International Neuroblastoma Staging System (INSS)

Staging

Staging is the process of finding out how far a cancer has spread. The prognosis for people with cancer depends, to a large extent, on the cancer’s stage. The stage of a cancer is one of the most important factors in choosing treatment.

The stage of the neuroblastoma is based on results of physical exams, imaging tests, and biopsies of the main tumor and other tissues, which were described in the section.

Since the mid-1990s, most cancer centers have used the INSS to stage neuroblastoma. In simplified form, the stages are:

Stage 1: Localized tumor with complete gross excision, with or without microscopic residual disease; representative ipsilateral lymph nodes negative for tumor microscopically (i.e., nodes attached to and removed with the primary tumor may be positive).

Stage 2A: Localized tumor with incomplete gross excision; representative ipsilateral nonadherent lymph nodes negative for tumor microscopically.

Stage 2B: Localized tumor with or without complete gross excision, with ipsilateral nonadherent lymph nodes positive for tumor. Enlarged contralateral lymph nodes must be negative microscopically.

Stage 3: Unresectable unilateral tumor infiltrating across the midline, with or without regional lymph node involvement; or localized unilateral tumor with contralateral regional lymph node involvement; or midline tumor with bilateral extension by infiltration (unresectable) or by lymph node involvement. The midline is defined as the vertebral column. Tumors originating on one side and crossing the midline must infiltrate to or beyond the opposite side of the vertebral column.

Stage 4: Any primary tumor with dissemination to distant lymph nodes, bone, bone marrow, liver, skin, and/or other organs, except as defined for stage 4S.

Stage 4S(also called “special” neuroblastoma): Localized primary tumor, as defined for stage 1, 2A, or 2B, with dissemination limited to skin, liver, and/or bone marrow (by definition limited to infants younger than 12 months). Marrow involvement should be minimal (i.e., <10% of total nucleated cells identified as malignant by bone biopsy or by bone marrow aspirate). More extensive bone marrow involvement would be considered stage 4 disease. The results of the MIBG (metaiodobenzylguanidine) scan, if performed, should be negative for disease in the bone marrow.

Recurrent: While not formally part of the staging system, this term is used to describe cancer that has come back (recurred) after it has been treated. The cancer may come back in the area where it first started or in another part of the body.

Дата добавления: 2014-10-15