The use of trastuzumab in New Zealand women with breast cancer

Impact of diabetes on surgery and radiotherapy for breast cancer

PURPOSES

This study aims to examine whether diabetes has an impact on the use of surgery and adjuvant radiotherapy in treating women with localised breast cancer.

METHODS

Women diagnosed with stage I-III breast cancer between 2005 and 2020 were identified from Te Rēhita Mate Ūtaetae-Breast Cancer Foundation New Zealand National Register, with diabetes status determined using New Zealand's Virtual Diabetes Register. The cancer treatments examined included breast conserving surgery (BCS), mastectomy, breast reconstruction after mastectomy, and adjuvant radiotherapy after BCS. Logistic regression modelling was used to estimate the adjusted odds ratio (OR) and 95% confidence interval (95% CI) of having cancer treatment and treatment delay (> 31 days) for patients with diabetes at the time of cancer diagnosis compared to patients without diabetes.

RESULTS

We identified 25,557 women diagnosed with stage I-III breast cancer in 2005-2020, including 2906 (11.4%) with diabetes. After adjustment for other factors, there was no significant difference overall in risk of women with diabetes having no surgery (OR 1.12, 95% CI 0.94-1.33), although for patients with stage I disease not having surgery was more likely (OR 1.45, 95% CI 1.05-2.00) in the diabetes group. Patients with diabetes were more likely to have their surgery delayed (adjusted OR of 1.16, 95% CI 1.05-1.27) and less likely to have reconstruction after mastectomy compared to the non-diabetes group-adjusted OR 0.54 (95% CI 0.35-0.84) for stage I cancer, 0.50 (95% CI 0.34-0.75) for stage II and 0.48 (95% CI 0.24-1.00) for stage III cancer.

CONCLUSIONS

Diabetes is associated with a lower likelihood of receiving surgery and a greater delay to surgery. Women with diabetes are also less likely to have breast reconstruction after mastectomy. These differences need to be taken in to account when considering factors that may impact on the outcomes of women with diabetes especially for Māori, Pacific and Asian women.

What affects the public healthcare costs of breast cancer in New Zealand?

BACKGROUNDS

The pressure to the healthcare system for providing ongoing monitoring and treatment for breast cancer survivors is increasing. This study aims to identify the factors that affect the public healthcare costs of stage I-III breast cancer and stage IV cancer in New Zealand.

METHODS

We identified women diagnosed with invasive breast cancer between July 1, 2010 and June 30, 2018 and who received services in a public hospital. Patients were identified from the National Breast Cancer Register and/or New Zealand Cancer Registry and were linked to the national administrative datasets. A two-part model was used to identify the factors that affect the public healthcare costs of stage I-III breast cancer and stage IV cancer.

RESULTS

We identified 16,977 stage I-III and 1,093 stage IV breast cancer patients eligible for this study. The costs of stage I-III cancer in the second to fifth year post diagnosis decreased over time, and the costs of stage IV cancer in the first year post diagnosis increased over time. After adjustment for other factors, the costs of stage I-IV cancer decreased with age but increased with cancer stage. HER2+ cancers had the highest costs, followed by triple negative cancers. After adjustment for other factors, Pacific and Asian women had lower costs, and Māori had similar costs compared to others. For stage I-III cancers, women living in nonmajor urban areas had a higher chance of incurring costs in follow-up years, and screen detected patients and patients having any services in a private hospital had a decreased probability of receiving any public healthcare services.

CONCLUSIONS

Pacific women had higher costs than others, but after adjustment for cancer stage, subtype, and other factors, they had lower costs than others. The early detection and better management of stage I-III breast cancer can lead to better outcome and lower costs in follow-up years.

Te Aho o Te Kahu: weaving equity into national-level cancer control

The purpose of this manuscript was to consider how mainstream health organisations can develop structures, processes, and functions to address inequity, using the New Zealand Cancer Control Agency (Te Aho o Te Kahu) as an example. In New Zealand (Aotearoa), as in other countries, inequities in cancer incidence and outcomes exist between population groups, including for indigenous populations. Despite much discussion regarding the need to address racial inequities, often the proposed solutions are at operational or programmatic levels, and disadvantaged communities are unable to have much of a say in the system design and service delivery of these solutions. The establishment of a dedicated cancer control agency has created a unique opportunity to centralise principles and approaches to achieving equity within the core functions of the agency, and enabled a new method of approaching cancer control with the aim of achieving equity for the most disadvantaged populations. Using a framework based on the founding agreement between New Zealand's Indigenous Māori people and the British Government (Te Tiriti o Waitangi), we consider how health system organisations can develop structures, processes, and functions to achieve equity, and summarise how this new agency has been shaped to achieve these objectives for Māori people in particular, including the innovative and equity-first approach to organisational structure and focus. Within this framework, we highlight the key equity-focused work programmes, initiatives, and other actions taken since the inception of the agency. Finally, we discuss the ongoing equity-related challenges the agency faces, as well as the current and future opportunities for achieving equity in health outcomes.

Differences in Breast Cancer Costs by Cancer Stage and Biomarker Subtype in New Zealand

BACKGROUND

Breast cancer requires the greatest expenditure among all cancer types, and the costs vary by cancer stage and biomarker status.

OBJECTIVE

This study aimed to examine the differences in public healthcare costs of breast cancer in New Zealand by stage and subtype.

METHOD

This study included patients diagnosed with invasive breast cancer between 1 July 2010 and 30 June 2018 and receiving services in public hospitals. These patients were identified from the National Breast Cancer Register and/or New Zealand Cancer Registry. Linking with the Pharmaceutical Collection, National Minimum Dataset, National Non-Admitted Patient Collection, and Mortality Collection, we estimated the median public healthcare costs of breast cancer by cancer stage and biomarker subtype.

RESULTS

We identified 22,948 eligible patients. The median costs of breast cancer increased with stage of disease, from $NZ26,930 for stage I disease to $NZ50,388 for stage IV disease. The median costs for human epidermal growth factor receptor 2-positive (HER2+) disease were three times those for HER2-negative (HER2-) disease: $NZ106,428 for HER2+ cancers compared with$NZ28,481 for oestrogen receptor-positive (ER+)/HER2- cancers and $NZ31,722 for triple negative disease. Over 55% of the costs for HER2+ breast cancers were targeted therapy costs. For HER2- cancers, surgery incurred the biggest cost, followed by radiotherapy.

CONCLUSIONS

Treating patients with early-stage breast cancer is less costly than treating those with metastatic disease. The costs vary considerably between the subtypes. Patients with HER2+ cancer incurred three times the costs of those with HER2- cancers. These results provide baseline costing data for clinicians and policy makers when considering new targeted treatments.

A pharmacokinetic study to comparatively evaluate the bioequivalence and safety of a humanized recombinant monoclonal antibody targeting human epidermal growth factor receptor-2 with the reference Herceptin in healthy Chinese subjects

PURPOSE

This study aimed to compare the safety, tolerability, pharmacokinetics (PK), and bioequivalence of a test humanized recombinant monoclonal antibody targeting human epidermal growth factor receptor-2 (HER-2) with the reference Herceptin®.

MATERIALS AND METHODS

The trial consisted of two parts (part I and part II). Part I was an open-label, sequential-cohort dose-escalation study, where 16 healthy subjects were either intravenously infused with QLHER2 (test) at single doses escalating from 0.2 to 6 mg/kg (0.2, 1, 2, 4, and 6 mg/kg) or given 4 mg/kg Herceptin (reference) for evaluating the safety, tolerability, and PK of QLHER2. Part II was a randomized, double-blind, parallel-group study to evaluate the bioequivalence of QLHER2 and Herceptin in 60 subjects.

RESULTS

Following a 1.5-h intravenous infusion of single ascending doses of QLHER2 (1, 2, 4, or 6 mg/kg) in part I, C_max and T_max were 19.43-120.01 μg/mL and 68.91-157.87 h, respectively. AUC_0-t and CL were 1.91-34.21 h·μg/mL and 0.54-0.12 mL/h/kg, indicating lower clearance at higher doses, with a greater than proportional increase in AUC_0-t and t_1/2 of 68.91-157.87 h. In part II, serum concentrations were comparable between QLHER2 and Herceptin over a 70-day sampling period, and the QLHER2/Herceptin ratios of C_max and AUC_0-t were 105.90% [90% confidence interval (CI): 95.69%-117.26%] and 95.79% (90% CI: 87.74%-106.40%), respectively.

CONCLUSION

The 90% CI value of C_max and AUC_0-t for QLHER2/Herceptin ratio ranged between 80.0%-125.00%, indicating that QLHER2 was bioequivalent to Herceptin. These results support further evaluation of QLHER2. Trial registration number: ChiCTR2000041577 and ChiCTR2100041802. Date of registration: 30th December, 2020 and 5th January 2021.

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. Māori or Pacific ethnicity did not influence the risk of developing metastatic disease, although Asian women seemed less likely to develop metastases.

The use of trastuzumab affected by health insurance policy in Jiangsu Province of China

BACKGROUND

Breast cancer recurrence and mortality have been shown to decrease after trastuzumab treatment in human epidermal growth factor 2 (HER2)-positive early-stage breast cancer (EBC) patients. In Jiangsu Province, trastuzumab has been subsidized for patients with HER2-positive EBC since 2013. Several studies showed that Jiangsu was one of the provinces with the highest rates of adjuvant trastuzumab therapy. To uncover the underlying reason, we designed the study to investigate trastuzumab use for HER2-positive breast cancer patients, and to examine the changes caused by medical insurance coverage for trastuzumab in Jiangsu province of China.

METHODS

This was a retrospective, multicenter clinical study with follow-up data. HER2-positive EBC patients diagnosed in 7 representative hospitals in 2010, 2011, and 2013 were enrolled. Demographic and clinical data, and details of diagnosis, treatments, and prognosis, were collected. Data analysis included univariate analysis, multivariate logistic regression, survival analysis, and subgroup analysis.

RESULTS

Of the 641 patients (mean age 51.01±10.79 years) included, 412 (64.27%) patients had medical insurance. Trastuzumab therapy was given to 214 (33.39%) patients. The multivariate logistic regression showed that medical insurance coverage, age, and radiotherapy were associated with trastuzumab use (P<0.05). The overall survival was significantly better in the trastuzumab group than in the non-trastuzumab group (HR: 1.607; 95% CI: 1.046-2.469; P=0.040). Subgroup analysis revealed that there was a trend towards more patients with medical insurance (P=0.073), and significantly more patients received trastuzumab therapy (P<0.001) in 2013 than in 2010-2011. Additionally, trastuzumab use in China was lower than in developed countries. Patients with medical insurance were more likely to use trastuzumab, and more patients could afford trastuzumab therapy with the development of China's health-care reform.

CONCLUSIONS

Our study suggested that the percentage of patients who received trastuzumab in China was lower than developed countries. Patients who had medical insurance were more likely to use trastuzumab than those without medical insurance. The health insurance policy in China has improved access for breast cancer patients who require trastuzumab therapy.

Characteristics and survival of de novo and recurrent metastatic breast cancer in New Zealand

BACKGROUND

We aim to examine the characteristics and survival of patients with de novo metastatic breast cancer (dnMBC) and recurrent metastatic breast cancer (rMBC) in New Zealand.

METHODS

This study included women diagnosed with dnMBC and women who developed rMBC between 2010 and 2017. The Kaplan-Meier method was used to examine cancer-specific survival. Cox proportional hazards regression was used to estimate the adjusted hazard ratio (HR) of cancer-specific mortality by ethnicity, age, year of diagnosis, socioeconomic deprivation, site of metastases, number of metastatic sites, biomarker subtype and MBC subgroup.

RESULTS

We included 2177 MBC patients (667 dnMBC and 1510 rMBC). The median survival of dn MBC patients was 26 months compared to 18 months for rMBC. There were no differences in breast-cancer specific mortality by ethnicity or socioeconomic deprivation. The adjusted HR for patients with visceral metastases compared to patients with non-visceral metastases was 1.41, and the adjusted HR for triple negative disease compared to Luminal A disease was 2.24. Compared to dnMBC, the adjusted HRs for rMBC patients with a metastatic-free interval of < 2 years, 2-4 years, 5-7 year and 8 + years were 1.81, 1.47, 1.08 and 0.82, respectively.

CONCLUSIONS

The survival for patients with MBC in New Zealand is very similar to other developed countries. Patients with dnMBC had a much better prognosis than those with recurrent disease. Patients with triple negative disease or non-luminal HER2 positive disease had the worst prognosis. The prognosis for patient with rMBC improved the longer the time from diagnosis to the development of metastases.