The role of Schlafen 11 as a predictive biomarker in ovarian cancer patients treated with platinum-based chemotherapy – results of the pilot analysis


Klin Onkol 2023; 36(Suppl 1): 127-130. DOI: 10.48095/ccko2023S127.

Background: Schlafen 11 (SLFN11), a recently discovered nuclear protein, has been identified as a promising biomarker capable to predict the response to DNA damage-inducing agents across various cancer types. In this article, we present the results of the pilot SLFN11 immunohistochemical (IHC) analyses in ovarian cancer (OC) patients treated with platinum-based chemotherapy (P-CHT). Materials and methods: The retrospective cohort of 61 ovarian cancer patients treated with primary P-CHT at University Hospital Brno in 2010–2021 was identified from the clinical database based on predefined criteria. The IHC analyses of SLFN11 expression were performed on tumor samples collected before P-CHT initiation using monoclonal antibody SLFN11 (D-2), sc-515071 (Santa Cruz Biotechnology, Texas, USA). The slides were evaluated for SLFN11 expression in tumor cells by H-score (total score = 1× weak + 2× mean + 3× strong positivity) and as a percentage of positivity of any intensity. Results: From the whole cohort of 61 patients, a total of 30 patients had P-resistant disease with a median platinum-free interval (TFIp) of 5 months; the interquartile range (IQR) was 2–10 and 31 patients had P-sensitive disease with median TFIp 43 months (IQR 26–81). The stage at diagnosis, histological type, and extent of surgical cytoreduction were equally distributed in both cohorts. Except for one patient in the P-sensitive cohort, all tumor samples were evaluable for IHC SLFN11 analyses. SLFN11 expression was generally low in the entire cohort (H-score 10, 10% positivity). Neither statistically significant differences in SLFN11 expression between P-resistant and P-sensitive disease, nor the correlation with main prognostic factors (stage at diagnosis, objective response to primary treatment, TFIp, overall survival) were observed. Conclusion: With the methodology used in this pilot study, we failed to demonstrate any predictive or prognostic significance of the immunohistochemical SLFN11 evaluation in ovarian cancer patients treated with platinum-based chemotherapy.

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