Paramita Dasgupta

Geographic remoteness and risk of advanced colorectal cancer at diagnosis in Queensland: a multilevel study.

Background:We examine the relationships between geographic remoteness, area disadvantage and risk of advanced colorectal cancer.Methods:Multilevel models were used to assess the area- and individual-level contributions to the risk of advanced disease among people aged 20–79 years diagnosed with colorectal cancer in Queensland, Australia between 1997 and 2007 (n=18 561).Results:Multilevel analysis showed that colorectal cancer patients living in inner regional (OR=1.09, 1.01–1.19) and outer regional (OR=1.11, 1.01–1.22) areas were significantly more likely to be diagnosed with advanced cancer than those in major cities (P=0.045) after adjusting for individual-level variables. The best-fitting final model did not include area disadvantage. Stratified analysis suggested this remoteness effect was limited to people diagnosed with colon cancer (P=0.048) and not significant for rectal cancer patients (P=0.873).Conclusion:Given the relationship between stage and survival outcomes, it is imperative that the reasons for these rurality inequities in advanced disease be identified and addressed.

Comparing multilevel and Bayesian spatial random effects survival models to assess geographical inequalities in colorectal cancer survival: a case study

BackgroundMultilevel and spatial models are being increasingly used to obtain substantive information on area-level inequalities in cancer survival. Multilevel models assume independent geographical areas, whereas spatial models explicitly incorporate geographical correlation, often via a conditional autoregressive prior. However the relative merits of these methods for large population-based studies have not been explored. Using a case-study approach, we report on the implications of using multilevel and spatial survival models to study geographical inequalities in all-cause survival.MethodsMultilevel discrete-time and Bayesian spatial survival models were used to study geographical inequalities in all-cause survival for a population-based colorectal cancer cohort of 22,727 cases aged 20–84 years diagnosed during 1997–2007 from Queensland, Australia.ResultsBoth approaches were viable on this large dataset, and produced similar estimates of the fixed effects. After adding area-level covariates, the between-area variability in survival using multilevel discrete-time models was no longer significant. Spatial inequalities in survival were also markedly reduced after adjusting for aggregated area-level covariates. Only the multilevel approach however, provided an estimation of the contribution of geographical variation to the total variation in survival between individual patients.ConclusionsWith little difference observed between the two approaches in the estimation of fixed effects, multilevel models should be favored if there is a clear hierarchical data structure and measuring the independent impact of individual- and area-level effects on survival differences is of primary interest. Bayesian spatial analyses may be preferred if spatial correlation between areas is important and if the priority is to assess small-area variations in survival and map spatial patterns. Both approaches can be readily fitted to geographically enabled survival data from international settings.

A systematic review of inequalities in psychosocial outcomes for women with breast cancer according to residential location and Indigenous status in Australia.

The aim of this systematic review was to examine variations in psychosocial outcomes by residential location and Indigenous status in women diagnosed with breast cancer (BC) in Australia.

Geographical disparity in breast reconstruction following mastectomy has reduced over time.

Breast reconstruction (BR) following mastectomy for breast cancer has been shown to improve quality of life and body image; however, there is significant geographic variation in BR rates. We explored factors associated with BR following mastectomy.

Geographical inequalities in surgical treatment for localized female breast cancer, Queensland, Australia 1997–2011: improvements over time but inequalities remain

The uptake of breast conserving surgery (BCS) for early stage breast cancer varies by where women live. We investigate whether these geographical patterns have changed over time using population-based data linkage between cancer registry records and hospital inpatient episodes. The study cohort consisted of 11,631 women aged 20 years and over diagnosed with a single primary invasive localised breast cancer between 1997 and 2011 in Queensland, Australia who underwent either BCS (n = 9223, 79%) or mastectomy (n = 2408, 21%). After adjustment for socio-demographic and clinical factors, compared to women living in very high accessibility areas, women in high (Odds Ratio (OR) 0.58 (95% confidence intervals (CI) 0.49, 0.69)), low (OR 0.47 (0.41, 0.54)) and very low (OR 0.44 (0.34, 0.56)) accessibility areas had lower odds of having BCS, while the odds for women from middle (OR 0.81 (0.69, 0.94)) and most disadvantaged (OR 0.87 (0.71, 0.98)) areas was significantly lower than women living in affluent areas. The association between accessibility and the type of surgery reduced over time (interaction p = 0.028) but not for area disadvantage (interaction p = 0.209). In making informed decisions about surgical treatment, it is crucial that any geographical-related barriers to implementing their preferred treatment are minimised.

Variations in outcomes for Indigenous women with breast cancer in Australia: A systematic review

&NA; This systematic review examines variations in outcomes along the breast cancer continuum for Australian women by Indigenous status. Multiple databases were systematically searched for peer‐reviewed articles published from 1 January 1990 to 1 March 2015 focussing on adult female breast cancer patients in Australia and assessing survival, patient and tumour characteristics, diagnosis and treatment by Indigenous status. Sixteen quantitative studies were included with 12 rated high, 3 moderate and 1 as low quality. No eligible studies on referral, treatment choices, completion or follow‐up were retrieved. Indigenous women had poorer survival most likely reflecting geographical isolation, advanced disease, patterns of care, comorbidities and disadvantage. They were also more likely to be diagnosed when younger, have advanced disease or comorbidities, reside in disadvantaged or remote areas, and less likely to undergo mammographic screening or surgery. Despite wide heterogeneity across studies, an overall pattern of poorer survival for Indigenous women and variations along the breast cancer continuum of care was evident. The predominance of state‐specific studies and small numbers of included Indigenous women made forming a national perspective difficult. The review highlighted the need to improve Indigenous identification in cancer registries and administrative databases and identified key gaps notably the lack of qualitative studies in current literature.

Sentinel node biopsy for early breast cancer in Queensland, Australia, during 2008–2012

Sentinel node biopsy (SNB) is now the standard of care for women with early‐stage breast cancer. Despite lower morbidity than axillary lymph node dissection, widespread variation in SNB rates by non‐clinical factors persists. We explored the factors associated with SNB usage and changes in those associations over time for recently diagnosed women.

Partner status and survival after cancer: A competing risks analysis

OBJECTIVE The survival benefits of having a partner for all cancers combined is well recognized, however its prognostic importance for individual cancer types, including competing mortality causes, is less clear. This study was undertaken to quantify the impact of partner status on survival due to cancer-specific and competing mortality causes. METHODS Data were obtained from the population-based Queensland Cancer Registry on 176,050 incident cases of ten leading cancers diagnosed in Queensland (Australia) from 1996 to 2012. Flexible parametric competing-risks models were used to estimate cause-specific hazards and cumulative probabilities of death, adjusting for age, stage (breast, colorectal and melanoma only) and stratifying by sex. RESULTS Both unpartnered males and females had higher total cumulative probability of death than their partnered counterparts for each site. For example, the survival disadvantage for unpartnered males ranged from 3% to 30% with higher mortality burden from both the primary cancer and competing mortality causes. The cause-specific age-adjusted hazard ratios were also consistent with patients without a partner having increased mortality risk although the specific effect varied by site, sex and cause of death. For all combined sites, unpartnered males had a 46%, 18% and 44% higher risk of cancer-specific, other cancer and non-cancer mortality respectively with similar patterns for females. The higher mortality risk persisted after adjustment for stage. CONCLUSIONS It is important to better understand the mechanisms by which having a partner is beneficial following a cancer diagnosis, so that this can inform improvements in cancer management for all people with cancer.

Estimating cancer survival – improving accuracy and relevance

Australian and New Zealand Journal of Public Health 403

Competing mortality risks among women aged 50–79 years when diagnosed with invasive breast cancer, Queensland, 1997–2012

BACKGROUND Understanding the burden of competing (non-breast cancer) mortality is important for the growing number of breast cancer survivors. We quantity these patterns, and the impact of two leading non-cancer causes of death, within ten years of breast cancer diagnosis. METHODS Population based cancer registry study of 23,809 women aged 50-79 diagnosed with first primary breast cancer in Queensland, Australia, 1997 to 2012 with additional data linkage to identify individual non-cancer mortality causes. Flexible parametric competing-risks models were used to estimate the crude and adjusted probabilities of death. RESULTS While overall mortality increased with age at diagnosis, this effect was strongest for non-cancer (such as cardiovascular and cerebrovascular disease) mortality. Women diagnosed with advanced breast cancer had a higher crude probability of breast cancer death (23.1% versus 4.5% for localised) but similar probability of competing mortality (11.6% versus 11.3%). Within each category of spread of disease, the probability of breast-cancer deaths remained relatively constant with age, while the probability of competing deaths increased. The 10-year probability of dying from breast cancer was 3.7%, 4.2% and 5.6% among women with localised disease aged 50 to 59, 60-69 and 70-79 respectively, but 3.1%, 7.8% and 22.9% for competing mortality. Increasing age, advanced disease and being unpartnered were independently associated with increased risk of breast cancer and competing deaths. CONCLUSIONS Promotion of improved health behaviors after a cancer diagnosis and development of individualized strategies for clinical management should be prioritized as part of optimal care for breast cancer survivors.