New Zealand Cancer Registry Research Articles

Ethnic Disparities for Survival and Mortality in New Zealand Patients With Head and Neck Cancer

It is essential to identify inequitable cancer care for ethnic minority groups, which may allow policy change associated with improved survival and decreased mortality and morbidity. To investigate ethnic disparities in survival and mortality among New Zealand (NZ) patients with head and neck cancer (HNC) and the association of other variables, including socioeconomic status, tumor stage, and age at diagnosis, with survival rates. This retrospective cohort study was conducted among NZ patients diagnosed with specific HNCs from 2010 to 2020. Anonymized data were obtained from the NZ Cancer Registry, including patients diagnosed from International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes C00-C14 and C30-C32. Data were analyzed from July 2020 through January 2024. Censored Kaplan-Meier estimates were used to analyze survival distribution. Cox regression models were used to estimate the association of age, tumor stage at diagnosis, and socioeconomic status with survival rates. Age-standardized mortality rates were assessed. Among 6593 patients with HNCs (4590 males [69.6%]; 4187 patients aged 51-75 years [63.5%]), there were 706 Māori individuals (10.7%) and 5887 individuals with other ethnicity (89.3%), including 4327 NZ European individuals (65.6%; defined as New Zealanders of European descent). Māori individuals had a decreased survival proportion at all years after diagnosis compared with individuals with other ethnicity (eg, 66.1% [95% CI, 62.6%% to 69.8%] vs 71.2% [95% CI, 70.0% to 72.4%] at 2 years). At 1 year after diagnosis, Māori individuals did not have a significantly increased mortality rate compared with 5795 individuals with other ethnicity with data (193 deaths [27.3%] vs 1400 deaths [24.2%]; P = .06), but the rate was significantly increased at 5 years after diagnosis (277 deaths [39.3%] vs 2034 deaths [35.1%]; P = .03); there was greater disparity compared with NZ European individuals (1 year: 969 deaths [22.4%]; P = .003; 5 years: 1441 deaths [33.3%]; P = .002). There were persistent age-adjusted mortality rate disparities: 40.1% (95% CI, -25.9% to 71.2%) for Māori individuals and 18.8% (95% CI, -15.4% to 24.4%) for individuals with other ethnicity. Māori individuals were diagnosed at a mean age of 58.0 years (95% CI, 57.1-59.1 years) vs 64.3 years. (95% CI, 64.0-64.7 years) for individuals with other ethnicity, or 5 to 7 years younger, and died at mean age of 63.5 years (95% CI, 62.0-64.9 years) compared with 72.3 years (95% CI, 71.8-72.9 years) for individuals with other ethnicity, or 7 to 10 years earlier. Māori individuals presented with proportionally more advanced disease (only localized disease, 102 patients [14.5%; 95% CI, 12.0%-17.4%] vs 1413 patients [24.0%; 95% CI, 22.9%-25.1%]; P < .001) and showed an increase in regional lymph nodes (276 patients [39.1%; 95% CI, 35.5%-42.9%] vs 1796 patients [30.5%; 95% CI, 29.3%-31.8%]; P < .001) at diagnosis compared with individuals with other ethnicity. Socioeconomic status was not associated with survival. This study found that Māori individuals experienced worse survival outcomes and greater mortality rates from HNC in NZ and presented with more advanced disease at a younger age. These findings suggest the need for further research to alleviate these disparities, highlight the importance of research into minority populations with HNC globally, and may encourage equity research for all cancers.

Cancer incidence, mortality and survival for Pacific Peoples in Aotearoa New Zealand.

Pacific Peoples comprise over 16 culturally diverse ethnic groups and experience a disproportionate burden of preventable cancers, attributable to infectious diseases and obesity. This study aims to provide updated evidence on cancer incidence, mortality and survival rates among Pacific Peoples in Aotearoa New Zealand. The study extracted incident cases of cancer diagnosed between 2007-2019 from the New Zealand Cancer Registry (NZCR) and linked them to the national Mortality Collection to determine individuals who died of cancer over the study period. The study also compared cancer survival rates between Pacific and European peoples in Aotearoa New Zealand. The most commonly diagnosed cancers and the most common causes of cancer death among Pacific Peoples were identified, and key findings were summarised. The European population was utilised as the comparator group for the analyses. The study employed a total ethnicity approach, wherein anyone with a record of Pacific ethnicity was classified as Total Pacific, regardless of other ethnicities. The age- and sex-standardised incidence and mortality rates were calculated, and 1-, 3- and 5-year survival rates determined. We used Cox proportional-hazards models to compare survival outcomes between Pacific and European peoples. The study results revealed that Pacific Peoples in Aotearoa New Zealand experience higher cancer incidence and a lower survival rate for several cancers, including lung, liver and stomach cancers, when compared to the European population. This study underscores the need for intervention to reduce the burden of cancer among Pacific Peoples and improve cancer outcomes. This study's findings can inform planning and delivery of interventions to achieve equitable outcomes across the cancer continuum for Pacific Peoples in Aotearoa New Zealand.

Ethnic and regional differences in the temporal trends of prostate cancer incidence and mortality in New Zealand.

Prostate cancer (Pca) is the most frequently diagnosed cancer in New Zealand (NZ) men and the third leading cause of cancer deaths. Temporal changes in Pca incidence and mortality have not been reported despite changes in the Pca landscape. This study aims to analyse the temporal trends in Pca with focus on ethnic and regional variations. The study cohort was identified from the NZ Cancer Registry and the mortality collection databases. Men who were diagnosed with Pca between 2000 and 2018 were included in the incidence analysis. Men who died from Pca between 2000 and 2015 were included in the mortality analysis. Other data collected were ethnicity and geographical information. Pca incidence and mortality were calculated as age-standardized rates using the 2001 World Health Organization population. A total of 58 966 men were diagnosed (incidence: 105.2 per 100 000) and 14 749 men died (mortality: 49.3 per 100 000) from Pca. When compared to European men, Māori and Asian men had significantly lower Pca incidence. Mortality rates demonstrated a steady decline, which was more prominent until 2010. Māori and Pacific men had higher mortality rates when compared to European men. In most recent years, the difference in mortality is decreasing for Māori but increasing for Pacific men. There were no regional differences in mortality. Pca incidence in NZ has fluctuated over the last 20 years, while mortality rates have shown to steadily decline. Pca mortality was shown to disproportionately affect Māori and Pacific men.

The Epidemiology of Myeloproliferative Neoplasms in New Zealand between 2010 and 2017: Insights from the New Zealand Cancer Registry.

Background: There is a paucity of data on ethnic disparities in patients with the classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs): polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF). Methods: This study analysed the demographic data for PV, ET and PMF collected by the New Zealand Cancer Registry (NZCR) between 2010 and 2017. Results: We found that the NZCR capture rates were lower than average international incidence rates for PV and ET, but higher for PMF (0.76, 0.99 and 0.82 per 100,000, respectively). PV patients were older and had worse outcomes than expected, which suggests these patients were reported to the registry at an advanced stage of their disease. Polynesian patients with all MPN subtypes, PV, ET and PMF, were younger than their European counterparts both at the time of diagnosis and death (p < 0.001). Male gender was an independent risk factor for mortality from PV and PMF (hazard ratios (HR) of 1.43 and 1.81, respectively; p < 0.05), and Māori ethnicity was an independent risk factor for mortality from PMF (HR: 2.94; p = 0.006). Conclusions: New Zealand Polynesian patients may have increased genetic predisposition to MPN, thus we advocate for modern genetic testing in this ethnic group to identify the cause. Further work is also required to identify modifiable risk factors for mortality in MPN, in particular those associated with male gender and Māori ethnicity; the results may benefit all patients with MPN.

Epidemiology of Acute Myeloid Leukaemia in New Zealand: A National Cancer Registry Analysis

Background: Acute myeloid leukaemia (AML) is a blood cancer characterised by the expansion of a malignant myeloid progenitor. The estimated age-standardised incidence rate in many western countries has remained static over the last 2 decades at 3-4 per 100,000, whilst long-term survival has improved, especially for the younger individuals. However, disparities remain for the older individuals, people of ethnic minority background, and those who are more socio-economically deprived. Previous evaluation of population data from New Zealand has shown a similar pattern, but a more recent analysis has not been done. Here we present the incidence and long-term survival of patients with AML in New Zealand (NZ), using the New Zealand Cancer Registry (NZCR). Method: The NZCR was established in 1948 and it became mandatory by law to report all new cases of malignancy by 1994. We extracted all AML cases from the registry between 1 January 1997 and 31 December 2016. Cases with an ICD-10-CM code for acute myeloid leukaemia and its subtypes including acute promyelocytic leukaemia (e.g. C92.0) were included. Individuals residing overseas or without an address were excluded, and individuals with a diagnosis of acute promyelocytic leukaemia (APML) were analyzed separately. The socio-economic status of the individual was estimated based on their domicile area using the New Zealand 2013 Index of Deprivation (NZDep2013) which is a geographically based composite measure of deprivation. Overall survival was calculated from the date of diagnosis to the date of death or last follow-up (31 December 2016). Multivariable Cox-proportional hazard models were used to evaluate potential associations with survival time in NZ AML cases. Results: During this 20-year period, 154 cases of APML and 2876 cases of AML (excluding APML) were reported to the registry on individuals residing in New Zealand. Of the AML cases, 53% were male and the median age at the time of diagnosis was 67 (IQR 52-77), with a small positive correlation between year of diagnosis and age at diagnosis (Spearman's rho=0.05, p=0.009). The majority of cases (77%) were of European descent, 12% were New Zealand Maori, and 6% were Pacific Islanders. Individuals of European descent were significantly older at diagnosis compared to other ethnicities (median of 70 vs 51 for Maori, 56 for Pacific Islanders, and 58 for all other ethnicities, p&amp;lt;0.001). AML appeared to disproportionally affect those more socio-economically deprived, with 23% of cases reported in the most deprived 20% of the population, compared with only 16% of the cases in the least deprived 20%. The annual crude incidence remained stable during this period at an average of 3.42 per 100,000 (ranging from 2.57 to 4.29, figure 1), and was significantly higher in the older adults (figure 2). Age-standardised rates were lower (figure 1), with an average of 2.6 (range 1.9 to 3.4) cases per 100,000, and a small but significant average annual decrease over the study period. The estimated 1, 2, and 5-year survival for the entire cohort was 38%, 27%, and 22%, respectively. Age at diagnosis was a significant predictor of inferior survival, with a hazard ratio (HR) for all-cause mortality of 2.06, 3.95, 6.39 and 10.84 for the 50-59, 60-69, 70-79 and &amp;gt;80 age groups, respectively, compared to those aged &amp;lt;50. Shorter overall survival was also noted in individuals in the more socio-economically deprived 50% of the population (HR 1.13, 95% CI 1.03-1.23). Conclusion The incidence of AML in New Zealand has remained static in the last 2 decades, consistent with data from other western countries. Lower age-standardised rates and the small decrease in these observed over the study period are likely to reflect the increasingly and comparatively older population in NZ. Maori and Pacific Islanders appeared to present at a younger age than individuals of European descent. Age at diagnosis and socio-economic deprivation were shown to be an adverse prognostic factor for overall survival. Further in-depth analysis is required to determine the cause of these observations at a population level. Disclosures Chan: AbbVie:Membership on an entity's Board of Directors or advisory committees;Janssen:Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding, Speakers Bureau;Celgene:Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company);Amgen:Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company);Roche:Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company).

Childhood cancer registration in New Zealand: A registry collaboration to assess and improve data quality

AimTo evaluate the completeness and accuracy of child cancer registration in New Zealand. MethodsRegistrations for children aged 0–14 diagnosed between 1/1/2010 and 31/12/2014 were obtained from the New Zealand Cancer Registry (NZCR) and the New Zealand Children’s Cancer Registry (NZCCR). Six key data fields were matched using National Health Index numbers in order to identify and resolve registration discrepancies. Capture-recapture methods were used to assess the completeness of cancer registration. RESULTS: 794 unique cases were reported; 718 from the NZCR, 721 from the NZCCR and 643 from both registries. 27 invalid cancer registrations were identified, including 19 residents of the Pacific Islands who had travelled to New Zealand for treatment. The NZCCR provided 55 non-malignant central nervous system tumour and 16 Langerhans cell histiocytosis cases which were not registered by the NZCR. The NZCR alerted the NZCCR to 18 cases missed due to human error and 23 cases that had not been referred to the specialist paediatric oncology centres. 762 cases were verified as true incident cases, an incidence rate of 166.8 per million. Registration accuracy for six key data fields was 98.6%. According to their respective inclusion criteria case completeness was 99.3% for the NZCR and 94.4% for the NZCCR. For childhood malignancies covered by both registries, capture-recapture methods estimated case ascertainment at greater than 99.9%. CONCLUSION: With two national registries covering childhood cancers, New Zealand is uniquely positioned to undertake regular cooperative activities to ensure high quality data is available for research and patient care.

Can pathological reports of rectal cancer provide national quality indicators?

Rectal cancer care has become increasingly complex and requires accurate information. The pathology report is a vital tool for accessing information to gauge a patient's prognosis and to guide treatment decisions. The aim of this study was to assess the quality of histopathological reporting and surgery for rectal cancer in New Zealand using defined quality indicators. This is a retrospective audit of pathological reports of all resected rectal cancer pathology reports submitted to the New Zealand Cancer Registry (NZCR) in 2015. The quality of reporting was assessed using specified criteria: synoptic report, adequate lymph node retrieval, reporting of circumferential resection margin (CRM) and mesorectal excision quality. Surgical outcomes were sphincter preservation rate, CRM clearance and complete mesorectal excision. A total of 803 patients with rectal cancer were reported to the NZCR in 2015, 505 underwent proctectomy. A total of 89.5% of reports were structured, 81.8% reported mesorectal excision quality and 86.7% reported CRM status. Adequate lymph node retrieval was obtained in 65.1%, complete mesorectal excision in 84.6% and positive CRM in 6.2% of cases. Quality varied between laboratories and district health boards. High-volume laboratories had higher quality reporting. Surgeon volume and training was related to adequate lymph node retrieval but not CRM clearance nor mesorectal excision quality. High-quality pathological reporting is associated with the use of synoptic reporting templates. Surgical outcomes for rectal cancer in New Zealand, especially the low rate of CRM involvement, compare favourably with international audits.

Breast Cancer Characteristics and Survival Differences between Maori, Pacific and other New Zealand Women Included in the Quality Audit Program of Breast Surgeons of Australia and New Zealand

The Quality Audit (BQA) program of the Breast Surgeons of Australia and New Zealand (NZ) collects data on early female breast cancer and its treatment. BQA data covered approximately half all early breast cancers diagnosed in NZ during roll-out of the BQA program in 1998-2010. Coverage increased progressively to about 80% by 2008. This is the biggest NZ breast cancer database outside the NZ Cancer Registry and it includes cancer and clinical management data not collected by the Registry. We used these BQA data to compare socio-demographic and cancer characteristics and survivals by ethnicity. BQA data for 1998-2010 diagnoses were linked to NZ death records using the National Health Index (NHI) for linking. Live cases were followed up to December 31st 2010. Socio-demographic and invasive cancer characteristics and disease-specific survivals were compared by ethnicity. Five-year survivals were 87% for Maori, 84% for Pacific, 91% for other NZ cases and 90% overall. This compared with the 86% survival reported for all female breast cases covered by the NZ Cancer Registry which also included more advanced stages. Patterns of survival by clinical risk factors accorded with patterns expected from the scientific literature. Compared with Other cases, Maori and Pacific women were younger, came from more deprived areas, and had larger cancers with more ductal and fewer lobular histology types. Their cancers were also less likely to have a triple negative phenotype. More of the Pacific women had vascular invasion. Maori women were more likely to reside in areas more remote from regional cancer centres, whereas Pacific women generally lived closer to these centres than Other NZ cases. NZ BQA data indicate previously unreported differences in breast cancer biology by ethnicity. Maori and Pacific women had reduced breast cancer survival compared with Other NZ women, after adjusting for socio-demographic and cancer characteristics. The potential contributions to survival differences of variations in service access, timeliness and quality of care, need to be examined, along with effects of co- morbidity and biological factors.

Breast cancer survival in New Zealand women.

The Quality Audit (BQA) of Breast Surgeons of Australia and New Zealand includes a broad range of data and is the largest New Zealand (NZ) breast cancer (BC) database outside the NZ Cancer Registry. We used BQA data to compare BC survival by ethnicity, deprivation, remoteness, clinical characteristic and case load. BQA and death data were linked using the National Health Index. Disease-specific survival for invasive cases was benchmarked against Australian BQA data and NZ population-based survivals. Validity was explored by comparison with expected survival by risk factor. Compared with 93% for Australian audit cases, 5-year survival was 90% for NZ audit cases overall, 87% for Maori, 84% for Pacific and 91% for other. BC survival in NZ appears lower than in Australia, with inequities by ethnicity. Differences may be due to access, timeliness and quality of health services, patient risk profiles, BQA coverage and death-record methodology.

Accuracy and completeness of the New Zealand Cancer Registry for staging of invasive breast cancer

PurposePopulation based cancer registries are an invaluable resource for monitoring incidence and mortality for many types of cancer. Research and healthcare decisions based on cancer registry data rely on the case completeness and accuracy of recorded data. This study was aimed at assessing completeness and accuracy of breast cancer staging data in the New Zealand Cancer Registry (NZCR) against a regional breast cancer register. MethodologyData from 2562 women diagnosed with invasive primary breast cancer between 1999 and 2011 included in the Waikato Breast Cancer Register (WBCR) were used to audit data held on the same individuals by the NZCR. WBCR data were treated as the benchmark. ResultsOf 2562 cancers, 315(12.3%) were unstaged in the NZCR. For cancers with a known stage in the NZCR, staging accuracy was 94.4%. Lower staging accuracies of 74% and 84% were noted for metastatic and locally invasive (involving skin or chest wall) cancers, respectively, compared with localized (97%) and lymph node positive (94%) cancers. Older age (>80 years), not undergoing therapeutic surgery and higher comorbidity score were significantly (p<0.01) associated with unstaged cancer. The high proportion of unstaged cancer in the NZCR was noted to have led to an underestimation of the true incidence of metastatic breast cancer by 21%. Underestimation of metastatic cancer was greater for Māori (29.5%) than for NZ European (20.6%) women. Overall 5-year survival rate for unstaged cancer (NZCR) was 55.9%, which was worse than the 5-year survival rate for regional (77.3%), but better than metastatic (12.9%) disease. ConclusionsUnstaged cancer and accuracy of cancer staging in the NZCR are major sources of bias for the NZCR based research. Improving completeness and accuracy of staging data and increasing the rate of TNM cancer stage recording are identified as priorities for strengthening the usefulness of the NZCR.

A cardiac sparing technique for breast cancer radiation treatment

s / The Breast 23 (2014) S1eS6 S2 A CARDIAC SPARING TECHNIQUE FOR BREAST CANCER RADIATION TREATMENT Christopher Kelly, Kirsten Stuart, Tim Wang, Drew Latty, Verity Ahern. Crown Princess Mary Cancer Centre (CPMCC), and Breast Cancer Institute NSW, Westmead Hospital, Australia Background: Historically left-sided breast cancer radiation treatment has been associatedwith an excess risk of cardiac deaths1, and every additional 1Gy mean cardiac dose results in a relative increase in cardiac events of 7.4%2. Methods: A deep inspiratory breath hold (DIBH) techniquewas introduced as a method of reducing the volume of heart in breast / chest wall tangential radiation treatment at CPMCC in 2010, one of the few centres using this technique in Australia. This study evaluates the impact of DIBH on cardiac radiation dose. Results: A total of 51 patients underwent an attempt at radiation treatment simulation by DIBH as well as the conventional ‘free breathing’ (FB) approach between December 2010 and April 2013. Thirty eight patients proceeded to treatment delivery by DIBH. Thirteen patients did not undergo treatment by DIBH, either because DIBH did not reduce the cardiac dose (6 patients) or because they were not able to follow instructions for DIBH (7 patients). For the 38 patients who underwent DIBH, the simulated size of the heart measured as a volume varied between FB and DIBH by 72% 115%. The mean irradiated heart dose calculated by simulation was 6.2Gy by the DIBH technique and higher by the FB technique for all 38 patients .It was a mean of 7.0Gy for the 13 patients treated by FB .Six of 38 patients underwent fluoroscopic imaging of one radiation field during treatment on at least two occasions. For the six patients as a group, the heart moved between 1 and 6mm during the fluoroscopic imaging. Conclusions: DIBH is a suitable technique to reduce the cardiac volume irradiated for some patients with left sided breast cancer. We are now exploring the best method of measuring cardiac position during treatment, and how we can help more women cope with this procedure.

Unstaged cancer in a population-based registry: Prevalence, predictors and patient prognosis

Purpose: Information on cancer stage at diagnosis is critical for population studies investigating cancer care and outcomes. Few studies have examined the factors which impact (1) staging or (2) outcomes for patients who are registered as having unknown stage. This study investigated (1) the prevalence of unknown stage at diagnosis on the New Zealand Cancer Registry (NZCR); (2) explored factors which predict unknown stage; (3) described receipt of surgery and (4) survival outcomes for patients with unknown stage. Methods: Patients diagnosed with the most prevalent 18 cancers between 2006 and 2008 (N=41,489) were identified from the NZCR, with additional data obtained from mortality and hospitalisation databases. Logistic and Cox regression were used to investigate predictors of unknown stage and patient outcomes. Results: (1) Three distinct groups of cancers were found based on proportion of patients with unknown stage (low=up to 33% unknown stage; moderate=33–64%; high=65%+). (2) Increasing age was a significant predictor of unknown stage (adjusted odds ratios [ORs]: 1.18–1.24 per 5-year increase across groups). Patients with substantive comorbidity were more likely to have unknown stage but only for those cancers with a low (OR=2.65 [2.28–3.09]) or moderate (OR=1.17 [1.03–1.33]) proportion of patients with unknown stage. (3) Patients with unknown stage were significantly less likely to have received definitive surgery than those with local or regional disease across investigated cancers. (4) Patients with unknown stage had 28-day and 1-year survival which was intermediate between regional and distant disease. Discussion: We found that stage completeness differs widely by cancer site. In many cases, the proportion of unknown stage on a population-based register can be explained by patient, service and/or cancer related factors.

Investigating reasons for ethnic inequalities in breast cancer survival in New Zealand

Objective. This study investigated the role that demographic and tumour factors play in explaining ethnic inequalities in breast cancer survival. Design. Breast cancer cases notified to the New Zealand Cancer Registry (NZCR) from April 2005 to April 2007 were followed up to April 2009. Māori, Pacific and non-Māori/non-Pacific women were categorised according to ethnicity on the NZCR. Deprivation was analysed as quintiles of the New Zealand area-based index of socio-economic position. Relative survival rates were estimated using ethnic-specific life tables. Missing values were imputed and excess mortality modelling was used to estimate the contribution of demographic and tumour factors to ethnic inequalities in survival. Results. There were 2968 breast cancer cases (76.5% non-Māori/non-Pacific, 17% Māori, and 6.5% Pacific) included and 433 recorded deaths. Relative survival rates at 4 years were 91.5% (95% confidence interval (CI) 89.7 to 92.9) for non-Māori/non-Pacific, 86.2% (CI 80.3 to 90.4) for Māori, and 79.6% (CI 68.2 to 87.2) for Pacific women. Using non-Māori/non-Pacific as the reference group, the age-adjusted hazard ratio (HR) dropped for Māori from 1.76 (CI 1.22 to 2.48) to 1.43 (CI 0.97 to 2.10) when further adjusted by deprivation. For Pacific the HR dropped from 2.49 (CI 1.57 to 3.94) to 1.94 (CI 1.20 to 3.13). Inequalities persisted after adjustment for subtype variables (ER/PR/HER2), but adjusting for access to care variables (extent/size) eliminated the ethnic inequalities in excess mortality. Conclusion. Ethnic disparities in breast cancer survival in New Zealand can be attributed to deprivation and differential access to health care rather than differences in breast cancer subtypes.

Abstract A93: Investigating reasons for ethnic disparities in breast cancer survival in New Zealand

Abstract Background: In New Zealand the burden of breast cancer is not shared equally among ethnic groups. Although incidence is similar for indigenous Maori women and Pacific women compared with non-Maori/non-Pacific women, Maori and Pacific women are more likely to die from breast cancer. This suggests much of the breast cancer mortality disparities are due to inequalities in survival rather than incidence. We investigated the role that demographic and tumor factors play in explaining ethnic disparities in breast cancer survival. Methods: Breast cancer cases notified to the New Zealand Cancer Registry (NZCR) from April 2005 to April 2007 were followed up to April 2009. Maori, Pacific and non-Maori/non-Pacific women were categorized according to ethnicity on the NZCR. Deprivation was analyzed as quintiles of the New Zealand area-based index of socioeconomic position. Relative survival rates were estimated using ethnic-specific life tables. Missing values were imputed and excess mortality modeling was used to estimate the contribution of demographic and tumor factors to ethnic inequalities in survival. Results: There were 2,968 breast cancer cases (76.5% non-Maori/non-Pacific, 17% Maori, and 6.5% Pacific) included and 433 recorded deaths. Relative survival rates at 4 years were 91.45% (CI 89.68 to 92.93) for non-Maori/non-Pacific, 86.15 (CI 80.33 to 90.36) for Maori, and 79.56% (CI 68.17 to 87.24) for Pacific women. Using non-Maori/non-Pacific as the reference group, the age-adjusted hazard ratio (HR) dropped for Maori from 1.76 (CI 1.22 to 2.48) to 1.43 (CI 0.97 to 2.10) when further adjusted by deprivation. For Pacific the HR dropped from 2.49 (CI 1.57 to 3.94) to 1.94 (CI 1.20 to 3.13). Inequalities persisted after adjustment for subtype variables (ER/PR/HER2), but adjusting for access to care variables (stage/size) eliminated the ethnic inequalities in excess mortality. Conclusion: Ethnic disparities in breast cancer survival in New Zealand can be attributed to differential access to health care rather than differences in breast cancer subtypes. Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A93.

Investigating reasons for socioeconomic inequalities in breast cancer survival in New Zealand

Background: This study investigated the role that demographic and tumour factors play in explaining socioeconomic inequalities in breast cancer survival. Methods: Breast cancer cases notified to the New Zealand Cancer Registry (NZCR) from April 2005 to April 2007 were followed up to April 2009. The New Zealand area-based deprivation index (NZDep) was used as a measure of socioeconomic position. Relative survival rates were estimated using sex-, deprivation- and ethnic-specific life tables. Multiple imputation was used to impute missing data. Excess mortality modelling was used to estimate the contribution of demographic and tumour factors to inequalities in survival. Results: There were 2968 breast cancer cases included and 433 recorded deaths. Relative survival rates at 4 years varied across deprivation groups. Using NZDep deciles 1–4 (least deprived) as the reference group, the age- and ethnicity-adjusted hazard ratio (HR) for NZDep deciles 7–8 was 2.03 (CI 1.36–3.04) and for NZDep deciles 9–10 was 1.93 (CI 1.28–2.92). In the fully adjusted model there remained 50% excess mortality for the two most deprived groups compared to the most affluent. Variables which measured timely access to care (extent/size) accounted for more of the survival disparity than breast cancer subtype variables (ER/PR/HER2). Conclusion: Women from deprived areas in New Zealand who are diagnosed with breast cancer are less likely to survive as long as those from affluent areas. A substantial proportion of these socioeconomic disparities can be attributed to differential access to health care although other factors, currently unknown, are also likely to play an important role.

The accuracy and completeness of childhood cancer registration in New Zealand.

The New Zealand Cancer Registry (NZCR) is the main source of data on cancer incidence in New Zealand. The accuracy and completeness of registration of childhood cancers (ages zero to 14 years) were assessed during the conduct of a case-control study. Newly diagnosed children (1990-93) were ascertained from three sources: the NZCR; the Patient Management System (hospital admissions and discharges); and the separate Children's Cancer Registry. Pathology reviews were conducted to verify the diagnoses. Capture-recapture methods were used to assess the completeness of ascertainment. During the four-year period, 409 incident cases of childhood cancer were confirmed, giving an age-standardized incidence rate of 131 per million person-years (95 percent confidence interval = 119-144). The NZCR ascertained 395 (97 percent) of these children. In addition, the NZCR notified us of 43 other 'childhood cancer' registrations which were not confirmed as new cases of childhood cancer according to our eligibility criteria. The main reasons for these were coding errors (20 registrations), duplicates (seven), and a change in the pathological diagnosis as a result of the pathology review (seven). The capture-recapture estimate of the total number of incident cases was 410. Overall, the NZCR had good completeness for childhood cancers, but the number of unconfirmed registrations was larger than expected.

Soft-tissue sarcoma, non-Hodgkin's lymphoma and other cancers in New Zealand forestry workers.

Several studies have suggested that forestry workers are at increased risk for certain types of cancer including soft-tissue sarcoma (STS) and non-Hodgkin's lymphoma (NHL). We now report a series of national case-control studies based on the New Zealand Cancer Registry (NZCR). These involved 19,904 male patients with cancer for the period 1980-1984 who were aged 20 years or more at the time of registration. For each cancer site, the registrations for the remaining sites formed the control group. Current or most recent occupational titles were coded. There was an increased risk for STS (OR = 3.24) in forestry workers which was confined to men under 60 years of age at registration. An elevation in risk for NHL (OR = 1.84) was due to an increase in risk for lymphosarcoma and reticulosarcoma (ICD 200) (OR = 3.18). Acute myeloid leukemia was also associated with forestry work, although the estimate of risk was imprecise (OR = 2.24). Among other cancer sites, an increase in risk of neoplasia of the upper gastro-intestinal tract (ICD 150, 151, 152) was demonstrated. Odds ratios were elevated for cancer of the esophagus (OR = 1.77), stomach (OR = 2.22), small intestine (OR = 5.22), gall-bladder (OR = 4.13) and pancreas (OR = 1.79), as well as for nasopharyngeal cancer (OR = 5.56). These increases in cancer risk were not present in sawmill workers in New Zealand during the same period. The factors responsible for the increased cancer risks in forestry workers remain unclear and require further study.