Victorian Cancer Registry Data Research Articles

Do age at diagnosis, tumour thickness and tumour site explain sex differences in melanoma survival? A causal mediation analysis using cancer registry data.

Women diagnosed with melanoma have better survival than men, but little is known about potential intervention targets to reduce this survival gap by sex. We conducted a population-based study using Victorian Cancer Registry data including 5833 women and 6780 men aged 15 to 70 years when diagnosed with first primary melanoma between 2007 and 2015. Deaths to the end of 2020 were identified through linkage to the Victorian and national death registries. We estimated the effect of age at diagnosis, tumour thickness and tumour site on reducing the melanoma-specific survival gap by sex (ie, interventional indirect effects [IIEs]) on risk difference (RD) scale. Compared to women, there were 211 (95% CI: 145-278) additional deaths per 10 000 in men within 5 years following diagnosis. We estimated that 44% of this gap would be reduced by a hypothetical intervention shifting the distribution of melanoma thickness in men to be the same as that observed for women (IIEthickness RD 93 [95% CI: 75-118] per 10 000) and 20% by an intervention on tumour site (head and neck/trunk vs upper limb/lower limb; IIEsite RD 42 [95% CI: 15-72] per 10 000), while an intervention on age at diagnosis would have a negligible effect. Tumour thickness, tumour site and age at diagnosis mediated 65% of the effect of sex on 5-year melanoma survival in Victoria. Of these factors, tumour thickness had the most considerable mediating effect, suggesting that effective promotion of earlier detection of melanoma in men could potentially nearly halve the gap in melanoma-specific survival by sex.

Assessment of Breast Cancer Mortality Trends Associated With Mammographic Screening and Adjuvant Therapy From 1986 to 2013 in the State of Victoria, Australia

Diagnosis of early breast cancer (EBC) in women by mammographic screening and postsurgical adjuvant endocrine therapy and chemotherapy (termed adjuvant therapy) began simultaneously in many countries in the 1990s. Subsequent breast cancer mortality declines were variously attributed to mammographic screening and/or adjuvant therapy. To determine the relative mortality reductions associated with these 2 interventions in women with EBC who had been exposed to both. This secondary analysis of cross-sectional studies assessed groups of women with invasive breast cancer in the State of Victoria, Australia, from January 1, 1982, to December 31, 2013, who were included in the Victorian Cancer Registry (VCR). The population consisted of participants in population-based studies of female breast cancer from 1986 to 2013 using data from 4 VCR population-based surveys of breast cancer treatment from 1986 to 1999; VCR data on breast cancer incidence, mortality, and TNM stage at diagnosis from 1986 to 2013; and Victorian mammographic screening program (BreastScreen Victoria) data from 1992 to 2007. Breast cancer incidence and mortality data were analyzed for all 76 630 women registered with invasive breast cancer with the VCR from January 1, 1982, to December 31, 2013, and breast cancer treatment and screening data were analyzed additionally for the groups of surveyed women as described above. Participation in BreastScreen Victoria and receipt of adjuvant therapy after surgery for EBC. Data were analyzed for associations between crude breast cancer mortality trends and uptake of adjuvant therapy and downstaging by mammographic screening. Of all 76 630 women registered with breast cancer with the VCR from January 1, 1982, to December 31, 2013. Joinpoint analyses of the time trend in crude mortality showed an increase from 31.6 per 100 000 women in 1982 to 34.3 per 100 000 women in 1994, with a single joinpoint at 1994, followed by a significant declining trend to 23.9 per 100 000 women in 2013 (annual percentage change, -1.3%; 95% CI, -1.6% to -0.9%). By 1999, 74% of all Victorian women with EBC (737 of 1001) had commenced adjuvant endocrine therapy, and 72% (187 of 260) of premenopausal and 29% (215 of 741) of postmenopausal women with EBC had commenced adjuvant chemotherapy. Crude incidence of advanced-stage breast cancer almost doubled from 12.2 per 100 000 women in 1986 to 23.9 per 100 000 women in 2013. This study found that mammographic screening did not downstage breast cancer in Victoria from advanced to early, so population mortality benefit is lacking. Adjuvant therapy uptake was associated with all of the decline in Victorian breast cancer mortality since 1994. Given these findings, monitoring the relative contributions of mammographic screening and adjuvant therapy for EBC to breast cancer mortality reductions in populations of women exposed to both should be mandatory.

Epidemiology of sepsis in cancer patients in Victoria, Australia: a population‐based study using linked data

ObjectiveTo determine the clinical characteristics, outcomes and longitudinal trends of sepsis occurring in cancer patients. MethodRetrospective study using statewide Victorian Cancer Registry data linked to various administrative datasets. ResultsAmong 215,763 incident cancer patients, incidence of sepsis within one year of cancer diagnosis was estimated at 6.4%. The incidence of sepsis was higher in men, younger patients, patients diagnosed with haematological malignancies and those with de novo metastatic disease. Of the 13,316 patients with a first admission with sepsis, 55% had one or more organ failures, 29% required care within an intensive care unit and 13% required mechanical ventilation. Treatments associated with the highest sepsis incidence were stem cell/bone marrow transplant (33%), major surgery (4.4%), chemotherapy (1.1%) and radical radiotherapy (0.6%). The incidence of sepsis with organ failure increased between 2008 and 2015, while 90‐day mortality decreased. ConclusionsSepsis in patients with cancer has high mortality and occurs most frequently in the first year after cancer diagnosis. Implications for public healthThe number of cancer patients diagnosed with sepsis is expected to increase, causing a substantial burden on patients and the healthcare system.

The increasing use of shave biopsy for diagnosing invasive melanoma in Australia.

To assess changes in the choice of skin biopsy technique for assessing invasive melanoma in Victoria, and to examine the impact of partial biopsy technique on the accuracy of tumour microstaging. Retrospective cross-sectional review of Victorian Cancer Registry data on invasive melanoma histologically diagnosed in Victoria during 2005, 2010, and 2015. 400 patients randomly selected from each of the three years, stratified by final tumour thickness: 200 patients with thin melanoma (<1.0mm), 100 each with intermediate (1.0-4.0mm) and thick melanoma (>4.0mm). Partial and excisional biopsies, as proportions of all skin biopsies; rates of tumour base transection and T-upstaging, and mean tumour thickness underestimation following partial biopsy. 833 excisional and 337 partial diagnostic biopsies were undertaken. The proportion of partial biopsies increased from 20% of patients in 2005 to 36% in 2015 (P<0.001); the proportion of shave biopsies increased from 9% in 2005 to 20% in 2015 (P<0.001), with increasing rates among dermatologists and general practitioners. Ninety-four of 175 shave biopsies (54%) transected the tumour base; wide local excision subsequently identified residual melanoma in 65 of these cases (69%). Twenty-one tumours diagnosed by shave biopsy (12%) were T-upstaged. With base-transected shave biopsies, tumour thickness was underestimated by a mean 2.36mm for thick, 0.48mm for intermediate, and 0.07mm for thin melanomas. Partial biopsy, particularly shave biopsy, was increasingly used for diagnosing invasive melanoma between 2005 and 2015. Shave biopsy has a high rate of base transection, reducing the accuracy of tumour staging, which is crucial for planning appropriate therapy, including definitive surgery and adjuvant therapy.

Validating the use of Medicare Australia billing data to examine trends in skin cancer

Background: Epidemiological data surrounding non-melanomatous skin cancer (NMSC) is highly variable, in part due to the lack of government cancer registries. Several studies employ the use of Medical Australia (MA) rebate data in assessing such trends, the validity of which has not been studied in the past. Conversely, melanoma skin cancer is a notifiable disease, and thus, MA and cancer registry data is readily available. The aim of the current study is to assess the use of MA for epidemiological measures for skin cancers, by using melanoma as a disease sample. Methods: Following ethics approval, data from MA and Victorian Cancer Registry (VCR) from 2004-2008 were extracted. Incidence of MA and VCR unique melanoma cases were compared and stratified by age and local government area (LGA). Regression and a paired-samples t-test were performed. Results: During the study period; 15,150 and 13,886 unique melanoma patients were identified through VCR and MA data sources respectively. An outlier in the >80­ year age group was noted between MA and VCR data. When stratified by age, significant correlation between MA and VCR was observed for all patients (gradient 0.91, R²= 0.936) and following exclusion of >80 patients (gradient 0.96, R²= 0.995). When stratified by LGA, a high degree of observation was observed for all patients (gradient 0.94, R²= 0.977) and following exclusion of >80 patients (gradient 0.996, R²= 0.975). Conclusion: Despite the inclusion of outlier data groups, acceptable correlation between MA and VCR melanoma data was observed, suggesting that MA may be suitable for assessing epidemiological trends. Such principals may be used to validate the use of MA data for similar calculations assessing NMSC trends.

Validating the use of Medicare Australia billing data to examine trends in skin cancer.

Epidemiological data surrounding non-melanomatous skin cancer (NMSC) is highly variable, in part due to the lack of government cancer registries. Several studies employ the use of Medical Australia (MA) rebate data in assessing such trends, the validity of which has not been studied in the past. Conversely, melanoma skin cancer is a notifiable disease, and thus, MA and cancer registry data is readily available. The aim of the current study is to assess the use of MA for epidemiological measures for skin cancers, by using melanoma as a disease sample. Following ethics approval, data from MA and Victorian Cancer Registry (VCR) from 2004-2008 were extracted. Incidence of MA and VCR unique melanoma cases were compared and stratified by age and local government area (LGA). Regression and a paired-samples t-test were performed. During the study period; 15,150 and 13,886 unique melanoma patients were identified through VCR and MA data sources respectively. An outlier in the >80- year age group was noted between MA and VCR data. When stratified by age, significant correlation between MA and VCR was observed for all patients (gradient 0.91, R²= 0.936) and following exclusion of >80 patients (gradient 0.96, R²= 0.995). When stratified by LGA, a high degree of observation was observed for all patients (gradient 0.94, R²= 0.977) and following exclusion of >80 patients (gradient 0.996, R²= 0.975). Despite the inclusion of outlier data groups, acceptable correlation between MA and VCR melanoma data was observed, suggesting that MA may be suitable for assessing epidemiological trends. Such principals may be used to validate the use of MA data for similar calculations assessing NMSC trends.

Monosomal Karyotype Is Associated With Worse Survival Independent Of Complex Karyotype In Patients With Myelodysplastic Syndrome

BackgroundThere are conflicting data on the impact of monosomal karyotype (MK) on overall survival (OS) in patients with myelodysplastic syndrome (MDS) and in particular whether MK is an independent predictor of survival in the subset of MDS patients with a complex karyotype (CK). We aimed to determine whether MK was associated with inferior survival independent of number of cytogenetic abnormalities. MethodsPatients and data sources: A retrospective cohort study was performed using three population-based datasets from the Australian state of Victoria (population approximately 5.3 million). All incident cases of MDS notified to the Victorian Cancer Registry (VCR) from 2000 to 2010 were included. VCR data was linked with cytogenetic testing results performed by The Victorian Cancer Cytogenetic Service, the single provider of cytogenetic services for hematological malignancies in Victoria, and with hospital admission records held within the Victorian Admission Episode Database (VAED), a database of all hospital admissions within the state of Victoria. Cytogenetics: Metaphase cytogenetic analysis was performed according to standard techniques and karyotypes were described using the International System for Cytogenetic Nomenclature (ISCN). Statistical analysis: MK was defined as the presence of 2 or more autosomal monosomies or one monosomy with at least one additional structural abnormality. CK was defined as 3 or more cytogenetic abnormalities (CA). Overall survival (OS) was defined from date of diagnosis until death, censoring surviving patients at study end. OS was estimated using Kaplan-Meier curves, with survival between groups compared with the log rank test. Multivariable analysis was performed using the Cox proportional regression method, including all those variables associated with OS with a p-value less than 0.2 on univariate analysis. Results1476 incident MDS cases notified to the VCR had cytogenetic testing performed. Metaphase cytogenetic testing was successful in 1407 cases (95%). The median age at diagnosis was 77 (interquartile range [IQR] 69-83) and 866 (62%) were male. The most common MDS subtypes were refractory anemia (RA) with multi-lineage dysplasia (n=482; 34%), RA with excess blasts (RAEB, n=243, 17%), RA (n=136, 9%), RA with ring sideroblasts (n=127, 9%) and not specified in 334 (24%). Hospital admission records were available for 1197 (85%), of whom 676 (56%) had one or more co-morbidity and 150 (12%) were red cell transfusion dependent (RC-TD) at diagnosis. 908 (65%) had a normal karyotype and 499 (34%) had at least one cytogenetic abnormality. CK was present in 129 (9%) and more than 5 CA in 96 (7%). MK was present in 90 (6%), of whom 82 (91%) also had CK and 74 (82%) also had 5 or more CA. Patients with a MK had worse overall survival compared to patients who did not have a MK (non-MK) (median OS 7 months vs. 41 months, Figure 1, p<0.001). Strikingly, MK was associated with worse survival than non-MK in patients with CK (median OS 6 months vs. 18 months, Figure 2, p<0.001) and in those with 5 or more CA (median OS 5 months vs. 9 months, p=0.0091, Figure 3). Variables included in the multivariable analysis were MDS subtype, age, sex, RC-TD, comorbidities, bone marrow blasts, MK, 5 or more CA, presence of monosomal 7 and/or monosomal 5, marker chromosomes and ring chromosomes. In multivariable analysis, stratified by MDS subtype, factors associated with worse survival were MK (hazard ratio [HR] 2.3, 95% CI 1.3 – 4.2, p=0.006), 5 or more CA (HR 2.4, 95% CI 1.4 – 3.9, p=0.001), aged 75 years or older (HR 2.1, 95% CI 1.6 – 2.7, p<0.001), RC-TD (HR 1.9, 95% CI 1.5 – 2.4, p<0.001), co-morbidity at diagnosis (HR 1.5, 95% CI 1.3 – 1.8, p <0.001) and bone marrow blasts more than 10% (HR 2.0, 95% CI 1.4 – 2.9, p<0.001). [Display omitted] [Display omitted] [Display omitted] ConclusionIn our representative cohort of MDS patients identified through population-level data sets from a large and well-defined population, MK is associated with worse OS in patients with MDS independent of the number of cytogenetic abnormalities. MK was one of the strongest predictors of survival in multivariable analysis and retained prognostic utility even in patients with CK where it was associated with an approximately 50% reduction in median survival. Thus, our data supports the clinical utility of MK as a predictor of adverse outcome in MDS. Disclosures:Wood:CSL Behring: Research Funding.

Cancer incidence and high environmental arsenic concentrations in rural populations: Results of an ecological study

A number of ecological studies have suggested associations between arsenic in drinking water and increased rates of some cancers. To investigate associations in areas with high environmental arsenic concentrations, geographical areas with surface soil inorganic arsenic concentrations of >100 mg/kg and/ or drinking water arsenic concentrations >0.01 mg/l were selected and the relationship with cancer incidence explored. Standardised incidence rates (SIRs) for cancer were generated for 22 areas between 1982 and 1991 using Victorian Cancer Registry data and Victorian cancer rates as a baseline. SIRs were also generated for combined areas according to environmental exposure type, i.e. whether an area had high soil and/or high water arsenic concentrations. The SIRs for both males and females for the combined 22 areas were increased for all cancers 1.06 (95% confidence interval, CI; 1.03-1.09), prostate cancer 1.14 (1.05-1.23), kidney cancer 1.16 (0.98-1.37), melanoma 1.36 (1.24-1.48), chronic myeloid leukemia 1.54 (1.13-2.10) and breast cancer in females 1.10 (1.03-1.18). When stratifying into exposure categories, the SIR for prostate cancer was significant at 1.20 (1.06-1.36) for the high soil/high water category only. No significant dose- response relationship between drinking water and individual cancers was observed. Of the a priori cancers associated with environmental arsenic exposure, only prostate cancer incidence was significantly elevated in this study. This result was likely confounded by a number of factors and was limited by low power and exposure misclassification.

Trebling of the incidence of testicular cancer in victoria, Australia (1950-1985).

Changes in the incidence of testicular cancer in Victoria, Australia were studied from 1950 to 1985. Cases from the period 1950 to 1978 were derived from many sources (1116 cases). Emphasis was placed on diagnostic reliability; 97% of cases were confirmed histologically, and of these, 86% were reviewed at the Peter MacCallum Cancer Institute. For the years 1982 to 1985, Victorian Cancer Registry data were used. The incidence rose by a factor of 2.9 from 1.44 (95% confidence interval [CI], 1.15 to 1.73) per 100,000 in 1950 to 1954 to 4.16 (95% CI, 3.73 to 4.59) per 100,000 in 1982 to 1985. Between 1950 to 1954 and 1965 to 1969, there was a sharp rise, followed by a plateau or dip, then a further rise. Among seminomas, the rates rose in most adult age groups, whereas among nonseminomas, the rise was concentrated in younger age groups. There was a significant trend to earlier age of occurrence among nonseminomas (P = 0.0004) but not among seminomas (P = 0.89). Cohort analysis revealed a trend toward increasing rates for both seminomas and nonseminomas, and confirmed the trend toward earlier age of onset for nonseminomas. Disproportionate increases were observed for the 1915 to 1924 cohort of seminomas and the 1930 to 1939 cohort of nonseminomas. Analysis of available data from other Australian states indicated comparable rising incidence in New South Wales, Tasmania, and Western Australia.