CD274 and neoplasm: Its mechanism of action is to bind to PD-1 receptors, block the PD-1/PD-L1 pathway, relieve the immune suppression of tumour cells in the body, reactivate the anti-tumour activity of T lymphocytes and generate a tumour immune response.15,16 Research has shown sintilimab to have therapeutic effects in the treatment of various tumour types.17 It is, therefore, included in various cancer treatment plans and shows good clinical efficacy.18,19 This study showed an ORR in the observation group treated with sintilimab and the AP regimen of 68.75%.