evolution of the staging system The key new features of the current 2002 AJCC staging system when compared with the previous 1997 system include the following: (a) tumour thickness rather than level of invasion as a primary determinant for staging; (b) ulceration of the primary tumour as a highly significant and independent negative prognostic factor; (c) grouping together satellite and in-transit metastases as manifestations of lymphatic involvement rather than as an extension of the primary tumour; (d) number of lymph node metastases as a more reliable and reproducible predictor of prognosis than the
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