Tumor-specific but not nonspecific cell-free circulating DNA can be used to monitor disease response in lymphoma

Recently, nontumor specific circulating DNA was shown to be elevated in a broad range of lymphomas, implicating a role as a potential biomarker. Epstein-Barr virus' (EBV) presence within a proportion of lymphomas implies EBV-DNA has potential as a lymphoma-specific disease response biomarker. However, application would be restricted to EBV-associated lymphomas. Neither detailed comparison has been performed of lymphoma-specific versus nonspecific DNA as disease response biomarkers nor have the kinetics of circulating DNA during treatment been established, and the optimal methodology remains unknown. We prospectively evaluated DNA levels and clinical response of 63 lymphoma patients. DNA was measured in paired serum, plasma, and cell samples at five predetermined time-points taken prior, during and following treatment. Both cell-free (c-f) circulating EBV-DNA (in EBV-associated lymphoma) and nonspecific c-f DNA levels (in all lymphomas) were elevated and discriminatory at presentation compared to healthy controls. Nonspecific c-f DNA was significantly associated with baseline serum lactate dehydrogenase. Within EBV-associated lymphomas at presentation, there was a strong correlation between specific and nonspecific circulating c-f DNA (r = 0.9, P < 0.0001). However, only c-f EBV-DNA correlated with clinical/radiological response. In addition, c-f EBV-DNA, and not nonspecific c-f DNA, provided an early marker of relapsed and refractory disease. Serum versus plasma, and single versus multiple-copy EBV-gene targets were equivalent. Lymphoma-specific DNA is a disease response biomarker; however, nonspecific DNA reflected neither lymphoma-specific DNA nor therapeutic response. Lymphoma disease response can be monitored by blood tests, but new lymphoma-specific biomarkers need to be identified to broaden applicability.     

The genetics of phaeochromocytoma: using clinical features to guide genetic testing

Phaeochromocytoma is a rare, usually benign, tumour predominantly managed by endocrinologists. Over the last decade, major advances have been made in understanding the molecular genetic basis of adrenal and extra-adrenal phaeochromocytoma (also referred to as adrenal phaeochromocytoma (aPCA) and extra-adrenal functional paraganglioma (eFPGL)). In contrast to the previously held belief that only 10% of cases had a genetic component, currently about one-third of all aPCA/eFPGL cases are thought to be attributable to germline mutations in at least nine genes (NF1, RET, SDHA, SDHB, SDHC, SDHD, TMEM127, MAX and VHL). Recognition of inherited cases of aPCA/eFPGL is critical for optimal patient management. Thus, the identification of a germline mutation can predict risks of malignancy, recurrent disease, associated non-chromaffin tumours and risks to other family members. Mutation carriers should be offered specific surveillance programmes (according to the relevant gene). In this review, we will describe the genetics of aPCA/eFPGL and strategies for genetic testing.     

Methodology matters: what type of research is suitable for evaluating community treatment supporters for HIV and tuberculosis treatment?

The choice of research method relevant to the evaluation of delivery of a health intervention is not always straightforward. We use the evaluation of HIV and tuberculosis community treatment supporters in promoting adherence to treatment in Africa as a case study to illustrate the pros and cons of operational research and randomised controlled trials. The choice of this intervention for the case study reflects the importance of maximising the benefits of unprecedented efforts to scale-up treatments of these two epidemics. International policy supporting the role of community treatment supporters in tuberculosis is largely based on the findings of operational research studies. This reflects the advantages that operational research is less costly than randomised controlled trials, provides more rapid answers to policy questions, enables standard evaluation of the intervention in 'real life' conditions in several diverse settings and has in-built potential to influence policy and practice, because the research is conducted within health programmes. Recent evidence on the role of community treatment supporters in HIV is largely based on randomised trials. This reflects the advantages that randomised trials compared to operational research are more rigorous and generate a more convincing result. Operational research and randomised trials may be viewed as providing complementary findings to inform new policies and practice aimed at improving programme performance and patient outcomes. However, in practice, insufficient funds are likely to be made available for randomised trials to answer all the current research questions on delivery of programme interventions. In deciding on the type of research to evaluate a particular health intervention, dialogue is necessary with policy-makers to weigh up explicitly the trade-offs between research rigour and other factors such as cost, speed of implementation of research and speed of policy uptake and of change in programme practice.