Key Points for This Section
- Childhood cancer survivors have an increased risk of a second cancer later in life.
- Certain genetic patterns or syndromes may increase the risk of a second cancer.
- Patients who have been treated for cancer need regular screening tests to check for a second cancer.
- The kind of test used to screen for a second cancer depends on the kind of cancer treatment the patient had in the past.
A different primary cancer that occurs at least two months after cancer treatment ends is called a second cancer. A second cancer may occur months or years after treatment is completed. The type of second cancer that occurs depends in part on the original type of cancer and the cancer treatment.
Second cancers that occur after cancer treatment include the following:
- Myelodysplastic syndrome and acute myeloid leukemia may appear less than 10 years after a primary cancer diagnosis of Hodgkin lymphoma, acute lymphoblastic leukemia, or sarcoma and treatment with chemotherapy that includes one of the following:
- Alkylating agent such as cyclophosphamide, ifosfamide, mechlorethamine, melphalan, busulfan, carmustine, lomustine, chlorambucil, or dacarbazine.
- Topoisomerase II inhibitor agent such as etoposide or teniposide.
- Solid tumors may appear more than 10 years after primary cancer diagnosis and treatment including:
- Breast cancer after high-dose chest radiation treatment for Hodgkin lymphoma. Treatment with low-dose chest radiation may also increase breast cancer risk.
- Thyroid cancer after neck radiation treatment for Hodgkin lymphoma, acute lymphocytic leukemia, or brain tumors, after radioactive iodine therapy for neuroblastoma, or after total-body irradiation (TBI) as part of a stem cell transplant.
- Brain tumors after radiation treatment to the head for a primary brain tumor or for acute lymphocytic leukemia or non-Hodgkin lymphoma. When intrathecal methotrexate chemotherapy and radiation therapy are given together, the risk of a brain tumor is even higher.
- Bone tumors after radiation treatment for retinoblastoma, Ewing sarcoma, and other cancers of the bone. Treatment with an alkylating agent also increases the risk of a bone tumor.
- Sarcomas after radiation therapy. The risk increases with higher doses of radiation. Chemotherapy with anthracyclines also increases the risk of sarcomas.
- Lung cancer after radiation treatment to the chest for Hodgkin lymphoma, especially in patients who smoke.
- Stomach, liver, or colorectal cancer after radiation therapy to the abdomen. The risk increases with higher doses of radiation. Treatment with chemotherapy alone or chemotherapy and radiation therapy combined also increases the risk of stomach, liver, or colorectal cancer.
- Nonmelanoma skin cancer after radiation therapy; it usually appears in the area where radiation is given. Being exposed to UV radiation may increase this risk. Patients who develop nonmelanoma skin cancer after radiation therapy have an increased chance of developing other types of cancers in the future.
- Malignant melanoma after radiation therapy or combination chemotherapy with alkylating agents and antimitotic drugs. Survivors of Hodgkin lymphoma, hereditary retinoblastoma, soft tissue sarcoma, and gonadal tumors are more likely to be at risk. Malignant melanoma as a second cancer is more rare after treatment than nonmelanoma skin cancer.
- Oral cavity cancer after chemotherapy followed by stem cell transplant or a history of chronic graft-versus-host disease.
- Kidney cancer after treatment for neuroblastoma, radiation therapy to the middle of the back, or chemotherapy such as cisplatin or carboplatin.
Some childhood cancer survivors may have an increased risk of developing a second cancer because they have a family history of cancer or an inherited genetic syndrome such as Li-Fraumeni syndrome. Problems with the way DNA is repaired in cells and the way anticancer drugs are used in the body may also affect the risk of second cancers.
It is important for patients who have been treated for cancer to be checked for a second cancer before symptoms appear. This is called screening for a second cancer and may help find a second cancer at an early stage. When abnormal tissue or cancer is found early, it may be easier to treat. By the time symptoms appear, cancer may have begun to spread.
It is important to remember that your child's doctor does not necessarily think your child has cancer if he or she suggests a screening test. Screening tests are given when your child has no cancer symptoms. If a screening test result is abnormal, your child may need to have more tests done to find out if he or she has a second cancer. These are called diagnostic tests.
All patients who have been treated for cancer should have a physical exam and medical history done once a year. A physical exam of the body is done to check general signs of health, including checking for signs of disease, such as lumps, changes in the skin, or anything else that seems unusual. A medical history is taken to learn about the patient’s health habits and past illnesses and treatments.
If the patient was treated for leukemia, a complete blood count (CBC) may be done. The CBC is usually done every year for 10 years after treatment with an alkylating agent or topoisomerase II inhibitor ends.
- Complete blood count (CBC) with differential : A procedure in which a sample of blood is drawn and checked for the following:
- The number of red blood cells and platelets.
- The number and type of white blood cells.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the blood sample made up of red blood cells.
If the patient received radiation therapy, the following tests and procedures may be used:
- Skin exam: A doctor or nurse checks the skin for bumps or spots that look abnormal in color, size, shape, or texture, especially in the area where radiation was given. It is suggested that a skin exam be done once a year to check for signs of skin cancer.
- Breast self-exam : An exam of the breast by the patient. The patient carefully feels the breasts and under the arms for lumps or anything else that seems unusual. It is suggested that women treated with radiation therapy to the chest do a monthly breast self-exam beginning at puberty until age 25 years.
- Clinical breast exam (CBE): An exam of the breast by a doctor or other health professional. The doctor will carefully feel the breasts and under the arms for lumps or anything else that seems unusual. It is suggested that women treated with radiation therapy to the chest have a clinical breast exam every 6 months beginning at puberty until age 25 years.
- Mammogram : An x-ray of the breast. A mammogram may be done in women who had radiation to the chest and who do not have dense breasts. It is suggested that these women have a mammogram once a year starting 8 years after treatment or at age 25 years, whichever is later.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). An MRI may be done in women who had radiation to the chest and who have dense breasts. It is suggested that these women have an MRI once a year starting 8 years after treatment or at age 25 years, whichever is later.
- Colonoscopy : A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer. It is suggested that childhood cancer survivors who had radiation to the abdomen, pelvis, or spine have a colonoscopy every 5 years. This begins at age 35 years or 10 years after treatment ended, whichever is later.