Objectives:To explore the value of improving the sensitivity of Epstein-Barr virus(EBV) DNA detection for the diagnosis and efficacy assessment of nasopharyngeal carcinoma.Methods:This was an observational study. The precision of the EBV DNA detection system used in this study was verified at the level of 100 copies/ml in accordance with the requirements of verification experiments, and the accuracy of the detection system was evaluated by comparing with digital PCR method. Totally 52 plasma samples were collected from patients who were newly diagnosed with undifferentiated non-keratinizing carcinoma of the nasopharynx at Nanfang Hospital of Southern Medical University from December 2021 to May 2022 in addition to156 plasma samples from nasopharyngeal carcinoma patients treated at the Radiotherapy Department of the hospital, and a retrospective analysis was also performed on 5 488 plasma samples that had been submitted for quantitative EBV DNA detection over the same period at the hospital. The effetcs of raising the EBV DNA detection threshold from 500 copies/ml to 100 copies/ml on the detection rate of nasopharyngeal carcinoma and the therapeutic efficacy assessment were compared.Results:The bias between the logarithmic values of the detected quantities and the target quantities was below±0.4 ( CV=6.94%) for the testings of 30 repetitions of the sample at the level of 100 copies/ml. The circulating EBV DNA of 156 patients with nasopharyngeal carcinoma was measured by the detection system and by digital PCR, and the results of the two methods showed good consistency ( r=0.95, P<0.001). By raising the EBV DNA detection threshold from 500 copies/ml to 100 copies/ml, the detection rate of nasopharyngeal carcinoma in untreated patients increased from 67.31% (35/52) to 82.69% (43/52). For nasopharyngeal carcinoma patients under treatment, the peripheral blood EBV DNA detection rates were 12.82% (20/156) and 23.72% (37/156) with detection thresholds of 500 copies/ml and 100 copies/ml, respectively. Conclusion:This research improved the EBV detection rate by increasing the sensitivity of EBV DNA assays, which is of great significance for the auxiliary diagnosis and therapeutic efficacy assessment in nasopharyngeal carcinoma patients.

Fecal Microbiota Transplantation (FMT) has achieved significant therapeutic effects in the treatment of various diseases such as Clostridium difficile infection, irritable bowel syndrome, inflammatory bowel disease et al. Researches have shown that FMT may affect the occurrence and development of malignant tumors by remodeling the composition of patients′ intestinal flora, which has potential therapeutic value. In recent years, key techniques of FMT such as washed microbiota transplantation, transendoscopic enteral tubing, spore transplantation, and manually prepared transplantation, provide more possibilities for diseases treatment of FMT. This review introduces the development status of FMT, the pivotal techniques of FMT, and summarizes the applicational advantages and disadvantages. We also focus on the applied researches of FMT in the treatment of malignant tumor diseases, such as adjuvant immunotherapy, chemotherapy, surgical treatment and endocrine therapy, so as to provide theoretical basis for the future clinical application of FMT in this field.