Patient-derived orthotopic xenograft models for cancer of unknown primary precisely distinguish chemotherapy,and tumor-targeting S.typhimurium A1-R is superior to first-line chemotherapy

Cancer of unknown primary(CUP)is a recalcitrant disease with poor prognosis because it lacks standard first-line therapy.CUP consists of diverse malignancy groups,making personalized precision therapy essential.The present study aimed to identify an effective therapy for a CUP patient using a patient-derived orthotopic xenograft(PDOX)model.This paper reports the usefulness of the PDOX model to precisely identify effective and ineffective chemotherapy and to compare the efficacy of S.typhimurium A1-R with first-line chemotherapy using the CUP PDOX model.The present study is the first to use a CUP PDOX model,which was able to precisely distinguish the chemotherapeutic course.We found that a carboplatinum(CAR)-based regimen was effective for this CUP patient.We also demonstrated that S.typhimurium A1-R was more effective against the CUP tumor than first-line chemotherapy.Our results indicate that S.typhimurium A1-R has clinical potential for CUP,a resistant disease that requires effective therapy.