Anal Intraepithelial Neoplasia and Squamous Cell Cancer of the Anus: Past, Present, and Future

Fia Yi, MD, FACS, FASCRS

The social stigma of diseases of the anus have plagued patients and providers in what can often be a fine balance in respecting the sensitivities of a part of the body not normally discussed or even examined on a routine basis. No other disease process has been tied to a social and medical revolution like anal intraepithelial neoplasia (AIN) and its relationship with squamous cell cancer of the anus; no other disease has required the intense cooperative effort across different specialties.

Patients afflicted with the once terminal diagnosis of AIDS were beginning to live full lives with the development of highly active antiretroviral therapy. As they began to live longer, the medical community began to witness increased incidences in what was once thought to be uncommon maladies. Infectious disease specialists were among the first to investigate and trail blaze the efforts in identifying the precursor of AIN. Coordination with pathology and colorectal surgeons has led to a multidisciplinary approach that continues to evolve today.

The effort at diagnosing and treating this condition is based on the now accepted theory that AIN is a precursor lesion to squamous cell cancer of the anus similar to cervical intraepithelial neoplasia. Since the inception of high-resolution anoscopy and rudimentary guidelines for screening at-risk populations, the literature continues to grow.

In an effort to keep the readers abreast of the ever-evolving literature, we present a volume reviewing the past, present, and future in the treatment of AIN and squamous cell cancer of the anus.

I would like to thank all of my contributors who have taken on the additional task of formulating their own theories based on their breadth of experience, on the directions where the treatment of both disease processes will go in the future. I draw this inspiration from Dr. Scott Steele who has always expected no less than the best and motivates colleagues alike to continue to push the envelope and never be complacent. I thank him for this opportunity to present what I hope will not only educate but also inspire the readership to contribute to this ever-evolving part of our practice as colorectal surgeons.