MATERIALS AND METHODS
basal cell carcinoma of the skin
MALIGNANCIES, SECONDARY, CARCINOMA IN SITU, ONCOLOGY, PATHOLOGY
This study was a secondary analysis of a phase II study which was approved by the ethics committee of our hospital (SH9H‐2020‐T73‐1). The design of study and the inclusion and exclusion criteria were detailed in previous publication.All patients included in this study had experienced dose reduction in the phase II study, and have discontinued apatinib for 6 months or more before accepting the treatment of this study. The inclusion criteria were (1) >18 years of age; (2) advanced or R/M ACCHN diagnosed by pathology or histology; (3) with measurable lesions by spiral computed tomography (CT)/ magnetic resonance imaging (MRI) scan ≥10 mm and meeting the RECIST 1.1 criteria; (4) apatinib was used in the last‐line therapy and discontinued for AEs or progression; (5) Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0–1, and (6) treated with ATRA 25 mg/mThe exclusion criteria were (1) previous or coexisting malignancies (except cured basal cell carcinoma of the skin, and carcinoma in situ of the cervix) or (2) incomplete data, such as missing outcome indicators.