Penile Cancer: Innovations in Ultrastructural and Vibrational Markers

Penile cancer (PCa) is a disease that manifests predominantly as squamous cell carcinomas (SCCs), which, although rare, represents a significant public health problem, especially in regions with less socioeconomic development. One of the biggest challenges in managing this disease is the difficulty in differentiating tumor subtypes, making accurate diagnosis and treatment challenging. In this context, new characterization techniques are needed to investigate these tumors more completely. Atomic force microscopy (AFM) and Raman spectroscopy (RS) are valuable in this context, providing quantitative and qualitative ultrastructural data and vibrational signatures of the analyzed samples. In this study, AFM and RS techniques were employed to investigate subtypes of penile cancer, including the highly aggressive basaloid subtype, which is closely associated with human papillomavirus (HPV), and the sarcomatoid subtype, comparing them with nontumorous tissues. The AFM results revealed nanoscale changes in the ultrastructural properties of tumor samples, such as increased roughness in tumor tissues, with emphasis on the basaloid type associated with the HPV virus, and reduction in the surface area and volume of tumor tissues at the nanoscale, suggesting deeper tissue infiltration and greater deformability of tumor samples at the nanoscale. RS results detected significant spectral differences between normal and cancerous tissues and between tumor subtypes, particularly in vibrational modes related to proteins and lipids. Principal component analysis (PCA) confirmed a strong discriminative power between control and PCa groups. The data presented here offers new insights into the characteristics of penile tumors that, when integrated with clinical analyses, could improve the understanding of penile cancer behavior, contributing to more accurate diagnostic methods and targeted treatments.