Use exosome microfluidic chips to establish a combination of exosome subgroup level (exosome barcode) markers for the early diagnosis of osteosarcoma lung recurrence, and establish the basis of microfluidic chip based exosome biomarker for monitoring the early therapeutic response of the second-line therapy for recurrent osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumor in adolescents, and lung metastasis is the main cause of its poor prognosis. Our previous data on the basis of second-line chemotherapy combined with VEGFRi targeted therapy for patients with lung metastases from osteosarcoma showed that some patients with early diagnosis of lung metastases may achieved long-term tumor-free survival upon prompt treatment. However, plasma biomarker for the early detection of recurrent osteosarcoma is still lacking to date. Our preliminary studies indicate that exosome is a potential source of liquid biomarker for the early diagnosis of osteosarcoma lung metastasis. We, therefore, have developed a microfluidic biochip based on nano-zinc oxide microcolumns. This chip can quickly and efficiently screen and capture exosomes and achieve quantitative and qualitative detection of exosome and its subgroups. This technology may be able to achieve early sensitive exosome quantification for lung metastasis of osteosarcoma. But the clinical efficacy and utility of the microfluidic chip based exosome detection for the early diagnosis osteosarcoma recurrence remains to be validated.

This research plan uses our newly developed microfluidic chip technology to capture and efficiently capture exosomes for quantitative and qualitative and marker screening, and establish a combination of exosome subgroups level as a biomarker for the early diagnosis of osteosarcoma lung metastasis.

Inclusion Criteria:

1. Biopsy pathologically diagnosed as primary high-grade osteosarcoma (including ordinary osteosarcoma, vasodilatory osteosarcoma, small cell osteosarcoma, high-grade surface osteosarcoma);
2. Age no less than 12 years old and no older than 60 years old;
3. New-onset patients who have not received chemotherapy, radiotherapy, surgery, Chinese medicine and other treatments.
4. The primary site is the limbs and pelvis.

Exclusion Criteria:

1. Pathological diagnosis of surgical gross specimens except primary high-grade osteosarcoma;
2. Failure to collect circulating exosomes as planned;
3. Suffering from chronic diseases, which may lead to an increase in non-tumor-related circulating exosomes, such as autoimmune diseases , Chronic infections, etc.;
4. The use of targeted drugs may lead to a decrease in tumor-related circulating exosomes;
5. Withdrawal from the trial for any reason.

1. Surgical specimens and peripheral blood specimens of previous patients with osteosarcoma in the specimen bank,
2. Patients who were diagnosed with osteosarcoma and were hospitalized in the Department of Orthopedics of Ruijin Hospital