Cancers in infancy: percent distribution and incidence rates.

Cancer occurring in infants often has clinical and biological properties that are different from those of the same histologic type of cancer occurring in older children. The histologic distribution of cancers in infants and that in older children are also different. We collected infant cases diagnosed as having cancer from the database of the Cancer Registry in our Medical Center between 1995 and 2004. One hundred and twenty infants (66 males and 54 females), including 17 neonates, were diagnosed with cancer over this 10-year period. The top five cancer subtypes were: leukemia in 34 infants (28.3%), retinoblastoma in 19 (15.8%), neuroblastoma in 16 (13.3%), germ cell tumor in 15 (12.5%), and brain tumor in 14 (11.7%). The overall disease-free survival rate was 54. 2% (65/120) with a median follow-up duration of 7.6 years for the survivors. From the cancer registry in our hospital during the same period, 1995-2004, infant cases accounted for 9.5% of the total 1,269 children with cancer diagnosed at the age younger than 15 years. The percent distribution of the major types of cancer was different in the infant and the childhood group. According to the Taiwan Pediatric Oncology Group's data analysis, the infant cancer incidence rate in Taiwan is 207.6 per million infants for years 1995-2004. Our study confirmed that the prognosis is very poor for infant leukemia and rhabdoid tumor, while that is good for embryonal tumors and germ cell tumors occurring in the infancy.