What is chemotherapy

Along with surgery or radiation therapy, chemotherapy is one of the most common ways to treat cancer. Chemotherapy treatment is designed to destroy cancer cells; it can be used for primary cancer (cancer that has not spread) as well as metastatic cancer (cancer that has spread).

While chemotherapy can help people with cancer survive the disease, the success of chemotherapy depends on the type of cancer and its stage, plus the age and overall health of the patient and other individual factors. 

Since cancer cells grow and multiply much more quickly than healthy cells, chemotherapy drugs have been developed and approved by the FDA for use alone or in combination with other safe and effective treatment methods.[1] 

Chemotherapy Treatment Objectives and Delivery Methods

According to the Mayo Clinic, chemotherapy involves the use of powerful chemicals to kill fast-growing cells in the body.[2] To destroy cancer cells is to give the patient the chance to fight back against the disease. In a best-case scenario, the chemotherapy drugs effectively target and destroy cancer cells, leading to remission before they can spread to other parts. Remission means all detectable signs of cancer disappear and the patient has been cured, but ongoing monitoring will take place to ensure that the cancer doesn’t return.

There are a few different types of chemotherapy drugs. These chemotherapy drugs differ in their mechanisms of action (some, for instance, damage cancer cell DNA, while others interfere with cell division), but all exist to kill cancer cells.

Chemotherapy drugs are typically given via infusion; intravenous delivery enables the combination of drugs to enter the bloodstream and begin to kill cancer cells directly. Oral medications and injections are other ways for people with cancer to receive chemotherapy treatment.[3] The method of delivery sometimes depends on the type of cancer treatment; chemotherapy creams and gels, for instance, are widely used among people with skin cancer. 

Chemotherapy Approaches

Surgery physically removes cancerous tumors, while radiation uses high-energy rays to destroy cancer cells and shrink tumors. Some people with cancer undergo chemotherapy treatment after they pursue these other targeted therapy treatments. Chemotherapy treatments following other treatments are called adjuvant chemotherapy; adjuvant chemotherapy aims to enhance the effectiveness of cancer treatment and kill microscopic cancer cells that might linger following the primary treatment method.

Adjuvant therapy is most often used to treat breast, colon, and lung cancer. While adjuvant therapy often requires additional cancer treatment time, it can reduce the likelihood of reoccurrence, which is why some people with cancer find adjuvant chemotherapy worthwhile.[4] 

Neoadjuvant chemotherapy can prepare people with cancer to receive other cancer treatments—a patient with breast cancer, for instance, might benefit from neoadjuvant chemotherapy, which would shrink the tumor and potentially make it possible for surgeons to perform a lumpectomy instead of a mastectomy. 

GetPalliativeCare.org notes that the goal of palliative chemotherapy is to improve the quality of life among people with cancer and ease or eliminate their symptoms.[5] Cancer Research UK reports that palliative chemotherapy can be used at any cancer stage, and for those battling advanced stages or incurable types of cancer, this type of chemotherapy aims to make it possible for them to live longer and more comfortably.[6] 

Chemotherapy Treatment Schedules

American Cancer Society (ACS) shares that chemotherapy treatment schedules—and doses—are an important aspect of helping patients get the maximum benefit from their chemotherapy treatment. They note that chemotherapy is commonly given at regular intervals called cycles. A cycle could include a dose of one or more chemotherapy drugs given on one day, every other day, or over the course of several days. The patient may go several days or weeks without treatment in order to give normal, healthy cells the time they need to recover.[7] 

ACS adds that people with cancer should get the full course of chemo and do their best to keep their treatment cycles on schedule because adhering to treatment schedules could potentially minimize chemotherapy treatment side effects.[7]

Side Effects of Chemotherapy

The side effects of chemotherapy can take both a physical and emotional toll on people with cancer and their immune system. One of the most well-known side effects of chemotherapy is hair loss. According to the National Cancer Institute (NCI), some types of chemotherapy cause hair loss. Following chemotherapy treatment, hair grows back within a few months’ time. When it does grow back, it may be very fine. It could come back curly or straight or even a different color. Some patients, however, find that their hair returns to how it was before chemotherapy treatment.[8]

In addition to hair loss, other common side effects of chemotherapy drugs include nausea, vomiting, diarrhea, fatigue, fever, mouth sores, and loss of appetite. Mayo Clinic notes that many of these side effects can be prevented or treated, and most side effects of chemotherapy subside after treatment ends.[2]

If the side effects of chemotherapy are severe enough, people with cancer may need to have their treatment schedules or doses adjusted. Since chemotherapy drugs are so potent, people with cancer should report the side effects of chemotherapy to their trusted healthcare team, get plenty of rest, eat a healthy diet, and consider joining a support group or attending counseling sessions to help cope with the side effects of chemotherapy. 

Final Thoughts on Chemotherapy Treatment

People with cancer might be nervous or hesitant to undergo adjuvant chemotherapy, palliative chemotherapy, or neoadjuvant chemotherapy to help treat cancer. Some do not even have the option to receive chemotherapy due to their age, underlying health conditions, or other circumstances (pregnancy, for example).

The chemotherapy dose and treatment schedule depend on the type of cancer and stage it has reached. Sometimes, an aggressive approach is needed if the cancer has spread or if the cancerous tumor is growing rapidly. Surgery or radiation therapy may also be recommended. The patient’s healthcare team will help the patient determine their options, understand the side effects of chemotherapy, and answer any questions or concerns throughout the chemotherapy treatment schedule.

People with cancer who undergo chemotherapy treatment do so with the hope of achieving a favorable outcome. Their decision to treat cancer comes from a desire to improve their chance of survival, manage their symptoms, and fight back against a disease that affects people of all ages, ethnicities, and socioeconomic backgrounds. Undergoing chemotherapy treatment—or deciding not to—is a personal decision that people with cancer must make in response to their diagnosis and recommended treatment for cancer. 


  1. Leukemia and Lymphoma Society. Creating Safe and Effective Cancer Treatments: FDA Approval Process for Cancer Drugs
  2. Mayo Clinic. Chemotherapy
  3. National Cancer Institute. Chemotherapy to Treat Cancer
  4. Cleveland Clinic. Adjuvant Therapy
  5. GetPalliativeCare.org. What Is Palliative Chemotherapy?
  6. Cancer Research UK. Palliative treatment
  7. American Cancer Society. How Is Chemotherapy Used to Treat Cancer?
  8. National Cancer Institute. Hair Loss (Alopecia) and Cancer Treatment