Cancer survival in Songkhla, Thailand, 1990-1999

The Songkhla registry, besides being hospital-based, has population-based cancer registration data available since 1990. Cancer registration is done by active methods. The registry is contributing data on survival for 36 cancer sites or types registered during 1990-1999. Follow-up has been carried out by passive and active methods with median follow-up ranging from 3-71 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged between 52-100%; death certificate only (DCO) cases comprised 0-34%; 54-93% of total registered cases were included for survival analysis. Complete followup at five years ranged from 50-85% for different cancers. Five-year age-standardized relative survival rates of common cancers were cervix (59%), lung (7%), breast (59%), thyroid (86%), oesophagus (11%), liver (2%), nonmelanoma skin (75%), colon (45%) and oral cavity (33%). Five-year relative survival by age group did not reveal any pattern or trend and was fluctuating. A majority were diagnosed with regional spread of disease, and survival decreased with increasing clinical extent of disease.