LIMITATIONS OF INHALED ANTICANCER AGENTS
To minimize occupational exposure of healthcare workers or others who are administering inhaled chemotherapeutic agents, a well-ventilated room with a HEPA filter air cleaning system for aerosol administration is mandatory. However, Verschraegen and colleagues allowed patients to take their inhaled chemotherapy at home (Verschraegen et al. 2004). Establishing the safety of domiciliary chemotherapy could have enormous implications for convenience and cost of treatment.
Further investigations are ongoing to establish the optimal drug regimens, formulations, and methods of inhaled drug delivery. When inhaled agents are used as adjuncts, whether they should be given before (neoadjuvant), concurrently with, or after (adjuvant) other forms of treatment have not been established. Future investigations will need to clarify if inhalation targeted only to the tumor site is more effective and less toxic compared to drug deposition in both lungs. Focused investigations could elucidate which tumor types (primary/secondary) respond best to inha- lational treatment, whether such therapy is more effective at an early or late stage of the disease, and if inhaled therapy effectively treats micrometastases in the lungs and at other sites following lymphatic or vascular spread of the tumor. Successfully addressing these questions with well-designed clinical trials will aid in clarifying the role of inhalational anticancer therapy in clinical practice.