Prospective medical assessment of adults surviving childhood cancer: study design, cohort characteristics, and feasibility of the St. Jude Lifetime Cohort study

Cerebral white matter integrity and executive function in adult survivors of childhood medulloblastoma

Survivors of pediatric medulloblastoma are at risk for neurocognitive dysfunction. Reduced white matter integrity has been correlated with lower intelligence in child survivors, yet associations between specific cognitive processes and white matter have not been examined in long-term adult survivors. Twenty adult survivors of medulloblastoma were randomly recruited from a larger institutional cohort of adult survivors of childhood cancer. Survivors underwent comprehensive neurocognitive evaluations and MRI. Data on brain volume and cortical thickness and diffusion tensor imaging were acquired, including measures of fractional anisotropy, apparent diffusion coefficient, and axial and radial diffusivity. Observed neurocognitive scores were compared with population norms and correlated to MRI indices. Survivors were, on average, 29 years of age and 18 years postdiagnosis. Mean full-scale intelligence quotient was nearly 1 SD below the normative mean (86.3 vs 100, P = .004). Seventy-five percent of survivors were impaired on at least one measure of executive function. Radial diffusivity in the frontal lobe of both hemispheres was correlated with shifting attention (left: r(s) = -0.67, P = .001; right: r(s) = -0.64, P = .002) and cognitive flexibility (left: r(s) = -0.56, P = .01; right: r(s) = -0.54, P = .01). Volume and cortical thickness were not correlated with neurocognitive function. Neurocognitive impairment was common and involved many domains. Reduced white matter integrity in multiple brain regions correlated with poorer performance on tasks of executive function. Future research integrating diffusion tensor imaging should be a priority to more rigorously evaluate long-term consequences of cancer treatment and to inform cognitive intervention trials in this high-risk population.

Screening adult survivors of childhood cancer for cardiomyopathy: comparison of echocardiography and cardiac magnetic resonance imaging

PURPOSE

To compare two-dimensional (2D) echocardiography, the current method of screening for treatment-related cardiomyopathy recommended by the Children's Oncology Group Guidelines, to cardiac magnetic resonance (CMR) imaging, the reference standard for left ventricular (LV) function.

PATIENTS AND METHODS

Cross-sectional, contemporaneous evaluation of LV structure and function by 2D and three-dimensional (3D) echocardiography and CMR imaging in 114 adult survivors of childhood cancer currently median age 39 years (range, 22 to 53 years) exposed to anthracycline chemotherapy and/or chest-directed radiation therapy.

RESULTS

In this survivor population, 14% (n = 16) had an ejection fraction (EF) less than 50% by CMR. Survivors previously undiagnosed with cardiotoxicity (n = 108) had a high prevalence of EF (32%) and cardiac mass (48%) that were more than two standard deviations below the mean of normative CMR data. 2D echocardiography overestimated the mean EF of this population by 5%. Compared with CMR, 2D echocardiography (biplane method) had a sensitivity of 25% and a false-negative rate of 75% for detection of EF less than 50%, although 3D echocardiography had 53% and 47%, respectively. Twelve survivors (11%) had an EF less than 50% by CMR but were misclassified as ≥ 50% (range, 50% to 68%) by 2D echocardiography (biplane method). Detection of cardiomyopathy was improved (sensitivity, 75%) by using a higher 2D echocardiography cutoff (EF < 60%) to detect an EF less than 50% by the reference standard CMR.

CONCLUSION

CMR identified a high prevalence of cardiomyopathy among adult survivors previously undiagnosed with cardiac disease. 2D echocardiography demonstrated limited screening performance. In this high-risk population, survivors with an EF 50% to 59% by 2D echocardiography should be considered for comprehensive cardiac assessment, which may include CMR.

Impact of survivorship-based research on defining clinical care guidelines

The growing number of individuals living five or more years from cancer diagnosis underscores the importance of providing guidance about potential late treatment effects to clinicians caring for long-term cancer survivors. Late treatment effects are commonly experienced by cancer survivors, increase in prevalence with aging, produce substantial morbidity, and predispose to early mortality. Findings from survivorship research permit providers to anticipate health risks among predisposed survivors and facilitate their access to interventions to prevent, detect, or rehabilitate cancer-related morbidity. This article reviews the impact that survivorship research has made in defining clinical care guidelines and the challenges that remain in developing and translating research findings into health screening recommendations that can optimize the quality and duration of survival after cancer.

Neuromuscular impairments in adult survivors of childhood acute lymphoblastic leukemia: associations with physical performance and chemotherapy doses

BACKGROUND

Treatment regimens for childhood acute lymphoblastic leukemia (ALL) contain neurotoxic agents that may interfere with neuromuscular health. In this study, the authors examined associations between neuromuscular impairments and physical function and between neuromuscular impairments and doses of vincristine and intrathecal methotrexate used to treat leukemia among survivors of childhood ALL.

METHODS

ALL survivors >10 years from diagnosis participated in neuromuscular performance testing. Treatment data were abstracted from medical records. Regression models were used to evaluate associations between treatment factors, neuromuscular impairments, and physical performance.

RESULTS

Among 415 survivors (median age, 35 years; age range, 21-52 years), balance, mobility, and 6-minute walk (6MW) distances were 1.3 standard deviations below age-specific and sex-specific values in 15.4%, 3.6%, and 46.5% of participants, respectively. Impairments included absent Achilles tendon reflexes (39.5%), active dorsiflexion range of motion (ROM) <5 degrees (33.5%), and impaired knee extension strength (30.1%). In adjusted models (including cranial radiation), survivors who received cumulative intrathecal methotrexate doses ≥215 mg/m(2) were 3.4 times more likely (95% confidence interval, 1.2-9.8 times more likely) to have impaired ROM than survivors who received no intrathecal methotrexate, and survivors who received cumulative vincristine doses ≥39 mg/m(2) were 1.5 times more likely (95% CI, 1.0-2.5 times more likely) to have impaired ROM than survivors who received lower cumulative doses of vincristine. Higher intrathecal methotrexate doses were associated with reduced knee extension strength and 6MW distances.

CONCLUSIONS

Neuromuscular impairments were prevalent in childhood ALL survivors and interfered with physical performance. Higher cumulative doses of vincristine and/or intrathecal methotrexate were associated with long-term neuromuscular impairments, which have implications on future function as these survivors age.

Association of muscle strength and bone mineral density in adult survivors of childhood acute lymphoblastic leukemia

OBJECTIVES

To investigate the association between bone mineral density (BMD) and muscle strength in survivors of childhood acute lymphoblastic leukemia (ALL), a population at increased risk for both decreased BMD and muscle strength from cancer and its treatment.

DESIGN

Cohort data from the St Jude Lifetime Cohort (SJLIFE) study.

SETTING

Department of Cancer Control at St Jude Children's Research Hospital.

PARTICIPANTS

Subjects were adults enrolled in St Jude Lifetime Cohort study and treated for childhood ALL between 1962 and 1999. As part of a comprehensive evaluation, participants had dual energy x-ray absorptiometry (DEXA) scans and muscle strength testing. The participants consisted of 261 women and 232 men who were 20.4 to 49.8 years old (median, 35.7y), and 12.7 to 46.5 years from diagnosis of childhood ALL (median, 27.2y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

BMD was determined by DEXA scan. Muscle strength of upper and lower extremities was assessed with physical performance testing.

RESULTS

After adjusting for covariates, we found significant (P<0.005) associations between BMD and muscle strength in lower extremities (R(2) range, 0.33-0.40) and strong, significant associations in upper extremities (left-side R(2)=0.558; right-side R(2)=0.560).

CONCLUSIONS

Muscle strength was associated with BMD in the extremities of long-term survivors of childhood ALL, a finding suggesting that muscle strengthening interventions may improve bone health in them.