Ethnic differences in the characteristics of patients with newly diagnosed lung cancer in the Te Manawa Taki region of New Zealand.

BACKGROUND: Maori have three times the mortality from lung cancer compared with non-Maori. The Te Manawa Taki region has a population of 900 000, of whom 30% are Maori. We have little understanding of the factors associated with developing and diagnosing lung cancer and ethnic differences in these characteristics. AIMS: To explore the differences in the incidence and characteristics of patients with newly diagnosed lung cancer between Maori and non-Maori. METHODS: Patients were identified from the regional register. Incidence rates were calculated based on population data from the 2013 and 2018 censuses. The patient and tumour characteristics of Maori and non-Maori were compared. The analysis used Χ2 tests and logistic models for categorical variables and Student t tests for continuous variables. RESULTS: A total of 4933 patients were included, with 1575 Maori and 3358 non-Maori. The age-standardised incidence of Maori (236 per 100 000) was 3.3 times higher than that of non-Maori. Maori were 1.3 times more likely to have an advanced stage of disease and 1.97 times more likely to have small cell lung cancer. Maori were more likely to have comorbidities, chronic obstructive pulmonary disease, cardiovascular disease and diabetes. They also had higher levels of social deprivation and tended to be younger, female and current smokers. CONCLUSIONS: The findings point to the need to address barriers to early diagnosis and the need for system change including the need to introduce a lung cancer screening focussing on Maori. There is also the need for preventive programmes to address comorbidities that impact lung cancer outcomes as well as a continued emphasis on creating a smoke-free New Zealand.

Incidence, trends, and survival of oropharyngeal squamous cell cancer in Aotearoa New Zealand, 2006-2020.

BACKGROUND: An increasing trend of oropharyngeal cancer (OPC) has been reported in several countries with different demographic characteristics, and often attributed to increases in human papillomavirus (HPV) infection. The survival of patients with OPC has steadily improved, especially for those with positive HPV status. This study assessed the incidence, trends, and survival of OPC in Aotearoa New Zealand (NZ) by age at diagnosis, sex and ethnicity. METHODS: The study included all 2109 patients resident in NZ with a primary diagnosis of oropharyngeal squamous cell carcinoma from 2006 to 2020, identified from the National Cancer Registry. We assessed age-standardised incidence rate (ASR), annual percent change (APC) and overall and relative survival rates. RESULTS: The average annual incidence of OPC was 2.2 per 100,000 population. There was a steady increase of 4.9% per year over 15 years. Although the incidence rates were higher in males over the study period, the overall rate of increase was similar in males (4.9%) and in females (4.3%). The incidence was highest in the 50-69-year group (8.8/100,000 population). This age group had an incidence that increased by 7.5% per year to 2018, and then declined. The main increase in rates was seen between the birth cohort of 1946-50 and that of 1956-60. The increase in incidence was seen in Maori and Pakeha/European populations, but no increase was seen in Pacific or Asian populations. The 5-year overall relative survival rate improved from 69% in 2006-13 to 78% in 2014-20. Survival rates were lower in older patients, females, and Maori patients. CONCLUSION: This study confirmed a substantial increase in OPC incidence in NZ, with some evidence to suggest a recent slowing in this increase. Maori and Pakeha/European had the highest incidence, while Pacific and Asian populations showed the lowest rates and no increase over the study period. Survival rates have improved over time, but remained lower in some demographic groups.

The risk of subsequent invasive melanoma after a primary in situ or invasive melanoma in a high incidence country (New Zealand).

Background: Patients with invasive melanoma are at increased risk of developing subsequent invasive melanoma, but the risks for those with primary in situ melanoma are unclear. Objectives: To assess and compare the cumulative risk of subsequent invasive melanoma after primary invasive or in situ melanoma. To estimate the standardized incidence ratio (SIR) of subsequent invasive melanoma compared to population incidence in both cohorts. Methods: Patients with a first diagnosis of melanoma (invasive or in situ) between 2001 and 2017 were identified from the New Zealand national cancer registry, and any subsequent invasive melanoma during follow-up to the end of 2017 identified. Cumulative risk of subsequent invasive melanoma was estimated by Kaplan-Meier analysis separately for primary invasive and in situ cohorts. Risk of subsequent invasive melanoma was assessed using Cox proportional hazard models. SIR was assessed, allowing for age, sex, ethnicity, year of diagnosis and follow up time. Results: Among 33 284 primary invasive and 27 978 primary in situ melanoma patients, median follow up time was 5.5 and 5.7 years, respectively. A subsequent invasive melanoma developed in 1777 (5%) of the invasive and 1469 (5%) of the in situ cohort, with the same median interval (2.5 years) from initial to first subsequent lesion in both cohorts. The cumulative incidence of subsequent invasive melanoma at 5 years was similar in the two cohorts (invasive 4.2%, in situ 3.8%); the cumulative incidence increased linearly over time in both cohorts. The risk of subsequent invasive melanoma was marginally higher for primary invasive compared to in situ melanoma after adjustment for age, sex, ethnicity and body site of the initial lesion (hazard ratio 1.11, 95% CI 1.02-1.21). Compared to population incidence, the SIR of invasive melanoma was 4.6 (95% CI 4.3-4.9) for the primary invasive and 4 (95% CI 3.7-4.2) for the primary in situ melanoma cohorts. Conclusions: The risk of subsequent invasive melanoma is similar whether patients present with in situ or invasive melanoma. Thus follow-up surveillance for new lesions should be similar, although patients with invasive melanoma require more surveillance for recurrence.

Shifting incidence and survival of epithelial ovarian cancer (1995-2014): A SurvMark-2 study.

The aim of the study is to provide a comprehensive assessment of incidence and survival trends of epithelial ovarian cancer (EOC) by histological subtype across seven high income countries (Australia, Canada, Denmark, Ireland, New Zealand, Norway and the United Kingdom). Data on invasive EOC diagnosed in women aged 15 to 99 years during 1995 to 2014 were obtained from 20 cancer registries. Age standardized incidence rates and average annual percentage change were calculated by subtype for all ages and age groups (15-64 and 65-99 years). Net survival (NS) was estimated by subtype, age group and 5-year period using Pohar-Perme estimator. Our findings showed marked increase in serous carcinoma incidence was observed between 1995 and 2014 among women aged 65 to 99 years with average annual increase ranging between 2.2% and 5.8%. We documented a marked decrease in the incidence of adenocarcinoma "not otherwise specified" with estimates ranging between 4.4% and 7.4% in women aged 15 to 64 years and between 2.0% and 3.7% among the older age group. Improved survival, combining all EOC subtypes, was observed for all ages combined over the 20-year study period in all countries with 5-year NS absolute percent change ranging between 5.0 in Canada and 12.6 in Denmark. Several factors such as changes in guidelines and advancement in diagnostic tools may potentially influence the observed shift in histological subtypes and temporal trends. Progress in clinical management and treatment over the past decades potentially plays a role in the observed improvements in EOC survival.

Pancreatic cancer survival by stage and age in seven high-income countries (ICBP SURVMARK-2): a population-based study.

BACKGROUND: The global burden of pancreatic cancer has steadily increased, while the prognosis after pancreatic cancer diagnosis remains poor. This study aims to compare the stage- and age-specific pancreatic cancer net survival (NS) for seven high-income countries: Australia, Canada, Denmark, Ireland, New Zealand, Norway, and United Kingdom. METHODS: The study included over 35,000 pancreatic cancer cases diagnosed during 2012-2014, followed through 31 December 2015. The stage- and age-specific NS were calculated using the Pohar-Perme estimator. RESULTS: Pancreatic cancer survival estimates were low across all 7 countries, with 1-year NS ranging from 21.1% in New Zealand to 30.9% in Australia, and 3-year NS from 6.6% in the UK to 10.9% in Australia. Most pancreatic cancers were diagnosed with distant stage, ranging from 53.9% in Ireland to 83.3% in New Zealand. While survival differences were evident between countries across all stage categories at one year after diagnosis, this survival advantage diminished, particularly in cases with distant stage. CONCLUSION: This study demonstrated the importance of stage and age at diagnosis in pancreatic cancer survival. Although progress has been made in improving pancreatic cancer prognosis, the disease is highly fatal and will remain so without major breakthroughs in the early diagnosis and management.

International differences in lung cancer survival by sex, histological type and stage at diagnosis: an ICBP SURVMARK-2 Study.

INTRODUCTION: Lung cancer has a poor prognosis that varies internationally when assessed by the two major histological subgroups (non-small cell (NSCLC) and small cell (SCLC)). METHOD: 236 114 NSCLC and 43 167 SCLC cases diagnosed during 2010-2014 in Australia, Canada, Denmark, Ireland, New Zealand, Norway and the UK were included in the analyses. One-year and 3-year age-standardised net survival (NS) was estimated by sex, histological type, stage and country. RESULTS: One-year and 3-year NS was consistently higher for Canada and Norway, and lower for the UK, New Zealand and Ireland, irrespective of stage at diagnosis. Three-year NS for NSCLC ranged from 19.7% for the UK to 27.1% for Canada for men and was consistently higher for women (25.3% in the UK; 35.0% in Canada) partly because men were diagnosed at more advanced stages. International differences in survival for NSCLC were largest for regional stage and smallest at the advanced stage. For SCLC, 3-year NS also showed a clear female advantage with the highest being for Canada (13.8% for women; 9.1% for men) and Norway (12.8% for women; 9.7% for men). CONCLUSION: Distribution of stage at diagnosis among lung cancer cases differed by sex, histological subtype and country, which may partly explain observed survival differences. Yet, survival differences were also observed within stages, suggesting that quality of treatment, healthcare system factors and prevalence of comorbid conditions may also influence survival. Other possible explanations include differences in data collection practice, as well as differences in histological verification, staging and coding across jurisdictions.

International variation in oesophageal and gastric cancer survival 2012-2014: differences by histological subtype and stage at diagnosis (an ICBP SURVMARK-2 population-based study).

OBJECTIVE: To provide the first international comparison of oesophageal and gastric cancer survival by stage at diagnosis and histological subtype across high-income countries with similar access to healthcare. METHODS: As part of the ICBP SURVMARK-2 project, data from 28 923 patients with oesophageal cancer and 25 946 patients with gastric cancer diagnosed during 2012-2014 from 14 cancer registries in seven countries (Australia, Canada, Denmark, Ireland, New Zealand, Norway and the UK) were included. 1-year and 3-year age-standardised net survival were estimated by stage at diagnosis, histological subtype (oesophageal adenocarcinoma (OAC) and oesophageal squamous cell carcinoma (OSCC)) and country. RESULTS: Oesophageal cancer survival was highest in Ireland and lowest in Canada at 1 (50.3% vs 41.3%, respectively) and 3 years (27.0% vs 19.2%) postdiagnosis. Survival from gastric cancer was highest in Australia and lowest in the UK, for both 1-year (55.2% vs 44.8%, respectively) and 3-year survival (33.7% vs 22.3%). Most patients with oesophageal and gastric cancer had regional or distant disease, with proportions ranging between 56% and 90% across countries. Stage-specific analyses showed that variation between countries was greatest for localised disease, where survival ranged between 66.6% in Australia and 83.2% in the UK for oesophageal cancer and between 75.5% in Australia and 94.3% in New Zealand for gastric cancer at 1-year postdiagnosis. While survival for OAC was generally higher than that for OSCC, disparities across countries were similar for both histological subtypes. CONCLUSION: Survival from oesophageal and gastric cancer varies across high-income countries including within stage groups, particularly for localised disease. Disparities can partly be explained by earlier diagnosis resulting in more favourable stage distributions, and distributions of histological subtypes of oesophageal cancer across countries. Yet, differences in treatment, and also in cancer registration practice and the use of different staging methods and systems, across countries may have impacted the comparisons. While primary prevention remains key, advancements in early detection research are promising and will likely allow for additional risk stratification and survival improvements in the future.

Patient-reported diagnostic intervals to colorectal cancer diagnosis in the Midland region of New Zealand: a prospective cohort study.

BACKGROUND AND OBJECTIVES: New Zealand (NZ) has high rates of colorectal cancer (CRC) but low rates of early detection. The majority of CRC is diagnosed through general practice, where lengthy diagnostic intervals are common. We investigated factors contributing to diagnostic delay in a cohort of patients newly diagnosed with CRC. METHODS: Patients were recruited from the Midland region and interviewed about their diagnostic experience using a questionnaire based on a modified Model of Pathways to Treatment framework and SYMPTOM questionnaire. Descriptive statistics were used to describe the population characteristics. Chi-square analysis and logistic regression were used to analyse factors influencing diagnostic intervals. RESULTS: Data from 176 patients were analysed, of which 65 (36.9%) experienced a general practitioner (GP) diagnostic interval of >120 days and 96 (54.5%) experienced a total diagnostic interval (TDI) > 120 days. Patients reporting rectal bleeding were less likely to experience a long TDI (odds ratio [OR] 0.34, 95% confidence interval [CI]: 0.14-0.78) and appraisal/help-seeking interval (OR, 0.19, 95% CI: 0.06-0.59). Patients <60 were more likely to report a longer appraisal/help-seeking interval (OR, 3.32, 95% CI: 1.17-9.46). Female (OR, 2.19, 95% CI: 1.08-4.44) and Maori patients (OR, 3.18, 95% CI: 1.04-9.78) were more likely to experience a long GP diagnostic interval. CONCLUSION: NZ patients with CRC can experience long diagnostic intervals, attributed to patient and health system factors. Young patients, Maori, females, and patients experiencing change of bowel habit may be at particular risk. We need to increase symptom awareness of CRC for patients and GPs. Concentrated efforts are needed to ensure equity for Maori in access to screening, diagnostics, and treatment.

New Zealand has high rates of colorectal cancer but low rates of early detection. We interviewed newly diagnosed patients about their diagnostic experience to identify factors influencing time to diagnosis. More than half of patients experienced a long diagnostic interval. Young patients, Maori, females, and patients experiencing changes of bowel habit may be at particular risk for long intervals. With the diagnostic difficulty of colorectal cancer (CRC), we need to increase CRC symptom awareness for patients and general practitioners.

Outcomes from colonoscopy following referral from New Zealand general practice: a retrospective analysis.

BACKGROUND: New Zealand has high rates of colorectal cancer (CRC) but poor outcomes. Most patients with CRC are diagnosed following referral from general practice, where a general practitioner (GP) assesses symptoms according to national guidelines. All referred patients are then re-prioritised by the hospital system. The first objective of this study was to identify what proportion of patients referred by general practice to surgical/gastroenterology at Waikato District Health Board (DHB) had a colonoscopy. The second objective was to determine what proportion of these referrals have an underlying CRC and the factors associated with the likelihood of this diagnosis. METHODS: This study is a retrospective analysis of e-referral data for patients aged 30-70+ who were referred from 75 general practices to general surgery, gastroenterology or direct to colonoscopy at Waikato DHB, 01 January 2015-31 December 2017. Primary and secondary outcome measures included the proportion and characteristics of patients who were having colonoscopy, and of those, who were diagnosed with CRC. Data were analysed using chi square and logistic regression. RESULTS: 6718/20648 (32.5%) patients had a colonoscopy and 372 (5.5%) of these were diagnosed with CRC. The probability of having CRC following a colonoscopy increased with age (p value < 0.001). Females (p value < 0.001), non-Maori (p value < 0.001), and patients with a high suspicion of cancer (HSCan) label originating from their GP were more likely to have a colonoscopy, while the odds ratio of Maori having a colonoscopy was 0.66 (95% CI 0.60-0.73). The odds ratio of a CRC diagnosis following colonoscopy was 1.67 (95% CI 1.35-2.07) for men compared to women, and 2.34 (95% CI 1.70-3.22) for those with a GP HSCan label. Of the 585 patients referred with a GP HSCan, 423 (72.3%) were reprioritised by the hospital and 55 patients had their diagnosis unnecessarily delayed. CONCLUSIONS: If a GP refers a patient with an HSCan, and the patient receives a colonoscopy, then the likelihood of having CRC is almost 15.0%. This would suggest that these patients should be routinely prioritised without further triage by the hospital. Further research is needed to understand why Maori are less likely to receive a colonoscopy following referral from general practice.

Use and results of systemic treatments for de novo and recurrent metastatic breast cancer: a population-based cohort study.

AIMS: To describe the systemic treatments in patients with de novo metastatic breast cancer (dnMBC, initial metastatic diagnosis) and recurrent metastatic breast cancer (rMBC). METHODS: Women diagnosed with dnMBC and rMBC in 2010-2017 were identified. Adjusted odds ratios of receiving systemic treatments were estimated by logistic regression model. Cox proportional hazards regression was used to estimate adjusted hazard ratio of breast cancer-specific mortality by treatments. RESULTS: The adjusted odds ratio of having chemotherapy and trastuzumab (for human epidermal growth factor receptor 2 positive (HER2+) disease) for Pacific women was 0.43 and 0.13 compared to European women. Patients receiving chemotherapy had improved survival for HER2+ non-luminal and triple negative metastatic breast cancer (MBC) (hazard ratios: 0.30, 0.66). Those with endocrine therapy was associated with better survival for luminal A and luminal B HER2+ MBC (hazard ratio: 0.25, 0.26). Trastuzumab was associated with superior survival in luminal B HER2+ and HER2+ non-luminal disease (hazard ratio: 0.34, 0.40). CONCLUSIONS: Pacific women with MBC were less likely to receive chemotherapy and trastuzumab than non-Pacific women. Chemotherapy was associated with improved survival in HER2+ non-luminal and triple negative MBC. Endocrine therapy improved survival in luminal A and luminal B HER2+ disease. Trastuzumab was associated with improved survival in luminal B HER2+ and HER2+ non-luminal disease.

The effect of exposure to radiofrequency fields on cancer risk in the general and working population: A protocol for a systematic review of human observational studies.

BACKGROUND: The World Health Organization (WHO) has an ongoing project to assess potential health effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in the general and working population. Here we present the protocol for a systematic review of the scientific literature on cancer hazards from exposure to RF-EMF in humans, commissioned by the WHO as part of that project. OBJECTIVE: To assess the quality and strength of the evidence provided by human observational studies for a causal association between exposure to RF-EMF and risk of neoplastic diseases. ELIGIBILITY CRITERIA: We will include cohort and case-control studies investigating neoplasia risks in relation to three types of exposure to RF-EMF: near-field, head-localized, exposure from wireless phone use (SR-A); far-field, whole body, environmental exposure from fixed-site transmitters (SR-B); near/far-field occupational exposures from use of handheld transceivers or RF-emitting equipment in the workplace (SR-C). While no restriction on tumour type will be applied, we will focus on selected neoplasms of the central nervous system (brain, meninges, pituitary gland, acoustic nerve) and salivary gland tumours (SR-A); brain tumours and leukaemias (SR-B, SR-C). INFORMATION SOURCES: Eligible studies will be identified through Medline, Embase, and EMF-Portal. RISK-OF-BIAS ASSESSMENT: We will use a tailored version of the OHAT's tool to evaluate the study's internal validity. DATA SYNTHESIS: We will consider separately studies on different tumours, neoplasm-specific risks from different exposure sources, and a given exposure-outcome pair in adults and children. When a quantitative synthesis of findings can be envisaged, the main aims of the meta-analysis will be to assess the strength of association and the shape of the exposure-response relationship; to quantify the degree of heterogeneity across studies; and explore the sources of inconsistency (if any). When a meta-analysis is judged inappropriate, we will perform a narrative synthesis, complemented by a structured tabulation of results and appropriate visual displays. EVIDENCE ASSESSMENT: Confidence in evidence will be assessed in line with the GRADE approach. FUNDING: This project is supported by the World Health Organization. Co-financing was provided by the New Zealand Ministry of Health; the Istituto Superiore di Sanità in its capacity as a WHO Collaborating Centre for Radiation and Health; ARPANSA as a WHO Collaborating Centre for Radiation Protection. REGISTRATION: PROSPERO CRD42021236798.

Impact of menopausal status on risk of metastatic recurrence of breast cancer.

OBJECTIVE: Menopausal status at diagnosis is an important factor for the management of breast cancer in younger women, and may affect the prognosis for these women. We aim to examine the association of menopausal status and risk of metastatic relapse for stage I-III breast cancer. METHODS: We included women diagnosed with stage I-III breast cancer at 45 to 55 years in the Auckland and Waikato Breast Cancer Registers. Cumulative incidence of metastatic relapse was examined by age group and by menopausal status after stratifying by estrogen receptor (ER) and progesterone receptor (PR) status. Cox proportional hazards model was used to estimate the adjusted hazard ratio of metastatic relapse by menopausal status after adjustment for age, ethnicity, year of diagnosis, socioeconomic status, public/private hospital treatment, mode of detection, cancer stage, grade and human epidermal growth factor receptor 2 status. RESULTS: We have identified 5,309 eligible women: 2,799 premenopausal, 929 perimenopausal, and 1,581 post-menopausal. There was significant difference in risk of metastatic recurrence between menopausal statuses for ER+ and/or PR+ cases, with a 10-year cumulative incidence of 11.2% for premenopausal, 12.4% for perimenopausal, and 15.6% for postmenopausal women. The adjusted hazard ratio of metastatic recurrence for postmenopausal compared to premenopausal women was 1.38 for ER+ and/or PR+ cases. Age did not affect the risk of metastatic relapse for ER+ and/or PR+ cases but affected the risk for ER- and PR- cases with a hazard ratio of 0.94 per year. CONCLUSIONS: Women with earlier age at menopause, and ER+ and/or PR+ stage I-III breast cancer were more likely to develop metastatic breast cancer. Age increased the risk of metastatic relapse for women with ER- and PR- disease, but not for ER+ and/or PR+ cancers.

Mobile phone use and trends in the incidence of cancers of the parotid and other salivary glands.

BACKGROUND: There has been a significant increase in the use of mobile phones over the last three decades and a possible association with head cancers has been suggested, including cancers of the parotic and other salivary glands. We examined the incidence time trends of parotid and other salivary gland cancers in Australia to ascertain the influence of increased mobile phone use. METHODS: Analyses of incidence time trends were carried out using Poisson regression to estimate the annual percentage change (APC) in the incidence of salivary gland cancers of all available national registration data from 1982 to 2016, as well as specific time periods (1982-1993, 1994-2005, 2006-2016) representing changes in the prevalence of mobile phone use. RESULTS: The incidence of parotid gland cancer was stable for the periods 1982-1993 and 1994-2005. During 2006-2016 there was a large decrease in parotid gland cancer for males (APC: -3.71, 95 %CI: -6.66 to -0.67) and a large increase in females (4.80, 1.77-7.91) for adults aged 20-59 years. The incidence for other salivary gland cancers was stable during all the periods. CONCLUSIONS: The results do not indicate that mobile phone use increased the incidence of parotid or other salivary gland cancers. An increase in parotid gland cancer in females since 2006 may be attributed to other possible risk factors specific to this gender.

The Scientific Basis for Occupational Exposure Limits for Hydrogen Sulphide-A Critical Commentary.

OBJECTIVES: Occupational exposure limits for hydrogen sulphide (H2S) vary considerably; three expert group reports, published from 2006 to 2010, each recommend different limits. Some jurisdictions are considering substantial reductions. METHODS: This review assesses the scientific evidence used in these recommendations and presents a new systematic review of human studies from 2006-20, identifying 33 studies. RESULTS: The three major reports all give most weight to two sets of studies: of physiological effects in human volunteers, and of effects in the nasal passages of rats and mice. The human studies were done in one laboratory over 20 years ago and give inconsistent results. The breathing style and nasal anatomy of rats and mice would make them more sensitive than humans to inhaled agents. Each expert group applied different uncertainly factors. From these reports and the further literature review, no clear evidence of detrimental health effects from chronic occupational exposures specific to H2S was found. Detailed studies of individuals in communities with natural sources in New Zealand have shown no detrimental effects. Studies in Iceland and Italy show some associations; these and various other small studies need verification. CONCLUSIONS: The scientific justification for lowering occupational exposure limits is very limited. There is no clear evidence, based on currently available studies, that lower limits will protect the health of workers further than will the current exposure limits used in most countries. Further review and assessment of relevant evidence is justified before exposure limits are set.

Associated Factors and Survival Outcomes for Breast Conserving Surgery versus Mastectomy among New Zealand Women with Early-Stage Breast Cancer.

This study aimed to investigate type of loco-regional treatment received, associated treatment factors and mortality outcomes in New Zealand women with early-stage breast cancer who were eligible for breast conserving surgery (BCS). This is a retrospective analysis of prospectively collected data from the Auckland and Waikato Breast Cancer Registers and involves 6972 women who were diagnosed with early-stage primary breast cancer (I-IIIa) between 1 January 2000 and 31 July 2015, were eligible for BCS and had received one of four loco-regional treatments: breast conserving surgery (BCS), BCS followed by radiotherapy (BCS + RT), mastectomy (MTX) or MTX followed by radiotherapy (MTX + RT), as their primary cancer treatment. About 66.1% of women received BCS + RT, 8.4% received BCS only, 21.6% received MTX alone and 3.9% received MTX + RT. Logistic regression analysis was used to identify demographic and clinical factors associated with the receipt of the BCS + RT (standard treatment). Differences in the uptake of BCS + RT were present across patient demographic and clinical factors. BCS + RT was less likely amongst patients who were older (75+ years old), were of Asian ethnicity, resided in impoverished areas or areas within the Auckland region and were treated in a public healthcare facility. Additionally, BCS + RT was less likely among patients diagnosed symptomatically, diagnosed during 2000-2004, had an unknown tumour grade, negative/unknown oestrogen and progesterone receptor status or tumour sizes ≥ 20 mm, ≤50 mm and had nodal involvement. Competing risk regression analysis was undertaken to estimate the breast cancer-specific mortality associated with each of the four loco-regional treatments received. Over a median follow-up of 8.8 years, women who received MTX alone had a higher risk of breast cancer-specific mortality (adjusted hazard ratio: 1.38, 95% confidence interval (CI): 1.05-1.82) compared to women who received BCS + RT. MTX + RT and BCS alone did not have any statistically different risk of mortality when compared to BCS + RT. Further inquiry is needed as to any advantages BCS + RT may have over MTX alternatives.

Metastatic relapse of stage I-III breast cancer in New Zealand.

PURPOSE: This study aims to investigate the factors that influence the risk of metastatic relapse in women presenting with stage I-III breast cancer in New Zealand. METHODS: The study included women diagnosed with stage I-III breast cancer. Cumulative incidence of distant metastatic relapse was examined with the Kaplan-Meier method by cancer stage and subtype. Cox proportional hazards models were used to estimate the adjusted hazard ratio of developing recurrent metastatic breast cancer by cancer stage and biomarker subtype after adjustment for other factors. RESULTS: A total of 17,543 eligible women were identified. The 5-year cumulative incidence of metastatic recurrence was 3.7% for stage I, 13.3% for stage II and 30.9% for stage III disease. The adjusted hazard ratios (HR) of stage II and stage III breast cancer developing metastatic disease were 2.07 and 4.82 compared to stage I. The adjusted risk of distant metastatic relapse was highest for luminal B HER2- cancers (adjusted HR: 1.59 compared to luminal A disease). Higher grade cancers were associated with a higher risk of metastases. After adjustment, women aged 60-69 years and Asian women had the lowest risk of distant metastatic relapse. CONCLUSIONS: The prognosis of women with locally invasive breast cancer differs greatly with the chance of developing metastatic disease depending on the stage of disease at diagnosis and the subtype. Grade of disease at diagnosis was also important. Maori or Pacific ethnicity did not influence the risk of developing metastatic disease, although Asian women seemed less likely to develop metastases.