Chemotherapy is the use of drugs to destroy cancer cells. This type of cancer treatment works by keeping cancer cells from growing, dividing, and making more cells.

There are many different kinds of chemotherapy. In general, drugs used for chemotherapy are powerful chemicals that treat cancer by attacking cells during specific parts of the cell cycle. All cells go through the cell cycle, which is how new cells are made. Cancer cells go through this process faster than normal cells, so chemotherapy has more of an effect on these fast-growing cells.

Chemotherapy is a systemic medication. This means it travels through the bloodstream and reaches all parts of the body.

Because chemotherapy travels through the whole body, it can also damage healthy cells as they go through their normal cell cycle. This is why chemotherapy can cause side effects like hair loss and nausea.

Chemotherapy Plan

There are many drugs available to treat cancer. A doctor who specializes in treating cancer with medication is called a medical oncologist. This type of doctor will prescribe your chemotherapy. You may receive a combination of drugs, because this sometimes works better than one drug by itself.

The drugs, dose, and treatment schedule depend on many factors. These include:

  • The type of cancer

  • The stage of the cancer. Cancer stage is determined by the size and location of the tumor and whether or not the cancer has spread, tumor size, its location, and if or where it has spread.

  • Your age and general health

  • Your body weight

  • The possible side effects of each drug. If a drug causes you to have too many side effects, this can also change your treatment plan.

  • Any other medical conditions you have

  • Previous cancer treatments

Chemotherapy Treatment Types

Chemotherapy may be given in several different ways, which are discussed below.

Intravenous (IV) chemotherapy. Many drugs require injection directly into a vein. This is called intravenous or IV chemotherapy. Treatment takes a few minutes to a few hours. Some IV drugs work better if you get them over a few days or weeks. You take them through a small pump you wear or carry. This is called continuous infusion chemotherapy.

Oral chemotherapy. Oral chemotherapy is taken by mouth. This can be as a pill, capsule, or liquid. This means that you may be able to pick up your medication at the pharmacy and take it at home. Oral treatments for cancer are now more common. Some of these drugs are given daily, and others are given less often.

Injected chemotherapy. This is when you receive chemotherapy as a shot. The shot may be given in a muscle or injected under the skin. You may receive these shots in the arm, leg, or abdomen.

Chemotherapy into an artery. An artery is a blood vessel that carries blood from your heart to another part of your body. Sometimes chemotherapy is injected into an artery that goes directly to the cancer. This is called intra-arterial or IA chemotherapy.

Chemotherapy into the peritoneum or abdomen. For some cancers, medication might be placed directly in your abdomen. This type of treatment works for cancers involving the peritoneum. The peritoneum covers the surface of the inside of the abdomen and surrounds the intestines, liver, and stomach. Ovarian cancer is one type of cancer that frequently spreads to the peritoneum.

Topical chemotherapy. Some types of chemotherapy come as a cream that you put on your skin. You get your medication at the pharmacy and apply it at home.

Chemotherapy for cancer includes more than a 100 different drugs. Although all chemotherapy drugs damage cells, they attack different cell targets at different times during the cell cycle. Combining drugs that damage the cancer cell in different ways can increase how well the treatment works.

Below are the main types of chemotherapy:

  • Alkylating agents

  • Antimetabolites

  • Anti-tumor antibiotics

  • Topoisomerase inhibitors

  • Mitotic inhibitors

  • Plant alkaloids

Chemotherapy Treatment Duration

Chemotherapy is often given for a specific time, such as 6 months or a year. Or you might receive chemotherapy for as long as it works.

Side effects from many anti-cancer drugs are too severe to give treatment every day. Doctors usually give these drugs with breaks, so you have time to rest and recover before the next treatment. This lets your healthy cells heal.

For example, you might get a dose of chemotherapy on the first day and then have 3 weeks of recovery time before repeating the treatment. Each 3-week period is called a treatment cycle. Several cycles make up a course of chemotherapy. A course usually lasts 3 months or more.

Some cancers are treated with less recovery time between cycles. This is called a dose-dense schedule. It can make chemotherapy more effective against some cancers. But it also increases the risk of side effects.