To evaluate the protective effect of Trilaciclib on myelosuppression in patients with limited-stage small cell lung cancer associated with concurrent chemoradiotherapy and discuss the effect of gut microbiota changes on myelosuppression

The occurrence of myelosuppression following chemotherapy, including severe neutropenia and hematological toxicity (Grade 3/4), as well as its association with dynamic changes in the gut microbiota, was investigated in conjunction with prophylactic administration of the CDK4/6 inhibitor Trilaciclib prior to the initiation of chemotherapy during radiotherapy for limited stage small cell lung cancer.

Inclusion Criteria:

1. The histopathology is limited-stage small cell lung cancer.
2. ECOG score 0-2.
3. Good organ function (no blood transfusions, no hematopoietic stimulating factors, no transfusions of albumin or blood products within 14 days prior to the examination).
4. It is suitable for patients treated with Trilaciclib combined with etoposide plus cisplatin or carboplatin.
5. Understand and can sign informed consent

Exclusion Criteria:

1. Brain metastases with clinical symptoms require local radiotherapy or hormone therapy.
2. Active infections require systemic treatment.
3. Subjects with active, known or suspected autoimmune disease or history of autoimmune disease.
4. Combined with other tumors.
5. The current or previous presence of a clinically significant and medically unstable condition, which in the investigator's professional judgment may compromise subject safety, interfere with study evaluation or endpoint assessment, or otherwise impact the reliability of study results.