Long-term outcomes of stage IIB-IV melanoma patients: nationwide data from Norway.

Aim: This study was performed to investigate the characteristics and overall survival (OS) of patients with completely resected stage IIB-IV cutaneous melanoma identified in the Cancer Registry of Norway. Methods: A retrospective cohort study of all adult patients with stage ≥IIB cutaneous melanoma was performed in Norway (January 2008 to December 2018), excluding patients with stage IV melanoma without evidence of surgery. Results: 5-year OS varied by stage (IIB 65%, IIC 38%, IIIA 79%, IIIB 66%, IIIC 52%, IIID 37% and IV 39%). Adjusted Cox models showed that stage IIIA and IIIB patients showed similar survival to stage IIB patients (hazard ratio [95% CI]: IIIA 0.67 [0.44-1.04]; IIIB 1.18 [0.96-1.45]), while all other stages had lower survival than IIB. Conclusion: Survival for stage II patients, particularly IIC, can be poor and in some cases worse than patients with more advanced stage melanoma. Our data highlight an unmet need for effective adjuvant treatment options among stage IIB/C patients.