RESUMEN
BACKGROUND: Advanced gastric cancers are usually associated with incurable conditions for which systemic treatments are indicated. Recent studies suggest that circulating cell-free plasma DNA of tumour origin (tDNA) is a promising non-invasive biomarker that can be used to predict the prognosis and monitor the efficacy of systemic treatments in patients with certain types of cancer. We conducted a pilot study to analyse the potential role of tDNA as a biomarker in patients with advanced gastric cancer. METHODS: We included 30 patients with locally advanced unresectable or metastatic gastric cancer. We obtained samples (10 mL of total blood) from each patient every 3 months and performed concomitant CT until disease progression or death. Total cell-free circulating DNA (cfDNA) samples were measured using GeneQuant RNA/DNA Calculator-Amersham Pharmacia Biotech (Biochrom) Ltd. The cfDNA was used to evaluate the ALU DNA sequences 247 and 115. The level of tDNA was calculated from the ratio of the expression of ALU DNA sequences and the concentration of total cell-free DNA. We utilized the RECIST criteria 1.1 to evaluate the tumour response. RESULTS: Patients with advanced gastric cancer had significantly higher concentrations of cfDNA compared with normal controls (p = 0.00015), which allowed us to conclude that the cfDNA in the patients originated from the tumour. We did not find any significant correlation between the level of tDNA and OS or tumour response. However, after the first cycles of chemotherapy (at 3 months), we observed that patients with lower tDNA levels had significantly longer DFS compared with those with higher levels (Cox Regression p = 0.0228). CONCLUSIONS: At 3 months after the beginning of chemotherapy, the tDNA levels are correlated with DFS in patients with advanced gastric cancer who receive systemic chemotherapy. tDNA may be a specific, non-invasive and cost effective new biomarker for these patients.
RESUMEN
OBJECTIVES: To evaluate the relationship between inflammatory parameters through the modified Glasgow Prognostic Score (mGPS) and other clinical characteristics of elderly patients with cancer, including frailty evaluated by the Edmonton Frailty Scale (EFS). MATERIALS AND METHODS: We included patients from the oncology service at Faculdade de Medicina do ABC with a confirmed diagnosis of solid tumor aged 65 years or more at diagnosis. Patients were assessed by applying the translated and validated to Portuguese version of the EFS and also had blood sample collection for the evaluation of C-reactive protein (CRP) and albumin for calculation of the mGPS. RESULTS: We included 52 patients of both sexes, with median age of 72.5 years, of these 67.3% had localized disease and 32.7% metastatic disease. The mGPS presented 17.3% of high-risk patients. The frailty evaluated by EFS occurred in 57.6% of patients. Patients with both abnormal parameters (CRP and albumin) in the mGPS had significantly higher scores on EFS when compared to those with no change (6 vs. 9.56 points, p=0.021). The mGPS correlated also with clinical staging (p=0.019) and performance status (p=0.039). CONCLUSIONS: Inflammatory parameters correlate significantly with frailty, more advanced clinical stage and poor functional status.
