Anal cancer and immunotherapy—are we there yet?

Anal cancer is a rare malignancy. An estimated 48,541 new cases were diagnosed in 2018, comprising 0.3% of all worldwide cancer diagnoses (1). The incidence of anal cancer has been increasing over the past 30 years (2). Squamous cell carcinoma of the anal canal (SCCA) is associated with HPV infection and is the most common histologic type of anal cancer.