Childhood cancers in Chennai, India, 1990-2001: incidence and survival.

Childhood cancers (age at diagnosis: 0-14 years) comprise a variety of malignancies, with incidence varying worldwide by age, sex, ethnicity and geography, that provide insights into cancer etiology. A total of 1,334 childhood cancers registered in population-based cancer registry, Chennai, India, during 1990-2001 and categorized by International Classification of Childhood Cancer norms formed the study material. Cases included for survival analysis were 1,274 (95.5%). Absolute survival was calculated by actuarial method. Cox proportional hazard model was used to elicit the prognostic factors for survival. The age-standardized rates for all childhood cancers together were 127 per million boys and 88 per million girls. A decreasing trend in incidence rates with increasing 5-year age groups was observed in both sexes. The top 5 childhood cancers were the same among boys and girls: leukemias, lymphomas, central nervous system neoplasms, retinoblastomas and renal tumors. The highest 5-year absolute survival was observed in Hodgkin's disease (65%) followed by Wilm's tumor (64%), retinoblastomas (48%), non-Hodgkin's lymphomas (47%), osteosarcomas (44%), acute lymphoid leukemia and astrocytoma (39%). Multifactorial analysis of age at diagnosis and sex showed no differences in the risk of dying for all childhood cancers. Completeness of treatment and type of hospital combination emerged as a prognostic factor for survival for all childhood cancers together (p < 0.001), acute lymphoid leukemia (p < 0.001) and non-Hodgkin's lymphoma (p = 0.04). A Childhood Cancer Registry with high-resolution data collection is advocated for in-depth analysis of variation in incidence and survival. (c) 2008 Wiley-Liss, Inc.