Proportion of population covered by cancer registries included in EUROCARE-5 (%)a
Number of germ cell tumor cases registered in 2000–2007
Austria
100
2.610
Belgium (Flanders)
58
1.215
Bulgaria
100
1.457
Croatia
100
900
Czech Republic
100
3.491
Estonia
100
190
Finland
100
944
France
23
1.213
Germany
23
6.950
Iceland
100
79
Ireland
100
1.210
Italy
35
3.450
Latvia
100
267
Lithuania
100
268
Malta
100
76
Norway
100
2.185
Poland
13
904
Portugal
76
698
Slovakia
100
1.683
Slovenia
100
812
Spain
17
778
Switzerland
30
923
The Netherlands
100
5.078
UK
100
16.626
Total
54.007
GCTs include different histological subtypes, internationally grouped as seminomas and non-seminomas. Throughout this chapter, the generic term seminoma and non-seminoma will be used. Seminoma, dysgerminoma and germinoma are histopathologic equivalent terms for a neoplasm of identical morphology in testis, ovary and extragonadal locations. Seminoma includes all seminoma histological types (ICD-O3 codes 9060–9064); non-seminomas in their turn include embryonal carcinoma (ICD-O3 codes 9070, 9072), yolk sac tumor (ICD-O3 code 9071), choriocarcinoma (ICD-O3 codes 9100, 9102), teratoma (ICD-O3 codes 9080,9082,9083), mixed germ cell tumors (ICD-O3 codes 9081,9085,9101), malignant struma ovarii (ICD-O3 code 9090), cystic teratoma with somatic malignant transformation (ICD-O3 code 9084) and other non-seminomatous germ cell tumors (ICD-O3 codes 9065). Spermatocytic tumor, an exclusively testicular neoplasm, is clinically and pathologically distinct from classic seminoma; thus data are provided separately for this specific type.
2.3 Incidence
The crude and age-adjusted (European standard population) incidence rates of GCT in Europe were both equal to 34/1.000.000 with marked differences between male (64/1.000.000) and female (4/1.000.000). In the USA, the incidence rate was 56/1.000.000 in white males contrasting with 3.2/1.000.000 in white females, over a period of more than 30 years from 1973 to 2007 [4]. In the same country, the incidence in black males was much lower (10/1.000.000), due to a lower incidence of seminomas, while no difference was reported between white and black females [4]. More than 90 % of testicular tumors were indeed GCT. Figure 2.1 shows incidence of testicular cancer across different continents in 2012. White males living in Western industrialised countries, particularly in Northern and Western Europe, showed the highest incidence rates of testicular tumors (12/100.000 in Denmark, Norway and Switzerland), whereas black males in Africa showed the lowest (<0.5/100.000 in the majority of African countries). In Australia and New Zealand, the incidence was 7/100.000. In North America (USA and Canada), it was 5/100,000; in South and Central America, it was 2/100.000 with differences among countries (Chile 7/100.000, Uruguay 6/100.000, Argentina and Costa Rica 5/100.000, Mexico and Colombia 3/100.000, Brazil 2/100.000 and remaining countries <1/100.000). In Japan, the incidence was 2/100.000; in South, Eastern and Central Asia, it was <1/100.000, being higher in Western Asia, 1.7/100.000, with regional countries (5/100.000 in Israel, 3/100.000 in Georgia and <1 in Oman, Qatar, Iraq and Azerbaijan). In China, the incidence was 0.5/100.000 [5].
Fig. 2.1
Testicular cancer age-standardised (world) incidence rate per 100.000 (Source http://globocan.iarc.fr/Pages/fact_sheets_cancer.aspx)
Incidence of malignant ovarian GCT was low in all continents: ≤0.9/100.000 in Japan, ≤0.7/100.000 in Central and South America and in China, ≤0.5/100.000 in Australia and Asia, 0.4/100.000 in Canada and <0.4/100.000 in Africa except Malawi where the incidence was 1.3/100.000 [2].
Gonadal GCT (GGCT)
Most GCTs arise in the gonads. The incidence in Europe is 33/1.000.000 being substantially higher in males than in females (62/1.000.000 vs 2.5/1.000.000, respectively). Histologic differences are observed between both genders: in males, seminomas are more common than non-seminomas, contrary to women who have more non-seminomas than seminomas (Table 2.2). In males, non-seminomas are mixed germ cell tumors, embryonal carcinoma and teratoma, while in females they are (immature) teratomas and yolk sac tumors (Table 2.2). In males, spermatocytic tumor is very unusual (Table 2.2).
Table 2.2
(EUROCARE) Gonadal germ cell tumors incidence rate per million, in Europe by histological type, and sex (age adjusted) with 95 % confidence interval (CI)
Male | Female | |||||
|---|---|---|---|---|---|---|
Rate | 95 % CI | Rate | 95 % CI | |||
Germ cell tumors | 62.1 | 61.6 | 62.7 | 2.5 | 2.4 | 2.7 |
Seminomas | 36.9 | 36.4 | 37.3 | 0.9 | 0.8 | 1.0 |
Spermatocytic tumor | 0.6 | 0.6 | 0.7 | – | – | – |
Non-seminomas | 25.3 | 24.9 | 25.6 | 1.7 | 1.6 | 1.8 |
Embryonal carcinoma | 6.8 | 6.7 | 7.0 | 0.1 | 0.0 | 0.1 |
Yolk sac tumor | 1.3 | 1.2 | 1.3 | 0.4 | 0.4 | 0.5 |
Choriocarcinoma | 0.4 | 0.4 | 0.5 | >0.1 | 0.0 | 0.1 |
Teratoma | 5.6 | 5.4 | 5.8 | 0.8 | 0.7 | 0.9 |
Mixed germ cell tumors | 10.6 | 10.4 | 10.9 | 0.2 | 0.2 | 0.2 |
Struma ovarii, malignant | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.1 |
Cystic teratoma with somatic malignant transformation | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.2 |
Testicular GCTs have an early incidence peak in the age group 0–4 years followed by a second peak in adolescents and young adults (15–19 and 25–29 and 30–34 years) (Fig. 2.2). The first peak is due to non-seminomas (incidence 1.5/1.000.000 vs 0.07/1.000.000 of seminomas) and mainly due to yolk sac tumour and teratoma, which have an incidence of 1/1.000.000 and 0.3/1.000.000, respectively.
Fig. 2.2
(EUROCARE) Testicular germ cell tumor incidence per 1.000.000 by age group overall (a) and by age group and histology (b)
Non-seminomas are more common than seminomas until the age of 30 years; however, the histologic types of those between 15 and 30 years are mainly embryonal carcinoma and mixed germ cell tumors and only to a lower extent teratoma and yolk sac tumor.
After the age of 30, seminomas are predominant. Overall, seminomas presented an incidence peak 10 years later than non-seminomas (Fig. 2.2).
Ovarian GCTs have a small peak in children under 5 years and a clear peak in the 15–19-year age group (Fig. 2.3). These results are coherent with those reported in the USA [4]. Both seminomas and non-seminomas have a peak at 15 to 19 years; non-seminomas are more common than seminomas in almost all age groups and in particular in young females (>25 years) (Fig. 2.3). Yolk sac tumour and teratoma represent the most common histologic types in the 0–4-year age group; teratoma incidence increases with age, and it is the most common type in all age groups as from 5 years old.
