors.
• A trial of 9-cis-retinoic acid demonstrated up-regulation of retinoic acid receptor beta (RAR-beta), a potential response marker.
• Early results from head and neck cancer bioadjuvant trials suggest combination chemoprevention is a promising strategy.

Conclusions:

• Micronutrient-based primary prevention trials for lung cancer have been largely unsuccessful.
• Biomarker-driven translational research, particularly with retinoids like 9-cis-retinoic acid, offers a new avenue for lung cancer prevention by targeting premalignancy.
• Future lung cancer prevention strategies may involve targeting specific molecular pathways and combination chemoprevention.