In Italy AIRTUM presented comprehensive epidemiological data
In Italy, AIRTUM presented comprehensive epidemiological data about the incidence (and prevalence) of STS and the associated survival of those affected . The distribution of cancer registries in Italy covers most of the regions where expert centres are available, other than Bologna. In addition, the AIRTUM cancer registries cover only 52% of the Italian population. Nevertheless, a total of 4072 new cases of STS was estimated for the entire country in 2015. Thus, STS accounted for ≈80% of all sarcomas (4072 of 4957), with the remainder being 499 cases of bone sarcoma and 386 cases of GIST, although the incidence of GIST is likely an underestimate. Crude incidence rates (CIR; the number of all new STS occurring in 2000–2010 divided by the overall Thymoquinone at risk) for STS according to anatomic localisation are shown in Table 2 and ICD-O-3 topography and morphology codes for AIRTUM  and RARECAREnet  are provided in a Supplementary table. An important limitation is that AIRTUM did not provide incidence data according to STS histological subtype, as this was not the purpose of the AIRTUM report. Such data are now urgently needed in the field of STS research. However, concerns have been raised about the accurate registration of STS and other rare cancers in cancer registries, primarily related to the need for correct morphologic specification which depends on the pathological diagnosis and how it is reported in the pathological report [6,15]. For example, when a morphology code is unspecified, usually due to genuine difficulties for the pathologist in assigning a specific morphologic category, it is not possible to assign the case to a specific rare cancer entity defined based on the morphology, resulting in an underestimation of the incidence for that entity . The overall incidence of STS in the AIRTUM population was 6.27 per 100,000 per year. The incidence in women (6.58 per 100,000 per year) was slightly greater than that in men (5.95 per 100,000 per year) because of gynaecological sarcomas (most often occurring in the uterus) and breast sarcomas. Among STS overall, the most frequently affected sites were limbs (1.27 per 100,000 per year), skin (0.78), uterus (0.69), and superficial trunk (0.69). The CIR of STS increased with age: 0–54 years, 3.49 per 100,000 per year; 55–64 years, 9.23 per 100,000 per year; and ≥65 years, 13.97 per 100,000 per year . The RARECAREnet project collected data from 94 population-based cancer registries in 27 European countries, including Italy; 19 were national registries covering the entire population in specific countries. Italy and seven other countries were covered by regional cancer registries partially representing the population of their country. Overall, during the period 2000–2007, the RARECAREnet project covered a total population of approximately 208 million (48% of the population of the participating countries). Within the current EU 28, 46% of the total population was covered. For the RARECAREnet data listed in Table 2, CIR (2000–2007) are based on the pool of 83 cancer registries [16,17]. Importantly, in comparison of AIRTUM with RARECAREnet data, the overall CIR of STS in Italy versus Europe was greater (6.27 [95% CI 6.17, 6.38] vs 4.71 [95% CI 4.68, 4.75] cases per 100,000 per year). However, comparison based on CIR should be interpreted with caution because differences could be related to potential differences in the age distribution in Italy versus the population of the countries included in RARECAREnet. AIRTUM aimed to present the burden of rare cancers and therefore did not provide age-adjusted rates, which limits data comparisons. Considerable AIRTUM–RARECAREnet discrepancies were also evident regarding CIRs of STS at the following body sites: retroperitoneum and peritoneum (CIR [95% CI]: 0.54 [0.51, 0.57] vs 0.31 [0.30, 0.32] cases per 100,000 per year); and skin (0.78 [0.74, 0.82] vs 0.30 [0.29, 0.31]) [1,16,17]. Much of the excess in rates for AIRTUM versus RARECAREnet was accounted for by these two sites.