Risk of cardiovascular disease in cancer survivors: A cohort study of 446,384 New Zealand primary care patients.

BACKGROUND: Given advances in the management of cancer, it is increasingly important for clinicians to appropriately manage the risk of cardiovascular disease (CVD) among cancer survivors. It is unclear whether CVD risk is increased among cancer survivors overall, and there is inconsistency in evidence to date about CVD incidence and mortality by cancer type. METHODS: Patients aged 30-74 years entered an open cohort study at the time of first CVD risk assessment, between 2004 and 2018, in primary care in New Zealand. Patients with established CVD or cancer within 2 years prior to study entry were excluded. Cancer diagnosis (1995-2016) was determined from a national cancer registry. Cause-specific hazard models were used to examine the association between history of cancer and two outcomes: (1) CVD-related hospitalization and/or death and (2) CVD death. RESULTS: The study included 446,384 patients, of whom 14,263 (3.2%) were cancer survivors. Risk of CVD hospitalization and/or death was increased among cancer survivors compared with patients without cancer at cohort entry (multivariable-adjusted hazard ratio, mHR, 1.11, 95% CI 1.05-1.18), more so for CVD death (1.31, 1.14-1.52). Risk of CVD hospitalization and/or death was increased in patients with myeloma (2.66, 1.60-4.42), lung cancer (2.19, 1.48-3.24) and non-Hodgkin lymphoma (1.90, 1.42-2.54), but not for some cancers (e.g., colorectal, 0.87, 0.71-1.06). Risk of CVD death was increased in several cancer types including melanoma (1.73, 1.25-2.38) and breast cancer (1.56, 1.16-2.11). CONCLUSION: CVD risk management needs to be prioritized among cancer survivors overall, and particularly in those with myeloma, lung cancer and non-Hodgkin lymphoma given consistent evidence of increased risk.

Receipt of mastectomy and adjuvant radiotherapy following breast conserving surgery (BCS) in New Zealand women with BCS-eligible breast cancer, 2010-2015: an observational study focusing on ethnic differences.

BACKGROUND: Women with early breast cancer who meet guideline-based criteria should be offered breast conserving surgery (BCS) with adjuvant radiotherapy as an alternative to mastectomy. New Zealand (NZ) has documented ethnic disparities in screening access and in breast cancer treatment pathways. This study aimed to determine whether, among BCS-eligible women, rates of receipt of mastectomy or radiotherapy differed by ethnicity and other factors. METHODS: The study assessed management of women with early breast cancer (ductal carcinoma in situ [DCIS] and invasive stages I-IIIA) registered between 2010 and 2015, extracted from the recently consolidated New Zealand Breast Cancer Registry (now Te Rehita Mate Utaetae NZBCF National Breast Cancer Register). Specific criteria were applied to determine women eligible for BCS. Uni- and multivariable analyses were undertaken to examine differences by demographic and clinicopathological factors with a primary focus on ethnicity (Maori, Pacific, Asian, and Other; the latter is defined as NZ European, Other European, and Middle Eastern Latin American and African). RESULTS: Overall 22.2% of 5520 BCS-eligible women were treated with mastectomy, and 91.1% of 3807 women who undertook BCS received adjuvant radiotherapy (93.5% for invasive cancer, and 78.3% for DCIS). Asian ethnicity was associated with a higher mastectomy rate in the invasive cancer group (OR 2.18; 95%CI 1.72-2.75), compared to Other ethnicity, along with older age, symptomatic diagnosis, advanced stage, larger tumour, HER2-positive, and hormone receptor-negative groups. Pacific ethnicity was associated with a lower adjuvant radiotherapy rate, compared to Other ethnicity, in both invasive and DCIS groups, along with older age, symptomatic diagnosis, and lower grade tumour in the invasive group. Both mastectomy and adjuvant radiotherapy rates decreased over time. For those who did not receive radiotherapy, non-referral by a clinician was the most common documented reason (8%), followed by patient decline after being referred (5%). CONCLUSION: Rates of radiotherapy use are high by international standards. Further research is required to understand differences by ethnicity in both rates of mastectomy and lower rates of radiotherapy after BCS for Pacific women, and the reasons for non-referral by clinicians.

Comparison of Cancer Mortality and Incidence Between New Zealand and Australia and Reflection on Differences in Cancer Care: An Ecological Cross-Sectional Study of 2014-2018.

BACKGROUND: Despite many background similarities, New Zealand showed excess cancer deaths compared to Australia in previous studies. This study extends this comparison using the most recent data of 2014-2018. METHODS: This study used publicly available cancer mortality and incidence data of New Zealand Ministry of Health and Australian Institute of Health and Welfare, and resident population data of Statistics New Zealand. Australian cancer mortality and incidence rates were applied to New Zealand population, by site of cancer, year, age and sex, to estimate the expected numbers, which were compared with the New Zealand observed numbers. RESULTS: For total cancers in 2014-2018, New Zealand had 780 excess deaths in women (17.1% of the annual total 4549; 95% confidence interval (CI) 15.8-18.4%), and 281 excess deaths in men (5.5% of the annual total 5105; 95% CI 4.3-6.7%) compared to Australia. The excess was contributed by many major cancers including colorectal, melanoma, and stomach cancer in both sexes; lung, uterine, and breast cancer in women, and prostate cancer in men. New Zealand's total cancer incidences were lower than those expected from Australia's in both women and men: average annual difference of 419 cases (-3.6% of the annual total 11 505; 95% CI -4.5 to -2.8%), and 1485 (-11.7% of the annual total 12 669; 95% CI -12.5 to -10.9%), respectively. Comparing time periods, the excesses in total cancer deaths in women were 15.1% in 2000-07, and 17.5% in 1996-1997; and in men 4.7% in 2000-2007 and 5.6% in 1996-1997. The differences by time period were non-significant. CONCLUSION: Excess mortality from all cancers combined and several common cancers in New Zealand, compared to Australia, persisted in 2014-2018, being similar to excesses in 2000-2007 and 1996-1997. It cannot be explained by differences in incidence, but may be attributable to various aspects of health systems governance and performance.

Post-diagnostic statin use and breast cancer-specific mortality: a population-based cohort study.

PURPOSE: Statins are the most widely prescribed cholesterol lowering medications and have been associated with both improved and unchanged breast cancer outcomes in previous studies. This study examines the association between the post-diagnostic use of statins and breast cancer outcomes (death and recurrence) in a large, representative sample of New Zealand (NZ) women with breast cancer. METHODS: Women diagnosed with a first primary breast cancer between 2007 and 2016 were identified from four population-based regional NZ breast cancer registries and linked to national pharmaceutical data, hospital discharges, and death records. Cox proportional hazard models were used to estimate the hazard of breast cancer-specific death (BCD) associated with any post-diagnostic statin use. RESULTS: Of the 14,976 women included in analyses, 27% used a statin after diagnosis and the median follow up time was 4.51 years. Statin use (vs non-use) was associated with a statistically significant decreased risk of BCD (adjusted hazard ratio: 0.74; 0.63-0.86). The association was attenuated when considering a subgroup of 'new' statin users (HR: 0.91; 0.69-1.19), however other analyses revealed that the protective effect of statins was more pronounced in estrogen receptor positive patients (HR: 0.77; 0.63-0.94), postmenopausal women (HR: 0.74; 0.63-0.88), and in women with advanced stage disease (HR: 0.65; 0.49-0.84). CONCLUSION: In this study, statin use was associated with a statistically significant decreased risk of breast cancer death, with subgroup analyses revealing a more protective effect in ER+ patients, postmenopausal women, and in women with advanced stage disease. Further research is warranted to determine if these associations are replicated in other clinical settings.

Performance of cardiovascular disease risk prediction equations in more than 14 000 survivors of cancer in New Zealand primary care: a validation study.

BACKGROUND: People with cancer have an increased risk of cardiovascular disease. Risk prediction equations developed in New Zealand accurately predict 5-year cardiovascular disease risk in a general primary care population in the country. We assessed the performance of these equations for survivors of cancer in New Zealand. METHODS: For this validation study, patients aged 30-74 years from the PREDICT open cohort study, which was used to develop the New Zealand cardiovascular disease risk prediction equations, were included in the analysis if they had a primary diagnosis of invasive cancer at least 2 years before the date of the first cardiovascular disease risk assessment. The risk prediction equations are sex-specific and include the following predictors: age, ethnicity, socioeconomic deprivation index, family history of cardiovascular disease, smoking status, history of atrial fibrillation and diabetes, systolic blood pressure, total cholesterol to HDL cholesterol ratio, and preventive pharmacotherapy (blood-pressure-lowering, lipid-lowering, and antithrombotic drugs). Calibration was assessed by comparing the mean predicted 5-year cardiovascular disease risk, estimated using the risk prediction equations, with the observed risk across deciles of risk, for men and women, and according to the three clinical 5-year cardiovascular disease risk groups in New Zealand guidelines (<5%, 5% to <15%, and ≥15%). Discrimination was assessed by Harrell's C statistic. FINDINGS: 14 263 patients were included in the study. The mean age was 61 years (SD 9) for men and 60 years (SD 8) for women, with a median follow-up of 5·8 years for men and 5·7 years for women. The observed cardiovascular disease risk was underpredicted by a maximum of 2·5% in male and 3·2% in female decile groups. When patients were grouped according to clinical risk groups, observed cardiovascular disease risk was underpredicted by less than 2% in the lower risk groups and overpredicted by 2·2% for men and 3·3% for women in the highest risk group. Harrell's C statistics were 0·67 (SE 0·01) for men and 0·73 (0·01) for women. INTERPRETATION: The New Zealand cardiovascular disease risk prediction equations reasonably predicted the observed 5-year cardiovascular disease risk in survivors of cancer in the country, in whom risk prediction was considered clinically appropriate. Prediction could be improved by adding cancer-specific variables and considering competing risks. Our findings suggest that the equations are reasonable clinical tools for use in survivors of cancer in New Zealand. FUNDING: Auckland Medical Research Foundation, Health Research Council of New Zealand.

Trends in brain cancers (glioma) in New Zealand from 1995 to 2020, with reference to mobile phone use.

BACKGROUND: Some case-control studies have suggested substantial increased risks of glioma in association with mobile phone use; these risks would lead to an increase in incidence over time. METHODS: Incidence rates of glioma from 1995 to 2020 by age, sex, and site in New Zealand (NZ) recorded by the national cancer registry were assessed and trends analysed. Phone use was based on surveys. RESULTS: In these 25 years there were 6677 incident gliomas, giving age-standardised rates (WHO world standard) of 6.04 in males, and 3.95 in females per 100,000. The use of mobile phones increased rapidly from 1990 to more than 50% of the population from about 2000, and almost all the population from 2006. The incidence of glioma from ages 10-69 has shown a small decrease over the last 25 years, during which time the use of mobile phones has become almost universal. Rates in the brain locations receiving most radiofrequency energy have also shown a small decrease. Rates at ages of 80 and over have increased. CONCLUSION: There is no indication of any increase related to the use of mobile phones. These results are similar to results in Australia and in many other countries. The increase in recorded incidence at ages over 80 is similar to that seen in other countries and consistent with improved diagnostic methods.

Cancer of the nasopharynx in Aotearoa New Zealand from 1994 to 2018: Incidence and survival in a population-based, national registry cohort study.

Background: Cancer of the nasopharynx has remarkable geographic and ethnic variation in incidence and outcomes globally. Recent advances in diagnostic and therapeutic technologies provide new opportunities for early detection and improved outcomes. This study aimed to determine the incidence, demographics, outcomes and time trends of cancer of the nasopharynx in Aotearoa New Zealand over the last 25 years. Methods: In a population-based, national registry cohort study of notifications of malignant neoplasms of the nasopharynx made to the New Zealand Cancer Registry between 1994 and 2018, age-specific and age-standardised incidence rates and survival outcomes were evaluated. Findings: 577 registrations of nasopharyngeal cancer from between 1994 and 2018 were analysed; median age at diagnosis 54 years; 72.4% male; 37.4% Asian, 24.3% New Zealand European, 25.3% Pacific peoples, 13.0% Maori. Age-standardised annual incidence remained low (<1/100,000 person-years) and stable from 1994 to 2018. Age-standardised incidence rates in Pacific peoples, Asian and Maori were 21 (95% CI 12.07-35.21)-, 17 (10.95-25.33)- and 4 (2.79-7.07)-fold higher, respectively, than New Zealand Europeans. Epstein-Barr virus-related morphologies predominated keratinising squamous cell carcinoma and not-otherwise-specified morphological subtypes. Ten-year overall survival rate for the cohort was 49.2% (95% CI 44.7-53.5). Older age at diagnosis (65-94 years), Maori or Pacific ethnicity, keratinising squamous cell carcinoma and distant disease were associated with shorter overall survival, whereas younger age at diagnosis (10-29 years), and Asian ethnicity were associated with longer survival. Interpretation: Aotearoa New Zealand has a distinct profile of nasopharyngeal cancer, with age, ethnicity and morphology among the main determinants of incidence and survival. Funding: None.

Nitrates in drinking water and cancers of the colon and rectum: a meta-analysis of epidemiological studies.

BACKGROUND: some recent studies have suggested that the risks of colon and rectal cancer increase with exposure to higher concentrations of nitrates in drinking water. This study is a meta-analysis of relevant studies. METHODS: literature published up to June 2021 was accessed and final results abstracted. Two cohort studies and seven case-control studies were analysed, and one case-control study not used because of limited data. Mixed effects meta-regression analysis was used to assess trends in colon cancer, rectal cancer, and colon cancer considered together, with nitrate concentrations in drinking water. RESULTS: The usually accepted exposure upper limit for nitrates is 11.3 mg/l NO3-N. However most studies assess a lower range, with only one study providing data over 8 mg/l. Colorectal cancer risk increased by 2.4% (95% limits 0.4-4.5%) per unit increase in nitrate concentration, over a range from very low values to mid-range values. Extrapolation to higher dosages has insufficient data. The trend for rectal cancer is less than that for colon cancer. CONCLUSION: The increase in colorectal cancer risk with increasing nitrate concentration is lower than in some recent studies, and applies only over a small range. Extrapolation of these results to higher nitrate levels is not warranted. The studies vary greatly in their design, the nitrate concentrations assessed, and in their results. This association is weak and inconsistent, and may be influenced by bias and confounding factors. Any association of drinking water nitrates with colorectal cancer risk is small, and is uncertain.

Post-diagnostic beta blocker use and breast cancer-specific mortality: a population-based cohort study.

PURPOSE: Beta blockers (BB) have been associated with improved, worsened, or unchanged breast cancer outcomes in previous studies. This study examines the association between the post-diagnostic use of BBs and death from breast cancer in a large, representative sample of New Zealand (NZ) women with breast cancer. METHODS: Women diagnosed with a first primary breast cancer between 2007 and 2016 were identified from four population-based regional NZ breast cancer registries and linked to national pharmaceutical data, hospital discharges, and death records. The median follow-up time was 4.51 years. Cox proportional hazard models were used to estimate the hazard of breast cancer-specific death (BCD) associated with any post-diagnostic BB use. RESULTS: Of the 14,976 women included in analyses, 21% used a BB after diagnosis. BB use (vs non-use) was associated with a small and nonstatistically significant increased risk of BCD (adjusted hazard ratio: 1.11; 95% CI 0.95-1.29). A statistically significant increased risk confined to short-term use (0-3 months) was seen (HR = 1.40; 1.14-1.73), and this risk steadily decreased with increasing duration of use and became a statistically significant protective effect at 3 + years of use (HR = 0.55; 0.34-0.88). CONCLUSION: Our findings suggest that any increased risk associated with BB use may be driven by risk in the initial few months of use. Long-term BB use may be associated with a reduction in BCD.

Population-based incidence rates and increased risk of EGFR mutated non-small cell lung cancer in Maori and Pacifica in New Zealand.

BACKGROUND: Non-squamous non-small cell lung cancer (NSCLC) patients with Epidermal Growth Factor Receptor (EGFR) mutation benefit from targeted treatments. Previous studies reported EGFR mutation-positive proportions among tested non-squamous NSCLC patients. However, incidence rates and population risk of EGFR mutation-positive and EGFR mutation-negative non-squamous NSCLC have not been assessed. This study therefore aimed to estimate the population-based incidence rates of EGFR mutation-positive and EGFR mutation-negative non-squamous NSCLC in different population groups defined by sex, ethnic group and smoking status. METHODS: This study included data from all non-squamous NSCLC patients diagnosed in northern New Zealand between 1/02/2010 and 31/07/2017 (N = 3815), obtained from a population-based cancer registry. Age-specific incidence rates, WHO age-standardised rates (ASRs) and rates adjusted for incomplete testing were calculated for EGFR mutation-positive and EGFR mutation-negative diseases for the study cohort as a whole and subgroups of patients. RESULTS: Among 3815 patients, 45% were tested for EGFR mutations; 22.5% of those tested were EGFR mutation-positive. The ASR of EGFR mutation-positive NSCLC was 5.05 (95%CI 4.71-5.39) per 100,000 person-years. ASRs for EGFR mutation-positive NSCLC were higher for females than males: standardised incidence ratio (SIR) 1.50 (1.31-1.73); higher for Pacifica, Asians and Maori compared with New Zealand Europeans: SIRs 3.47 (2.48-4.85), 3.35 (2.62-4.28), and 2.02 (1.43-2.87), respectively; and, only slightly increased in ever-smokers compared with never-smokers: SIR 1.25 (1.02-1.53). In contrast, the ASR of EGFR mutation-negative NSCLC was 17.39 (16.75-18.02) per 100,000 person-years, showing a strong association with smoking; was higher for men; highest for Maori, followed by Pacifica and then New Zealand Europeans, and lowest for Asians. When corrected for incomplete testing, SIRs by sex, ethnicity and smoking, for both diseases, remained similar to those based on tested patients. CONCLUSION: The population risk of EGFR mutation-positive NSCLC was significantly higher for Maori and Pacifica compared with New Zealand Europeans.

Use of Non-Cancer Medications in New Zealand Women at the Diagnosis of Primary Invasive Breast Cancer: Prevalence, Associated Factors and Effects on Survival.

BACKGROUND: Assessing the use of multiple medications in cancer patients is crucial as such use may affect cancer outcomes. This study reports the prevalence of non-cancer medication use at breast cancer diagnosis, its associated factors, and its effect on survival. METHODS: We identified all women diagnosed with primary invasive breast cancer between 1 January 2007 and 31 December 2016, from four population-based breast cancer registries, in Auckland, Waikato, Wellington, and Christchurch, New Zealand. Through linkage to the pharmaceutical records, we obtained information on non-cancer medications that were dispensed for a minimum of 90 days' supply between one year before cancer diagnosis and first cancer treatment. We performed ordered logistic regressions to identify associated factors and Cox regressions to investigate its effect on patient survival. RESULTS: Of 14,485 patients, 52% were dispensed at least one drug (mean-1.3 drugs; maximum-13 drugs), with a higher prevalence observed in patients who were older, treated at a public facility, more economically deprived, and screen-detected. The use of 2-3 drugs showed a reduced non-breast cancer mortality (HR = 0.75, 95%CI = 0.60-0.92) in previously hospitalised patients, with other groups showing non-significant associations when adjusted for confounding factors. Drug use was not associated with changes in breast cancer-specific mortality. CONCLUSIONS: Non-cancer medication use at breast cancer diagnosis was common in New Zealand, more prevalent in older and disadvantaged women, and showed no effect on breast cancer-specific mortality, but a reduction in other cause mortality with the use of 2-3 drugs.

Factors associated with overall survival in a population-based cohort of non- squamous NSCLC patients from northern New Zealand: A comparative analysis by EGFR mutation status.

BACKGROUND: Previous studies have reported inconsistent results regarding the effect of epidermal growth factor receptor (EGFR) mutations on overall survival in patients with non-squamous non-small-cell lung cancer (NSCLC). This study assesses the effect of EGFR mutation on overall survival, and how the effects of other survival predictors differ by EGFR mutation status. METHODS: The study used a population- based cohort of 1534 non-squamous NSCLC patients diagnosed in northern New Zealand between 1st February 2010 and 31st July 2017. Cox regression survival analyses were used to explore the associations between clinicopathological factors and overall survival by EGFR mutation status. The factors included were age at diagnosis, sex, ethnicity, smoking status, performance status, metastasis status and tumour site. RESULTS: In this cohort, 20% had anEGFR mutation. The median overall survival times were 0.8 years and 2.79 years in EGFR-mutation-negative and -positive groups, respectively (p < 0.0001). Metastasis at diagnosis showed large effects on overall survival in both EGFR-mutation- negative (hazard ratio (HR) = 3.6) and mutation-positive (HR = 3.3) groups. In subgroup analyses by mutation status and metastasis, females had lower survival only if they were mutation-positive; Maori had lower survival (than European New Zealanders) only if the disease was metastatic, and tumour site had significant effects only in patients without metastasis. Age, performance status and smoking status showed consistent effects in all subgroups. CONCLUSION: EGFR mutation status and metastasis are the main predictors for overall survival in non-squamous NSCLC patients. The effects of sex, ethnicity and tumour site vary depending on EGFR mutation and metastasis status.

Development and validation of a predictive model for estimating EGFR mutation probabilities in patients with non-squamous non-small cell lung cancer in New Zealand.

BACKGROUND: Targeted treatment with Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) is superior to systemic chemotherapy in non-small cell lung cancer (NSCLC) patients with EGFR gene mutations. Detection of EGFR mutations is a challenge in many patients due to the lack of suitable tumour specimens for molecular testing or for other reasons. EGFR mutations are more common in female, Asian and never smoking NSCLC patients. METHODS: Patients were from a population-based retrospective cohort of 3556 patients diagnosed with non-squamous non-small cell lung cancer in northern New Zealand between 1 Feb 2010 and 31 July 2017. A total of 1694 patients were tested for EGFR mutations, of which information on 1665 patients was available for model development and validation. A multivariable logistic regression model was developed based on 1176 tested patients, and validated in 489 tested patients. Among 1862 patients not tested for EGFR mutations, 129 patients were treated with EGFR-TKIs. Their EGFR mutation probabilities were calculated using the model, and their duration of benefit and overall survival from the start of EGFR-TKI were compared among the three predicted probability groups: < 0.2, 0.2-0.6, and > 0.6. RESULTS: The model has three predictors: sex, ethnicity and smoking status, and is presented as a nomogram to calculate EGFR mutation probabilities. The model performed well in the validation group (AUC = 0.75). The probability cut-point of 0.2 corresponds 68% sensitivity and 78% specificity. The model predictions were related to outcome in a group of TKI-treated patients with no biopsy testing available (n = 129); in subgroups with predicted probabilities of < 0.2, 0.2-0.6, and > 0.6, median overall survival times from starting EGFR-TKI were 4.0, 5.5 and 18.3 months (p = 0.02); and median times remaining on EGFR-TKI treatment were 2.0, 4.2, and 14.0 months, respectively (p < 0.001). CONCLUSION: Our model may assist clinical decision making for patients in whom tissue-based mutation testing is difficult or as a supplement to mutation testing.

Utilisation and Determinants of Epidermal Growth Factor Receptor Mutation Testing in Patients with Non-small Cell Lung Cancer in Routine Clinical Practice: A Global Systematic Review.

BACKGROUND: Epidermal growth factor receptor (EGFR) mutation testing is recommended for selecting patients with non-squamous non-small cell lung cancer (NSCLC) for EGFR tyrosine kinase inhibitor drug treatment. OBJECTIVE: The objective of this article was to systematically review available evidence on the utilisation and determinants of EGFR mutation testing of patients with NSCLC in routine clinical practice. PATIENTS AND METHODS: Searches were made of five electronic databases (Web of Science, MEDLINE [Ovid], Science Direct, EMBASE and Scopus), bibliographies of relevant articles, studies that cited included studies and relevant cancer websites. Studies were included if they: (1) reported the rate of uptake of EGFR testing in patients with NSCLC; (2) were conducted in routine clinical practice settings; (3) were published in English prior to July 2017; and (4) had full text available. Studies were appraised using the STROBE and the National Institutes of Health (National Heart, Lung and Blood Institute) checklists. RESULTS: Eighteen eligible studies were identified for this systematic review, published between 2011 and 2017, from the USA (n = 7), Canada (n = 2), Republic of Korea (n = 2), Norway (n = 1), Sweden (n = 1), Germany (n = 1), Spain (n = 1), New Zealand (n = 1), China (n = 1) and multiple countries from the Asia-Pacific region (n = 1). Overall, testing for EGFR mutations was undertaken in 16,146 of 52,257 study patients (31%), although testing rates varied widely between different studies (from 7.8% to 78.3%). Single institution retrospective audits reported higher rates of testing (median 65.7%, range 31.3-78.3%) than population-based retrospective cohort analyses (median 23%, range 11-69%) and multi-institutional cross-sectional practitioner surveys (median 19.8%, range 7.8-31.8%). Nine studies reported increasing rates of testing over the study period but maximum testing rates remained less than 75% in most studies. Factors associated with higher testing uptake rates included: female sex; younger age; former/no smoking; advanced stage of lung cancer; adenocarcinoma histology; better mobility; radiation therapy; available tissue specimen; and private insurance. Among 16,146 tested patients, EGFR mutations were detected in 4328 patients (26.8%). However, estimates of mutation prevalence were biased by incomplete and selective testing in many studies. CONCLUSIONS: The uptake of EGFR mutation testing of patients with NSCLC is suboptimal in many parts of the world. Incomplete uptake of testing is fuelled by selective testing referral practices, sample limitations, and funding constraints.

Prognostic models for breast cancer: a systematic review.

BACKGROUND: Breast cancer is the most common cancer in women worldwide, with a great diversity in outcomes among individual patients. The ability to accurately predict a breast cancer outcome is important to patients, physicians, researchers, and policy makers. Many models have been developed and tested in different settings. We systematically reviewed the prognostic models developed and/or validated for patients with breast cancer. METHODS: We conducted a systematic search in four electronic databases and some oncology websites, and a manual search in the bibliographies of the included studies. We identified original studies that were published prior to 1st January 2017, and presented the development and/or validation of models based mainly on clinico-pathological factors to predict mortality and/or recurrence in female breast cancer patients. RESULTS: From the 96 articles selected from 4095 citations found, we identified 58 models, which predicted mortality (n = 28), recurrence (n = 23), or both (n = 7). The most frequently used predictors were nodal status (n = 49), tumour size (n = 42), tumour grade (n = 29), age at diagnosis (n = 24), and oestrogen receptor status (n = 21). Models were developed in Europe (n = 25), Asia (n = 13), North America (n = 12), and Australia (n = 1) between 1982 and 2016. Models were validated in the development cohorts (n = 43) and/or independent populations (n = 17), by comparing the predicted outcomes with the observed outcomes (n = 55) and/or with the outcomes estimated by other models (n = 32), or the outcomes estimated by individual prognostic factors (n = 8). The most commonly used methods were: Cox proportional hazards regression for model development (n = 32); the absolute differences between the predicted and observed outcomes (n = 30) for calibration; and C-index/AUC (n = 44) for discrimination. Overall, the models performed well in the development cohorts but less accurately in some independent populations, particularly in patients with high risk and young and elderly patients. An exception is the Nottingham Prognostic Index, which retains its predicting ability in most independent populations. CONCLUSIONS: Many prognostic models have been developed for breast cancer, but only a few have been validated widely in different settings. Importantly, their performance was suboptimal in independent populations, particularly in patients with high risk and in young and elderly patients.

Bias in survival estimates created by a requirement for consent to enter a clinical breast cancer registry.

BACKGROUND: A requirement for consent for inclusion may bias the results from a clinical registry. This study gives a direct measure of this bias, based on a population-based clinical breast cancer registry where the requirement for consent was removed after further ethical review and data could be re-analysed. METHODS: In Auckland, New Zealand, the population-based clinical breast cancer registry required written patient consent for inclusion from 2000-2012. A subsequent ethical review removed this requirement and allowed an analysis of consented and non-consented patients. Kaplan-Meier survival to 10 years (mean follow-up 5.1 years, maximum 13.9 years), demographic and clinical characteristics were compared. Of 9244 women with invasive cancer, 926 (10.4%) were not consented, and of 1642 women with ductal carcinoma in situ, 245 (14.9%) were not consented. RESULTS: Survival was much higher for consenting patients; invasive cancer, 5 year survival 83.2% (95% confidence limits 82.2-84.1%) for consenting patients, 57.1% (53.0-60.9%) for non-consenting, and 80.8% in all patients. Analyses based only on consenting patients overestimate survival in all patients by around 2% at 2, 5, and 10 years. Non-consented patients were older, more often of Pacific ethnicity, had fewer screen-detected cancers, and more often had metastatic disease; they less frequently had primary surgery or systemic treatments. CONCLUSION: Data from a registry requiring active consent gives an upward bias in survival results, as non-consenting patients have more extensive disease, less treatment, and lower survival. To give unbiased results active consent should be not required in a clinical cancer registry.

Rapid increase in endometrial cancer incidence and ethnic differences in New Zealand.

PURPOSE: Endometrial cancer accounts for 3.9% of all female cancers globally, and its incidence appears to be increasing in women under 40 years of age. This paper investigated ethnic-specific trends in endometrial cancer across different age groups in New Zealand. METHODS: Women who were diagnosed with endometrial cancer between 1996 and 2012 were identified from the New Zealand Cancer Registry. Annual age-standardized incidence and mortality rates were calculated for each ethnicity (Maori, Pacific, and non-Maori non-Pacific) in four age groups (< 40, 40-49, 50-74, and 75 +). The estimates were adjusted for hysterectomy. Joinpoint regression analysis was used to assess trends over time and annual percentage changes (APCs) were estimated. RESULTS: Between 1996 and 2012, age-standardized incidence rates increased in all women and significantly in the < 40, 40-49, and 50-74 age groups (APC 9.22, 3.56, and 1.65 respectively). Incidence rates were highest in Pacific women and increased most rapidly in those under 50 years of age (APC 9.36). Conversely, age-standardized mortality rates decreased in all women and significantly in the 50-74 and 75 + age groups (APC - 5.25 and - 5.06 respectively), with the highest rate observed in Pacific women. CONCLUSION: Pacific women had the highest incidence of endometrial cancer and the trend was increasing, particularly in young women. This could be attributed, at least in part, to a high and increasing rate of obesity in these women and should be explored in future research.

In situ and invasive melanoma in a high-risk, New Zealand, population: A population-based study.

BACKGROUND: Few population-based studies assess both invasive and in situ melanoma. We document all patients with a first biopsied melanoma in a general population in New Zealand (NZ). METHODS: All residents in a defined area of New Zealand with a biopsy showing a new primary invasive or in situ melanoma from 2010 to 2012 were identified, 974 patients; analysis used multivariate methods. RESULTS: Age-standardised incidence rates were 34.3 in females (F) and 41.4 in males (M) for invasive, 20.9 F and 27.6 M for in situ, and 55.2 F and 69.0 M for total melanoma. More in situ melanoma occurred in older patients and on the head and neck. Geometric mean Breslow thickness for invasive was 0.78 mm F and 0.85 mm M, with thicker lesions at ages over 60 and on the lower limb; there was no significant relationship with sex, distance from care or social deprivation assessed from residential address. Nodular melanomas (15%) were more frequent in older and male patients, and on the limbs, and were thicker. The estimated cumulative risk for melanoma is 4.4% F and 4.6% M by age 70. The body site distribution and sex differences were consistent with sun exposure patterns. Estimated incidence of melanoma in New Zealand in 2018 is 2500 invasive and 1700 in situ cases. CONCLUSIONS: Assessing both in situ and invasive melanoma expands the clinical picture, better estimating health care demand and costs. Results suggest that in situ disease is a more slowly growing lesion than the early phase of invasive disease. The features of thicker or nodular melanoma show priorities for prevention and early detection.

Incomplete uptake of EGFR mutation testing and its impact on estimation of mutation prevalence in patients with non-squamous NSCLC: A population-based study in New Zealand.

BACKGROUND: Epidermal Growth Factor Receptor (EGFR) mutation testing is recommended for patients with non-squamous non-small cell lung cancer (NSCLC) but not all eligible patients get tested, which may bias the mutation prevalence estimated. This study aims to examine trends in the uptake of EGFR mutation testing in patients with non-squamous NSCLC in New Zealand; to develop a composite metric that quantifies the influences of demographic and clinico-pathological factors on the testing uptake; and to estimate the prevalence of EGFR mutation if all patients were tested. METHODS: This population-based study involved all patients who were diagnosed with non-squamous NSCLC in four health regions in New Zealand between January 2010 and December 2015. Eligible patients were identified from the New Zealand Cancer Registry and information on EGFR mutation testing was obtained through linkage to TestSafe, a clinical information sharing service, and laboratory records. RESULTS: Of 2701 eligible patients, 1059 (39.2%) were tested for EGFR mutation. The testing prevalence increased (3.7% in 2010 to 64.6% in 2014) and the influences of demographic and clinic-pathological factors decreased from 2010 to June 2014, and remained stable afterward. Of the tested patients, 229 (21.6%) were mutation positive with a decreasing trend observed from 2010 (43.8%) to June 2014 (16.8%). The best-fit log-linear model estimated the prevalence of EGFR mutation, if all patients were tested, as 15.5% (95% CI: 13.2%-18.0%). CONCLUSION: The methods described here allowed a more accurate estimation of the prevalence of EGFR mutation.