Recent findings show that after the institution of the 7^th 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%.