Osteosarcoma in Pediatric and Adult Populations: Are Adults Just Big Kids?

Malignant bone tumors are commonly classified as pediatric or adolescent malignancies, and clinical trials for these diseases have generally focused on these populations. Of primary bone cancers, osteosarcoma is among the most common. Osteosarcoma has a bimodal age distribution, with the first peak occurring in patients from 10 to 14 years old, and the second peak occurring in patients older than 65, with about 25% of cases occurring in adults between 20 and 59 years old. Notably, adult osteosarcoma patients have worse outcomes than their pediatric counterparts. It remains unclear whether age itself is a poor prognostic factor, or if inherent differences in tumor biology exist between age groups. Despite these unknowns, current treatment strategies for adults are largely extrapolated from pediatric studies since the majority of clinical trials for osteosarcoma treatments are based on younger patient populations. In light of the different prognoses observed in pediatric and adult osteosarcoma, we summarize the current understanding of the molecular etiology of osteosarcoma and how it may differ between age groups, hypothesizing why adult patients have worse outcomes compared to children.

The incidence and risk factors for venous thromboembolism in adolescent and young adult oncology patients.

BACKGROUND: Venous thromboembolism (VTE) is a known complication among pediatric and adult cancer patients. Adolescent and young adult oncology (AYAO) patients have unique biological and physiological characteristics that make them distinct from other populations. Our objective was to study the VTE incidence, risk factors, and outcomes, which have been understudied in this population. PROCEDURE: A retrospective case-control study was conducted on AYAO participants with new or relapsed cancer and an imaging confirmed VTE from January 2011 to November 2016 at our institution. Eligible AYAO participants without a history of VTE were designated as controls and were randomly selected from our institution's tumor registry. Demographics, medical history, surgeries, central venous catheter (CVC) data, VTE diagnosis and treatment, relapses, and deaths were abstracted. RESULTS: Thirty-five VTE cases and 70 controls were included in this analysis. Eighty percent of cases had leukemia or lymphoma (vs. a solid tumor) compared to 58% of controls. The majority of VTEs (57%) were CVC associated, and more than 70% of cases had more than one CVC placed during their cancer treatment versus 34% of controls. Infection was associated with increased VTE risk (OR = 6.35, 95% CI = 2.30, 17.55, p < .0001). VTE cases had increased cancer relapse (23% vs. 10%) and mortality rates (29% vs. 16%) than controls. CONCLUSION: AYAO participants with a VTE were more likely to have leukemia or lymphoma, more than one CVC or infection. Further studies are needed to identify patients who would benefit from modifiable prevention measures, such as limiting to one CVC, preventing infections, or considering prophylactic anticoagulation for those with a liquid tumor.

Risk stratification in febrile neutropenic episodes in adolescent/young adult patients with cancer.

BACKGROUND: Risk-stratified management of febrile neutropenia (FN) allows intensive management of high-risk cases and early discharge of low-risk cases. Most risk stratification systems predicting severe infection from admission variables have been derived from childhood or adult populations and consequently their value in adolescents/young adults (AYA) may vary. Our objective was to determine their value in this population. METHODS: Data from the 'predicting infectious complications in children with cancer' (PICNICC) individual participant data collaboration were used to evaluate six previously described risk stratification schema in the AYA population. Complete case analyses were undertaken for five 'paediatric' rules, with imputation for specific missing variables of the 'adult' rule. The predictive performance of the rules or the outcome microbiologically defined infection (sensitivity, specificity and predictive values) were compared. RESULTS: Among the 5,127 episodes of FN in 3,504 patients in the PICNICC collaboration data set, 603 episodes of FN from 478 patients in 20 studies were of patients 16-25 years old. The six rules demonstrated variable sensitivity (33-96%) and specificity (13-83%). Their overall discriminatory ability was poor (area under the receiver operator curve estimates 0.514-0.593). CONCLUSIONS: Both paediatric and adult FN risk stratification schema perform poorly in AYA with cancer. An alternative rule or clinical recognition of their limitations is required.

Toxicity of Cancer Therapy in Adolescents and Young Adults (AYAs).

OBJECTIVES: To identify treatment-related toxicities that are either more frequent or more severe in the adolescent and young adult (AYA) oncology population. To explore differences in drug pharmacology and patient physiology that contribute to toxicities in the AYA population and to describe the impact of treatment-related toxicities on outcomes for AYA patients. DATA SOURCES: A PubMed search was undertaken using the key words Adolescent Young Adult Oncology, AYA, toxicity, bone marrow transplant, late effects, and chemotherapy. Additional toxicity information was also obtained from recent publications from cancer cooperative groups treating AYA patients. CONCLUSION: AYA patients often experience more severe toxicities than children when treated with identical chemotherapy regimens, which can interfere with successful administration of planned treatment, as well as have profound effects on quality of life. AYA patients with cancer face the dual challenge of disease biology associated with inferior response to treatment, thus necessitating treatment intensification, while at the same time suffering higher rates of specific toxicities such as vincristine-induced neuropathy, osteonecrosis, and treatment-related mortality caused by infection. IMPLICATIONS FOR NURSING PRACTICE: AYA patients are at a higher risk for toxicities from regimens that may be tolerated by younger patients. Staff should be aware of toxicities facing this population so that appropriate supportive care measures can be utilized. Future research on the pharmacology of drugs in adolescence, hormonal effects on drug-metabolizing enzymes, cumulative exposure to different drugs in combination, and risk and severity of specific toxicities will be critical to improving the treatment of AYA patients.