Trends in net survival of patients with cutaneous melanoma in Japan, 2000-14 (CONCORD-3)

We assessed survival trends and international comparisons of patients with cutaneous melanoma from Japanese regional population-based cancer registries participating in the CONCORD-3 study.

Subjects were patients aged 15-99 years diagnosed with cutaneous melanoma during 2000-2014, with follow-up completed either 5 years after diagnosis or through 31 December 2014. Five-year net survival was estimated by morphological type and calendar period of diagnosis, using the Pohar Perme estimator, and age-standardized using the International Cancer Survival Standard weights.

Age-standardized 5-year net survival for cutaneous melanoma remained stable among 4018 eligible subjects as follows: 68.9% during 2000-2004 (862 patients), 68.3% during 2005-2009 (1819 patients), and 69.0% during 2010-2014 (1337 patients). Five-year net survival in 2010-2014 was highest for lentigo maligna melanoma (89.0%, 64 patients, not age-standardized), followed by superficial spreading melanoma (88.4%, 91 patients) and acral lentiginous melanoma (83.7%, 163 patients, not age-standardized). However, survival for malignant melanoma not otherwise specified (68.0%, 1120 patients) and nodular melanoma was lower (56.5%, 58 patients). Five-year net survival for all types of cutaneous melanoma combined during 2010-2014 was lower in Japan (69.0%) and South Korea (59.9%) than in Australia, France, Germany, Italy, UK, Canada and the US (>85.7%).

International disparities in net survival for cutaneous melanoma may be attributable to differences in the distribution of histological sub-types of melanoma and to variation in the availability and utilization of treatment modalities. Continuous monitoring of cancer survival is crucial for developing effective cancer control strategies.