International Experts Propose New Pediatric NHL Staging System

Details of a revised International Pediatric Non-Hodgkin Lymphoma Staging System (IPNHLSS) were published recently in the Journal of Clinical Oncology, with the expectation that this update will allow for more “precise staging” for children and adolescents with non-Hodgkin lymphoma (NHL).

According to the article, the St Jude staging system still used today to stage children and adolescents with NHL was developed in 1980 and does not incorporate many of the advances in knowledge acquired during the last 35 years.

“Stage is determined by the number and anatomic pattern of disease sites, their resectability, and involvement of marrow and the [central nervous system],” wrote Angelo Rosolen, MD, of the University of Padova, Italy, and colleagues. “Since the introduction of the St Jude staging system, the pathologic classification of NHL has changed significantly, and new subtypes of pediatric NHL have been identified, some of which display unique patterns of organ involvement, including mucosal sites, skin, bone, ovary, and kidney.”

In addition, more recent systems, such as the Ann Arbor and Lugano classification systems were developed without input from the pediatric oncology community, they wrote.

To develop this staging system, an international multidisciplinary expert panel was convened in Frankfurt, Germany in 2009 at the Third International Childhood, Adolescent, and Young Adult NHL Symposium. The panel reviewed evidence-based disease distribution and behavior from a variety of pediatric cooperative group studies of NHL.

The proposed new IPNLSS breaks down the disease into four stages:

• Stage I disease is defined as a single tumor with exclusion of mediastinum and abdomen.

• Stage II disease is a single extranodal tumor with regional node involvement, two or more nodal areas on the same side of the diaphragm, or primary gastrointestinal tract tumor with or without the involvement of associated mesenteric nodes, that is completely resectable.

• Stage III disease is two or more extranodal tumors above and/or below the diaphragm, two or more nodal areas above and below the diaphragm, intra-abdominal and retroperitoneal disease, including liver, spleen, kidney, and/or ovary localizations, regardless of degree of resection, with or without involvement of associated mesenteric nodes that is completely resectable, any paraspinal or epidural tumor, and a single bone lesion with concomitant involvement of extranodal and/or nonregional nodal sites.

• Stage IV disease is any of the stage I-III findings with initial involvement of the central nervous system, bone marrow, or both.

Additional staging information is also included in the system to help clinicians more closely analyze bone marrow and central nervous system involvement.

“For full clinical use of a staging system, we need to identify the objectives of the classification and the methodology and techniques used for staging,” the authors wrote. “A staging system is most valuable when it guarantees reproducibility over extended periods of time, is applicable to different subtypes of the disease of interest, and has relevance for prognosis and treatment stratification.”