Trends in colon and rectal cancer mortality in Australia from 1972 to 2015 and associated projections to 2040.

Previously published sub-site Australian projections for colon and rectal cancers to 2035 using the World Health Organization's mortality database sourced from the Australian Bureau of Statistics (ABS) predicted mortality rate decreases for colon cancer and increases for rectal cancer. There are complexities related to the interpretation of ABS's Australian colon and rectal cancer mortality rates, which could lead to possible inaccuracies in mortality rates for these sub-sites. The largest Australian population-wide registry, New South Wales Cancer Registry (NSWCR), compares routinely-reported causes of death with the recorded medical history from multiple data sources. Therefore, this study used the NSWCR data to project mortality rates for colon and rectal cancers separately to 2040 in Australia. The mortality rates for colon cancer are projected to continuously decline over the period 2015-2040, from 7.0 to 4.7 per 100,000 males, and from 5.3 to 3.2 per 100,000 females. Similar decreasing trends in mortality rates for rectal cancer were projected over the period 2015-2040, from 4.9 to 3.7 per 100,000 males, and from 2.6 to 2.3 per 100,000 females. These projections provide benchmark estimates for the colorectal cancer burden in Australia against which the effectiveness of cancer control interventions can be measured.

Assessing a modified-AJCC TNM staging system in the New South Wales Cancer Registry, Australia.

BACKGROUND: In 2017, the New South Wales Cancer Registry (NSWCR) participated in a project, supported by Cancer Australia, aiming to provide national stage data for melanoma, prostate, colorectal, breast, and lung cancers diagnosed in 2011. Simplified business rules based on the American Joint Committee for Cancer (AJCC) Tumour-Node-Metastasis (TNM) stage were applied to obtain Registry-Derived (RD) stage, defined as the best estimate of TNM stage at diagnosis using routine notifications available within cancer registries. RD-stage was compared with Degree of Spread (DoS), which has been recorded for all applicable cancers in NSWCR at a population-based level since 1972, and a summary AJCC-TNM stage group, which has been collected variably since 2006. For each of the five high incidence cancers, we compared the level of improvements RD-staging provided in terms of completeness and accuracy (alignment to more clinically relevant AJCC-TNM) over DoS. METHODS: For each of the five cancers, stage data were extracted from NSWCR pre- and post- RD-staging to compare data completeness across all three staging systems. The alignment between DoS/RD-stage and AJCC-TNM was compared, as were the expected and observed cross-tabulated frequency distributions using a subset of NSWCR data. To determine differences between use of DoS, RD-stage, and AJCC-TNM in an epidemiological analysis, we compared survival models developed from each of the three stage variables. RESULTS: We found RD-staging provided greatest stage data completeness and alignment to AJCC-TNM for prostate cancers, followed by breast, then melanoma and lung cancers. For colorectal cancer, summary stage from DoS was confirmed as an equivalent surrogate staging system to both AJCC-TNM and RD-stage. CONCLUSIONS: This analysis provides an evidence-based approach that can be used to inform decision-making for resource planning and potential implementation of a new stage data field in population-based cancer registries.

Competing risk analysis of mortality from invasive cutaneous melanoma in New South Wales: a population-based study, 1988-2007.

OBJECTIVE: Accurate estimates of risk of death from melanoma, based on the most recent information, are desirable, especially if secular improvements in survival have occurred. This study aims to investigate prognostic factors and temporal changes in mortality from primary invasive cutaneous melanoma (CM) and to predict cumulative probabilities of death from CM. METHODS: Cases of CM from the NSW Central Cancer Registry (NSWCCR) diagnosed in 1988-2007 were analysed. We used Fine and Gray competing risks models to investigate prognostic factors associated with CM mortality, along with period effects of year of diagnosis. Adjusted cumulative probabilities of CM death were then estimated. RESULTS: Of 52,330 CM cases, 5291 (10%) died from CM and 8290 (16%) from other causes. Patients with tumours thicker than 4 mm had 9.5 times the risk of death from CM compared to those with tumours 1 mm or less (subhazard ratio [SHR] 9.52; 95%CI:8.42-10.77). Risk of melanoma death was 31% lower in 2003-2007 compared to 1988-1992 (SHR 0.69; 95%CI: 0.63-0.76). Other risk factors for CM mortality included older age and male gender. Assuming the estimated period effect for a diagnosis in 2003-2007 applies now, the predicted probability of CM death within 10 years of diagnosis of a tumour 4+ mm thick is 26% in males and 19% in females. CONCLUSION: This study highlights the importance of awareness and early detection and shows a significant improvement in survival from CM since 1988.

Degree-of-spread artefact in the New South Wales Central Cancer Registry.

OBJECTIVE: To describe a data artefact in degree-of-spread at first presentation in the New South Wales Central Cancer Registry (NSW CCR), the only Australian cancer registry that records degree-of-spread data for all solid tumours. METHOD: Trends in the proportions of cancer cases diagnosed annually over 1972-2004 by degree-of-spread categories of localised, regional, distant and unknown were calculated for each major cancer type. RESULTS: Excepting breast cancer and melanoma, the proportion of localised cancer cases reported from 1993-1998 was approximately 5% lower than expected, and was mirrored by an artefactual increase in unknown degree-of-spread cases. CONCLUSION: This artefact was caused by the introduction of the Electronic Notification System and cannot easily be remedied retrospectively. However, regional and distant categories of degree-of-spread in the NSW CCR data are reliably recorded for the 1972-2004 period. IMPLICATIONS: It is important that past and present cancer data users are notified and understand the quality issues with NSW CCR degree-of-spread data, and use it as recommended to avoid anomalous results or conclusions.