Cumulative burden of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma: an analysis from the St Jude Lifetime Cohort Study

BACKGROUND

The magnitude of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma is not known. Using medically ascertained data, we applied the cumulative burden metric to compare chronic cardiovascular health conditions in survivors of Hodgkin's lymphoma and general population controls.

METHODS

For this study, participant data were obtained from two ongoing cohort studies at St Jude Children's Research Hospital: the St Jude Lifetime Cohort Study (SJLIFE) and the St Jude Long-term Follow-up Study (SJLTFU). SJLIFE is a cohort study initiated on April 27, 2007, to enable longitudinal clinical evaluation of health outcomes of survivors of childhood cancer treated or followed at St Jude Children's Research Hospital, and SJLTFU is an administrative system-based study initiated in 2000 to collect outcome and late toxicity data for all patients treated at the hospital for childhood cancer. The patient cohort for our study was defined as patients treated at St Jude Children's Research Hospital who reached 18 years of age and were at least 10 years post-diagnosis of pathologically confirmed primary Hodgkin's lymphoma. Outcomes in the Hodgkin's lymphoma survivors were compared with a sample of SJLIFE community control participants, aged 18 years or older at the time of assessment, frequency-matched based on strata defined by 5-year age blocks within each sex, who were selected irrespective of previous medical history. All SJLIFE participants underwent assessment for 22 chronic cardiovascular health conditions. Direct assessments, combined with retrospective clinical reviews, were used to assign severity to conditions using a modified Common Terminology Criteria of Adverse Events (CTCAE) version 4.03 grading schema. Occurrences and CTCAE grades of the conditions for eligible non-SJLIFE participants were accounted for by multiple imputation. The mean cumulative count (treating death as a competing risk) was used to estimate cumulative burden.

FINDINGS

Of 670 survivors treated at St Jude Children's Research Hospital, who survived 10 years or longer and reached age 18 years, 348 were clinically assessed in the St Jude Lifetime Cohort Study (SJLIFE); 322 eligible participants did not participate in SJLIFE. Age and sex frequency-matched SJLIFE community controls (n=272) were used for comparison. At age 50 years, the cumulative incidence of survivors experiencing at least one grade 3-5 cardiovascular condition was 45·5% (95% CI 36·6-54·3), compared with 15·7% (7·0-24·4) in community controls. The survivor cohort at age 50 experienced a cumulative burden of 430·6 (95% CI 380·7-480·6) grade 1-5 and 100·8 (77·3-124·3) grade 3-5 cardiovascular conditions per 100 survivors; these numbers were appreciably higher than those in the control cohort (227·4 [192·7-267·5] grade 1-5 conditions and 17·0 [8·4-27·5] grade 3-5 conditions per 100 individuals). Myocardial infarction and structural heart defects were the major contributors to the excess grade 3-5 cumulative burden in survivors. High cardiac radiation dose (≥35 Gy) was associated with an increased proportion of grade 3-5 cardiovascular burden, whereas increased anthracyline dose was not.

INTERPRETATION

The true effect of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma is reflected in the cumulative burden. Survivors aged 50 years will experience more than two times the number of chronic cardiovascular health conditions and nearly five times the number of more severe (grade 3-5) cardiovascular conditions compared with community controls and, on average, have one severe, life-threatening, or fatal cardiovascular condition. The cumulative burden metric provides a more comprehensive approach for assessing overall morbidity compared with currently used cumulative incidence based analytic methodologies, and will assist clinical researchers when designing future trials and refining general practice screening guidelines.

FUNDING

US National Cancer Institute, St Baldrick's Foundation, and American Lebanese Syrian Associated Charities.

Radiation Therapy and Cardiac Death in Long-Term Survivors of Esophageal Cancer: An Analysis of the Surveillance, Epidemiology, and End Result Database

Objective

Radiation therapy (RT) for esophageal cancer often results in unintended radiation doses delivered to the heart owing to anatomic proximity. Using the Surveillance, Epidemiology, and End Results (SEER) database, we examined late cardiac death in survivors of esophageal cancer that had or had not received RT.

Methods

5,630 patients were identified that were diagnosed with esophageal squamous cell carcinoma (SCC) or adenocarcinoma (AC) from 1973–2012, who were followed for at least 5 years after therapy. Examined risk factors for cardiac death included age (≤55/56-65/66-75/>75), gender, race (white/non-white), stage (local/regional/distant), histology (SCC/AC), esophageal location (<18cm/18-24cm/25-32cm/33-40cm from incisors), diagnosis year (1973-1992/1993-2002/2003-2012), and receipt of surgery and/or RT. Time to cardiac death was evaluated using the Kaplan-Meier method. A Cox model was used to evaluate risk factors for cardiac death in propensity score matched data.

Results

Patients who received RT were younger, diagnosed more recently, had more advanced disease, SCC histology, and no surgery. The RT group had higher risk of cardiac death than the no-RT group (log-rank p<0.0001). The median time to cardiac death in the RT group was 289 months (95% CI, 255–367) and was not reached in the no-RT group. The probability of cardiac death increased with age and decreased with diagnosis year, and this trend was more pronounced in the RT group. Multivariate analysis found RT to be associated with higher probability of cardiac death (OR 1.23, 95% CI 1.03–1.47, HR 1.961, 95% CI 1.466–2.624). Lower esophageal subsite (33–40 cm) was also associated with a higher risk of cardiac death. Other variables were not associated with cardiac death.

Conclusions

Recognizing the limitations of a SEER analysis including lack of comorbidity accountability, these data should prompt more definitive study as to whether a possible associative effect of RT on cardiac death could potentially be a causative effect.

Hodgkin lymphoma: Late effects of treatment and guidelines for surveillance

Long-term survivors of Hodgkin lymphoma (HL) are at risk for a range of late effects, with second malignant neoplasm and cardiovascular diseases being the leading causes of death in these patients. The excess risks remain significantly elevated decades after treatment, and are clearly associated with extent of treatment exposures. Other late effects have also been identified, such as pulmonary dysfunction, endocrinopathies, muscle atrophy, and persistent fatigue. Systemic documentation of late effects and recognition of treatment- and patient-related risk factors are important, as they inform optimal surveillance and risk-reduction strategies, as well as guide therapeutic modifications in newly diagnosed patients to minimize treatment-related complications. As HL therapy evolves over time, with adoption of novel agents and contemporary treatment techniques, late effect risks and follow-up recommendations need to be continuously updated.

Cardiac Mortality in Children and Adolescents with Hodgkin's Lymphoma: A Surveillance, Epidemiology and End Results Analysis

PURPOSE

The purpose of this study was to evaluate the risk of cardiac death in pediatric Hodgkin's lymphoma (HL) survivors and identify high-risk groups that may need additional surveillance.

METHODS

The Surveillance, Epidemiology and End Results program database was queried to analyze the rates of radiation therapy (RT) use and cardiac-specific mortality (CSM) in HL patients, aged 0-21 years, treated from 1973 to 2007. Primary endpoint was cardiac mortality.

RESULTS

A total of 6552 patients were included. Median follow-up was 12 years (range, 0-40). Median age at diagnosis was 17 years (range, 0-21). The majority were white (85.5%), from western states (41.2%), had nodular sclerosis HL (73.2%), presented with stage I or II disease (51.5%), and received RT (56.1%). Death from cardiac disease occurred in 114 patients (9.2% of all deaths). CSM for the entire cohort at 10-, 20-, and 30-year time points was 0.3%, 1.6%, and 5.0%, respectively. Median age at the time of cardiac death was 39 years (range, 18-58 years). Under multivariate analysis (MVA), adolescent patients (ages 13-21) had higher rates of CSM (hazard ratio [HR], 3.05; p = 0.005). Female gender (HR, 0.43; p < 0.001), patients treated from 1998 to 2007 (HR, 0.19; p = 0.018), and those with lymphocyte-rich histology (HR, 0.14; p = 0.047) had significantly lower rates of CSM. Use of RT was not associated with CSM under MVA (HR, 1.18, p = 0.452).

CONCLUSION

The cumulative incidence of CSM in this population analysis of pediatric HL was 9.2%, with a steady decline over the past several decades. Adolescent patients at diagnosis and males were more likely to die of cardiac-related causes.

Functional Imaging Using 18-Fluorodeoxyglucose PET in the Management of Primary Mediastinal Large B-Cell Lymphoma: The Contributions of the International Extranodal Lymphoma Study Group

Primary mediastinal large B-cell lymphoma (PMLBCL) is recognized as a distinct disease entity. Treatment outcomes appear better than in other diffuse large B-cell lymphoma (DLBCL) types, partly because of their earlier stage at presentation and the younger age of most patients. If initial treatment fails, however, the results of salvage chemotherapy and myeloablative treatment are poor. The need to avoid relapses after initial therapy has led to controversy over the extent of front-line therapy, particularly whether consolidation radiotherapy to the mediastinum is always required and whether the 18-fluorodeoxyglucose ((18)F-FDG) uptake detected by PET-CT scan can be used to determine its requirements. Functional imaging using PET-CT generally allows distinguishing of residual mediastinal masses containing active lymphoma from those with only sclerotic material remaining. The International Extranodal Lymphoma Study Group (IELSG) conducted the prospective IELSG-26 study, which showed that a five-point visual scale can be used to define metabolic response after immunochemotherapy and that a cut point based on liver uptake discriminates effectively between high or low risk of failure, with 5-year progression-free survival (PFS) of 99% versus 68% and 5-year overall survival (OS) of 100% versus 83%. This study also showed that a baseline quantitative PET parameter, namely the total lesion glycolysis describing the metabolic tumor burden, can be a powerful predictor of PMLBCL outcomes and warrants further validation as a biomarker. The ongoing IELSG-37 randomized study addresses the need for consolidation mediastinal radiotherapy in patients in whom a complete metabolic response (CMR) can be seen on PET scans after standard immunochemotherapy.