Alteration of PD-L1 (SP142) status after neoadjuvant chemotherapy and its clinical significance in triple-negative breast cancer.

PURPOSE: The tumor immune microenvironment can change after neoadjuvant chemotherapy (NAC) for triple-negative breast cancer (TNBC). We aimed to investigate the effects of NAC on PD-L1 (SP142) status and its clinical significance in TNBC. METHODS: Paired samples of biopsy and resection specimens were collected from 182 patients with TNBC before and after NAC. PD-L1 (SP142) expression in immune cells in pre- and post-NAC breast cancer samples and the changes between them were analyzed, along with their relationships with the clinicopathological features and clinical outcomes of the patients. RESULTS: Of the 182 patients, 61 (33.5%) achieved pathologic complete response (pCR) after NAC. PD-L1 (SP142) positivity, defined as immune cell staining in ≥ 1% of tumor area, was a predictor for pCR. PD-L1-positive immune cells significantly increased after NAC (2.8% to 5.2% on average) in 109 patients with measurable residual disease. Alteration of PD-L1 status was observed in 24 (22.0%) of the 109 patients with measurable residual tumors after NAC, and all PD-L1 status-converted patients, except one, revealed negative-to-positive conversion. Regarding chemotherapeutic agents, the use of platinum agents was associated with a significant increase in PD-L1-positive immune cells after NAC. In survival analyses, a positive PD-L1 status after NAC and increase of PD-L1-positive immune cells after NAC were associated with better recurrence-free survival of the patients. CONCLUSION: PD-L1 (SP142) status changes after NAC, mostly as a positive conversion. As PD-L1 (SP142) status can convey prognostic and predictive information, it needs to be tested before and after NAC.

PD-L1 (SP142) Expression in Primary and Recurrent/Metastatic Triple-Negative Breast Cancers and Its Clinicopathological Significance.

PURPOSE: The programmed death-ligand 1 (PD-L1) SP142 assay identifies patients with triple-negative breast cancer (TNBC) who are most likely to respond to the anti-PD-L1 agent atezolizumab. We aimed to compare PD-L1 (SP142) expression between primary and recurrent/metastatic TNBCs and elucidate the clinicopathological features associated with its expression. MATERIALS AND METHODS: Primary and recurrent/metastatic TNBCs tested with PD-L1 (SP142) were collected, and clinicopathological information of these cases was obtained through a review of slides and medical records. RESULTS: PD-L1 (SP142) positivity was observed in 50.9% (144/283) of primary tumors and 37.8% (31/82) of recurrent/metastatic TNBCs with a significant difference. Recurrent or metastatic sites were associated with PD-L1 positivity, with high PD-L1 positivity in the lung, breast, and soft tissues, and low positivity in the bone, skin, liver, and brain. When comparing PD-L1 expression between primary and matched recurrent/metastatic TNBCs using 55 paired samples, 20 cases (36.4%) showed discordance; 10 cases revealed positive conversion, and another 10 cases revealed negative conversion during metastatic progression. In primary TNBCs, PD-L1 expression was associated with a higher histologic grade, lower T category, pushing border, and higher tumor-infiltrating lymphocyte infiltration. In survival analyses, PD-L1 positivity, especially high positivity, was found to be associated with favorable prognosis of patients. CONCLUSION: PD-L1 (SP142) expression was lower in recurrent/metastatic TNBCs, and substantial cases showed discordance in its expression between primary and recurrent/metastatic sites, suggesting that multiple sites may need to be tested for PD-L1 (SP142) when considering atezolizumab therapy. PD-L1 (SP142)-positive TNBCs seems to be associated with favorable clinical outcomes.

Continuous quality improvement program and its results of Korean Society for Cytopathology.

BACKGROUND: Since 1995, the Korean Society for Cytopathology has overseen the Continuous Quality Improvement program for cytopathology laboratories. The Committee of Quality Improvement has carried out an annual survey of cytology data for each laboratory and set standards for proficiency tests. METHODS: Evaluations were conducted four times per year from 2008 to 2018 and comprised statistics regarding cytology diagnoses of previous years, proficiency tests using cytology slides provided by the committee, assessment of adequacy of gynecology (GYN) cytology slides, and submission of cytology slides for proficiency tests. RESULTS: A total of 206 institutes participated in 2017, and the results were as follows. The number of cytology tests increased from year to year. The ratio of liquid-based cytology in GYN gradually decreased, as most of the GYN cytology had been performed at commercial laboratories. The distribution of GYN diagnoses demonstrated nearly 3.0% as atypical squamous cells. The rate for squamous cell carcinoma was less than 0.02%. The atypical squamous cell/squamous intraepithelial lesion ratio was about 3:1 and showed an upward trend. The major discordant rate of cytology-histology in GYN cytology was less than 1%. The proficiency test maintained a major discordant rate less than 2%. The rate of inappropriate specimens for GYN cytology slides gradually decreased. CONCLUSIONS: The Continuous Quality Improvement program should be included in quality assurance programs. Moreover, these data can contribute to development of national cancer examination guidelines and facilitate cancer prevention and treatment.