Recent findings show that after the institution of the 7th edition of AJCC Cancer Staging Manual (AJCC 7), there was an overall decrease in the number of T1 melanomas (Breslow depth ≤1.0 mm) undergoing nodal biopsy without a clinically relevant change in sentinel lymph node positivity, with an increase in the number of T1b melanomas (0.8mm – 2.0mm thick, without ulceration or <0.8mm – 1.0mm thick, with ulceration) undergoing nodal evaluation. Researchers conducted a cross-sectional study from 2004 through 2013 of all adults (aged ≥18 years) diagnosed with a T1 melanoma using The National Cancer Database that captures 70% of all newly diagnosed cancers from accredited Commission on Cancer organizations. 141,280 patients met inclusion criteria. They found:
- After 2010, there was a 3.8% decrease in the number of nodal surgeries performed (32,485 of 86,846 patients [37.6%] vs 18,379 of 54,434 patients [33.8%]).
- The nodal positivity rate decreased 1.0% from 9.8% (3,166 of 86,846) to 8.8% (1,618 of 54,434).
- An increase was seen in the proportion of T1b melanomas being evaluated, from 48.8% to 62.2%.
Isom C, Wheless L, Hooks MA, Kauffmann RM. Early melanoma nodal positivity and biopsy rates before and after implementation of the 7th Edition of the AJCC Cancer Staging Manual. [Published online ahead of print March 6, 2019]. JAMA Dermatol. doi:10.1001/jamadermatol.2018.5902.
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Melanoma Rates Before and After AJCC 7 Enactment, JAMA Dermatol; ePub 2019 Mar 6; Isom, et al
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Sentinel Lymph Node Positivity Markers in Melanoma, J Am Acad Dermatol; ePub 2018 Sep 18; Conic, et al
Recurrent Morphological Patterns in Melanomas, J Am Acad Dermatol; ePub Aug 27; Klebanov, et al