OBJECTIVETo explore the patterns of cancer incidence from 1972 to 2005 in Qidong, Jiangsu province.

METHODSA population-based cancer registration system was established in Qidong region with 1.1 millions residents to collect data of cancer incident cases. 70,646 cases were registered during the years from 1972 to 2005, and ICD-10 was administrated for classification and coding, and crude rate (CR) and age-standardized rate (ASR), percent change (PC), annual percent change (APC) were calculated using annual data on population size. Changes within age-groups for different periods of incidence, and for different years of birth (birth cohort) for the leading sites of cancers were analyzed.

RESULTSThe average annual incidence for cancers during the years of 1972-2005 was 184.77 per 100,000 (ASR: 109.32 per 100,000), of which, the incidence for male was 239.22 (ASR: 136.08), and 131.58 (ASR: 79.26) per 100,000 for female. The cumulative risk of cancer occurrence was 16.31% (21.62% in males, and 11.11% in females). The most common leading sites in rank in this area were liver (CR: 60.69 per 100,000), stomach (32.97), lung (27.59), oesophagus (9.34), rectum (8.06), breast (6.48), pancreas (5.97), leukaemia (3.84), bran and CNS (3.43), and colon (2.93). Female breast cancer (12.59) and cervix cancer (4.62) were the forth and the eighth in rank among all sites for women. Liver cancer accounted for almost one third (32.84) of the malignancies. Furthermore, the cancers from digestive organs accounted for 65.85% of all sites. CR rates were rising overall, at 87.19% for PC, and at 1.85% for APC. The ASR, however, reduced by 12.14% for PC, and by 0.51% for APC. The rising trends were also observed for the ASR from cancers in lung, female breast, and colon-rectum, while the decreasing trends were observed for stomach and oesophagus cancer. Birth cohort analysis showed that there was a decline in ages under 35 for the incidence of liver cancer, in ages over 40 for stomach cancer, and in those aged over 45 for bladder cancer and over 50 for oesophagus cancer. Rising trends existed for incidence rates from lung cancer in the aged over 30, pancreas cancer in aged 45-59, and female breast cancer in those aged 40 and above.

CONCLUSIONMonitoring of cancer incidence rates through population-based cancer registration in 34 years did help to show the burden and patterns of main cancer sites and time trends, which provides some references to future aetiological study, and policy making on cancer control in Qidong.