PD-L1 expression in head and neck cancer tissue specimens decreases with time.

BACKGROUND: PD-L1 immunohistochemical expression is used as an important theranostic marker in various malignancies, including head and neck squamous cell carcinoma (HNSCC) where the combined positive score (CPS) guides treatment decisions. Despite indirect evidence that there is loss of antigenicity for archived tissues, there is no direct comparison between PD-L1 expression of the same tissue upon arrival and after its storage. MATERIAL AND METHODS: We compared the immunohistochemical expression of PD-L1 (22C3) in 106 HNSCC upon their arrival and after their storage (interval ranging from 20 to 48 months, mean 30.8 months). The evaluation was performed by two different pathologists' groups. RESULTS: We found a statistically significant decrease in the PD-L1 tumor proportional score (TPS), immune cells expression (IC) and CPS between the initial and the newly stained slides. CONCLUSION: This is the first study comparing PD-L1 expression between a tissue and "himself" later in time, highlighting an important decrease in expression by tumor and immune cells, and suggesting that an immediate rather than a retrospective assay of PD-L1 expression should be preferable in the routine practice. DATA AVAILABILITY: Data are available upon reasonable request.

Development of Body Modification and Excessive Exercise Scales for adolescents.

The present study was designed to develop a Body Modification Scale (BMS) to measure body change among adolescents and to modify an Excessive Exercise Scale (EES) into a shorter form for adolescents. Two hundred and twenty-one girls and 192 boys from Grades 7 to 10 completed the BMS and the EES. Factor analysis revealed three identical factors for the BMS for girls and boys: weight loss, weight gain, and muscle mass. Two identical factors for girls and boys were also revealed for the EES. Both factor structures were further validated on a separate sample of 286 adolescents (140 girls, 146 boys). The BMS and EES demonstrated excellent reliability (alpha > .86) and high test-retest reliability (alpha > .82) over 1 month. Good concurrent validity was also found for the weight loss factor of the BMS. These findings demonstrate the utility of these two scales for use with adolescents.