A systematic review and meta-analysis of the impact of radiation-related lymphopenia on outcomes in pancreatic cancer

Background: Pancreatic cancer is a devastating disease with a 5-year survival rate of 5-10%. Radiation is commonly used in neoadjuvant and adjuvant settings to improve local control. Studies have shown that circulating lymphocyte count depletion after radiation has been associated with poor tumor control and inferior overall survival (OS) outcomes. Method: To better understand the impact of radiation-associated lymphopenia in pancreatic cancer, the authors undertook this systematic review and meta-analysis of clinical studies that have reported radiation-related lymphopenia in pancreatic cancer. Results: A systematic methodology search of PubMed, Embase and the Cochrane Library resulted in 2969 abstracts. Nine studies fulfilled the inclusion criteria. Six studies reported on outcomes in patients undergoing definitive chemoradiation and three studies comparing outcomes in stereotactic body radiotherapy versus definitive chemoradiation. The patients with severe lymphopenia were at increased risk of death with a pooled hazard ratio of 2.33 (95% CI: 1.79, 3.03; I2: 36%; p < 0.001) compared with patients with no severe lymphopenia. The odds of developing severe lymphopenia were 1.12 (95% CI: 0.45, 2.79; I2: 95%; p < 0.81). The pooled mean difference for OS was -6.80 months (95% CI: -10.35, -3.24; I2: 99%; p < 0.002), suggesting that patients who develop grade 3 or 4 lymphopenia have inferior median OS outcomes. Limiting the mean splenic dose to less than 9 Gy as well as various spleen dosimetric parameters such as visit (V)10 <32%, V15 <23% and V20 <15.4% can reduce the incidence of severe lymphopenia. Conclusion: Radiation-related lymphopenia is associated with an increased hazard of death and inferior median OS. Spleen dosimetric parameters correlate with the incidence of severe lymphopenia and with sub-optimal survival outcomes. There is a need to validate these findings in prospective studies.

The mechanistic rationale of drugs, primary endpoints, geographical distribution of clinical trials against severe acute respiratory syndrome-related coronavirus-2: A systematic review

There are numerous ongoing studies assessing treatment options for preventing, treating, and managing complications of coronavirus disease-2019 disease. The objective of this study was to do a systematic review and critical appraisal of the ongoing clinical trials with an aim to provide insight into the various interventions tested, clinical rationale, geographical distribution of the trials as well as the endpoints assessed in the studies. ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, and PubMed were assessed till 11 May 2020. The search resulted in 3242 ongoing studies of which 829 studies were included. There are 134 different drug-based interventions being assessed in 463 clinical trials as treatment options China accounts for 35% of all ongoing clinical studies followed by USA 23% and other countries together account for 42%. Amongst the 463 studies assessing drug-based treatment options, studies that are funded by federal and academic institutions are 79.6%, pharmaceutical company-funded studies are 15.11%, and no funding information is available in 5.10%. The definitive outcomes like mortality are being assessed as primary outcome in 22.8% of the studies only and need for ventilator in 6.2% of the studies. Amongst the pharmaceutical company-funded drug-based studies, only 20% of the studies had mortality as the primary outcome. Only 5.5% of the ongoing clinical trials are specifically designed to assess the most vulnerable population like elderly, patients with comorbidities and cancer. Multiple intervention-based clinical studies against severe acute respiratory syndrome-related coronavirus-2 are being performed throughout the world with a high concentration of clinical trials in the developed world with concern that of elderly and patients with comorbidities are being underrepresented and definite endpoints like mortality are being assessed in only one-fifth of the studies.