Survival of children with Wilms' tumour in Europe

A total 2535 cases of Wilms' tumours registered in children aged 0--14 years by 34 population-based cancer registries in 16 countries of Europe in 1978--1992 and followed-up until the end of 1994 were included in this EUROCARE study. Overall 5-year observed survival of all children diagnosed in 1985--1989 was 83%, 95% confidence interval (CI) 80--85. Relatively large differences were observed between the European countries, with significantly lower survival of patients registered in the formerly socialist countries, Estonia, Poland and Slovakia. Overall European survival was slightly lower in comparison with results reported from the USA and Australia, which demonstrate a potential for improvement. Over the study period, overall survival adjusted for age, sex and country has increased significantly. This favourable trend is attributed primarily to improvements in treatment, particularly to the introduction of new chemotherapeutic agents.

Survival of children with malignant germ cell, trophoblastic and other gonadal tumours in Europe

Collaborators of the EUROCARE study had provided records on 1263 cases of germ cell, trophoblastic and other gonadal neoplasms, registered in 34 cancer registries in 16 European countries over the period 1978--1992 and followed-up until the end of 1994. Observed 5-year actuarial survival for 490 cases diagnosed in 1985-1989 was 80% (95% confidence interval (CI)=(76, 83)). The corresponding figures were calculated for the intracranial and intraspinal germ cell tumours (68%, 95% CI=(57, 76)), other non-gonadal germ cell tumours (76%, 95% CI=(68, 82)), gonadal germ-cell tumours (89%, 95% CI=(85, 93)) and gonadal carcinomas (50%, CI=(24, 76)). Relatively large differences in survival were observed between age-sex subgroups, which also differed with histology, with extremely poor survival of young children with intracranial and intraspinal germ cell tumours. Lower survival was observed in the countries with formerly socialist economies. Time trends in survival were examined for the entire study period, including only the cases registered in the large contributing registries. For all germ cell tumours, the risk ratios calculated in the Cox regression analysis were markedly lowered for the years after the reference period of 1978--1981. The improved outcome is attributed to treatment advances.

Incidence of childhood cancer in Ho Chi Minh City, Vietnam, 1995-97

Incidence rates of childhood cancer for the city of Ho Chi Minh are presented for the first time. For the 3-year period 1995-97, a total of 302 cancer cases were registered in children under 15 years of age, with a male to female ratio of 1.1. The overall crude rate was 78.8 and the age-standardised incidence rate was 88.4 per million person-years, which was low in comparison with other countries in eastern Asia and with the predominantly white population of Australia. Leukaemia (principally acute lymphocytic), brain tumours and lymphomas were the most common childhood neoplasms, which is consistent with the pattern observed in other registries of the region. The rate of retinoblastoma was higher than in the other regional registries. On the other hand, no cases of hepatocellular carcinoma were registered.

Exposure to Agent Orange and occurrence of soft-tissue sarcomas or non-Hodgkin lymphomas: an ongoing study in Vietnam

Agent Orange was the most common herbicide used in the Second Indochina War in the course of military operations in the former South Vietnam. Agent Orange is contaminated by the carcinogen 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) in mean concentrations of 2 mg/kg. After much dispute of a causal association between exposure to herbicides containing TCDD and occurrence of soft-tissue sarcoma and non-Hodgkin lymphoma, two simultaneous case-control studies were set up in Vietnam to examine possible relationships. Subject recruitment is ongoing, with target numbers of 150 cases of soft-tissue sarcoma and 150 cases of non-Hodgkin lymphoma and diagnoses at the Cancer Center at Ho Chi Minh City, Vietnam. Two hospital controls are matched to each case. As in other studies of cancer in persons occupationally or otherwise exposed to herbicides and their contaminants, evaluation of past exposure of the recruited subjects is among the most complicated issues. Because accurate records are usually unavailable, surrogate measures of likely exposure are often calculated. As a first approach in our studies we used the Stellman and Stellman exposure index. The index is based on matching subjects' history of residence and the information on times and locations of Agent Orange spraying recorded on HERBS tape by the U.S. Army and taking into account the distance from the spraying as well as environmental and biologic half-life of TCDD. The exposure index is calculated in two centers, New York and Hanoi, with slightly different assumptions. In addition, samples of body tissues from the subjects (20 ml blood, 2 g adipose tissue, and tumor sections in paraffin blocks) are taken and stored. Their future analysis will provide additional source of exposure assessment. Strengths and weaknesses of both exposure measures are discussed in this paper.

Plantar melanoma: a case-control study in Paraguay

In Paraguay, the plantar surface of the foot is the most common site for malignant melanoma, as it is in several other populations worldwide, most notably in those of African descent. Here, we report the results of the first case-control study of plantar melanoma, carried out in Paraguay. Sixty incident, histologically confirmed cases of plantar melanoma and 256 hospital controls were recruited in 11 hospitals throughout the country during 1988-93. Information was collected on general demographic, social, and lifestyle variables, on external exposures of feet (shoewear, work activities, injuries), and on some constitutional factors (skin, eye and hair color, and pigmented lesions of the feet). Few of the factors examined appeared to be associated with the risk of plantar melanoma. Adjusted for possible confounders, the strongest association was found for reported injuries (odds ratio [OR] = 40.9, 95 percent confidence interval [CI] = 14.8-112.7) and for occurrence of naevi on the soles (OR = 5.9, CI = 2.5-14.3). Walking barefoot did not seem to contribute to the risk although an outdoor workplace was associated with an increased melanoma occurrence (OR = 2.3, CI = 1.1-4.8). Future studies should be aware of problems of recall bias with respect to previous injuries, and ensure that evaluation of pigmentation of the sole is carried out blind to case/control status.

The international classification of childhood cancer

The International Classification of Childhood Cancer (ICCC) updates the widely used Birch and Marsden classification scheme. ICCC is based on the second edition of the International Classification of Diseases for Oncology (ICD-O-2). The purpose of the new classification is to accommodate important changes in recognition of different types of neoplasms, while preserving continuity with the original classification. The grouping of neoplasms into 12 main diagnostic groups is maintained. The major changes are: (1) intracranial and intraspinal germ-cell tumours now constitute a separate subgroup within germ-cell tumours; (2) histiocytosis X (Langerhans-cell histiocytosis) is excluded from ICCC; (3) Kaposi's sarcoma is a separate subgroup within soft-tissue sarcomas; (4) skin carcinoma is a separate subgroup within epithelial neoplasms; (5) "other specified" and "unspecified" neoplasms are now usually separate sub-categories within the main diagnostic groups. Draft copies of the ICCC were distributed to some 200 professionals with interest and expertise in the field and their comments are considered in this final version. This classification will be used for presentation of data in the second volume of the IARC Scientific Publication "International Incidence of Childhood Cancer." A computer programme for automated classification of childhood tumours coded according to ICD-O-1 or ICD-O-2 is now available from IARC.

The role of the registry in the study of relation between cancer and environment experiences from Slovakia

Highly complete and detailed data on cancer incidence collected in National Cancer Registry of Slovakia in the years 1968-1988 contributed largely to the study of the relations between cancer occurrence and environment. The study of temporal trends of age-adjusted rates revealed the rapid increase of overall cancer incidence and mortality rates in males influenced mainly by extreme increase and high proportion of lung cancer. The lower but increasing overall incidence rates in females could be related to the increase in breast, other skin and genital organs cancers, while the stabilized mortality trends were caused by improving prognosis of these major cancers in females. The possible role of environmental factors in adults could be stressed also by the temporal trends of childhood malignancies which remained fairly stable during the same period. The role of environmental factors in cancer etiology is further documented with the dramatically increasing incidence of malignant skin melanoma caused probably by the overexposition to the sunlight and with prevailing incidence of the majority of cancer sites in urban areas. Finally, the significantly increased incidence rates of other skin cancers are shown in two districts and in both sexes in relation to the environment, highly polluted with arsenic.

[Incidence of malignant tumors in Slovakia. I. Levels and trends 1968-1989]

In the period from 1968-1989 an increase in the overall incidence of malignant tumors was recorded in men. Of the individual localizations a particularly marked increase was recorded in tumors of the lung, followed by tumors of the oral cavity, pharynx, esophagus, pancreas, urinary bladder, kidney (related to smoking), as well as of the testis and prostate gland. In women the values of overall incidence were lower and the trends were relatively stabilized. This is due to the relatively slow increase in the incidence in cancer of the breast and female reproductive organs and to the slight increase in cancer of the lung. Cancer of the kidney, urinary bladder and pancreas exhibited increased incidence. Low values, stabilized and even decreasing trends were recorded in the incidence of cancer of the oral cavity, pharynx, esophagus, and larynx, as compared to values found in men. In both sexes the incidence of cancer of the stomach showed a pronounced decrease, while the incidence of cancer of the colon and rectum was increasing. A smaller or greater rise was found also in the incidence of tumors of the hematopoietic and lymphatic tissues (except Hodgkins's disease). The trends observed in the incidence of malignant tumors in Slovakia are suggestive of their uncontrolled course, not affected by preventive measures. Yet the findings provide important information for directing the measures so as to aim at localizations of priority. (Tab. 2, Fig. 7, Ref. 20.)

Development of registration and cancer incidence rates and trends in Slovakia

The development of cancer registration, from the introduction of obligatory notification and the establishment of National Cancer Registry of Slovakia, is described. The activity of the registry is illustrated by the list of publications which have emanated from this institution in recent years. The survey is completed by the analysis of the incidence rates of individual cancer sites in the last 5-year period (1984-1988) and by their trends in the decade 1979-1988. The positive role of the registry in the establishment of a cancer control programme and the investigation of cancer epidemiology is stressed.