High ALDH-1 Expression Predicts Non-Complete Response of Radiotherapy in Stage III Squamous Cell Cervical Carcinoma Patients

Background: ALDH1 is a cervical cancer stem cell marker that has radioresistance profile. Recurrence and metastasis following radiotherapy are still being problems of most patients. This study aimed to determine the correlation between ALDH1 and radiotherapy response in stage III squamous cell cervical carcinoma (SCCC) of the cervix. Methods: A total 58 of 360 patients of stage III SCCC who received external beem radiation and brachytherapy (2016-2021) at Cipto Mangunkusumo Hospital met the eligibility criteria of this study. Pre and post-irradiation MRI examinations and ALDH expression with immunohistochemistry (Santa Cruz®) were performed on formalin-fixed paraffin-embedded of pre-treatment cervical tissue biopsy taken from RSCM pathological anatomy laboratory. Patients were divided into two groups, complete responders vs non-complete responders. ALDH-1 scores were compared between two groups to assess ALDH-1 expression. The statistical analyses were carried out by SPSS 24. Results: The optimal ALDH-1 score cut-off point on the radiation response was 166.05 pg/mL which was obtained from the analysis of the ROC curve. The AUC value was 0.682 with sensitivity and specificity, 63,6% and 64%, respectively. ALDH score ≥166.05 increased the risk by 3.127 times for not achieving complete response (adj OR 3.127, 95% CI 1.034 – 9.456, p = 0.043). Pre-radiation tumor size (p = 0.593), degree of differentiation (p = 0.161), renal abnormalities (p = 0.114), and keratinization (p = 0.477) were not associated with radiation response. Conclusions: High ALDH expression was associated with non-complete radiation response in stage III squamous cell cervical carcinoma.