Clinical outcomes of immunohistochemistry of the p53 Staining pattern in high-grade serous ovarian carcinoma

OBJECTIVE: To investigate the prevalence of p53 mutations and associated factors between immunohistochemistry (IHC) and p53 staining patterns among patients with high-grade serous ovarian carcinoma (HGSOC). METHODS: This study is a retrospective review. A total of 62 patients with HGSOC underwent surgery at Srinagarind Hospital between January 2016 and December 2020. Histological examination was performed based on a combination of morphology and IHC staining with p53. The p53 immunostaining pattern was interpreted as a missense mutation, nonsense mutation, or a wild-type pattern. Missense (p53 overexpression pattern) and nonsense (null expression p53 pattern) mutations were considered p53 mutations. A wild-type pattern was defined as a p53 non-mutation. RESULTS: p53 mutations were identified in 93.6% of the patients. Subgroup analysis of the p53 mutation group between the p53 overexpression pattern and the p53 null expression pattern in terms of clinicopathological characteristics and initial treatment was performed. Patients with the p53 overexpression pattern had significantly more omental metastases than those with the p53 null expression pattern (87.8% vs. 64.7%, P=0.042). There were no statistically significant differences in median progression-free survival (PFS) (9 vs. 10 months, P=0.813) or median overall survival (OS) (12 vs. 17 months, P=0.526) between the two groups. CONCLUSION: The prevalence of p53 mutations in HGSOC patients in this study was 93.6%. Omental metastasis is a significant pathological factor in predicting overexpression p53 pattern in HGSC. However, IHC analysis of the p53 staining pattern did not affect OS or PFS among patients with HGSOC.