Introduction: The life expectancy of cancer patients has increased in recent decades due to better diagnostic and screening tools as well as better treatment modalities. Hence, it becomes increasingly important to study trends in long-term cancer patient survival in order to document that medical progress has conveyed benefit at the population level. In this paper, we assessed the long-term survival experience of all incident cancer patients in Singapore. Materials and Methods: The study population consisted of patients diagnosed with single primary invasive cancer from 1 January 1968 to 31 December 2002, and passively followed up to 31 December 2005. The data was derived from the Singapore Cancer Registry, which has been in existence since 1968. Relative survival via the period approach was used to provide a more up-to-date estimate by looking at recent cohorts of patients. Sex- and stage-specific survival was compared for each cancer. Results: The overall age-standardised 10-year relative survival ratios for the calendar years of 1998 to 2002 were 30.5% in males and 44.2% in females. A steady improvement in overall long-term cancer survival was observed over the study period. This upward trend in survival was observed in localised tumours and cancers with a favourable prognosis such as breast, cervical and colorectal cancers. In contrast, survival of cancers with poor prognosis such as lung, liver and pancreas remained low. Conclusions: Although factors such as changes in diagnostic criteria could influence the trend in survival, we believed that the improvement in survival predominantly reflected real progress in cancer control in Singapore.
With increasing health awareness and the greater extent of healthcare provision over the years, the life expectancy of Singaporeans has increased from 75.3 in 1990 to 78.4 in 2001. This suggests that cancer patients are surviving longer than before, due to an increasing number of delayed cancer deaths. Hence, this may also indicate that the remaining life expectancy at the average age of cancer occurrence has increased. Although there have been reports about cancer survival in Singapore, they mainly referred to the prognosis of cancer patients with respect to a shorter period of 5-year follow-up.2 It is not clear how well cancer patients survive beyond 5 years. However, extensive information regarding cancer cases can be obtained from the Singapore Cancer Registry, which has been functioning for almost 40 years. It provides a comprehensive database for studying the cancer survival as a function of an increased length of follow-up. Hence with an increase in the remaining life expectancy of cancer patients as well as the length of cancer registration, it becomes increasingly important and relevant to use longer-term survival estimates for comparison and evaluation of cancer prevention programmes.
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