Although a rare disease, Wilms' tumor, a type of kidney cancer probably of congenital origin, is one of the most common abdominal tumors found in infants and children. The cancer metastasizes in 60 to 80 percent of the patients to the lungs and regional lymph nodes draining the kidney area, less frequently to the liver and brain, and occasionally to the skeleton.
Drs. Farber at the Children's Cancer Research Foundation, D. J. Fernbach at the Baylor University College of Medicine, and others have reported results of studies showing the important role of the antibiotic, dactinomycin, in improving the survival rate of children with Wilms' tumor. When dactinomycin was added to the conventional therapy of surgery followed by irradiation, metastases were prevented in almost all patients and the 2-year survival was raised from the average level of 40 percent when surgery and irradiation were used alone to more than double that figure (89 percent). With rare exceptions, patients who survive at least 2 years do not relapse and are considered cured. Administration of the dactinomycin in repeated courses over a period of 2 years was more effective in preventing recurrence of the disease than was a single course of drug therapy.
When metastases to the lungs were present, the combination of dactinomycin and irradiation in amounts not harmful to the lungs destroyed completely all evidences of tumor in the lungs and permitted long-term survival, good health, and apparent cure in 58 percent. In those patients who have metastases widely disseminated throughout the body and have large tumor masses, not enough chemotherapy can be given with safety to achieve cure. Studies are under way to devise methods of utilizing dactinomycin safely in larger doses and also to attempt to alter the chemical structure of the compound to reduce its toxicity while retaining its cancer-destroying properties.
Vincristine sulfate is another drug found useful in the management of patients with metastatic Wilms' tumor. A study was reported in which dramatic results were obtained in a small group of children given preoperative vincristine therapy. After surgery, vincristine treatment was continued and irradiation was given. At the time the report was made, all four children in the study were alive without evidence of malignant disease 5 to 21 months after treatment was begun.
In recent years, drug treatment has contributed to improved survival of children with other cancers of the soft tissues, particularly neuroblastoma, an embryonic nerve cell tissue tumor; rhabdomyosarcoma, a cancer of the muscle fibers; and retinoblastoma, a malignant tumor of the eye. When possible, chemotherapy was given in combination with surgery and/or radiotherapy- In other instances it was used alone when no further response to conventional treatment could be anticipated. Hopefully, drugs will be used as primary treatment and the possibilities of cure increased as new information from controlled studies becomes available.
Neuroblastoma may occuranywhere from the base of the skull to the lower pelvis but usually originates in the adrenals, the two small glands on top of the kidneys. One of the most common soft tissue cancers in children, it has responded to cyclophosphamide or to vincristine sulfate in a high percentage of patients. One study was reported in which nine children with inoperable neuroblastomas were treated with both these drugs concurrently. Objective tumor regression was observed in all nine patients and complete remission obtained in seven for periods of 2 to 23 months at the time of reporting. The conclusions of this study were that some inoperable neuroblastomas will respond to chemotherapy alone or chemotherapy followed by radiation therapy to an extent that allows complete surgical removal.
Rhabdomyosarcoma has responded temporarily to dactinomycin, vincristine, and cyclophosphamide administered in a variety of ways: alone, in combination, and following or preceding surgery or radiation therapy. In one of the studies, 10 of 12 children showed objective response to treatment with intermittent, large doses of cyclophosphamide for periods of 2 to 37 weeks; of these, 6 had good responses and 4 had partial responses. This study also indicated the need for further controlled studies of the three agents, in various combinations and as adjuncts to surgery and irradiation.
Retinoblastoma usually is found in children under the age of 4, and it is considered to be a congenital tumor. One-third of the cases involve both eyes. The aim of treatment is to save not only the life of the patient but the vision of at least one eye.
One study was reported following treatment of 250 children with retinoblastoma affecting both eyes and with an outlook ranging from very favorable to very unfavorable. After treatment with triethylene melamine (TEM) before and following radiotherapy, the disease was arrested and useful vision preserved to a variable degree ranging from 85 percent of patients with a very favorable prognosis to 22 percent of patients whose prospects were very unfavorable. In another small study, 15 children with retinoblastoma were treated surgically and with intra-arterial TEM and irradiation. Ten remained alive at the time of reporting with no evidence of disease and with useful vision in the remaining eye; 3 remained alive without vision; and 2 had died with widespread retinoblastoma.