Is p53 immunohistochemistry alone useful for delineating adjuvant endometrial treatment in low-middle-income countries?

ABSTRACT

OBJECTIVE: Endometrial cancer (EC) treatment changed substantially with the introduction of molecular classification. Low-middle income (LMIC) countries will face barriers to including molecular classification to guide treatment. This study aims to analyse the value of p53 immunohistochemistry to delineate adjuvant treatment in FIGO stages I and II. METHODS: Patients with EC treated between 2010 and 2016 were retrospectively evaluated. Patients included in this analysis must have reviewed FIGO stage I/II high-grade histologies (endometrioid grade 3, serous, clear cell, carcinosarcoma, mixed and undifferentiated). Samples were subjected to p53 immunohistochemistry. Recurrence-free and overall survival were analysed using the Kaplan-Meier method and log-rank test. Cox proportional hazards regression was performed for multivariable analysis. RESULTS: From 2010 to 2016, 265 patients met the inclusion criteria. Patients with aberrant p53 (71.4 %) were associated with older age (59.7 % vs 77.8 % with more than 60 years), relapse (12.5 vs 29.6 %) and death (22.2 vs 46.7 %). The pattern of relapse was not different, with most being at extrapelvic sites (55.5 % vs 62.3 % for p53 wild type and aberrant, respectively). The median overall survival was not reached versus 92.2 months for p53 wild type and aberrant, respectively (p = 0.003). In multivariate analysis, chemotherapy decreased death (p = 0.014) in p53 aberrant tumours, a benefit not seen in the wild-type cohort (p = 0.22). CONCLUSION: This retrospective analysis corroborates the finding of worse outcomes for p53 aberrant tumours in stage I/II EC and the benefit of more aggressive adjuvant treatment (systemic therapy and radiotherapy). Although not ideal as a sole molecular marker, p53 immunohistochemistry could complement the classical anatomopathological features and be part of the decision-making process with patients in LMIC.