Showing papers by "Peter D. Baade published in 2010"

Clinical whole-body skin examination reduces the incidence of thick melanomas

Abstract: Survival from melanoma is strongly related to tumour thickness, thus earlier diagnosis has the potential to reduce mortality from this disease. However, in the absence of conclusive evidence that clinical skin examination reduces mortality, evidence-based assessments do not recommend population screening. We aimed to assess whether clinical whole-body skin examination is associated with a reduced incidence of thick melanoma and also whether screening is associated with an increased incidence of thin lesions (possible overdiagnosis). We conducted a population-based case-control study of all Queensland residents aged 20-75 years with a histologically confirmed first primary invasive cutaneous melanoma diagnosed between January 2000 and December 2003. Telephone interviews were completed by 3,762 eligible cases (78.0%) and 3,824 eligible controls (50.4%). Whole-body clinical skin examination in the three years before diagnosis was associated with a 14% lower risk of being diagnosed with a thick melanoma (>0.75 mm) (OR = 0.86, 95% CI = 0.75, 0.98). Risk decreased for melanomas of increasing thickness: the risk of being diagnosed with a melanoma 0.76-1.49 mm was reduced by 7% (OR = 0.93, 95% CI 0.79, 1.10), by 17% for melanomas 1.50-2.99 mm (OR = 0.83, 95% CI = 0.65, 1.05) and by 40% for melanomas > or =3 mm (OR = 0.60, 95% CI = 0.43, 0.83). Screening was associated with a 38% higher risk of being diagnosed with a thin invasive melanoma (< or =0.75 mm) (OR = 1.38, 95% CI = 1.22, 1.56). This is the strongest evidence to date that whole-body clinical skin examination reduces the incidence of thick melanoma. Because survival from melanoma is strongly related to tumour thickness, these results suggest that screening would reduce melanoma mortality.

Trends in incidence of childhood cancer in Australia, 1983–2006

Abstract: There are few population-based childhood cancer registries in the world containing stage and treatment data. Data from the population-based Australian Paediatric Cancer Registry were used to calculate incidence rates during the most recent 10-year period (1997–2006) and trends in incidence between 1983 and 2006 for the 12 major diagnostic groups of the International Classification of Childhood Cancer. In the period 1997–2006, there were 6184 childhood cancer (at 0–14 years) cases in Australia (157 cases per million children). The commonest cancers were leukaemia (34%), that of the central nervous system (23%) and lymphomas (10%), with incidence the highest at 0–4 years (223 cases per million). Trend analyses showed that incidence among boys for all cancers combined increased by 1.6% per year from 1983 to 1994 but have remained stable since. Incidence rates for girls consistently increased by 0.9% per year. Since 1983, there have been significant increases among boys and girls for leukaemia, and hepatic and germ-cell tumours, whereas for boys, incidence of neuroblastomas and malignant epithelial tumours has recently decreased. For all cancers and for both sexes combined, there was a consistent increase (+0.7% per year, 1983–2006) at age 0–4 years, a slight non-significant increase at 5–9 years, and at 10–14 years, an initial increase (2.7% per year, 1983–1996) followed by a slight non-significant decrease. Although there is some evidence of a recent plateau in cancer incidence rates in Australia for boys and older children, interpretation is difficult without a better understanding of what underlies the changes reported.

Population-based survival estimates for childhood cancer in Australia during the period 1997-2006

Abstract: This study provides the latest available relative survival data for Australian childhood cancer patients. Data from the population-based Australian Paediatric Cancer Registry were used to describe relative survival outcomes using the period method for 11 903 children diagnosed with cancer between 1983 and 2006 and prevalent at any time between 1997 and 2006. The overall relative survival was 90.4% after 1 year, 79.5% after 5 years and 74.7% after 20 years. Where information onstage at diagnosis was available (lymphomas, neuroblastoma, renal tumours and rhabdomyosarcomas), survival was significantly poorer for more-advanced stage. Survival was lower among infants compared with other children for those diagnosed with leukaemia, tumours of the central nervous system and renal tumours but higher for neuroblastoma. Recent improvements in overall childhood cancer survival over time are mainly because of improvements among leukaemia patients. The high and improving survival prognosis for children diagnosed with cancer in Australia is consistent with various international estimates. However, a 5-year survival estimate of 79% still means that many children who are diagnosed with cancer will die within 5 years, whereas others have long-term health morbidities and complications associated with their treatments. It is hoped that continued developments in treatment protocols will result in further improvements in survival.

Diagnostic and treatment pathways for men with prostate cancer in Queensland: investigating spatial and demographic inequalities.

Abstract: Background Patterns of diagnosis and management for men diagnosed with prostate cancer in Queensland, Australia, have not yet been systematically documented and so assumptions of equity are untested. This longitudinal study investigates the association between prostate cancer diagnostic and treatment outcomes and key area-level characteristics and individual-level demographic, clinical and psychosocial factors.

A multilevel study of the determinants of area-level inequalities in colorectal cancer survival.

Abstract: Background In Australia, associations between geographic remoteness, socioeconomic disadvantage, and colorectal cancer (CRC) survival show that survival rates are lowest among residents of geographically remote regions and those living in disadvantaged areas. At present we know very little about the reasons for these inequalities, hence our capacity to intervene to reduce the inequalities is limited.

A multilevel study of the determinants of area-level inequalities in colorectal cancer survival

Abstract: Background: In Australia, associations between geographic remoteness, socioeconomic disadvantage, and colorectal cancer (CRC) survival show that survival rates are lowest among residents of geographically remote regions and those living in disadvantaged areas. At present we know very little about the reasons for these inequalities, hence our capacity to intervene to reduce the inequalities is limited. Methods/Design: This study, the first of its type in Australia, examines the association between CRC survival and key area- and individual-level factors. Specifically, we will use a multilevel framework to investigate the possible determinants of area- and individual-level inequalities in CRC survival and quantify the relative contribution of geographic remoteness, socioeconomic and demographic factors, disease stage, and access to diagnostic and treatment services, to these inequalities. The multilevel analysis will be based on survival data relating to people diagnosed with CRC in Queensland between 1996 and 2005 (n = 22,723) from the Queensland Cancer Registry (QCR), area-level data from other data custodians such as the Australian Bureau of Statistics, and individual-level data from the QCR (including extracting stage from pathology records) and Queensland Hospitals. For a subset of this period (2003 and 2004) we will utilise more detailed, individual-level data (n = 1,966) covering a greater range of risk factors from a concurrent research study. Geo-coding and spatial technology will be used to calculate road travel distances from patients’ residence to treatment centres. The analyses will be conducted using a multilevel Cox proportional hazards model with Level 1 comprising individual-level factors (e.g. occupation) and level 2 area level indicators of remoteness and area socioeconomic disadvantage. Discussion: This study focuses on the health inequalities for rural and disadvantaged populations that have often been documented but poorly understood, hence limiting our capacity to intervene. This study utilises and develops emerging statistical and spatial technologies that can then be applied to other cancers and health outcomes. The findings of this study will have direct implications for the targeting and resourcing of cancer control programs designed to reduce the burden of colorectal cancer, and for the provision of diagnostic and treatment services.

Supportive care intervention in prostate cancer: recent advances and future challenges

Abstract: Prostate cancer is highly heterogeneous in its nature, effects, pattern of progression and outcomes. Survival, treatment approaches and mortality, differ substantially by socio-economic and geographic factors, and psychosocial outcomes are also likely to be affected by these factors and other personal characteristics. While a number of therapeutic approaches to supportive care have been found to have efficacy, unless these are responsive to patient preferences and can be integrated into routine clinical services or existing community services infrastructure, these are unlikely to translate broadly in the field. Accordingly, a framework to underpin the development of supportive care interventions is suggested that has application in not only genitourinary cancer, but cancer more generally.

No role for melanoma treatment in the association between melanoma and amyotrophic lateral sclerosis or Parkinson's disease.

Abstract: In 2007 we published the results of our study of all people diagnosed as having melanoma in Australia between 1982 and 2001, and compared their mortality risk of amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD) to the general population [1]. Although the absolute risk was small, the melanoma cohort had a 70% higher risk of death due to ALS and a nearly 3-fold higher risk of death due to PD than the general population, consistent with a US study [2], strengthening the evidence for an association between melanoma and each of the 2 neurodegenerative diseases. In Australia, surgical excision is the preferred treatment for melanoma, with no patient receiving adjuvant therapy after resection of a primary lesion. Patients with stage III disease rarely receive interferon, with most being watched or treated in clinical trials. The only melanoma patients who receive chemotherapy are those diagnosed as having a stage IV melanoma. We suggested that it was unlikely that treatment was an explanation for the observed association [3]. However, in the absence of definitive data about the thickness of melanomas in the study cohort, it was possible that a large proportion of melanoma patients who died of either ALS or PD had thicker melanomas. Thus this treatment hypothesis remained a possibility, particularly when several chemotherapeutics that could be used in the treatment of more advanced melanoma have neurotoxic effects [4,5]. While specific treatment data are not available, we sought additional information about the thickness of the melanoma among our original melanoma cohort. In the absence of stage information, thickness is the strongest predictor of survival [6]. This information was provided by the Australian Institute of Health and Welfare, who matched the melanoma cohort information with the melanoma thickness details collected by each of the state and territory cancer registries. Before 1990 there was a relatively large proportion of melanoma cases with missing thickness data (∼27%), so we have presented thickness data for the full period and the restricted 1990–2001 period (∼9% missing thickness). These results (table ​(table1)1) show that of the 53 melanoma patients who died of ALS, only 1 (2%) was known to have melanoma diagnosed >4 mm thickness. The corresponding percentage among the 128 melanoma patients who died of PD was 13% (n = 16). Table 1 Melanoma thickness for persons diagnosed as having melanoma in Australia between 1982 and 2001 While not definitive, the thickness distribution for the melanoma patients who died of ALS or PD provides greater weight to the hypothesis that chemotherapeutics have played minimal or no role in the previously reported association. As such we felt it was important to disseminate this information in order to more appropriately focus future research efforts in understanding the biological bases of the co-occurrence of both diseases. Alternative mechanisms to explain the co-occurrence could include genetic variants and gene expression changes in pigmentation genes occurring in PD [7] and in ALS [8]; shared embryological origin for melanocytes and neurons, commonalities between melanin and dopamine synthesis and variants of melastatins (TRPMs) [9,10], due to the involvement of selected TRPMs in this cancer and in neuronal cell death.

care intervention in prostate cancer: recent advances and future challenges

Abstract: Prostate cancer is the most common invasive cancer among males, with 16,349 men diagnosed in Australia in 2005, more than twice as many than with colorectal cancer. 1 Prostate cancer incidence trends are highlighted by the rapid rise in incidence soon after the introduction of prostate specific antigen (PSA) testing in the early 1990s, followed by a sharp reduction in rates, and then a gradual increase since 2000. 2 Mortality rates due to prostate cancer in Australia started to decrease from 1993 onwards, with these reductions in mortality also being seen internationally. 2 The implications of these trends for supportive care services are that the cohort of men in our community who are living with the consequences of prostate cancer is increasing. In 2004, there were about 100,000 Australian men estimated to be living with a diagnosis of prostate cancer, 3 with prevalence increasing due to current incidence and survival patterns. Hence, an understanding of effective approaches to psychosocial care for these men and their families, and the challenges to be faced in delivering this care in an approach that is both equitable and evidence-based, is crucial for public health in Australia.