High p53 protein expression as a risk factor for poor neoadjuvant paclitaxel-carboplatin chemotherapy response in stage IB3, IIA2, and IIB cervical cancer

Introduction: Expression of the p53 protein plays a critical role in the regulation of cell proliferation, apoptosis, and genomic stability, which has been implicated in chemoresistance in cervical cancer. This study aimed to evaluate high p53 expression is a risk factor for poor response to neoadjuvant paclitaxel-carboplatin chemotherapy in stage IB3, IIA2, and IIB cervical cancer. Methods: Nested case-control study at Prof. Dr. I G. N. G. Ngoerah General Hospital, Denpasar (October 2022-April 2023). Cases were FIGO 2018 IB3, IIA2, IIB patients with poor response by the response evaluation criteria in solid tumours (RECIST) 1.1 after three 3 to 4-weekly cycles of paclitaxel-carboplatin; controls received the same regimen with good response. p53 expression was assessed by immunohistochemistry (IHC). High p53 was defined by a semi-quantitative score >7. Association with response was tested using Pearson’s chi-square and expressed as odds ratios (OR) with 95% confidence intervals (CI) and p-value<0.05. Results: Fifty-six patients were analyzed (28 cases; 28 controls). Baseline characteristics (age, parity, body mass index (BMI), tumor size, histologic grade, histology) were comparable (p>0.05). High p53 expression occurred in 25/28 cases (89.3%) versus 10/28 controls (35.7%). High p53 was strongly associated with poor response (OR 8.33; 95% CI 3.60-62.39; p<0.001). Representative case sections showed strong nuclear staining in 50-95% of tumor cells; control sections showed 10-40% or absent staining. Conclusions: High p53 expression is a significant predictor of poor response to neoadjuvant paclitaxel-carboplatin in stage IB3-IIB cervical cancer. p53 immunohistochemistry may aid pre-treatment risk stratification and inform therapeutic planning.