Bleomycin is best described as which type of chemotherapeutic agent?

• A. Cell cycle-specific
• B. Cell cycle-non-specific
• C. Targeted therapy
• D. Immunotherapy

Answer: (B)

Bleomycin damages DNA in a way that can affect cells at any stage of the cell cycle. It forms an iron-bleomycin complex that, with oxygen, generates free radicals and causes DNA strand breaks. Because this damage isn’t restricted to a specific phase (like only S-phase or M-phase), bleomycin is classified as cell cycle-non-specific.

It isn’t targeted therapy, since it doesn’t seek out a particular molecular abnormality or receptor, and it isn’t immunotherapy, since it doesn’t act by engaging or boosting the immune system. A helpful note: its toxicity profile, especially pulmonary toxicity, is related to low bleomycin hydrolase activity in the lungs, not to a phase-specific effect.

So, the best description is that bleomycin is a cell cycle-non-specific chemotherapeutic agent.