Anal Cancer and Retrorectal Tumors

Tumors and neoplasms of the anal canal, perianal region, and pelvis have historically been some of the most difficult diagnostic and management problems encountered by specialists in this area, as well as the patients affected by these diseases. Surgeons have come a long way from the generalized use of extensive surgical extirpative procedures, with the attendant morbidity, recurrence risk, and loss of function, to the specific management choices now available. This refinement of treatment is often traced back to the work of Dr. Norman Nigro and his colleagues, regarding the use of combined chemotherapy and radiation as primary therapy for anal cancers. Since that seminal breakthrough, clinical and laboratory investigators have continued to expand current knowledge regarding tumors and neoplasms of the anal canal, perianal region, and pelvis in pursuit of more specific methods for diagnosis and therapy, endeavoring to gain the best tumor-related outcome while maintaining the best possible quality of life for patients living with these diseases. Although these diseases are often managed by a multidisciplinary group of specialists, colorectal surgeons remain the keystone of the team, providing surgical and imaging diagnostic procedures, often directing or performing the bulk of the treatment plan, and providing surveillance physical examinations.

As evidenced by the contributors to this issue of Clinics in Colon and Rectal Surgery, colorectal surgeons also maintain an active and influential presence in clinical and laboratory investigations into tumors and neoplasms of the anal canal, perianal region, and pelvis. The authors in this issue include many who are leaders in their field. As Guest Editor, it has been my distinct honor and pleasure to work with them.

Drs. Jennifer Blumetti and Amir L. Bastawrous discuss current therapy, outcomes, and complications of epidermoid cancers of the anal canal, and touch upon advances to minimize morbidity of treatment. The problem of persistent or recurrent disease and salvage therapies is explored, stressing the proper selection of patients for salvage therapy.

Drs. Imran Hassan and E. Dawn Wietfeldt discuss retrorectal tumors. This is a heterogeneous group of lesions, and gaining the best outcome is overwhelmingly dependent on choosing the correct initial approach for diagnosis and treatment. The authors present evidence-based guidelines for the management of these tumors.

Drs. Carlos Pineda and Mark Welton tackle the controversial subject of anal intraepithelial neoplasia. Their article underscores the tremendous amount of progress that has been made in understanding AIN, and also the tremendous amount of knowledge yet to be gained in this insidious presentation of anal neoplastic change.

Dr. Deborah Nagle has done considerable investigation into anal cancer in the HIV-positive population, and provides an updated treatise dealing with this subset of anal cancer patients. She clarifies the risks of this population, discusses treatment, and explains why the incidence of anal cancer in this population is expected to increase.

Dr. Elizabeth Peralta presents an in-depth discussion of gastrointestinal stromal tumors (GIST), rectal carcinoid, and anorectal lymphoma. The current data regarding diagnosis and management will help guide colorectal specialists when managing these rare lesions.

Drs. Sherjeel Sana and Aziz Khan provide an overview of recently completed and ongoing clinical trials in anal cancer, including trials specific for HIV-associated anal cancers. The rationale behind trial design is discussed, allowing the reader to follow the development of clinical thought in this area.

Drs. David Row and Martin Weiser provide a thoughtful and thorough review of anorectal melanoma. New appreciation of tumor behavior and long-term outcomes has engendered important changes in the management of this rare anal neoplasm.

Drs. E. Dawn Wietfeldt and James Thiele review diagnosis and management of cancers of the anal margin. They stress the roles of thorough diagnostic maneuvers and selection of best treatment based on patient criteria.