Is melanoma mortality declining in Spain? Analysis of trends from 1975 to 2016

Dear Editor, Although melanoma mortality rates levelled off in several regions in the 1980s and 1990s, and even decreased in others,1 recent studies have found that melanoma mortality rates are increasing in Southern Europe.2 3 The melanoma mortality rate in Spain increased from 1975 to 2001.4 Examination of mortality trends by age group and birth cohort revealed less rapidly rising (men) or stabilizing (women) age‐adjusted melanoma mortality rates because of declining mortality in younger age groups and more recent birth cohorts.5 Herein, we update and refine earlier assessments of melanoma mortality rates in Spain from 1975 to 2016, using Joinpoint Regression models. For each of the sexes, from the matrices of certified deaths and resident populations obtained from official publications of the National Statistics Institute (http://www.ine.es), age‐specific and age‐standardized (Segi's world standard population) rates of melanoma were computed and expressed as rates per 100 000 population. Trends were analysed using Joinpoint Regression software with default settings.6 This helped to identify inflection points where a significant change in linear slope of the trend occurred. To quantify the trend over the whole period, we computed the average annual percentage change (AAPC) as a geometric weighted average of the annual percentage changes (APCs) from the Joinpoint model. We allowed a maximum of three Joinpoints and an associated P‐value < 0·05 represented the likelihood that the APC or AAPC was significantly different from zero. In describing the trend analysis results, the terms ‘increase’ or ‘decrease’ indicate statistical significance (P <0·05), whereas nonsignificant results are reported as ‘stable’. A pairwise comparison parallel test by Joinpoint software was used to compare trends by sex. In both sexes, the age‐standardized rate (ASR) increased from 1975 to 1993 (APC 7·2%; P <0·05), after which mortality rates levelled off (APC −0·03%; nonsignificant). Age‐adjusted (35–64 years) melanoma mortality rates increased steadily from 1975 to 1994 (APC 7·1%; P <0·05) and then decreased (APC −1·0%; P <0·05). Age group analysis (Table 1) revealed that for the entire study period, rates increased significantly in all those over the age of 30 years in both sexes. However, Joinpoint analysis made it possible to distinguish two periods (in all age groups except the 60–69‐year‐old age group): in the first, melanoma mortality rates increased; in the second, there were three different trends – a decrease in the age groups below the age of 50, a levelling off in those aged 50–59 years and an increase in those > 69 years of age (although this was more marked in men). The Joinpoint regression analysis identified three periods for the 60–69‐year‐old age group: in the first (1975–90) rates increased (APC 7·3%; P <0·05) and in the following two periods (1990–2003 and 2003–16) the rates slowed down (APC 2·8%; P <0·05) and even stabilized (APC −0·3; nonsignificant). Melanoma mortality trends in men and women were parallel (for 30–69‐year‐olds; P >0·05) or coincident (for those age < 30 years; P >0·05). In those aged 70–79 and 80+ years, the comparability test showed that the melanoma mortality trends in men and women were not parallel. Trend changes according to Joinpoint regression analysis AAPC, average annual percentage change; APC, annual percentage change; CR, crude rate; ASR, age‐standardized rate. aThe APC or AAPC is significantly different from 0 (P < 0·05). Trend changes according to Joinpoint regression analysis AAPC, average annual percentage change; APC, annual percentage change; CR, crude rate; ASR, age‐standardized rate. aThe APC or AAPC is significantly different from 0 (P < 0·05). In Spain (1975–2016), we confirmed that melanoma mortality rates rose dramatically from the mid‐1970s to the beginning of the 1990s, but we also found that ASRs are now levelling off (global) or decreasing (in 35–64‐year‐olds) in both sexes. After steady rises between 1960 and 1990, melanoma mortality rates among young adults have tended to decline since the mid‐1990s in several European countries, with a fall of 14% in men and of 11% in women. In middle‐aged adults, the trends were less favourable, although mortality started to level off in the mid‐1990s.7 In Spain, since the beginning of the 1990s ASRs decreased in all groups aged < 50 years, stabilized in people aged 50–69 and kept rising in those aged ≥ 70 years. In Spain, despite the increase in the incidence of melanoma, this increase has been accompanied by a marked improvement in the 5‐year survival rate over time.8 Poor clinical outcomes among elderly patients with melanoma can be explained by more advanced stages of the disease and additional factors, such as a dysfunctional immune response, the impact of frailty syndrome and comorbidities, as well as adverse variations in clinical management. In summary, the results presented here reveal a stable or falling melanoma mortality rate in those < 70 years of age in Spain. Modern standard treatments for patients with metastatic melanoma are well tolerated and have the same efficacy in elderly patients as in younger patients; we therefore may see a decrease in mortality in elderly patients.