Are all chemo agents toxic?

Short answer: no.  Longer answer: all drugs have side effects but we do not normally consider most drugs toxic.  Chemo agents are intended to kill malignant cells or retard their growth, but they are not intended to kill the person.  The “old” chemo agents, which are still widely used, are cytotoxic, meaning they kill cells. The idea is that cancerous cells will be killed faster and/or at lower levels of agent.

How is chemotherapy different from other drugs?

Chemotherapy is given for cancer. Unlike some drugs, chemotherapy is intended to be given over a long period of time.  The chemotherapy drugs don’t directly attack an infectious agent. The conventional cytotoxic drugs are intended to kill cells, while most drugs are not intended to kill bodily cells, although they may target invasive pathogens. Chemotherapy is often given in spurts – a course of several weeks followed by a recovery period followed by another course.  Most drugs are either taken continuously for long terms or in a short campaign until the disease is cured or another drug is tried.

Many chemotherapy medicines are administered intravenously.  Many are delivered at a clinic or doctor’s office. Chemotherapy, especially older drugs, tends to produce serious side effects.  The drugs can be very expensive, especially the newer ones that are under patent. The drugs are often given as part of a treatment regimen in conjunction with surgery or radiation.

How is targeted chemotherapy agents different from conventional agents?

Conventional agents attack all cells, and count on the fact that they will kill malignant cells faster than healthy ones.  There are different types of targeted therapies, but they are all called targeted because they have better specificity and closer focus on cancer cells. Targeted agents tend to leave the healthy cells alone.  The result is fewer and less severe side effects. (All drugs have some side effects.) That means the therapeutic window is wider for targeted agents than for conventional agents and doctors can prescribe higher doses with less fear of harming the patient.  Many targeted treatments are administered along with conventional agents as part of a combination regimen.

How is hormone therapy different from drug therapy?

Hormone therapy is also called hormone suppressant therapy and it is designed to lower the levels of hormone in the body or to block the effects of hormones.  The agents given to produce these effects to not directly attack cancer the way drugs do. The idea is that some hormones facilitate the growth of tumors, so stopping the action of those hormones will slow the cancer.