To stimulate greater German-Chinese cooperation in the field of oncology, the Ger man Cancer Research Center (DKFZ) carried through a "Chinese-German Sympo sium on Cancer of the Liver, the Esophagus, and the Nasopharynx" in Heidelberg from 3 to 5 July 1985. These three forms of cancer were chosen as they are extremely rare in Europe but some of the most frequently found forms in China. Almost half of the roughly 260000 cases of primary liver cancer occurring annually worldwide are Chinese; of the roughly 300000 esophagus cancers occurring annually, more than half are Chinese; nasopharyngeal cancer is roughly 100 times more frequent among Chinese people than in Caucasians. Under these circumstances, it is not surprising that the Chinese guest speakers of the Heidelberg symposium - selected specialists in the three subsections of oncolo gy mentioned - were able to report about extensive experiences with patient popu lations of a size hardly imaginable in Europe. The great clinical experience of the Chinese guests was supplemented by special contributions of European experts. Thus, this volume permits a topical survey of the state of the art in these three can cers, with subsections of epidemiology, pathology, and clinical treatment. The editors wish to thank the Federal Ministry of Research and Technology (BMFT) for their encouragement and direct help in preparing and carrying through the symposium, the Management Board of the DKFZ for their generous assistance and Springer-Verlag for the publication and excellent production of this volume.

I Opening Presentation

Selenium as a Possible Chemopreventive Agent Against Cancer
II Cancer of the Liver
Epidemiology of Primary Liver Carcinoma
Epidemiology of Primary Liver Cancer in a West German Population: The Saarland
Risk Factors of Primary Liver Cancer in the High Prevalence Area Chongming County; Results from a 5-Year Follow-up
Cytopathology and Pathogenesis of Primary Liver Tumors
Proliferation and Clonal Selection in Hepatocarcinogenesis
Oncogenes in Primary Hepatic Cancer
Hepatitis B Virus Sequences and Their Expression in Human Hepatoma Cells
Subclinical Hepatocellular Carcinoma
Effects of 13 Mutagens on Rat Hepatic Microsomal Enzymes
Four Hundred Cases of Hepatic Resection for Primary Liver Cancer
III. Cancer of the Esophagus
Epidemiology of Esophageal Cancer in China
Cancer of the Esophagus in Migrants from Different Areas in China
Cocarcinogens of the Diterpene Ester Type as Principal Risk Factors of Cancer in Curaçao and Possibly in South China: Identification of Second Order Risk Factors of Cancer in Multifactorial Carcinogenesis
A Survey of the Familial Aggregation of Esophageal Cancer in Yangcheng County, Shanxi Province
Chemical Factors in the Pathogenesis of Esophageal Carcinoma
Vitamin Intervention in Precancerous Lesions of the Esophagus in a High-Risk Population of China
Effect of N-Nitrosamine on Human Esophageal Epithelium Collected from Populations from a High-Risk Area for Esophageal Cancer in Northern China
Papillomavirus Infections in Esophageal Cancer
Experience with Combined Preoperative Irradiation and Surgery for Squamous-Cell Carcinoma of the Esophagus
A Study of Tumor-Associated Antigens
IV Cancer of the Nasopharynx
Epidemiology of Nasopharyngeal Carcinoma with Special Reference toEarly Detection and Pre-NPC Conditions
Histopathological Aspects of Nasopharyngeal Carcinoma
Prospective Study of Serum VCA-IGA Antibody in the Normal Population in Guangdong Province of China
Prospective Studies on Nasopharyngeal Carcinoma and Epstein-Barr Virus Inducers
Control of Epstein-Barr Virus-Related Disease
The Role of Epstein-Barr Virus in Nasopharyngeal Carcinoma
The Role of Promotion in the Carcinogenesis of Nasopharyngeal Carcinoma
Clinical Course and Therapy of Nasopharyngeal Carcinoma.