FR5+1234

Many drugs with potent cytotoxic effects are available for the treatment of malignant tumors. These chemotherapeutic agents can effectively kill rapidly dividing cancer cells, and in some cases, they significantly reduce tumor burden. However, despite their high potency against cancer cells, the clinical efficacy of these drugs is often limited. One of the major challenges is their low tumor-targeting ability. Most of these drugs are not highly selective and circulate throughout the body, affecting both cancerous and healthy tissues. This lack of selectivity can lead to severe adverse effects, including damage to bone marrow, gastrointestinal tract, liver, and other vital organs. Such side effects not only reduce patients’ quality of life but may also limit the maximum tolerable dose, ultimately constraining the overall effectiveness of the therapy. Consequently, the therapeutic window for many cytotoxic drugs remains narrow, and their clinical application must carefully balance antitumor activity with toxicity management. To overcome these limitations, researchers are actively investigating targeted drug delivery systems, prodrugs, and combination therapies that could enhance the selective accumulation of drugs in tumor tissues while sparing normal cells. These strategies aim to improve treatment outcomes and minimize systemic toxicity, thereby maximizing the potential of cytotoxic agents in cancer therapy.