BACKGROUND: Programmed cell death ligand 1 (PD-L1) plays a major role in the immune responses of a variety of cancers. Recently, several studies revealed that PD-L1 is differently expressed in some cases of non-melanoma skin cancer. The expression of PD-L1 in cutaneous squamous cell carcinoma has not yet been described in Korea. OBJECTIVE: To investigate the expression of PD-L1 in cutaneous squamous cell carcinoma and its association with variable clinicopathological factors. METHODS: We performed immunohistochemical staining of 52 cutaneous cell carcinoma cases, including 28 high-risk cases and 24 low-risk cases. Cases were selected from patients who had visited the department of dermatology of our hospital from 2001 to 2017. The expression patterns were assessed using the H-score. Cases demonstrating at least 1+ of PD-L1 in more than 1% of tumor cells were considered positive. RESULTS: PD-L1 expression of tumor cells was 19.2% (10/52) for all cases, 0.0% (0/24) for the low-risk group, and 35.7% (10/28) for the high-risk group. PD-L1 positive cutaneous squamous cell carcinoma cases showed a significantly higher proportion of large tumors and tumors with deep invasion and a higher lymphatic metastasis rate when compared to PD-L1 negative cutaneous squamous cell carcinoma cases. CONCLUSION: Our study shows that cutaneous squamous cell carcinoma exhibits PD-L1 expression in 19.2% of cases. PD-L1 positive tumors are associated with high-risk cases of cutaneous squamous cell carcinoma, which may help guide the choice of therapeutic strategy.
Carcinoma, Squamous Cell* ; Cell Death ; Dermatology ; Epithelial Cells* ; Humans ; Korea ; Lymphatic Metastasis ; Neoplasm Metastasis* ; Skin Neoplasms

PURPOSE: The purpose of this study was to compare the success rate of re-excision and breast-conserving surgery (BCS) between patients who received neoadjuvant chemotherapy and those who did not. METHODS: In this retrospective cohort study, 256 women who had clinical T2 breast cancer and planned to receive, as initial treatment either BCS (n=197) or neoadjuvant chemotherapy (n=59) between January 2009 and December 2012 were included. The data, including age, initial tumor size, mammographic microcalcification, ultrasound multifocality and axillary nodal status, were collected. The pathologic tumor size, p-multifocality, histologic type, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67, ductal carcinoma in situ (DCIS) and extensive intraductal component (EIC) were also reviewed. The re-excision and BCS success rates were investigated. Univariate analysis and regression model were used. To reduce the effect of selection bias, propensity score matching-based analysis was also performed. RESULTS: Of the 256 patients, 178 patients (90.4%, 178/197) in the non-neoadjuvant group and 56 patients (94.9%, 56/59) in the neoadjuvant group received BCS (p=0.406). In propensity-matched cohorts (n=118), the re-excision rate was similar in the two groups (35.6% in neoadjuvant group vs. 35.6% in non-neoadjuvant group, p=1.000). BCS success rate was slightly higher in neoadjuvant group (94.9%, 56/59) than in non-neoadjuvant group (86.4% [51/59], p=0.205). In logistic regression model, clinicopathologic factors associated with re-excision were pathologic multifocality (odds ratio [OR], 4.56; p=0.0142), high Ki-67 (≥50%) (OR, 0.7; p=0.0243) and DCIS component (OR, 2.67; p=0.0261). CONCLUSION: This study showed that neoadjuvant chemotherapy could increase the success rate of BCS but could not decrease that of re-excision. The re-excision rate is more associated with pathologic finding rather than the effect of neoadjuvant chemotherapy.
Breast Neoplasms ; Breast* ; Carcinoma, Intraductal, Noninfiltrating ; Cohort Studies ; Drug Therapy* ; Estrogens ; Female ; Humans ; Logistic Models ; Mastectomy, Segmental ; Propensity Score ; Receptor, Epidermal Growth Factor ; Receptors, Progesterone ; Retrospective Studies ; Selection Bias ; Ultrasonography