Increases in Melanoma Incidence and Mortality Unremitting Over 6 Decades, Study Finds
In a study reported in Journal of Clinical Oncology, Alan C. Geller, MPH, RN, of the Harvard School of Public Health, and colleagues assessed long-term trends in the incidence and mortality of melanoma in Connecticut, a state with complete and consistent tumor registration. They found “unremitting” increases in incidence and mortality across 6 decades.
The study used data from the Connecticut Tumor Registry, the original National Cancer Institute Surveillance Epidemiology and End Results site, to determine trends in invasive melanoma (1950-2007), in situ melanoma (1973-2007), tumor thickness (1993-2007), mortality (1950-2007), and mortality to incidence ratio (1950-2007) among 19,973 white Connecticut residents diagnosed with invasive melanoma (1950-2007) and 3,635 and who died from melanoma (1950-2007).
Incidence Rates Over Time
Women accounted for 58% of cases in 1950, whereas men accounted for 56% of cases by 2007. Median age at diagnosis increased from 53 years in men and 52 years in women in 1950 to 65 years in men and 58 years in women in 2007.
In the initial period of 1950 to 1954, there were 1.9 cases of melanoma per 100,000 men and 2.6 per 100,000 women. Between 1950 and 2007, overall incidence rates rose more than 17-fold in men, to 33.5 per 100,000, and more than 9-fold in women, to 25.3 per 100,000. The average annual increase in incidence over this period was 0.6 per 100,000 in men and 0.4 per 100,000 in women; the rate of increase rose steadily until the last decade, when the increase accelerated to 0.8 per 100,000 in men and 0.6 per 100,000 in women.
This trend was particularly evident in middle-age and older people. After age 50 years, rates for men in all age groups increased more than 20-fold, including a 45-fold increase in men aged 65 to 69 years. From the 1950s to 1970s, incidence rates were relatively consistent for younger vs older individuals. A shift toward onset at middle and older age was noted by the mid-1980s, particularly in men. By 2003 to 2007, diagnoses among men aged ≥ 50 years were nearly 4 times more common than among younger men.
Since 1973, the rate of increase in incidence of in situ melanoma has increased, with the greatest increase observed in the most recent decade. Among persons aged ≥ 50 years, the ratio of in situ melanoma to invasive melanoma increased from 0.36 to 0.66 in men and from 0.54 to 1.05 in women. Since the mid-1970s, the proportion of melanomas on the head and neck and upper limbs and shoulders has increased slightly and the proportion on the trunk has remained basically unchanged. The proportion of melanomas of ≥ 2.01 mm in thickness decreased from 12.8% in 1993 to 1997 to 11.3% in 2003 to 2007 and the proportion of melanomas of < 1.00 mm in thickness increased from 72.7% to 75.1% between these two time periods when excluding melanomas with unknown thickness.
Mortality
For the overall study period, melanoma deaths were more common in men (58%) than women (42%) and increased more steeply over time in men. Women had steady increases in melanoma mortality of approximately 0.01 to 0.02 per 100,000 per year, whereas mortality in men increased by 0.05 to 0.06 per 100,000 per year until 1993, when it increased to 0.11 per 100,000 per year. From the period 1950 to 1954 to the period 2003 to 2007, mortality rates in middle-aged and older persons doubled in women, from 1.3 to 2.6 per 100,000, and tripled in men, from 1.6 to 4.9 per 100,000). The median age at melanoma death increased from 55 years in men and 58 years in women in 1950 to 1954 to 72 years in men and 70.5 years in women in 2003 to 2007. Across the study period, mortality rates were generally stable or decreased in men and women aged < 55 years and increased in older persons, with men aged ≥ 65 exhibiting a 6-fold increase in mortality. No deaths from melanoma were observed in women aged < 45 years or men aged < 40 years in 2003 to 2007.
Mortality-Incidence Ratio
The ratio of melanoma deaths to patient cases decreased steadily over the study period, from 1 death per 1.5 cases in 1950 to 1954, to 1 death per 7.8 cases in 2003 to 2007. In this latter period, there was 1 death per 4.9 patient cases in men aged 70 to 74 years and 1 death per 5.4 cases in men aged 75 to 79 years. For persons aged 45 to 49 years, there was 1 death per 14.2 cases in men and per 12.0 cases in women.
The investigators concluded: “Unremitting increases in incidence and mortality of melanoma call for a nationally coordinated effort to encourage and promote innovative prevention and early-detection efforts.”
The Connecticut Tumor Registry is supported by a contract between the National Cancer Institute and State of Connecticut Department of Public Health.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
