How Chemotherapy Works

Chemotherapy uses drugs to kill cancer cells. The drugs enter the bloodstream and travel through the body in order to kill cancer cells. The side effects come from the fact that it destroys normal cells as well as cancer cells. Chemotherapy may be given either alone or along with radiation therapy . When given alone, it is given in a higher dose designed to kill off cancer cells. When given along with radiation therapy, it is delivered at a lower dose and is designed to make the cancer more sensitive to the radiation.

How Many Cycles Are Needed

Chemotherapy is usually given by vein, but some forms can be given by mouth. Your medical oncologist will tell you how many cycles or courses of chemotherapy are best for you. Usually there are between 4-6 cycles of chemotherapy given when the chemotherapy is delivered on its own, and up to 10 cycles of chemotherapy when the drugs are given along with radiation therapy. The side effects and amount of time required in the doctor’s office depend on the type of chemotherapy you receive, as well as how many cycles you get and how often.

What Kinds of Agents Are Used

Chemotherapy agents used in treating lung cancer include:

Most treatment regimens will combine two or more of these drugs. The types, dosages, and duration of treatment will depend on the stage and type of your tumor and how well it responds to treatment.

What Side Effects Commonly Occur

While undergoing chemotherapy, most patients suffer from:

  • Fatigue and weakness
  • Loss of appetite
  • Nausea and vomiting
  • Hair loss
  • Fuzziness in thinking, memory problems (called “chemo brain”)

Other side effects of chemotherapy agents include:

  • Risk of infection
  • Skin irritation, cracked nails
  • Rash
  • Allergic reactions
  • Mouth sores
  • Diarrhea
  • Constipation
  • Tendency to bleed and bruise easily
  • Fluid retention
  • Bladder problems
  • Numbness in limbs
  • Infertility
  • Fever or chills—If your fever is over 100.3°F (37.9°C), call the doctor right away.
  • Low blood cell counts (eg, anemia )—If you have low blood cell counts combined with fever, this is a serious side effect that requires emergency care.

The cancer itself or the chemotherapy can cause anemia. This occurs when you have a low number of red blood cells, which carry oxygen throughout your body. Your doctor may treat this condition with a blood transfusion or with medication, such as pegfilgrastim (Neulasta) or epoetin alfa (Epogen, Procrit). These treatments may be necessary to maintain an adequate blood count, particularly if you get high dose chemotherapy. In general, your doctor will draw blood every week to check your counts.

To manage other side effects, you may need to make diet and lifestyle changes and take medication. For example, your doctor may recommend that you eat several small meals throughout the day and avoid alcohol. Light exercise (eg, walking for 30 minutes) may help to fight fatigue.

Some of these side effects go away soon after chemotherapy has ended, while others linger after treatment.

When to Contact Your Doctor

Contact your doctor if you develop:

  • Signs of infection, including fever (100.3°F [37.9°C]) and chills
  • Nosebleeds
  • Sores in your mouth or throat
  • Black and blue marks on your skin
  • Nausea, vomiting, loose or runny bowel movements
  • Pain that you can't control with the medications you've been given
  • Cough, shortness of breath, or chest pain
  • Joint pain, fatigue, stiffness, rash, or other new symptoms
  • Tingling in your fingers, toes or ringing in your ears
  • Weight gain or loss of 10 lbs. or more