Medicines and Medical Procedures
Research has singled out x-rays as a factor in causing cancer in children. Pregnant women who undergo medical x-rays can give birth to children with a higher subsequent incidence of childhood cancer. Women of childbearing age must be carefully screened before medical x-rays are taken, although fetal ultrasound is considered safe.
Occupational exposure to some chemicals carries a risk for children in the household. Benzene and similar substances used in painting, automotive work, and the like should be avoided as much as possible.
In yet another indictment of tobacco, paternal smoking has been shown to lead to an increased incidence of Burkitt lymphoma, acute lymphocytic leukemia (ALL), and brain tumors. The longer the father smoked and the more cigarettes he consumed, the greater the risk. The actual cause is not yet known, although damage to sperm is suggested.
An interesting study in China bears out this risk. Children of smoking fathers were more likely to contract ALL, lymphoma, and brain tumors. Because the cultural norm in China is for men but not women to smoke, these results are not related to maternal smoking. The effects of passive smoke during and after pregnancy have not been determined. Studies in the United Kingdom support these findings.
A study in France agrees with these findings too -- paternal smoking is significantly associated with childhood ALL, acute myelocytic leukemia, and Burkitt lymphoma, while maternal smoking and alcohol consumption do not seem to carry this risk.
Viruses
A virus has been identified as a probable factor in the development of some types of leukemia. However, this does not mean that leukemia or lymphomas are contagious in the common sense. There has been a great deal of research over the past few years on RNA tumor viruses, or retroviruses. Subsequent mutations and the anomalies they cause are the subject of much speculation and clinical work.
Recently researchers have discovered the link between human papillomavirus (HPV) and cervical cancer, leading to a preventive vaccine for adolescent girls. HPV may cause 10% to 15% of adult cancers, including cervical carcinomas. The majority of HPV carriers do not get these cancers, so additional factors are required for malignant change.
Epstein-Barr virus (EBV), a herpes virus, is more strongly related to the development of cancer, including Burkitt lymphoma in Africa and Hodgkin lymphoma and other lymphomas in patients with compromised immune systems, like those with HIV or organ transplants.
Congenital Problems
Some congenital problems increase the tendency to develop certain malignancies. A disorder of unusual growths such as an enlarged tongue and umbilical hernia called Beckwith syndrome is sometimes found in conjunction with Wilms tumor and hepatoblastoma (a kidney tumor and a liver tumor, respectively). Children with Down syndrome are more likely to contract cancers such as neuroblastoma and leukemia.
What Are the Odds?
Those involved with childhood cancer, whether patients, parents, or specialists, talk a lot about statistics. Maybe it's easier to have a number to cling to, whether or not it really means anything. Certainly the chances of contracting a malignancy in childhood are mercifully small, but our pediatrician put it in perspective. Most parents ask about SIDS (crib death), she said, yet she had never had a case in her practice, although she had at that time three young patients with cancer.
In terms of survival, the statistics are educated guesses at best. Now the majority live. Prognosis is based on generalities derived from past experience with the particular tumor involved.
Improvements in therapy have increased the odds significantly in the child's favor. While a few decades ago there was perhaps a 20% overall survival rate, today three in four cancer patients recover and live a normal life span. The percentage is much higher for several childhood forms of cancer, such as Wilms tumor and Hodgkin disease as well as ALL.
Many people delay going to the doctor because they fear the worst, that they or someone they love has cancer. Having a child referred from a general practitioner is particularly terrifying for the family.
Still, it would be comforting for those awaiting diagnosis at a clinic to know that between 80% and 90% of the children referred for evaluation do not have cancer. Nobody told me this when I was sitting there. But I have a vivid memory of more than one lucky mother who had heard the good news that her child didn't have cancer, gathering her things and almost running out of the clinic, never looking back.
Parents and others also want to know how long they will have to wait to find out if their child will be one of the survivors. One doctor says that we will know for sure that they are cured when they die at the age of 72 of some other cause. In the meantime, some experts consider 5-year survivors to be cured; in other words, if a child lives for 5 years after diagnosis in remission or without evidence of disease, it is less likely that there will be a relapse of the original malignancy. Other experts discount this notion and are waiting until the dust of recent advances in treatments has settled to see if the 5-year-period theory still holds.
Children can be cruel and may sometimes single out the cancer patient for ridicule or abuse. In other instances teachers may feel uncomfortable or reluctant to have a child with cancer in the classroom. Some uninformed people still fear that cancer is contagious and ostracize the victim and his or her family. Fortunately, this is not always the case, and for those seeking help, it is available through support groups such as Candlelighters, whose members have "been there, done that." Some clinics have formal parents' groups, and in others, those waiting for treatments can shore each other up informally. The advent of the Internet has been another boon, with numerous online chat or discussion groups specific to the various forms of cancer. The World Wide Web is such a valuable resource that it gets a separate chapter in this book.
We were extremely fortunate in meeting many parents who helped us through some rough times and others whom we could help later. Some of them are still close friends. I am in regular contact with a mother I met in what was to be one of the darkest hours of Lisa's ordeal, when we were all exhausted and afraid. This marvelous woman has been my salvation on more occasions than I can count, and I hope I have been able to reciprocate. We discovered that no matter how wonderful and helpful your friends are (and ours were), it is not the same as having someone beside you who is going through the same thing. Parents who cannot attend any groups might ask at their clinic if there is a family living near them who has been through a similar situation and who might be willing to lend reassurance and advice.
Tumors can also invade organ systems and inhibit vital functions. If the stomach is blocked, for example, the patient can starve to death. If the kidneys are blocked, the child can die of the poisoning that results when the body cannot cleanse itself of waste. If the tumor metastasizes to the lungs, the body does not get enough oxygen to survive. Invasion of the brain or liver stops other vital life-support systems. Some patients succumb to severe anemia or, if the cancer eats through a major blood vessel, massive bleeding. The tumor may press on nerves or block intestines or other body passages, but doctors can ease any resulting pain with powerful sedatives and painkillers.
What About the Survivors?
What will happen to the survivors? We are just learning whether they will face discrimination in obtaining an education, a good job, or insurance benefits as they mature. Late consequences of cancer are being studied. There may be future physical effects caused by the radiation, chemotherapy, or surgery, including a second cancer. Some may have serious social or psychological disorders as a result of having had such a serious illness in childhood. Delayed physical development may occur.
Long-term survivors will have to be followed throughout their lives to seek the answers to these questions and to care for any recurrence or late effects that surface. It is certainly a blessing that there are enough long-term survivors to warrant a special chapter in this edition.
Who Treats Childhood Cancer?
The question of where to go for help brings up a very important point. These diseases are rare; with thousands of pediatricians and general or family practitioners in the United States and only 12,400 or so children diagnosed annually with a wide variety of cancers, it is immediately obvious that regular pediatricians and family doctors will see very few cases in a lifetime of medical practice. As shown in Section II of this book, the treatments are continually changing and improving rapidly.
For these reasons, the National Cancer Institute and the American Academy of Pediatrics strongly recommend, almost insist, that children with cancer go to centers or clinics where they can be diagnosed and treated by specialists in pediatric oncology (the study of tumors) or hematology. Here they will receive the best, most up-to-date care by a team of people intimately familiar with the disease and its therapies. Studies have shown that the survival rate of children cared for at these centers is double and possibly triple that of those treated by local physicians. The most important question in interviewing a physician is, "How many times have you seen and treated this illness, and what was the outcome?"
Using a cancer center is not without its problems. Costs not covered by insurance can escalate: transportation, parking, housing, meals, and so on. Also, being some distance from your own local support system, whether friends, neighbors, place of worship, or family, can be very difficult when your needs are so great. Still, the results overbalance the problems at these "centers of excellence."
This is not to say that the local pediatrician or practitioner should be discarded. Far from it! We were in regular contact with our pediatrician throughout Lisa's treatment. She was kept up to date by the clinic and by the surgeon, and when the ordeal was over we resumed regular checkups and immunizations with her, traveling to the clinic on an increasingly infrequent basis.
Fortunately we could handle Lisa's illness this way because we live within an hour's drive of several major cancer centers. For families who must commute much longer distances, centers can often evaluate and stabilize the patient, then arrange for some treatments to be continued by local doctors close to home and supervised by the long-distance specialists, who perform infrequent examinations but provide advice and expertise as required. This happy collaboration, when it is possible, allows the family to live as normally as possible and still receive optimal care.
Amy and Tommy
Recently, treatments have saved some youngsters with advanced disease. I didn't know Amy when, at the age of 11 months, she was dying from widely metastasized stage IV neuroblastoma. Test after test was made, each result worse than the one before it. Her parents were given no reason to hope for her survival. Yet today she is a college graduate; we danced at her wedding and we fuss over her son and her daughter.
On the other hand, I did meet Tommy and his parents when he was about 2 months old. This beautiful infant was diagnosed as having stage I (localized) Wilms tumor, described as "almost as curable as the common cold" with 90% survival. The affected kidney was removed, treatment was begun, and his relieved family settled down to a semblance of normal life. Then, inexplicably, a tumor began to grow in his brain and metastases appeared elsewhere in his body. Tragically, he died at the age of 5.5 months.
Both of these children received the best care available and the newest treatments at pediatric centers of excellence. We may never understand in our lifetimes why one lived and one died.