Development and validation of a nomogram to predict overall survival in patients with External auditory canal cancer.

Aim: We aimed to examine the influence of various prognostic factors on the outcome of external auditory canal (EAC) cancer and create a graphical prediction tool, marking a first in this field, premised on these determinants.

Methods: We retrospectively analysed 173 patients with EAC cancer, making this the largest patient cohort in the literature. Survival analysis was performed using the Kaplan-Meier method, and the log-rank test was used to assess the differences between established prognostic variables. The risk factors for overall survival (OS) rates were analysed by univariate and multivariable Cox regression analyses.

Results: The cohort demonstrated 2-, 5-, and 10-year progression-free survival (PFS) rates of 86.9%, 72.7%, and 60.1%, respectively. The overall survival (OS) rates for the cohort at 2, 5, and 10-years were 93.6%, 80.6%, and 65.8%, respectively. The key predictors of both OS and PFS were squamous cell carcinoma, T stage, margin status, and radiotherapy. The nomogram showed good predictive accuracy and discriminative ability. Post-radiotherapy follow-up data indicated that the incidence rates of allotriogeustia, saprodontia, xerostomia, difficulty in opening the mouth, and facioplegia were 1.3%, 6.5%, 22.7%, 8.4%, and 3.2%, respectively.

Conclusion: Our findings highlight the significance of squamous cell carcinoma, T stage, margin status, and radiotherapy as predictors of OS and PFS. Validation analysis confirmed the applicability of the developed nomogram in predicting individual survival probabilities for patients with EAC cancers, signifying a notable progression in the diagnosis and treatment of EAC cancers.