Anticancer agents, also known as anticancer drugs or chemotherapy drugs, are medications used to treat cancer by inhibiting the growth and spread of cancer cells. These agents work through various mechanisms, targeting different aspects of cancer cell biology. Here’s a detailed overview:

1. Chemotherapy Drugs: These are the most common type of anticancer agents and include a wide range of drugs such as alkylating agents, antimetabolites, anthracyclines, and taxanes. They work by interfering with the DNA synthesis or cell division process, ultimately leading to the death of rapidly dividing cancer cells.
2. Targeted Therapy: Unlike chemotherapy drugs, targeted therapy drugs specifically target molecules that are involved in the growth, progression, and spread of cancer cells. Examples include monoclonal antibodies, small molecule inhibitors, and immunotherapy drugs. They can target receptors on the surface of cancer cells or molecules within cancer cells, disrupting specific pathways crucial for cancer cell survival.
3. Hormonal Therapy: Hormonal therapy is used to treat hormone-sensitive cancers such as breast and prostate cancer. These drugs either block the production of hormones or interfere with hormone receptors, thereby slowing down or inhibiting the growth of hormone-dependent cancer cells.
4. Immunotherapy: Immunotherapy drugs harness the body’s immune system to recognize and attack cancer cells. They work by enhancing the immune response against cancer cells, either by activating immune cells or by blocking the mechanisms that cancer cells use to evade the immune system. Examples include checkpoint inhibitors, cytokines, and adoptive cell therapy.
5. Angiogenesis Inhibitors: Angiogenesis is the process of forming new blood vessels, which is crucial for the growth and spread of tumors. Angiogenesis inhibitors block the formation of new blood vessels, starving the tumor of oxygen and nutrients, thereby inhibiting its growth.
6. Radiation Therapy: While not strictly drugs, radiation therapy is another important treatment modality for cancer. It uses high-energy radiation to kill cancer cells or shrink tumors by damaging their DNA. Radiation therapy can be used alone or in combination with other anticancer agents.
7. Gene Therapy: This is a relatively new approach that involves introducing genetic material into cancer cells to either replace or repair faulty genes, inhibit the expression of certain genes, or stimulate the immune system to target cancer cells. Gene therapy holds promise for treating various types of cancer, but it is still in the experimental stage for many cancers.

Each type of anticancer agent has its own mechanism of action, side effects, and indications for use. Treatment plans often involve a combination of different anticancer agents tailored to the specific type and stage of cancer, as well as the patient’s overall health and treatment goals.