The American Society for Radiation Oncology (ASTRO) issued its first clinical guidance on radiation therapy as a treatment for patients with primary squamous cell carcinoma (SCC) of the anal canal and margin.
Brian Czito, MD, co-director of the Duke Cancer Institute’s Gastrointestinal Cancer disease group, chaired the task force that led to this guideline.
A relatively uncommon malignancy, anal cancer is primarily localized and tends to have a low propensity to metastasize. However, incidence and mortality rates for anal cancer have consistently increased in recent years, especially among adults older than 50.
Historically, treatment involved radical surgery and permanent colostomy placement, but the current standard of care involves radiation combined with drug therapies, allowing many patients to avoid colostomies.
While there has been generalized guidance around radiation therapy, no official recommendations have been issued before this ASTRO guidance.
“Radiation is the backbone for anal cancer treatment,” Czito said. “These treatments can be hard on patients, but they are generally effective and often lead to this type of localized anal cancer being curable.”
Key recommendations issued in the new guidance include specific outlines for radiation therapy and drug combinations, relative indication for diversion surgery – or surgery that re-routes part of the body’s waste pathways – as well as highly selected situations where surgical tumor removal may be indicated.
Specific recommendations surrounding the use of intensity-modulated radiation therapy (IMRT) are also included in the guidance. This approach has now replaced three-dimensional conformal radiation therapy (3D-CRT), which is generally considered more disruptive to surrounding healthy tissue. Specific guidance is given surrounding ongoing monitoring of these patients following completion of chemoradiation.
In addition to the U.S., these guidelines have also been endorsed by similar organizations in Europe, Australia and New Zealand. Czito said the ultimate hope is that these will become parameters by which oncologists worldwide will operate.
Czito and his team plan to continue researching anal cancer treatments to find further enhancements in care, including increasing or decreasing the amount of radiation used in treatment of individual situations, modifying therapies during treatment based on response, determining the role immunotherapy plays in these patients and analyzing how circulating DNA could be used to guide therapies. The hope is to revisit these guidelines in two years to determine if adjustments should be recommended.
“These new guidelines will help optimize treatment for anal cancer patients,” Czito said. “Our hope is that they will help guide and refine treatment to not only increase cure rates but also minimize morbidity.”
