br Conclusion Prevalence is useful for quantifying the numbe
Conclusion Prevalence is useful for quantifying the number of people with potentially specific medical needs or social difficulties. In France, as in most other developed countries where incidence and survival are high, prevalent cases are numerous, representing around 5% of the AMG 925 and up to 20% of the elderly. These figures justify the interest in the post-cancer period. Due to the sensitivity of prevalence to changes in incidence and survival, we recommend that the results of projections are presented under different scenarios. We propose a robust and flexible prevalence estimate, based on the P = IxS relationship, with flexible modeling of incidence and survival available in both STATA© and R.
Authorship contribution statement
Funding This work was supported by the Institut National du Cancer (INCa) [grant number 2015-235]. The funding source had no involvement in the conduct of the research, the preparation of the article, the study design; the collection, analysis and interpretation of data, the writing of the report or in the decision to submit the article for publication.
Conflicts of interest
Introduction Testicular cancer is the most common cancer in men aged 15–44 (13% of cancer diagnoses in this age range).  Testicular cancer incidence peaks near birth followed by very low rates until a second peak after puberty . Therefore, testicular cancer in children below the age of 15 is uncommon and comprises only 4% of childhood cancers . In the 15–19 year age range, 12% of cancers are testicular, making them the fourth most common cancer for this age group . Testicular cancer incidence follows a bimodal distribution with a first peak occurring between the ages of 0–4 years and a second occurring following puberty . The incidence in adolescence and young adulthood is much higher than in the pediatric age group with a peak in the late 20 s and early 30s . Comparisons of testicular cancer incidence rates in adults have found that rates are highest in Europe, with particularly high rates in northern Europe. [, , , , , , , ] Rates are much lower in Africa and Asia [4,, , , , , ] and in non-white men who live in the United States [9,, , , , , ]. Pediatric testicular cancer, on the other hand, seems to have a different incidence pattern. One previous analysis of incidence trends for testicular cancer in boys and young adults found less variability in childhood incidence rates when compared with adult rates . Studies have found that Asian American  and Taiwanese  boys aged 0–9 have higher rates of TGCT (testicular germ cell tumors, the most common type of testicular cancer) when compared with white Americans. However, as most of the existing papers describing pediatric testicular cancer or germ cell tumors (GCT) have been limited to single or small groups of countries, it is difficult to use them to compare worldwide geographic patterns. In addition, many of these previous studies were focused on GCTs in all locations, making comparisons with adult testicular cancer or TGCT more challenging. In this analysis, we compared incidence rates for pediatric (ages 0–14) and adolescent and young adult (AYA; ages 15–39) testicular cancer using data from the three latest volumes of Cancer Incidence in Five Continents (CI5) [22,23]. We also utilized the National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) 18 data from 2000 to 2014 to compare incidence rates in racial and ethnic groups in the United States. The upper age limit of 39 years was chosen to be consistent with the U.S. National Cancer Institute’s criteria for defining the adolescent and young adult population . We highlight the differences between incidence rate patterns in children and AYA, as this may aid in understanding the different etiologies of testicular cancer by age group.