Paul C. Nathan

Improved Survival with MEK Inhibition in BRAF-Mutated Melanoma

BACKGROUND Activating mutations in serine-threonine protein kinase B-RAF (BRAF) are found in 50% of patients with advanced melanoma. Selective BRAF-inhibitor therapy improves survival, as compared with chemotherapy, but responses are often short-lived. In previous trials, MEK inhibition appeared to be promising in this population. METHODS In this phase 3 open-label trial, we randomly assigned 322 patients who had metastatic melanoma with a V600E or V600K BRAF mutation to receive either trametinib, an oral selective MEK inhibitor, or chemotherapy in a 2:1 ratio. Patients received trametinib (2 mg orally) once daily or intravenous dacarbazine (1000 mg per square meter of body-surface area) or paclitaxel (175 mg per square meter) every 3 weeks. Patients in the chemotherapy group who had disease progression were permitted to cross over to receive trametinib. Progression-free survival was the primary end point, and overall survival was a secondary end point. RESULTS Median progression-free survival was 4.8 months in the trametinib group and 1.5 months in the chemotherapy group (hazard ratio for disease progression or death in the trametinib group, 0.45; 95% confidence interval [CI], 0.33 to 0.63; P<0.001). At 6 months, the rate of overall survival was 81% in the trametinib group and 67% in the chemotherapy group despite crossover (hazard ratio for death, 0.54; 95% CI, 0.32 to 0.92; P=0.01). Rash, diarrhea, and peripheral edema were the most common toxic effects in the trametinib group and were managed with dose interruption and dose reduction; asymptomatic and reversible reduction in the cardiac ejection fraction and ocular toxic effects occurred infrequently. Secondary skin neoplasms were not observed. CONCLUSIONS Trametinib, as compared with chemotherapy, improved rates of progression-free and overall survival among patients who had metastatic melanoma with a BRAF V600E or V600K mutation. (Funded by GlaxoSmithKline; METRIC ClinicalTrials.gov number, NCT01245062.).

The Childhood Cancer Survivor Study: A National Cancer Institute–Supported Resource for Outcome and Intervention Research

Survival for childhood cancer has increased dramatically over the last 40 years with 5-year survival rates now approaching 80%. For many diagnostic groups, rapid increases in survival began in the 1970s with the broader introduction of multimodality approaches, often including combination chemotherapy with or without radiation therapy. With this increase in rates of survivorship has come the recognition that survivors are at risk for adverse health and quality-of-life outcomes, with risk being influenced by host-, disease-, and treatment-related factors. In 1994, the US National Cancer Institute funded the Childhood Cancer Survivor Study, a multi-institutional research initiative designed to establish a large and extensively characterized cohort of more than 14,000 5-year survivors of childhood and adolescent cancer diagnosed between 1970 and 1986. This ongoing study, which reflects the single most comprehensive body of information ever assembled on childhood and adolescent cancer survivors, provides a dynamic framework and resource to investigate current and future questions about childhood cancer survivors.

Social Outcomes in the Childhood Cancer Survivor Study Cohort

Difficulties with negotiating and achieving desired social outcomes in life may be exacerbated by the experience of childhood cancer, including adverse effects from therapies used to achieve a cure. This review of previous publications from the Childhood Cancer Survivor Study (CCSS) and other relevant literature provides insight into the prevalence of, and risk factors for, poor educational attainment, less than optimal employment status, and interpersonal relationship issues among long-term survivors of childhood cancer. The impacts of emotional health and physical disability on social outcomes are also examined. Study results suggest that childhood cancer survivors generally have similar high school graduation rates, but are more likely to require special education services than sibling comparison groups. Survivors are slightly less likely than expected to attend college, and are more likely to be unemployed and not married as young adults. Cancers and treatments that result in impairment to the CNS, particularly brain tumors, or that impact sensory functioning, such as hearing loss, are associated with greater risk for undesirable social outcomes, as are emotional health problems and physical disability. This review of relevant data from CCSS and other studies provides information on risk factors for social problems into adulthood. A greater understanding of the long-term social impacts from the diagnosis and treatment of childhood cancer is critically important for developing targeted interventions to prevent or ameliorate adverse psychosocial effects.

Medical Care in Long-Term Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study

PURPOSE To evaluate whether childhood cancer survivors receive regular medical care focused on the specific morbidities that can arise from their therapy. PATIENTS AND METHODS We conducted a cross-sectional survey of health care use in 8,522 participants in the Childhood Cancer Survivor Study, a multi-institutional cohort of childhood cancer survivors. We assessed medical visits in the preceding 2 years, whether these visits were related to the prior cancer, whether survivors received advice about how to reduce their long-term risks, and whether screening tests were discussed or ordered. Completion of echocardiograms and mammograms were assessed in patients at high risk for cardiomyopathy or breast cancer. We examined the relationship between demographics, treatment, health status, chronic medical conditions, and health care use. RESULTS Median age at cancer diagnosis was 6.8 years (range, 0 to 20.9 years) and at interview was 31.4 years (range, 17.5 to 54.1 years). Although 88.8% of survivors reported receiving some form of medical care, only 31.5% reported care that focused on their prior cancer (survivor-focused care), and 17.8% reported survivor-focused care that included advice about risk reduction or discussion or ordering of screening tests. Among survivors who received medical care, those who were black, older at interview, or uninsured were less likely to have received risk-based, survivor-focused care. Among patients at increased risk for cardiomyopathy or breast cancer, 511 (28.2%) of 1,810 and 169 (40.8%) of 414 had undergone a recommended echocardiogram or mammogram, respectively. CONCLUSION Despite a significant risk of late effects after cancer therapy, the majority of childhood cancer survivors do not receive recommended risk-based care.

Health Behaviors, Medical Care, and Interventions to Promote Healthy Living in the Childhood Cancer Survivor Study Cohort

Childhood cancer survivors are at risk for medical and psychosocial late effects as a result of their cancer and its therapy. Promotion of healthy lifestyle behaviors and provision of regular risk-based medical care and surveillance may modify the evolution of these late effects. This manuscript summarizes publications from the Childhood Cancer Survivor Study (CCSS) that have examined health behaviors, risk-based health care, and interventions to promote healthy lifestyle practices. Long-term survivors use tobacco and alcohol and have inactive lifestyles at higher rates than is ideal given their increased risk of cardiac, pulmonary, and metabolic late effects. Nearly 90% of survivors report receiving some form of medical care. However, only 18% report medical visits related to their prior cancer that include discussion or ordering of screening tests or counseling on how to reduce the specific risks arising from their cancer. One low-cost, peer-driven intervention trial has been successful in improving smoking cessation within the CCSS cohort. On the basis of data from CCSS investigations, several trials to promote improved medical surveillance among high-risk groups within the cohort are underway. Despite their long-term risks, many survivors of childhood cancer engage in risky health behaviors and do not receive adequate risk-based medical care.

Combined hereditary and somatic mutations of replication error repair genes result in rapid onset of ultra-hypermutated cancers

DNA replication−associated mutations are repaired by two components: polymerase proofreading and mismatch repair. The mutation consequences of disruption to both repair components in humans are not well studied. We sequenced cancer genomes from children with inherited biallelic mismatch repair deficiency (bMMRD). High-grade bMMRD brain tumors exhibited massive numbers of substitution mutations (>250/Mb), which was greater than all childhood and most cancers (>7,000 analyzed). All ultra-hypermutated bMMRD cancers acquired early somatic driver mutations in DNA polymerase ɛ or δ. The ensuing mutation signatures and numbers are unique and diagnostic of childhood germ-line bMMRD (P < 10−13). Sequential tumor biopsy analysis revealed that bMMRD/polymerase-mutant cancers rapidly amass an excess of simultaneous mutations (∼600 mutations/cell division), reaching but not exceeding ∼20,000 exonic mutations in <6 months. This implies a threshold compatible with cancer-cell survival. We suggest a new mechanism of cancer progression in which mutations develop in a rapid burst after ablation of replication repair.

Comparison of Long-Term Neurocognitive Outcomes in Young Children With Acute Lymphoblastic Leukemia Treated With Cranial Radiation or High-Dose or Very High-Dose Intravenous Methotrexate

PURPOSE Cranial radiation therapy (CRT) is associated with neurocognitive morbidity in survivors of childhood acute lymphoblastic leukemia (ALL). For most patients, CRT has been replaced with intensified systemic and intrathecal chemotherapy, often including methotrexate (MTX). The impact of chemotherapy-only protocols on neurocognitive outcomes is unclear, and the importance of systemic MTX dose has not been established. PATIENTS AND METHODS Seventy nine of 120 eligible children diagnosed with high-risk ALL between the ages of 1.0 and 4.9 years participated in this retrospective cohort study. All patients were treated on a uniform chemotherapy protocol with one of three modalities of CNS prophylaxis, depending on their treatment era. In addition to intrathecal therapy, CNS-directed therapy consisted of CRT (18 Gy in 10 fractions) in 25 patients, high-dose intravenous (IV) MTX (8 g/m2 x 3 doses) in 32 patients and very high-dose IV MTX (33.6 g/m2 x 3 doses) in 22 patients. Participants completed tests of intelligence, academic achievement, attention, and memory. RESULTS Neurocognitive assessment was conducted at least 5 years after diagnosis (mean, 10.5 years, standard deviation, 2.7 years). No difference was detected on any neurocognitive measure between children treated with high-dose or very high-dose IV MTX. The combined MTX groups scored near the population mean on 17/18 measures. Children treated with CRT performed more poorly than the MTX group on most measures. CONCLUSION Treatment strategies for young children with ALL that avoid CRT are associated with good long-term neurocognitive outcomes. In this cohort, the dose of IV MTX did not influence these outcomes.

Recommendations for Cardiomyopathy Surveillance for Survivors of Childhood Cancer: A Report from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Survivors of childhood cancer treated with anthracycline chemotherapy or chest radiation are at an increased risk of developing congestive heart failure. In this population, congestive heart failure is well recognised as a progressive disorder, with a variable period of asymptomatic cardiomyopathy that precedes signs and symptoms. As a result, several clinical practice guidelines have been developed independently to help with detection and treatment of asymptomatic cardiomyopathy. These guidelines differ with regards to definitions of at-risk populations, surveillance modality and frequency, and recommendations for interventions. Differences between these guidelines could hinder the effective implementation of these recommendations. We report on the results of an international collaboration to harmonise existing cardiomyopathy surveillance recommendations using an evidence-based approach that relied on standardised definitions for outcomes of interest and transparent presentation of the quality of the evidence. The resultant recommendations were graded according to the quality of the evidence and the potential benefit gained from early detection and intervention.

Prophylactic Granulocyte Colony-Stimulating Factor and Granulocyte-Macrophage Colony-Stimulating Factor Decrease Febrile Neutropenia After Chemotherapy in Children With Cancer: A Meta-Analysis of Randomized Controlled Trials

PURPOSE To determine whether prophylactic hematopoietic colony-stimulating factors (CSFs) used in children with cancer reduce the rate of febrile neutropenia, hospitalization duration, documented infection rate, parenteral antibiotic duration, amphotericin B use, or infection-related mortality. METHODS We included studies in this meta-analysis if their populations consisted of children, if there was randomization between CSFs and placebo or no therapy, if CSFs were administered prophylactically (before neutropenia or febrile neutropenia), and if chemotherapy treatments preceding CSFs and placebo or no therapy were identical. From 971 reviewed study articles, 16 were included. RESULTS The mean rate of febrile neutropenia in the control arms was 57% (range, 39% to 100%). Using a random effects model, CSFs were associated with a reduction in febrile neutropenia, with a rate ratio of 0.80 (95% CI, 0.67 to 0.95; P =.01), and a decrease in hospitalization length, with a weighted mean difference of -1.9 days (95% CI, -2.7 to -1.1 days; P <.00001). CSF use was also associated with reduction in documented infections (rate ratio, 0.78; 95% CI, 0.62 to 0.97; P =.02) and reduction in amphotericin B use (rate ratio, 0.50; 95% CI, 0.28 to 0.87; P =.02). There was no difference in duration of parenteral antibiotic therapy (weighted mean difference, -4.3; 95% CI, -10.6 to 2.0 days; P =.2) or infection-related mortality (rate ratio, 1.02; 95% CI, 0.34 to 3.06; P =.97). CONCLUSION CSFs were associated with a 20% reduction in febrile neutropenia and shorter duration of hospitalization; however, CSFs did not reduce infection-related mortality.

Twenty years of follow-up among survivors of childhood and young adult acute myeloid leukemia: A report from the Childhood Cancer Survivor Study

Limited data exist on the comprehensive assessment of late medical and social effects experienced by survivors of childhood and young adult acute myeloid leukemia (AML).