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  • Cancers and other neoplasms are

    2019-08-11

    Cancers and other neoplasms are still the leading cause of premature death in Australia despite gains in survival [3]. Five-year relative survival increased for all cancers combined from 48% in 1984-88 to 68% in 2009-13, with increases affecting a broad range of cancers [4]. Increased survival is also reported for the United Kingdom and USA [5,6], and attributed variously to treatment gains, improved diagnostic technologies, and screening [7]. Cancer incidence increases steeply with age whereas survival generally declines [4]. In 2009-13, the five-year relative survival from cancer in Australia (keratinocyte skin cancers excluded) was 50% for patients aged 75+ years, which was substantially lower than the corresponding 65% for 70–74, 72–79% for 50–69, and >80% for <50 years [4]. Similar survival gradients by age have been reported for the United Kingdom and USA [5,6]. Factors responsible for lower survival in older people would include frailty, co-morbidity, and potentially less comprehensive and intensive treatment [8]. The lower survival from breast cancer in Australian women aged 70+ years, after adjusting for stage other cancer characteristics, was attributed to these factors.9 Older women had a lower exposure to adjuvant therapies [9]. Other factors potentially affecting outcomes in older people include changes in pharmacodynamics and pharmacokinetics [9]. Also, because older people are often excluded from clinical trials, there is more limited evidence available on best treatments and best trade-offs needed to accommodate poorer general health [8,9]. Age bias (ageism) has also been raised as a potential contributor to poorer outcomes [9]. Poorer outcomes for older patients could be affected by not offering or not accepting offered treatment. While there is consistent evidence in Australia, the United Kingdom, North America and other countries of lower survival from cancer in older patients [[4], [5], [6]], the contribution of age bias to these disparities has not been determined. In this study, we explore whether post-diagnostic reductions in cancer mortality (due to survival increases) have applied equally in New South Wales (NSW) by age or whether older cases experienced smaller mortality reductions, leading to a growing survival gap by age. Our (-)-Bicuculline methiodide is that the gap has increased. The basis for this hypothesis is: (a) limited trial evidence available on the comparative effectiveness of different treatments in older people; and (b) reluctance to provide new aggressive treatment protocols to many older people with low resilience, limiting opportunities for survival gain [8,9]. Nonetheless, despite this hypothesis, we recognized that the gap may have reduced due to increased (-)-Bicuculline methiodide awareness since the 1980s of the need to address poorer outcomes in older cancer patients [10,11].
    Methods
    Results
    Discussion Multivariate analyses showed similar trends when five-year age strata were used instead of 10-year strata, and when further adjustment was made for single year of age within these narrower age strata. Further, this analysis showed smaller secular reductions in adjusted HRs with increasing age over 85 years. This also applied in supplementary analyses by sex, and when excluding prostate and breast cancer to avoid possible effects from changes in coverage of screening and other early-detection initiatives during the study period. A smaller downward secular trend in sub-hazards ratios was also suggested in supplementary analyses for cases aged 80+ years for most cancer sites, when using competing risk regression. This strengthened the evidence given the potential for overestimating hazards, and introducing bias, by censoring cases at death from other causes in the proportional hazards regression [17]. This would apply in particular in older cohorts where risks of death from competing causes is high. These NSW results are consistent with USA study findings of smaller gains in survival for older cancer patients [[23], [24], [25]]. Unadjusted relative survival for Australia also show lower survival estimates and lower gains over time for patients aged 80 years compared with younger ages since the early 1980 s, and similar survival estimates to the present NSW data [4,26]. Although numbers of life years lost through premature death at an old age would generally be much lower than for deaths at a young age, the question arises whether gains in survival for older patients can be increased.