Stage III melanoma incidence and impact of transitioning to the 8th AJCC staging system: a US population-based study

Aim: To estimate incidence of stage III melanoma using the American Joint Committee on Cancer (AJCC) staging, 7th and 8th edition. Patients & methods: The SEER US cancer registry was analyzed (2010–2014). AJCC7 stages were recorded in the data; AJCC8 stages were inferred. Results: Of 106,195 melanoma patients, 7669 and 7342 had stage III melanoma by AJCC7 and AJCC8, respectively (95% overlap). Nearly 30% of patients with AJCC7 stage III melanoma were reclassified in a higher stage III group by AJCC8 versus 7% in lower stage group. Regardless of the AJCC edition, incidence of stage III melanoma has increased from 2010 to 2014 both overall and within each stage III group. Conclusion: Providing appropriate management to this growing population of high-risk patients is a priority.