Immunotherapy in Penile Cancer: A Systematic Review

Penile cancer (PeCa) ranks as the 30th most prevalent cancer globally, predominantly affecting populations in developing countries. Phimosis and Human Papillomavirus (HPV) infection are recognized as the primary risk factors. Early-stage diagnosis typically warrants limited excision or non-invasive therapies. However, recent research into the carcinogenesis, tumour microenvironment, and the role of the host immune system in its development suggests that immunotherapy could be a promising treatment for PeCa. The rarity of the disease, combined with the success of standard treatments and the fact that many patients in clinical trials lack alternative options, contributes to the challenges in patient recruitment for these studies. Additionally, the psychological burden stemming from the stigma associated with such an aggressive genital disease and the preference for quicker treatment options, such as surgery with reconstructive procedures, exacerbates these recruitment difficulties. This systematic review aimed to explore various immunotherapy approaches in treating PeCa to elucidate the potential role of immunotherapy in this context. The literature was sourced from freely accessible, full-text randomized controlled trials, non-randomized controlled trials, and original articles published in English between 2017 and 2023. Eligible clinical trials were required to be in phase 2 and have published results. Although only one study met the inclusion criteria-a significant limitation-the objective response rate recorded was 6% across nineteen patients with different tumour histologies, of which only six had PeCa. Currently, other studies are either recruiting or ongoing, necessitating further observation, as results from a single study cannot be generalized to the broader population.