Childhood tumors

Childhood and adolescent cancer has histological, clinical and epidemiolo-gical characteristics which differ from adult cancer which makes it necessary for these cancers to be studied separately from one another. The childhood cancer incidence rate in Spain is stable, the mortality rate having decline thanks to the success of the advancements in treatment.

The predominant histological types in childhood are leukemias, brain tumors, lymphomas and sarcomas (Fig. 2), unlike in adults, in whom car-cinomas are predominant. Approximately 140 cases for every 10⁶ children within the 0-14 age range are diagnosed with cancer every year in Spain (Table 8). Taking Spain’s 2006 population, the annual of new cases within the 0-14 age range is 925-950; and within the 15-19 age range, 425-450 cases.

The National Childhood Tumor Registry (RNTI) is the reference point for ascertaining the epidemiological data of this disease in Spain (Peris-Bo-net, 2008). Currently, the National Childhood Tumor Registry has recorded a total of 19,798 new cases since the beginning of the 1980’s for Spain as a whole. A total of 18,918 (96%) of the aforementioned cases are within the 0-14 age range, 880 /5.5%) being over 14 years of age; 57% being male chil-dren and 43% female chilchil-dren.

Leukemias

Fig. 2. Cases registered in the National Childhood Tumor Registry. Age: 0-19.

Period: 1980-2008.

Source: National Childhood Tumor Registry. 2009 Report.

The incidence rate of childhood cancer in Spain is similar to that of Europe.

Tables 8 and 9 show the incidence rate (0-14 years of age) in Spain based on the geographic area of Aragon, Catalonia, Basque Country and Nava-rre, where the thoroughness of the National Childhood Tumor Registry is around 100% (Ratio observed/expected = 1.04 (95% CI: 1.01-1.08), and Fig.

2 shows the incidence rate for Spain in conjunction with the European inci-dence rate (Stiller et al., 2006).

Table 8. All childhood tumors. Average incidence rate in Spain. 1990-2006 period.

Age: 0-14.

Incidence rate x 106 All tumors

0 years of age 194.1

1-4 years of age 190.9

5-9 years of age 122.6

10-14 years of age 111.6

Gross rate 140.9

Rate adjusted by age 147.1

Source: National Childhood Tumor Registry (Peris-Bonet, 2008 690)

Table 9. Childhood cancer incidence rate in Spain. Period: 1990-2006. Age: 0-14.

Source: National Childhood Tumor Registry (Peris-Bonet, 2008, 690).

Incidence rates x 106 (*Rate adjusted by age by world population IARC).

% 0 1-4 5-9 10-14 Gross ASRw M/F

Leukemias 28 33.9 69.8 36.6 23.3 39.8 42.8 1.5

Lymphomas 14 4.4 14.2 18.4 25.8 19.2 18.1 2.2

HL 5 0.0 2.6 4.4 15.1 7.6 6.6 1.7

NHL 8 3.1 11.1 13.8 10.7 11.3 11.2 2.5

CNS 23 20.7 36.3 36.9 26.6 31.9 32.5 1.3

SNS 8 77.1 20.1 4.0 1.0 11.5 13.9 0.9

Retinal blastomas 3 19.4 8.0 1.1 0.0 3.6 4.4 1.1

Renal 5 17.6 16.2 3.3 1.2 6.6 7.8 0.8

Liver 1 6.3 2.9 0.4 0.1 1.3 1.5 1.7

Bone 7 1.9 4.0 8.4 16.3 9.8 8.8 1.3

STS 7 11.9 12.5 8.4 7.1 9.2 9.6 1.4

Germ cell 3 10.7 4.3 2.0 3.9 3.8 4.0 1.0

Carcinomas and skin 3 2.5 1.9 2.9 6.3 3.9 3.5 0.9

Others and

unspecified 0 0.6 0.5 0.1 0.1 0.2 0.3 1.0

TOTAL 100 194.1 190.9 122.6 111.6 140.9 147.1 1.3

The childhood cancer survival rate in Spain is likewise similar to that of the countries in our surrounding environment, totaling 78% (Fig. 4).

50

Leukemias Lymph. SNS Retin blast Renal Kidney STS Europe (Ajusted rate, all tumors: 137.7%) Spain (Ajusted rate, all tumors: 147.1%)

CNS . Bone Germ cell

Lenght of time survived, in years

Carc&Skin

Fig. 3. Incidence rate of childhood cancer in Spain (1990-2006) and Europe (1988-1997) by tumor type. Age: 0-14.

Source: Spain: National Childhood Tumor Registry {Peris-Bonet, 2008 690 /id}; Europa: ACCIS (Stiller et al., 2006)

Leukemias Lymph. SNS Retin blast Renal Kidney STS

Europe (Ajusted rate, all tumors: 137.7%) Spain (Ajusted rate, all tumors: 147.1%)

CNS . Bone Germ cell

Lenght of time survived, in years

Carc&Skin

Fig. 4. All tumors. Survival rate observe at 5 years following the diagnosis in the NCTR by cohorts of years of diagnosis. Period: 1980-2003. Age: 0-14 years.

Source: National Childhood Tumor Registry, 2009 Report.

The secondary effects resulting from childhood and adolescent cancer treatments are currently cause for concern, the design of new protocols thus aiming at modifying or reducing the treatment for those children who have a good prognosis, whilst continuing to intensify the treatment in those tumors which are still as yet incurable. The sequelae of cancer treatment in children are well-known: early death, secondary tumors, organic sequelae (cardiac, pulmonary, endocrinological, neurological), psychological and social (diffi-culty of finding a job or of taking out life insurance or health insurance). In short, sequelae which may lead to a lesser quality of life than their peers who had not become ill (Robinson et al., 2009).

SUMMARY

• According to the estimates made based on the data furnished by the population-based registries, a total of 183,201 new cases of cancer were diagnosed in Spain in 2006. In males, prostate cancer was the most frequent, following by lung cancer and colorectal cancer. In fe-males, the cancer most commonly diagnosed was breast cancer, fo-llowing by colorectal cancer and lung cancer.

• In comparison to the incidence rate of the countries in our surrounding environment, the males in Spain show an incidence rate slightly lower than the EU average. However, Spanish females show low incidence rates compared to other EU countries.

• In 2006, three out of every 10 deaths in males and two out of every 10 deaths in females were due to cancer. In terms of absolute mortality, the most important tumors for the males were lung cancer (16,859 deaths), colorectal cancer (7,703 deaths) and prostate cancer 5,409 deaths)in 2006; and in females, breast cancer (5,939 deaths), colorec-tal cancer (5,631) and lung cancer (2,624 deaths).

• Within the last ten years, the cancer mortality rate for Spanish males underwent an average 1.3% decline annually, this drop being found in most tumors, to a greater or lesser degree. Solely the cancers of the small intestine, colon and rectum, melanoma and pancreatic cancer showed a slight rise in the annual mortality rate (less than 2%). Lung cancer in males shows itself to be declining in our country over the last ten years.

• In females, for the 1997-2006 period, the cancer mortality rate declined by an average of 1% annually. This decline becomes patent in most of the malignant tumors, although special mention must be made of the decline in the mortality rate due to breast cancer (1.8% annually) and the sharp drop in skin, gallbladder, stomach and bone tumors, with over 3% drops annually. However, the lung cancer mortality rate

in Spanish females shows a clear rise (3.1% annually). The pancreatic cancer mortality rate also showed an increase (1.3%).

• The main etiological factor involved in cancer is tobacco. The males in Spain show high incidence rates and mortality rates for smoking-rela-ted tumors. Nevertheless, the surveys on smoking show a downward trend in males. On the contrary, a low incidence rate and mortality rate is currently noted for Spanish women for this type of tumors, but the rise in smoking among females has meant an increase in lung cancer in the 1990’s, and the forecasts for the future are not very optimistic.

• In all of Spain’s registries, breast cancer is the most frequent tumor in females, being responsible for over 25% of all of the cancer cases, followed by colon cancer and lung cancer. The early breast cancer detection programs, in conjunction with the advancements made in treatment have contributed to reducing the mortality rate for this tumor in our country. The new screening programs must be implemented with a population-based criteria and allocated the necessary resources and must have quality indicators making their evaluation possible.

• Spain is one of the European countries which has one of the lowest cervical cancer incidence and mortality rates. The evolution of the cer-vical cancer mortality rate could change following the HPV vaccine being included in the childhood vaccination schedule and the mea-sures which are being adopted regarding early detection programs.

Monitoring the incidence rate and mortality rate will serve to assess whether these strategies are achieving the desired goals.

• Colorectal cancer is the most frequent tumor in Spain if both genders are considered together and is the second-ranked cause of cancer mortality in both males and females. Sufficient scientific evidence exists as to the benefit of early detection programs. Although there are some pilot programs in place in Spain, and the high-risk individuals are gene-rally excluded from monitoring protocols, these programs have not as yet been expanded to the general population.

• The childhood cancer incidence rate in Spain is similar to the European incidence rate, whilst the childhood cancer mortality rate has declined thanks to the success of the advancements in treatment. However, spe-cial emphasis must be place on the secondary effects resulting from chil-dhood and adolescent cancer treatments. Numerous studies address the design of new treatment products, so as to be able to modify or reduce these effects in those children who have a good prognosis.