1 period: limited to the primary organ, no metastasis;
Stage 2A: subtotal resection of unilateral tumor; There was no metastasis in ipsilateral and contralateral lymph nodes;
Stage 2B: subtotal or total resection of unilateral tumor; There is definite metastasis in ipsilateral lymph nodes, but no metastasis in contralateral lymph nodes.
Stage 3: the tumor invaded the midline with or without local lymph node metastasis; Or unilateral tumor with contralateral lymph node metastasis; Or the tumor grows across the midline with bilateral lymph node metastasis;
Stage 4: the tumor spreads to distant lymph nodes, bone marrow, liver or other organs (except those defined in stage 4S).
4S stage: children younger than 1 year; Tumors are confined to primary organs; Tumor spread is limited to liver, skin or bone marrow (tumor cells are less than 10% bone marrow nucleated cells).
Since 2005, several collaborative groups of children's tumor research around the world have started a retrospective comparative study of 8800 cases of neuroblastoma treated in Europe, Japan, the United States, Canada and Australia from 65438 to 0990 to 2002. According to the results of this retrospective study, neuroblastoma was reclassified according to the degree of risk (INRGSS). Retrospective study found that the prognosis of neuroblastoma children aged from12 to18 months was good. According to this, the new classification system reclassifies children without N-myc mutation for 12- 18 months from the previous high-risk group to the middle-risk group. The risk classification system is as follows:
L 1 phase: the focus is limited and there is no risk factor determined by imaging;
L2 stage: limited focus but risk factors determined by imaging;
M stage: focus metastasis;
MS stage: focus-specific metastasis (the same as the above 4S stage);
The new risk stratification system will divide neuroblastoma patients into extremely low risk group, low risk group, medium risk group and high risk group according to the new INRGSS staging system, onset age, tumor grade, N-myc amplification status, chromosome 1 1q unbalanced mutation and polymorphism factors.