Melanoma-specific survival rates in the Central Malignant Melanoma Registry (CMMR) and European Organization for Research and Treatment of Cancer (EORTC) stage III data sets are less favorable than those published in the American Joint Committee on Cancer version 8 (AJCCv8), according to an original report published in the Journal of Clinical Oncology (online June 12, 2020; doi:10.1200/JCO.19.03034).
Two immunotherapies and one targeted therapy for adjuvant treatment of stage III melanoma were approved in 2018 in Europe and the US on the basis of improved relapse-free, distant metastases-free, and overall survival benefits. According to the AJCCv8 classification, the prognosis of patients with stage III melanoma—especially those with stage IIIA and IIIB disease—is favorable.
Claus Garbe, MD, Eberhard Karls University of Tuebingen (Germany), and colleagues examined three independent cohorts of patients with stage III melanoma to clarify the survival probabilities of such patients. The CMMR evaluated 1553 patients with a melanoma primary diagnosis from 2000 to 2012. The 18891 and 18071 studies from the EORTC included 573 patients in an observation arm and 445 patients in a placebo arm, respectively, as reference cohorts.
Melanoma-specific survival outcomes from these data sets were compared with the published AJCCv8 stage III survival data.
When comparing the CMMR stage III cohort vs the AJCCv8 cohort, researchers found the melanoma-specific survival rates at 5 years were 67% and 77%, respectively. At 10 years, the rates were 56% and 69%, respectively.
For stage IIIA, the melanoma-specific survival rates at 5 years were 80% and 93%, respectively. At 10 years, the rates were 71% and 88%, respectively.
For stage IIIB, the melanoma-specific survival rates at 5 years were 75% and 83%, respectively. At 10 years, the rates were 61% and 77%, respectively.
Additionally, Dr Garbe and colleagues noted that the melanoma-specific survival rates from the EORTC studies either overlapped with or were lower than the CMMR data.
“The melanoma-specific survival rates in the CMMR and EORTC cohorts over the entire stage III are less favorable than those published in AJCCv8,” authors of the study concluded, adding that this trend is particularly true for stage IIIA and IIIB disease. “The difference shown here should be taken into account in clinical decision-making (eg, on initiation of adjuvant therapy) and in the planning of clinical trials.”—Zachary Bessette
