The role of COL6A1and PD-1 expressions in renal cell carcinoma.

OBJECTIVE: The COL6A1 is a gene encoding the alpha 1 polypeptide subunit of collagen 6 (COL6A1), an extracellular matrix protein subunit. Programmed cell death receptor-1 (PD-1) and its ligand, programmed cell death receptor ligand-1 (PD-L1) have been shown to have a prognostic significance in clear cell renal cell carcinomas (RCCs). In this study, we evaluated the expressions of COL6A1 and PD-1 in four different RCC subtypes. MATERIALS AND METHODS: A total of 161 radical nephrectomy and nephron-sparing surgery cases with RCCs from five different health care centers were included in this study. Clinical data of the cases were taken from electronic records of the institutions. The pathological data were collected by an expert uropathologist and re-evaluated with slides obtained from paraffin blocks of the cases. The correlation of COL6A1 and PD-1 expression with sex, age, tumor type, lymphovascular invasion (LVI), World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade, and tumor stage (pT) was analyzed with the Pearson chi-squared test. RESULTS: Patients with sarcomatoid RCC and clear cell RCC had significantly higher COL6A1 scores and intensities than in other types of RCC (p=0.004 and p=0.002, respectively). WHO/ISUP grade and, COL6A1 and PD-1 staining scores also showed positive correlation (r=0.230, p=0.004 and r=0.277, p=0.001, respectively for COL6A1 and r=0.191, p=0.018 and r=0.166, p=0.041, respectively for PD-1). The staining scores and intensities of COL6A1 and PD-1 were not different between the patients with positive and negative LVI (p>0.05). CONCLUSION: In high-grade RCCs, we found the relationship between immunohistochemical staining scores of COL6A1 and PD-1 proteins and clinical, demographic, and histopathological parameters. Our results proved that COL6A1 and PD-1 are really promising proteins as prognostic parameters and for targeted immunotherapy.

Intraoperative Consultations of Central Nervous System Tumors: A Review for Practicing Pathologists and Testing of an Algorithmic Approach.

Intraoperative consultations or frozen sections for central nervous system (CNS) tumors present a significant challenge for surgical pathologists because of their relative rarity and diversity. Yet, such lesions are encountered by every surgical pathologist, and a basic understanding of clinical, radiological and genetic information is critical to successfully evaluate CNS frozen sections. It is often beneficial to have a systematic approach or an algorithm, and to be aware of the common pitfalls and mimickers when dealing with these lesions. We propose such an algorithm in an effort to construct a sensible approach to CNS frozen sections that considers recent developments in the WHO CNS tumor classification. The algorithm was developed for surgical pathologists who are occasionally faced with making diagnosis of CNS tumors on frozen sections. To test the algorithm and its practicability, we selected a group of tumors among a total of 3288 consecutive intraoperative consultations performed at UCSF between 2013 and 2017. The selected cases represented lesions that may be encountered in everyday surgical pathology and constituted a fair reflection of the main group. The algorithm was used by three of the authors who did not have formal neuropathology training and had been in surgical pathology practice for at least 3 years. There was a very high level of concordance among the authors' diagnosis (interobserver concordance: 0.83-0.97-kappa value) using the algorithm with high intraobserver reliability (concordance 93%, p < 0.001). We suggest that an algorithmic approach is an effective means for the surgical pathologists, and may help reach diagnosis during frozen sections.