Antitumor drugs are considered pathogenic toxin-attacking agents， whose intense and biased pharmacological effects on the body may induce secondary pathological factors and subsequent pathological changes， that is， drug toxin. Its pathogenic features include rapid and marked impairment of healthy qi and constitution-dependent transformation. Zang-fu （脏腑） organs involvement is characterized by an early response of the middle jiao （焦）， later involvement of the kidney and marrow， and extension to the five zang organs， while its temporal evolution may manifest as acute injury， cumulative injury， and persistent or delayed injury. Cancer toxin， drug toxin， and deficiency of healthy qi interact to form a dynamically evolving complex pathogenic pattern. Clinically， treatment should take disease stage as the framework， toxin differentiation as the focus， and reinforcement of healthy qi as a principle throughout the course， while coordinating toxin reduction and elimination of cancer toxin with reinforcement of healthy qi. Furthermore， intervention against drug toxin should be initiated early and throughout the entire course of antitumor therapy. This framework may provide a theoretical basis for integrating traditional Chinese medicine throughout comprehensive cancer treatment.