Long-term survival and conditional survival of cancer patients in Japan using population-based cancer registry data.
Bottom Line: We estimated the 10-year relative survival of patients who were followed-up between 2002 and 2006 using period analysis.Conditional 5-year survival for most cancer sites increased according to years, whereas those for liver cancer and multiple myeloma did not increase.It is important for patients and clinicians to report these relevant figures using population-based data.
Affiliation: Center for Cancer Control and Statistics, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.Show MeSH
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Mentions: In our research project, we used data of cancer patients who were followed-up for at least 5 years post-diagnosis. Follow-up methods, years of diagnosis, and follow-up for each registry are shown in Table S2. All cancer registries adopted linkage to the death certificate database in the prefecture to confirm the vital status of patients. Patients without linkage to the prefecture death certificate database are considered as alive based on this method. This assumption will be biased and cause overestimation of survival, because if patients die in a prefecture other than that in which they were diagnosed, their death will not be noted. Registries of Yamagata, Fukui, Osaka (for the whole period), and Nagasaki (partial period) additionally confirm the vital status of patients who were considered as alive 5 (and 10) years after diagnosis using linkage to the residential database from the death certificate. This method can complement data on patients who moved outside the prefecture where they were registered. In total, the percentage of lost to follow-up was <4%. We used a subset of the study period in which all prefectures had covered years of diagnosis and follow-up, shown in Figure 1.
Affiliation: Center for Cancer Control and Statistics, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.