Chemotherapy is the use of powerful anticancer drugs that are carried through the body in the bloodstream. It works by preventing lymphoma cells from multiplying and by removing or reducing the number of cancerous cells in the body. Chemotherapy may be taken by mouth or injected into a vein, and is often chosen when cancer is present in different parts of the body. Often, a combination of drugs is prescribed to improve the chances for success. After a round of chemotherapy drugs are administered, the patient will undergo a recovery period. This cycle allows the body to rest. Then another round of drugs is administered. The total course for chemotherapy may range from three to nine months. Depending on the type of cancer, chemotherapy may be effective after surgery in preventing the cancer from returning. Depending on the type of cancer and its stage, chemotherapy may be used as a cure, to prevent spreading, slow growth, kill cancerous cells that may have spread to other parts of the body, or relieve symptoms.
As with all treatments, side effects vary from patient to patient and depend upon the degree and duration of treatment. Ask your doctor for more information on managing chemotherapy-related side effects.
How does Chemotherapy Work?
Chemotherapy is a systemic therapy (affecting the whole body) that targets and kills rapidly dividing cells in the body, such as cancer cells. There are normal cells in the body which are rapidly dividing as well, and chemotherapy may damage these healthy cells. This is why chemotherapy can have side effects including hair loss, diarrhea, nausea and vomiting. Not all patients experience side effects from chemotherapy; if side effects do occur they can often be mild and treated effectively. Ask your doctor for more information on managing chemotherapy-related side effects.
Chemotherapy drugs work on the premise that cancer cells are always dividing and that normal cells, even those that have a fast turnover rate, are most often found in the resting (non-dividing) state in the body, dividing only when necessary. Chemotherapy tries to exploit this difference between normal and cancerous cells, aiming to preferentially attack tumour cells as they divide.
How is Chemotherapy Given?
Each dose of chemotherapy kills only a percentage of cancer cells. Chemotherapy is, therefore, often given in multiple treatments in order to destroy as many cancer cells as possible. Treatments are scheduled as frequently as possible to minimize the growth of the tumour and achieve the best possible outcome.
Chemotherapy is often given in cycles where the treatment is given for a period of time (e.g., every three weeks) followed by a rest period where no treatment is given. The rest period allows the healthy cells to recover. Together each period of treatment and rest is called a chemotherapy cycle. A full course of chemotherapy (the number of chemotherapy cycles given in total, e.g., six cycles) often takes several months. Most chemotherapy treatments can be given in an outpatient clinic, so patients can go home the same day.
Chemotherapy may be given in different forms: pills, injections or intravenous administration (administered directly into the bloodstream over a period of time through a needle). If you are going to be receiving multiple cycles of intravenous chemotherapy, your doctor may recommend having a venous catheter inserted. A venous catheter is a device, usually a flexible tube that is inserted into a vein for easier administration of intravenous drugs. A central line is a more permanent catheter that is usually inserted into a vein at the top of the chest. Both central lines and venous catheters can be left in place so you will not require a new needle with each intravenous treatment. As well, both central lines and venous catheters may be used to transfuse blood products into a patient or to easily remove blood for blood tests.
A cancer is often defined as chemosensitive or chemoresistant. Chemosensitive means that the tumour is responsive to chemotherapy and the chemotherapy treatment is effective in killing the cancer cells, whereas chemoresistant means that the tumour does not respond to chemotherapy and an alternate treatment is required.