Characteristics of malignant tumors in young people, with particular emphasis on carcinomas and sarcomas.

The aims of the study are to investigate the characteristic patterns related to different aged subgroups of young Chinese patients with malignant tumors. The subjects were young Chinese patients (defined as age > 1 and < 40 years) who underwent autopsy for malignant tumors in a teaching hospital in Hong Kong from 1970 to 1999. They were divided into four age groups: 1 to 9 years, 10 to 19 years, 20 to 29 years, and 30 to 39 years. The malignant tumors were classified into subgroups according to the pathological classification. The clinicopathologic features of patients with carcinomas and sarcomas were reviewed in depth. Four hundred sixty-three (22%) of 2,080 young patients had malignant tumors detected at autopsies. The male-to-female ratio was 1.5. The two most common malignant tumors were malignant lymphoid tumors and carcinomas, accounting for 49.9% and 29.8%, respectively, of all malignant tumors. In children (ages 1-9 years), 78.9% of malignant tumors found were malignant lymphoid tumors and neuroendocrine tumors. In teenagers (ages 10-19 years), malignant lymphoid tumors were the most important group of malignant tumor, accounting for 69% of malignant tumors in this age group. Carcinomas and malignant lymphoid tumors were seen in more than 80% of malignancies in young adults (ages 20-39). Overall, carcinomas and sarcomas were noted in 29.8% and 4.1%, respectively, of young patients with malignant tumors. The common primary sites of carcinomas were liver, stomach, lung, and nasopharynx. Sarcomas were more common in females (11 females, seven males), and rhabdomyosarcoma was the most common sarcoma found. Compared with other malignant tumors, carcinomas were less often diagnosed before death. In conclusion, malignant tumor is a common cause of death in young patients. Different types of malignant tumors were seen in various groups of young patients.