Protocol for evaluating the fitness for purpose of an artificial intelligence product for radiology reporting in the BreastScreen New South Wales breast cancer screening programme.

INTRODUCTION: Radiologist shortages threaten the sustainability of breast cancer screening programmes. Artificial intelligence (AI) products that can interpret mammograms could mitigate this risk. While previous studies have suggested this technology has accuracy comparable to radiologists most have been limited by using 'enriched' datasets and/or not considering the interaction between the algorithm and human readers. This study will address these limitations by comparing the accuracy of a workflow using AI alongside radiologists on a large consecutive cohort of examinations from a breast cancer screening programme. The study will combine the strengths of a large retrospective design with the benefit of prospective data collection. It will test this technology without risk to screening programme participants nor the need to wait for follow-up data. With a sample of 2 years of consecutive screening examinations, it is likely the largest test of this technology to date. The study will help determine whether this technology can safely be introduced into the BreastScreen New South Wales (NSW) population-based screening programme to address radiology workforce risks without compromising cancer detection rates or increasing false-positive recalls. METHODS AND ANALYSIS: A retrospective, consecutive cohort of digital mammography screens from 658 207 examinations from BreastScreen NSW will be reinterpreted by the Lunit Insight MMG AI product. The cohort includes 4383 screen-detected and 1171 interval cancers. The results will be compared with radiologist single reading and the AI results will also be used to replace the second reader in a double-reading model. New adjudication reading will be performed where the AI disagrees with the first reader. Recall rates and cancer detection rates of combined AI-radiologist reading will be compared with the rates obtained at the time of screening. ETHICS AND DISSEMINATION: This study has ethical approval from the NSW Health Population Health Services Research Ethics Committee (2022/ETH02397). Findings will be published in peer-reviewed journals and presented at conferences. The findings of this evaluation will be provided to programme managers, governance bodies and other stakeholders in Australian breast cancer screening programmes.

Breast screening participation and degree of spread of invasive breast cancer at diagnosis in mental health service users: A population linkage study.

BACKGROUND: Women living with mental health conditions may not have shared in improvements in breast cancer screening and care. No studies have directly examined the link between reduced screening participation and breast cancer spread in women using mental health (MH) services. METHODS: Population-wide linkage of a population cancer register, BreastScreen register, and mental health service data set in women aged 50 to 74 years in New South Wales, Australia, from 2008 to 2017. Incident invasive breast cancers were identified. Predictors of degree of spread (local, regional, metastatic) at diagnosis were examined using partial proportional odds regression, adjusting for age, socioeconomic status, rurality, and patterns of screening participation. RESULTS: A total of 29 966 incident cancers were identified and included 686 (2.4%) in women with MH service before cancer diagnoses. More than half of MH service users had regional or metastatic spread at diagnosis (adjusted odds ratio, 1.63; 95% CI, 1.41-1.89). MH service users had lower screening participation; however, advanced cancer was more common even when adjusting for screening status (adjusted odds ratio, 1.53; 95% CI, 1.32-1.77). Advanced cancer was more common in women with severe or persistent MH conditions. CONCLUSIONS: Low screening participation rates explain only small part of the risk of more advanced breast cancer in women who use MH services. More study is needed to understand possible mechanisms contributing to more advanced breast cancer in women living with MH conditions. Health systems need strategies to ensure that women living with MH conditions enjoy population gains in breast cancer outcomes.

Variation in ovarian cancer care in Australia: An analysis of patterns of care in diagnosis and initial treatment in New South Wales.

OBJECTIVE: Ovarian cancer has the highest mortality of all gynaecological cancers. This study aimed to identify the extent to which women across New South Wales experienced variation in their care in diagnosis and initial treatment for ovarian cancer against the national optimal care pathway for ovarian cancer. METHOD: Clinical audit methodology was utilised to explore variations for women with primary ovarian cancer; 171 eligible cases were identified through by the NSW Cancer Registry for the period of 1 March 2017 to 28 February 2018. RESULTS: Limited variation was detected with 86% of women being reviewed by a specialist gynaecological oncology multidisciplinary team; 54% of women received their first treatment within 28 days of their first specialist appointment, 66% of women having their first surgery completed by a gynaecological oncologist and 45% of women received their first treatment in a specialist gynaecological oncology hospital. CONCLUSION: Deviation from effective ovarian cancer care is apparent particularly in the location and timeliness of first treatment, with implications for the quality of care received and care outcomes. Understanding factors that contribute to variation is critical to ensure optimal and appropriate ovarian cancer care and to tackle systemic barriers to the provision of effective care.

The blue palate-A case series of imatinib-related oral pigmentation and literature review.

Pigmented oral mucosal lesions are diverse, and differential diagnosis can range from benign conditions such as oral melanotic macule to malignancies such as oral malignant melanoma. Imatinib mesylate is a tyrosine kinase inhibitor used as a first-line medication in the management of oncohematological conditions such as chronic myeloid leukemia and gastrointestinal stromal tumors. Side effects of imatinib therapy are common, and paradoxically imatinib has been associated with both hypo- and hyperpigmented lesions, the underlying mechanism for which is still unclear. Hyperpigmentation associated with imatinib therapy is a potentially underreported phenomenon. This article presents an in-depth, clinicopathological review of the literature surrounding imatinib-related hyperpigmentation, alongside a case series of imatinib-related oral pigmentation with notable practical learning points. A pragmatic flowchart to help clinicians in the diagnosis and management of oral pigmented lesions is provided, as well as advice on the application of the ABCDE criteria to standardize recording of oral pigmented lesions.

A service evaluation of the diagnostic testing for mucous membrane pemphigoid in a UK oral medicine unit.

BACKGROUND: Mucous membrane pemphigoid (MMP) is an uncommon bullous disease typically involving the oral cavity. The most commonly used laboratory test for the diagnosis of MMP is direct immunofluorescence (DIF) on fresh perilesional tissue; however, the sensitivity of this test may be hampered by technical difficulties. Immune-serological investigations can also be employed to render a diagnosis. The purpose of this paper was to present an evaluation of diagnostic testing for MMP within an Oral Medicine Unit in UK. METHODS: A retrospective analysis of the medical records was undertaken for patients who had undergone biopsy and DIF testing from January 2016 to December 2018. Parameters analysed included clinical presentation, histopathological features, DIF, salt-split skin indirect immunofluorescence, ELISA anti-BP180 and BP 230 and HLA-DQB1*03:01 findings. RESULTS: Thirty patients (23 females and 7 males, mean age 66.8 years old) were diagnosed with MMP through a combination of histopathology and serological testing. Sixteen patients (53%) were DIF positive, whereas in 14 (47%), MMP diagnosis was achieved using immune-serologic tests. HLA DQB1*03:01 status was undertaken in 15 DIF-positive and 12 DIF-negative patients, and HLA DQB1*03:01 was found in 73% and 58% of the cases, respectively. CONCLUSIONS: This service evaluation has shown that when DIF is informative, it remains the gold standard technique for diagnosis of MMP. However, we have also highlighted the value of serological testing for increasing diagnostic yield for patients with suspected MMP and the potential for HLA DQB1*03:01 as an adjunctive test for the evaluation of MMP.

Patterns of surgical care for women with ovarian cancer in New South Wales.

BACKGROUND: Little is known about the delivery of surgical services and outcomes for women with ovarian cancer across New South Wales (NSW). AIM: The study objective was to provide a descriptive analysis of the proportion of women who had surgery for ovarian cancer in NSW in specialist gynaecological oncology hospitals and compare outcomes for women attending specialist and non-specialist services in NSW. MATERIALS AND METHODS: This study is a retrospective analysis of women with primary ovarian, fallopian tube or peritoneal cancer from 2009 to 2012. Data were analysed from the NSW Cancer Registry, NSW Admitted Patient Data Collection and Register of Births Deaths and Marriages. Treating hospitals were characterised as public specialist, public non-specialist and private. Morbidity and mortality outcomes are reported. RESULTS: The study included 1106 women. Fifty-seven hospitals performed surgery: seven public specialist, 27 private and 23 public non-specialist hospitals. The highest proportion of surgery was performed in public specialist hospitals (61%). There was considerable variation in the utilisation of public specialist hospitals between local health districts. There was no significant difference in outcomes related to the type of hospital where surgery was performed. CONCLUSIONS: Although the majority of women are having surgery in a specialist gynaecological oncology public hospital across NSW, many are not. Women living in regional and remote NSW were less likely to have their surgery in a specialist hospital. This is the first step in understanding where women in NSW are currently receiving their surgical care, as well as the outcomes related to this.

The intercalation of 1,10-phenanthroline into layered NiPS3via iron dopant seeding.

Using 2% percent of iron dopants as reaction active sites yields a series of single crystals of 1,10-phenanthroline intercalated NiPS3, via a solution reaction with aniline chloride, not possible by a direct reaction. Experimental magnetic susceptibility measurements demonstrate that 1,10-phenanthroline intercalation suppresses the anti-ferromagnetism ordering at around 150 K in Fe0.02Ni0.98PS3, and gives rise to a ferrimagnetic phase transition at a temperature around 75 K. An intercalation mechanism is proposed for the reaction, and this dopant seeding method provides a new approach for intercalation into layered materials.

Synthesis and Polymorphism of Mixed Aluminum-Gallium Oxides.

The synthesis of a new solid solution of the oxyhydroxide Ga5-xAlxO7(OH) is investigated via solvothermal reaction between gallium acetylacetonate and aluminum isopropoxide in 1,4-butanediol at 240 °C. A limited compositional range of 0 ≤ x ≤ 1.5 is produced, with the hexagonal unit cell parameters refined from powder X-ray diffraction (XRD) showing a linear contraction in unit cell volume with an increase in Al content. Solid-state 27Al and 71Ga nuclear magnetic resonance (NMR) spectroscopies show a strong preference for Ga to occupy the tetrahedral sites and Al to occupy the octahedral sites. Using isopropanol as the solvent, γ-Ga2-xAlxO3 defect spinel solid solutions with x ≤ 1.8 can be prepared at 240 °C in 24 h. These materials are nanocrystalline, as evidenced by their broad diffraction profiles; however, the refined cubic lattice parameter shows a linear relationship with the Ga:Al content, and solid-state NMR spectroscopy again shows a preference for Al to occupy the octahedral sites. Thermal decomposition of Ga5-xAlxO7(OH) occurs via poorly ordered materials that resemble ε-Ga2-xAlxO3 and κ-Ga2-xAlxO3, but γ-Ga2-xAlxO3 transforms above 750 °C to monoclinic ß-Ga2-xAlxO3 for 0 ≤ x ≤ 1.3 and to hexagonal α-Ga2-xAlxO3 for x = 1.8, with intermediate compositions of 1.3 < x < 1.8 giving mixtures of the α- and ß-polymorphs. Solid-state NMR spectroscopy shows only the expected octahedral Al for α-Ga2-xAlxO3, and for ß-Ga2-xAlxO3, the ∼1:2 tetrahedral:octahedral Al ratio is in good agreement with the results of Rietveld analysis of the average structures against powder XRD data. Relative energies calculated by periodic density functional theory confirm that there is an ∼5.2 kJ mol-1 penalty for tetrahedral rather than octahedral Al in Ga5-xAlxO7(OH), whereas this penalty is much smaller (∼2.0 kJ mol-1) for ß-Ga2-xAlxO3, in good qualitative agreement with the experimental NMR spectra.

Assessment of the healing process after percutaneous implantation of a cardiovascular device: a systematic review.

The healing process, occurring after intra-cardiac and intra-vascular device implantation, starts with fibrin condensation and attraction of inflammatory cells, followed by the formation of fibrous tissue that slowly covers the device. The duration of this process is variable and may be incomplete, which can lead to thrombus formation, dislodgement of the device or stenosis. To better understand this process and the neotissue formation, animal models were developed: small (rats and rabbits) and large (sheep, pigs, dogs and baboons) animal models for intra-vascular device implantation; sheep and pigs for intra-cardiac device implantation. After intra-vascular and intra-cardiac device implantation in these animal models, in vitro techniques, i.e. histology, which is the gold standard and scanning electron microscopy, were used to assess the device coverage, characterize the cell constitution and detect complications such as thrombosis. In humans, optical coherence tomography and intra-vascular ultrasounds are both invasive modalities used after stent implantation to assess the structure of the vessels, atheroma plaque and complications. Non-invasive techniques (computed tomography and magnetic resonance imaging) are in development in humans and animal models for tissue characterization (fibrosis), device remodeling evaluation and device implantation complications (thrombosis and stenosis). This review aims to (1) present the experimental models used to study this process on cardiac devices; (2) focus on the in vitro techniques and invasive modalities used currently in humans for intra-vascular and intra-cardiac devices and (3) assess the future developments of non-invasive techniques in animal models and humans for intra-cardiac devices.

Trainee-led versus specialist-led management of neovascular age-related macular degeneration: a registry-based study.

OBJECTIVE: To compare the outcomes of trainee-led and specialist-led management of neovascular age-related macular degeneration. DESIGN: Prospective multicentre registry-based observational study. SETTING: Ophthalmology training centres in Australia and Europe where both trainee-led and specialist-led models of care coexist. PARTICIPANTS: Treatment-naïve eyes with neovascular age-related macular degeneration and at least 12 months follow-up. 726 eyes were included in the study from two centres, 534 receiving trainee-led treatment and 192 specialist-led treatment. INTERVENTIONS: The management and outcomes of patients receiving trainee-led care were compared with those receiving specialist-led care. MAIN OUTCOMES MEASURES: The primary outcome was the mean change in visual acuity at 12 months from first injection. Outcomes were also presented at 36 months where available. RESULTS: The mean age of participants was 79 years and 65% were female. The adjusted change in acuity at 12 months in trainee-led vs specialist-led eyes was +3.2 letters vs +4.1 letters (difference -0.9 letters, 95% CI -3.4 to 1.5, p=0.473). The mean adjusted change in acuity at 36 months was -0.9 letters in trainees vs +0.2 letters for specialists (difference -1.1 letters, 95% CI -5.1 to 2.9, p=0.596). Eyes treated by trainees received fewer injections on average to 36 months (15.0 vs 19.0, p=0.004), although this trend was observed at one centre only. CONCLUSIONS: No significant differences in outcome between eyes managed by trainees and eyes managed by specialists were observed. Appropriately structured trainee-led management of neovascular age-related macular degeneration is a reasonable approach where regulatory and practical considerations allow it.

Self-selection in a population-based cohort study: impact on health service use and survival for bowel and lung cancer assessed using data linkage.

BACKGROUND: In contrast to aetiological associations, there is little empirical evidence for generalising health service use associations from cohort studies. We compared the health service use of cohort study participants diagnosed with bowel or lung cancer to the source population of people diagnosed with these cancers in New South Wales (NSW), Australia to assess the representativeness of health service use of the cohort study participants. METHODS: Population-based cancer registry data for NSW residents aged ≥45 years at diagnosis of bowel or lung cancer were linked to the 45 and Up Study, a NSW population-based cohort study (N~ 267,000). We measured hospitalisation, emergency department (ED) attendance and all-cause survival, and risk factor associations with these outcomes using administrative data for cohort study participants and the source population. We assessed bias in prevalence and risk factor associations using ratios of relative frequency (RRF) and relative odds ratios (ROR), respectively. RESULTS: People from major cities, non-English speaking countries and with comorbidites were under-represented among cohort study participants diagnosed with bowel (n = 1837) or lung (n = 969) cancer by 20-50%. Cohort study participants had similar hospitalisation and ED attendance compared with the source population. One-year survival after major surgical resection was similar, but cohort study participants had up to 25% higher post-diagnosis survival (lung cancer 3-year survival: RRF = 1.24, 95% confidence interval 1.12,1.37). Except for area-based socioeconomic position, risk factors associations with health service use measures and survival appeared relatively unbiased. CONCLUSIONS: Absolute measures of health service use and risk factor associations in a non-representative sample showed little evidence of bias. Non-comparability of risk factor measures of cohort study participants and non-participants, such as area-based socioeconomic position, may bias estimates of risk factor associations. Primary and outpatient care outcomes may be more vulnerable to bias.

A pharmacoepidemiologic study of ranibizumab and aflibercept use 2013-2016. The Fight Retinal Blindness! Project.

INTRODUCTION: To report 12-month pharmacoepidemiologic data on aflibercept and ranibizumab use in treatment-naïve eyes with neovascular age-related macular degeneration (nAMD). METHODS: Participants were treatment-naïve eyes with nAMD tracked by the Fight Retinal Blindness! registry starting therapy with aflibercept or ranibizumab treatment between January 1st, 2013 and 31st December, 2016. Demographic and clinical characteristics were compared between treatment groups. RESULTS: During the study period, 689 eyes initiated treatment with ranibizumab compared to 568 with aflibercept. We found a similar rate of use of both drugs. Ranibizumab-treated patients were older than aflibercept-treated patients (overall mean [SD] 82.0 [8.4] vs. 78.6 [8.1], P < 0.001). Median (Q1, Q3) lesion size was significantly larger in aflibercept-treated patients (2450 µm [1242, 3000]) compared with ranibizumab patients (2000 µm [1148, 2890], P = 0.008). Eyes treated with ranibizumab and aflibercept received a similar mean number of injections in the first 3 months (3.1 [0.7] vs. 3.0 [0.6]; P = 0.233) and at 12 months (7.3 [2.4] vs. 7.2 [2.2]; P = 0.139). The 12-month switching rates from 2013 onwards for eyes completing 12 months of follow-up were much higher for switching from ranibizumab to aflibercept (19.2%) compared with switching from aflibercept to ranibizumab (5.4%). The proportion of eyes that did not complete 12 months of treatment was 23.2% for ranibizumab and 22.2% for aflibercept-treated groups. CONCLUSION: A similar rate of use for ranibizumab and aflibercept among Australian practitioners was observed between 2013 and 2016. Ranibizumab was used more often in older patients while aflibercept tended to be used more often in eyes with larger lesions.

Cancer survival disparities worsening by socio-economic disadvantage over the last 3 decades in new South Wales, Australia.

BACKGROUND: Public concerns are commonly expressed about widening health gaps. This cohort study examines variations and trends in cancer survival by socio-economic disadvantage, geographical remoteness and country of birth in an Australian population over a 30-year period. METHODS: Data for cases diagnosed in New South Wales (NSW) in 1980-2008 (n = 651,245) were extracted from the population-based NSW Cancer Registry. Competing risk regression models, using the Fine & Gray method, were used for comparative analyses to estimate sub-hazard ratios (SHR) with 95% confidence intervals (CI) among people diagnosed with cancer. RESULTS: Increased risk of cancer death was associated with living in the most socio-economically disadvantaged areas compared with the least disadvantaged areas (SHR 1.15, 95% CI 1.13-1.17), and in outer regional/remote areas compared with major cities (SHR 1.05, 95% CI 1.03-1.06). People born outside Australia had a similar or lower risk of cancer death than Australian-born (SHR 0.99, 95% CI 0.98-1.01 and SHR 0.91, 95% CI 0.90-0.92 for people born in other English and non-English speaking countries, respectively). An increasing comparative risk of cancer death was observed over time when comparing the most with the least socio-economically disadvantaged areas (SHR 1.07, 95% CI 1.04-1.10 for 1980-1989; SHR 1.14, 95% CI 1.12-1.17 for 1990-1999; and SHR 1.24, 95% CI 1.21-1.27 for 2000-2008; p < 0.001 for interaction between disadvantage quintile and year of diagnosis). CONCLUSIONS: There is a widening gap in comparative risk of cancer death by level of socio-economic disadvantage that warrants a policy response and further examination of reasons behind these disparities.

After accounting for competing causes of death and more advanced stage, do Aboriginal and Torres Strait Islander peoples with cancer still have worse survival? A population-based cohort study in New South Wales.

BACKGROUND: Aboriginal and Torres Strait Islander peoples in Australia have been found to have poorer cancer survival than non-Aboriginal people. However, use of conventional relative survival analyses is limited due to a lack of life tables. This cohort study examined whether poorer survival persist after accounting for competing risks of death from other causes and disparities in cancer stage at diagnosis, for all cancers collectively and by cancer site. METHODS: People diagnosed in 2000-2008 were extracted from the population-based New South Wales Cancer Registry. Aboriginal status was multiply imputed for people with missing information (12.9%). Logistic regression models were used to compute odds ratios (ORs) with 95% confidence intervals (CIs) for 'advanced stage' at diagnosis (separately for distant and distant/regional stage). Survival was examined using competing risk regression to compute subhazard ratios (SHRs) with 95%CIs. RESULTS: Of the 301,356 cases, 2517 (0.84%) identified as Aboriginal (0.94% after imputation). After adjusting for age, sex, year of diagnosis, socio-economic status, remoteness, and cancer site Aboriginal peoples were more likely to be diagnosed with distant (OR 1.30, 95%CI 1.17-1.44) or distant/regional stage (OR 1.29, 95%CI 1.18-1.40) for all cancers collectively. This applied to cancers of the female breast, uterus, prostate, kidney, others (those not included in other categories) and cervix (when analyses were restricted to cases with known stages/known Aboriginal status). Aboriginal peoples had a higher hazard of death than non-Aboriginal people after accounting for competing risks from other causes of death, socio-demographic factors, stage and cancer site (SHR 1.40, 95%CI 1.31-1.50 for all cancers collectively). Consistent results applied to colorectal, lung, breast, prostate and other cancers. CONCLUSIONS: Aboriginal peoples with cancer have an elevated hazard of cancer death compared with non-Aboriginal people, after accounting for more advanced stage and competing causes of death. Further research is needed to determine reasons, including any contribution of co-morbidity, lifestyle factors and differentials in service access to help explain disparities.

Vertical root fracture: Factors related to identification.

BACKGROUND: Vertical root fracture (VRF) requires root removal. Diagnostics for proper identification are critical. The author conducted a study to relate subjective, objective, and radiographic findings for VRF identification. They noted visual changes of root and overlying bone patterns after flap reflection. METHODS: The author examined a case series of roots with suspected VRF after flap reflection and root or root-end removal; 42 roots were identified with a fracture. Before reflection, the author obtained diagnostic and periapical radiographic data that included symptoms, soft-tissue changes, percussion, mobility, probing patterns, and radiographic findings. After flap reflection, the author evaluated bony changes and root surfaces. VRF was visually confirmed after tooth or root removal. RESULTS: Signs and symptoms diagnostic of VRF were inconsistent. All patients had endodontic therapy, many with posts, and for all patients, the pain was none to mild. In addition, the author found a history or presence of swelling (77%) or sinus tract (31%), that probing patterns differed (narrow-rectangular 66%), and that there was no defect in some patients (21%). Radiographic patterns varied from no change to extensive bone loss, and mobility ranged from none (55%) to slight or moderate (45%). Flap reflection revealed a "punched-out" bony lesion with granulomatous tissue (100%), and patterns were fenestration (21%) or dehiscence (79%). A fracture was visible on roots or resected root ends. CONCLUSIONS: The author found no consistent signs, symptoms, or radiographic changes of VRF. Flap reflection was found to be predictably useful; fractured roots had bony defects filled with granulomatous tissue. PRACTICAL IMPLICATIONS: VRF may be suspected from clinical findings; however, flap reflection is usually required for identification. Characteristic bony pattern and root visualization reveals the fracture, although root-end resection and examination is occasionally required.

INCREASED INTRAOCULAR PRESSURE IS A RISK FACTOR FOR UNEXPLAINED VISUAL LOSS DURING SILICONE OIL ENDOTAMPONADE.

PURPOSE: To identify the incidence rate and risk factors for unexplained visual loss associated with silicone oil endotamponade used during primary repair of macula-sparing rhegmatogenous retinal detachments. METHODS: This retrospective cohort study included patients undergoing pars plana vitrectomy for primary surgical repair of macula-sparing rhegmatogenous retinal detachments in whom silicone oil endotamponade was used. The primary outcome measure was the incidence rate of unexplained visual loss and identification of risk factors associated with vision loss. RESULTS: Of 1,218 eyes undergoing pars plana vitrectomy for primary retinal detachment repair, 44 eyes were included for analysis. In 9 eyes (20%), an unexplained vision loss occurred. Logistic regression identified increased intraocular pressure (IOP) (prospectively defined as IOP readings during silicone oil endotamponade ≥21 mmHg on two consecutive visits or ≥25 mmHg at any time during this period) as significant predictor (odds ratio = 4.9; P = 0.04) and a classification tree ranked IOP as the most important variable for vision loss. Incidence rate of vision loss in eyes experiencing IOP increase was 4.5 vision loss events per 1,000 days at risk compared with 1 event per 1,000 days in eyes without IOP increase, yielding an incidence rate ratio of 4.5 (95% confidence interval: 1.1-17.9; P = 0.02). CONCLUSION: Sufficient control of IOP during silicone oil endotamponade for primary retinal detachment repair is warranted to reduce the probability of vision loss.

Pancreatectomy is underused in NSW regions with low institutional surgical volumes: a population data linkage study.

OBJECTIVE: To examine differences in the proportions of people diagnosed with pancreatic cancer who underwent pancreatectomy, post-operative outcomes and 5-year survival in different New South Wales administrative health regions of residence. DESIGN, SETTING AND PARTICIPANTS: Retrospective analysis of NSW data on pancreatic cancer incidence and surgery, 2005-2013. MAIN OUTCOME MEASURES: The proportion of newly diagnosed patients with pancreatic cancer who were resected in each region; 90-day post-operative mortality; one-year post-operative survival; 5-year post-diagnosis survival. RESULTS: 14% of people diagnosed with pancreatic cancer during 2010-2013 (431 of 3064) underwent pancreatectomy, an average of 108 resections per year. After adjusting for age, sex and comorbidities, the proportion that underwent resection varied significantly between regions, ranging between 8% and 21% (P<0.001). Higher resection rates were not associated with higher post-operative 90-day mortality or lower one-year survival (unadjusted and risk-adjusted analyses). Higher resection rates were associated with higher 5-year post-diagnosis survival: the mean survival in regions with resection rates below 10% was 3.4%, compared with 7.2% in regions with rates greater than 15% (unadjusted and adjusted survival analyses; P<0.001). There was a positive association between regional resection rate and the pancreatectomy volume of hospitals during 2005-2009. An additional 32 people would be resected annually if resection rates in low rate regions were increased to the 80th percentile regional resection rate (18%). CONCLUSION: There is significant geographic variation in the proportion of people with pancreatic cancer undergoing pancreatectomy, and the 5-year survival rate is higher in regions where this proportion is higher.