Moderator: Catherine Bollard, MD, FRACP, FRCPA1
Discussants: Mitchell S. Cairo, MD2; Eric J. Lowe, MD3; Thomas G. Gross, MD, PhD4
Address for correspondence: Catherine Bollard, MD, FRACP, FRCPA, 111 Michigan Avenue, NW, 5th Floor Main, Suite 5225, Washington, DC 20010
E-mail: cbollard@cnmc.org
Biographical sketch: From The George Washington University, School of Medicine and Health Sciences, Washington, DC1; Westchester Medical Center, New York Medical College, Valhalla, NY2; Children’s Hospital of the King’s Daughters, Norfolk, VA3; Center for Global Health at the National Cancer Institute, Rockville, MD
DR. BOLLARD: My name is Dr. Catherine Bollard. I'm Chief of the Division of Allergy and Immunology at Children's National Health System and the Chair of the NHL Committee of the Children's Oncology Group. I hope that today we can provide some clarity and give you some of our first-hand expertise and experience regarding some of the challenges and controversies of treating pediatric patients with non-Hodgkin lymphoma (NHL). Here with me are Drs. Mitchell Cairo, Chief of Pediatric Hematology/Oncology and Stem Cell Transplantation at New York Medical College in the Maria Fareri Children's Hospital, Westchester Medical Center; Eric Lowe, Division Director for Pediatric Hematology/Oncology at the Children's Hospital of the King's Daughters; and Thomas Gross, Deputy Director for Science at the Center for Global Health at the National Cancer Institute.
I'd like to start the questioning, firstly to Dr. Cairo, who recently published with a group of leaders in the pediatric lymphoma field, new staging and response classifications. Dr. Cairo, I’d like you to highlight how these are different from the current classifications, and what you see are the strengths and the limitations at this time.
DR. CAIRO: Thank you, Cath. The original staging classification was developed in the late 1970s by Dr. Murphy while she was at St. Jude's hospital, and either goes by the name the Murphy Staging Classification or the St. Jude's Classification. That classification I think was quite useful at that time when we recognized really only a couple subtypes of NHL, as well as the capabilities we had in those days both imaging as well as further molecular identification as well as trying to identify sites of spread. As some 35 years have evolved, new pathological entities have been identified, much more precise imaging techniques, new methods of detecting more evidence of minimal disease, and also identifying new organ sites of involvement, allowed the creation of a multidisciplinary international task force to look at how we could enhance the original observations by the St. Jude's group.
As Dr. Bollard pointed out, we eventually, over 9 years of evidence-based review, came up with an enhanced staging classification called the International Pediatric NHL Staging System (IPNHLSS).1 In this new system we account for new histological subtypes, allow for different organ distributions, improve on the new imaging techniques to identify areas of involvement, and also to more molecularly identify extent of disease. I think the advantages are stated above. The disadvantage is that like all staging systems it's a breathing document. It will require international collaboration. As time evolves, this staging system will of course need to be updated as we gain new experience.
Briefly, in terms of the response classification that also came out of the same international multidisciplinary task force that was led by Dr. Sandlund at St. Jude's2; there had never been a response criteria that had been focused entirely in childhood and adolescent NHL. The previous response criteria had been developed by adult NHL investigators, and there was a need to develop the first response criteria for pediatric NHL because of different histologies, different sites of sanctuary disease, and now obviously enhanced imaging capabilities. That also now has been named the International Pediatric Non-Hodgkin Lymphoma Response Criteria (IPNHLRC)—hopefully for harmonizing a response across new studies, but also a breathing document that is going to be limited as we gain new knowledge into how we can better assess response as new techniques are developed.