Outcomes of the Nigro Protocol in the Treatment of Anal Cancer

The Nigro protocol marked a turning point in the treatment of anal cancer. Developed in 1974 by Dr. Norman Nigro, this therapeutic approach combined chemotherapy (5-fluorouracil and mitomycin C) with external beam radiation therapy as the primary treatment—challenging the traditional standard of radical surgery.

The original study included 30 patients diagnosed with anal canal cancer, all of whom received this combined treatment. Remarkably, a significant number of patients achieved complete tumor remission without the need for surgical intervention. Over the years, various studies have confirmed these outcomes, solidifying the Nigro protocol as the foundation of non-surgical treatment for this disease.

Five-year survival curves from subsequent studies have shown local control rates exceeding 70% and overall survival rates approaching 80%, particularly in early-stage cases. Radiation Oncology has played a central role in achieving these outcomes, providing effective treatment while preserving the anatomy and function of the anus—greatly enhancing patients’ quality of life.

In terms of side effects, acute toxicities such as skin irritation in the treatment area, fatigue, and gastrointestinal symptoms have been commonly reported, though these are generally temporary. Long-term side effects, which are less frequent, may include anal stenosis or bowel dysfunction, depending on the radiation dose and treatment area.

Compared to other regimens, such as those using capecitabine instead of 5-FU, or intensified radiation strategies, the Nigro protocol remains highly effective and well-tolerated. It continues to be widely endorsed in international clinical guidelines and is a standard of care in oncology centers across Costa Rica.

Dr. Rolando Loría, a Radiation Oncologist in Costa Rica, emphasizes the relevance of the Nigro protocol as the first-line treatment for most cases of anal cancer. On his website, www.drrolandoloria.com, Dr. Loría provides updated and reliable information on this and other cancer treatments, helping patients and families make informed decisions.

This approach has not only transformed the management of anal cancer but also ensured the preservation of patient dignity and function—core goals of modern medicine.