Incidence of multiple myeloma in Olmsted County, Minnesota

The report by Kyle et al.1 updates trends in multiple myeloma incidence in Olmsted County, Minnesota, and indicates that the incidence of multiple myeloma has remained stable over the 56-year period considered (1945–2001). Likewise, in Malmö, Sweden, the incidence of multiple myeloma remained stable between 1950 and 1979.2 However, in several other cancer registration areas, trends in the incidence of multiple myeloma have been rising over the last few decades. Furthermore, mortality from myeloma has tended to rise steadily over the last few decades in the United States and across Europe. In the European Union, age-standardized (world standard) mortality from myeloma increased for men from 0.9 per 100,000 in 1960 to 2.2 per 100,000 in 2000 and from 0.7 per 100,000 to 1.5 per 100,000 for women.3 However, the upward trends were larger in the elderly4 and were not observed in several countries that originally had high mortality rates, such as Sweden, Denmark, the Netherlands, and Norway.3 The Swiss canton of Vaud is another population that can contribute toward addressing the issue of trends in multiple myeloma, because it long has been covered with optimal and uniform surveillance for lymphohemopoietic conditions.5 We analyzed trends in myeloma incidence over the period from 1978 to 1987 and found no appreciable change in rates.5 Here, we update incidence rates in the Vaud population to the year 2001. The Vaud cancer registry includes information concerning incident cases of malignant neoplasms occurring in the resident population of the Canton (≈ 640,000 inhabitants in 2000). The current series includes 674 patients who were diagnosed with multiple myeloma (341 males and 333 females) from 1978 to 2001. For men, the overall, age-standardized rates (world standard) were 3.6 per 100,000 in 1978–1982 (95% confidence interval [CI], 2.7–4.5 per 100,000) and 2.4 per 100,000 (95%CI, 1.7–3.1 per 100,000) in 1998–2001. The corresponding rates for women were 1.9 per 100,000 (95%CI, 1.3–2.4 per 100,000) and 2.1 per 100,000 (95%CI, 1.5–2.7 per 100,000). Among the population aged ≥ 65 years, multiple myeloma incidence rates for men were 27.7 per 100,000 in 1978–1982 and 18.8 per 100,000 in 1998–2001. For women, the corresponding rates were 15.4 per 100,000 and 18.0 per 100,000. The current data, together with those from Olmsted County,1 provide conclusive evidence that the incidence of multiple myeloma in well surveilled populations from different areas of the world has been constant for several decades. Therefore, the apparent upward trends in incidence in several other populations and the rises in mortality rates from most countries are artifactual and attributable to improved diagnosis and certification of the disease.1-3