Background: We determined the relative contribution of decreased tumour thickness to the favourable trend in survival from cutaneous malignant melanoma (CMM) in Italy. Methods: Eleven local cancer registries covering a population of 8 056 608 (13.4% of the Italian population in 2010) provided the records of primary CMM cases registered between 2003 and 2017. Age standardized 5-year net survival (NS) was calculated. Multivariate analysis of 5-year NS was done by calculating the relative excess risk of death (RER). The relative contribution of the decrease in tumour thickness to the RER was evaluated using a forward stepwise flexible parametric survival model including the available prognostic factors. Results: Over the study period, tumour thickness was inversely associated with 5-year NS and multivariate RER in both sexes. The median thickness was 0.90 mm in 2003-2007, 0.85 mm in 2008-2012 and 0.75 mm in 2013-2017 among men, and 0.78 mm, 0.77 mm and 0.68 mm among women, respectively. The 5-year NS was 86.8%, 89.2% and 93.2% (men), and 91.4%, 92.0%, and 93.4% (women). In 2013-2017, thus, men exhibited the same survival as women despite still having thicker lesions. For them, the increasing survival trend was more pronounced with increasing thickness, and the inclusion of thickness into the forward stepwise model made the RER in 2013-2017 versus 2003-2007 to increase from 0.64 (95% confidence interval, 0.51-0.80) to 0.70 (0.57-0.86). This indicates that thickness trend accounted for less than 20% of the survival increase. For women, the results were not significant but, with multiple imputation of missing thickness values, the RER rose from 0.74 (0.58-0.93) to 0.82 (0.66-1.02). Conclusions: Especially for men, the decrease in tumour thickness accounted for a lesser part of the improvement in survival observed in 2013-2017. The introduction of targeted therapies and immune checkpoint inhibitors in 2013 is most likely to account for the remaining component.
The relative contribution of the decreasing tumour thickness trend to the 2010s increase in net survival from cutaneous malignant melanoma in Italy: a population-based investigation
Villani, Simona;
2022-01-01
Abstract
Background: We determined the relative contribution of decreased tumour thickness to the favourable trend in survival from cutaneous malignant melanoma (CMM) in Italy. Methods: Eleven local cancer registries covering a population of 8 056 608 (13.4% of the Italian population in 2010) provided the records of primary CMM cases registered between 2003 and 2017. Age standardized 5-year net survival (NS) was calculated. Multivariate analysis of 5-year NS was done by calculating the relative excess risk of death (RER). The relative contribution of the decrease in tumour thickness to the RER was evaluated using a forward stepwise flexible parametric survival model including the available prognostic factors. Results: Over the study period, tumour thickness was inversely associated with 5-year NS and multivariate RER in both sexes. The median thickness was 0.90 mm in 2003-2007, 0.85 mm in 2008-2012 and 0.75 mm in 2013-2017 among men, and 0.78 mm, 0.77 mm and 0.68 mm among women, respectively. The 5-year NS was 86.8%, 89.2% and 93.2% (men), and 91.4%, 92.0%, and 93.4% (women). In 2013-2017, thus, men exhibited the same survival as women despite still having thicker lesions. For them, the increasing survival trend was more pronounced with increasing thickness, and the inclusion of thickness into the forward stepwise model made the RER in 2013-2017 versus 2003-2007 to increase from 0.64 (95% confidence interval, 0.51-0.80) to 0.70 (0.57-0.86). This indicates that thickness trend accounted for less than 20% of the survival increase. For women, the results were not significant but, with multiple imputation of missing thickness values, the RER rose from 0.74 (0.58-0.93) to 0.82 (0.66-1.02). Conclusions: Especially for men, the decrease in tumour thickness accounted for a lesser part of the improvement in survival observed in 2013-2017. The introduction of targeted therapies and immune checkpoint inhibitors in 2013 is most likely to account for the remaining component.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
