Detection Technology of Peripheral Blood ctDNA Based on CRISPR/Cas and Gold Nanoparticles

This study tests a new, fast blood test that may help detect very small traces of tumor DNA in the bloodstream. When tumor cells die, they release small pieces of DNA called circulating tumor DNA (ctDNA) into the blood. Finding these pieces can help doctors diagnose cancer, monitor how well treatment is working, and detect cancer recurrence earlier. However, ctDNA is present in very small amounts and is hard to detect with current methods. Newer techniques such as next-generation sequencing (NGS) can find ctDNA, but they are expensive, require specialized laboratories, and take days to return results. This study evaluates a new testing method called "CRISPR/Cas12a combined with gold nanoparticle detection." This method uses a gene-editing protein (Cas12a) that can recognize a specific mutation in the BRCA1 gene and a gold nanoparticle-based readout that shows results within about 30 minutes, using portable equipment. The main purpose of this study is to find out how accurate, sensitive, and specific this new test is compared with NGS, which is considered the gold standard. The study will also check whether the portable device works consistently across different hospitals and whether the test results match patients' responses to treatment. The study will enroll adult cancer patients treated at participating hospitals and a group of healthy volunteers. All participants will provide about 3 mL of blood (less than one teaspoon). No additional invasive procedures or extra hospital visits are required beyond routine blood draws. For cancer patients, part of the blood sample will be tested with the new method and part will be tested with standard NGS, and the two results will be compared. Healthy volunteers' blood will be used to confirm that the test does not produce false positive results. There is no direct physical harm from the test itself, since it is performed on blood samples in the laboratory. Participants will receive the ctDNA test free of charge, and their test results may help their doctors better understand their disease. The results of this study may help develop a rapid, low-cost, bedside test for tumor DNA, which could improve cancer diagnosis and monitoring in the future.

Inclusion Criteria: * Adults (≥18 years of age) diagnosed with a malignant tumor at one of the participating hospitals * Patients willing and able to provide written informed consent Exclusion Criteria: * Patients who refuse or are unable to sign the informed consent form * Patients with severe hematologic or coagulation disorders that make blood collection infeasible * Healthy volunteers: adults (≥18 years) with no history of cancer, willing to provide written informed consent