The No Mo’ Chemo celebration is a joyful rite of passage — a colorful and melodic event signifying the completion of treatment. But St. Jude Children’s Research Hospital continues to care for its patients long after the confetti has been swept up and the last strains of the No Mo’ Chemo song have faded away.
As more children survive childhood cancer, the hospital’s researchers feel an increasing obligation to develop cures that minimize long-term side effects. Survivors share their experiences with the hospital’s scientists, who in turn educate community health care providers about the screenings and tests that childhood cancer survivors need in order to lead long and healthy lives.
Below you’ll find a few recent St. Jude studies that offer new details about the long-term effects of childhood cancer and its treatment.
No mo’ extra scans
St.Jude investigators recently found that routine pelvic computed tomography (CT) screenings are unnecessary for most survivors of Wilms tumor, a type of kidney cancer that occurs in children. In medical centers nationwide, Wilms survivors have received pelvic scans as part of standard follow-up treatment. Eliminating extra scans will reduce their lifetime exposure to radiation and may minimize their chance of developing treatment-related cancers.
The research is the largest study to date exploring the benefits of regular pelvic CT screening for patients who have completed treatment for Wilms tumor.
“The results show there is no need for continual pelvic imaging of patients with stage I or stage II Wilms tumor, which account for about two-thirds of all children with Wilms,” says Sue Kaste, DO, of St. Jude Radiological Sciences. “Pelvic relapse is a rare event in these patients. This study found that if Wilms tumor recurs in the pelvis, survivors usually experience symptoms, which aid in diagnosis.”
Additional research is needed to determine the best monitoring approach for higher-risk Wilms tumor survivors, including those who were older or had more advanced disease when their tumors were discovered. Investigators say other imaging approaches, including MRI and ultrasound, may be reasonable alternatives that do not involve radiation.
Survivors, take heart
Thousands of adult survivors of childhood cancer received treatment that may put them at risk for heart problems. Recent St. Jude research indicates that these adults may benefit from revised guidelines to identify those in danger of heart failure.
Children who received chest-directed radiation therapy or certain chemotherapies, such as the anthracycline class of drugs, are at increased risk of reduced left ventricular function. Greg Armstrong, MD, of St. Jude Epidemiology and Cancer Control and his colleagues found that current national screening guidelines based on echocardiography may overestimate the heart function of childhood cancer survivors when compared to another test called cardiac magnet resonance (CMR) imaging. As a result, echocardiography may miss up to 75 percent of survivors who need more comprehensive cardiac evaluation and possible treatment of heart muscle problems known as cardiomyopathy. Treatment-related cardiomyopathy sets the stage for heart failure.
Echocardiography and CMR imaging use different methods to calculate ejection fraction, which measures the strength of the heart’s main pumping chamber. Although cost and availability limit its usefulness, CMR imaging is the best method for measuring the ejection fraction.
This scores an A+
St. Jude researchers recently found that survivors of childhood acute lymphoblastic leukemia (ALL) treated with chemotherapy alone — rather than chemotherapy plus cranial irradiation — performed as well as healthy children on most tests of intellectual functioning, academic performance and related skills.
Scientists reached that conclusion after analyzing how 243 St. Jude ALL survivors fared on a battery of tests measuring intelligence, learning and memory. The outcome was good news for childhood ALL survivors. The findings indicate that dropping radiation therapy, once a standard part of ALL treatment, reduced the risk to survivors of treatment-related cognitive deficits. An earlier St. Jude study, called Total Therapy XV, showed that childhood ALL could be cured without cranial irradiation.
“These results suggest that not only have pediatric ALL survival rates remained high, with better than 90 percent of patients still alive 10 years after diagnosis, but that survivors also have better cognitive outcomes when radiation is eliminated,” says Heather Conklin, PhD, of St. Jude Psychology.
Survivors still faced challenges, including a greater risk for attention problems. Researchers plan to continue monitoring the survivors to determine how or if the cognitive challenges they face change with age.
Preventing colorectal cancer
St. Jude researchers recently found that the colorectal cancer risk facing aging childhood cancer survivors is linked to the dose of abdominal radiation they received as children and the amount of the colon that was irradiated.
While previous studies have linked childhood radiation therapy to an increased risk of second cancers, this analysis showed the risk of colorectal cancer was associated with the radiation dose.
The odds jumped 70 percent for each 10 units of absorbed abdominal radiation survivors received as part of their childhood cancer treatment. Investigators also reported for the first time that the greater the volume of colon tissue exposed to radiation, the greater the risk of a colorectal cancer diagnosis. In addition, researchers associated treatment with drugs known as alkylating agents with a nearly nine-fold increased risk of secondary colorectal cancer.
The results also underscore the importance of cancer screenings and possibly the need to revisit current screening guidelines. “Childhood cancer survivors are at higher risk of developing this cancer, but they can take steps to protect themselves,” says Kerri Nottage, MD, of St. Jude Hematology. “Colonoscopy offers a proven method of detecting colorectal cancer early, offering the best chance of cures.”
BMT survivor, make a muscle
Childhood cancer survivors whose treatment included bone marrow transplantation might benefit from such efforts as additional nutrition counseling and exercise training to help preserve muscle as they age, according to St. Jude researchers.
The study of St. Jude transplant patients found body mass index (BMI) fell significantly in the decade after transplantation as survivors lost lean mass but not fat. BMI is calculated using a person’s weight adjusted for height. A major component of lean mass is muscle.
The change leaves survivors at increased risk for later health problems, including diabetes, musculoskeletal disorders and heart disease, said Hiroto Inaba, MD, PhD, of St. Jude Oncology.
Wing Leung, MD, PhD, chair of Bone Marrow Transplantation and Cellular Therapy, adds that the results will likely shape care of future transplant patients.
“The novel finding of substantial reduction in lean mass is alarming and useful for the development of preventive and remedial strategies for this group of survivors,” he says. The research underscores the importance of assessing lean body mass as well as BMI during long-term follow-up.
Reprinted from Promise Winter 2013