Recent research finds that many internists do not feel comfortable or prepared to care for survivors of childhood cancer. Although the rarity of childhood cancer may explain this, the fact remains that as more and more pediatric cancer patients survive into adulthood busy internists often have some survivors in their practices. These patients would have been treated during the last decades of the 20th century or the beginning of this century with therapies that may or may not still be used. In addition, the amount of data available about long-term outcomes varies widely depending on the type of cancer treatment the patient had.
Despite these challenges, there are several things that can help internists and other primary care physicians caring for adult patients who had cancer as children:
1. Patients should obtain a cancer treatment summary. Most major cancer centers and hospitals that treat pediatric cancers have developed clinics where survivors can be seen well into adulthood. Refer your patient for a one-time consultation, at which a treatment summary and survivorship care plan can be created, based on a careful review of the patient’s records and discussion with the patient and, sometimes, the parent.
For instance, if you refer a 35-year-old woman who had Hodgkin’s lymphoma when she was 15, she will get a treatment summary that may document the chemotherapy agents she received as well as her sites of therapeutic radiation treatment. She may learn about her risk of secondary breast cancer, skin cancer, heart disease, lung disease and premature menopause. She will also learn whether she should return for subspecialty care. Often adults who survived childhood cancer know very little about how they were treated. This process gives them ownership.
2. Children’s Oncology Group provides guidelines for monitoring survivors of pediatric cancer. The guidelines are based on research results, best practice and clinical opinion. They list the various cancer treatments that children underwent over the decades, the risks associated with each, and recommendations for screening. If a primary care provider has information about the patient’s treatment, the guidelines will provide the information needed to construct a plan to screen the patient for secondary effects of the cancer and/or the cancer treatment.
3. The use of radiation to treat childhood cancer is associated with significant morbidities in adulthood. Between two-thirds and three-quarters of children treated in the 1970s-1990s received radiation. In addition to the risk of radiation-induced secondary cancers, radiation also increases a patient’s risk of organ dysfunction. Patients who received chest radiation, for instance, may develop pulmonary fibrosis, heart valve disease or early coronary artery disease. Patients who received brain radiation during childhood may have chronic issues with learning, vocational success and organizational skills, as well as neuro-endocrine dysfunction. Patients who received neck radiation are at increased risk of thyroid failure, and patients who received radiation to the pelvis, particularly women, are at risk for ovarian failure, as well as pregnancy complications should they become pregnant.
Recommendations on how to monitor patients for these risks vary based on the site of radiation. Women who received chest radiation, for instance, should start mammography screening early and have breast MRIs. Patients who received neck radiation should be screened for hypothyroidism, and those who received abdominal radiation should be screened early for colon cancer.
4. Two classes of chemotherapy drugs are associated with serious late effects. Anthracyclines and alkylating agents, both of which continue to be used to treat childhood cancer, have been linked respectively to heart disease and infertility. When administered to adults in high doses, doxorubicin, the most commonly use anthracycline, carries a well-known risk of acute congestive heart failure.
In children, on the other hand, high doses of doxorubicin can lead first to asymptomatic left ventricular dysfunction which then progresses to congestive heart failure Pharmacologic intervention with beta-blockers and/or ACE inhibitors at early signs of asymptomatic left ventricular dysfunction may delay the onset of overt congestive heart failure, which makes it important to implement a cardiac screening plan for these patients. Alkylating agents have been linked to low or no sperm count in men and early menopause or primary ovarian failure in women. Encourage male patients who are ready to become fathers to obtain a semen analysis and, if indicated, explore assisted reproductive technology.
While my colleagues and I recently reported encouraging news in a large cohort of cancer survivors about the chances of female survivors becoming pregnant, the fact remains that women treated with alkylators as girls face an elevated risk of infertility. While menstrual history can be a reasonable indicator of ovarian function, women treated with alkylators as children have ovaries that may function with limited reserve, and their fertility may decline faster with age than other women’s. Female patients trying to become pregnant should see a fertility specialist if they haven’t conceived within six months, rather than the year recommended for other women.
5. Survivors of childhood cancer should embrace a healthy lifestyle. In addition to making sure survivors of childhood cancer understand their particular health risks and screening recommendations, urge them to embrace the same healthy lifestyle you encourage for all your patients. This includes not smoking, exercising regularly, maintaining a healthy weight and getting routine screenings unrelated to their cancer. Smoking is a risk for everyone, but adults who had chest radiation as children are at greater risk of developing lung cancer if they smoke.
Likewise, patients who had chest radiation have an elevated risk of heart disease due to their cancer treatment in addition to the general risk of coronary artery disease from high cholesterol and plaque formation. And being overweight places an extra burden on hearts weakened by early cancer treatment. A healthy lifestyle is absolutely important for childhood cancer survivors.
Lisa Diller is chief medical officer, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center.