Cancer in Pacific people in New Zealand

Disparities in Testicular Cancer: A Review of the Literature

Background: Testicular cancer is the most common malignancy diagnosed in adolescents and young adults, and evidence has emerged regarding disparities that affect different groups of patients. Methods: In this article, we conducted a thorough review of this area and summarized the existing literature. Results: Some of the pertinent findings from our review include poorer outcomes for various groups including the native Māori population of New Zealand, those who live in the United States-Mexico border region, those who live in Eastern Europe, those who are uninsured and those with poorer socioeconomic status, amongst others. In the United States specifically, there is significant evidence showing that racial/ethnic minorities, compared to white patients, tend to fare worse with later presentation at higher stages and worse survival rates. Hispanic patients in particular appear to have the potential for more aggressive tumor biology than other groups and are projected to have the highest incidence rates in the US by 2026. Conclusions: Overall, disparities exist in many aspects of testicular cancer and are striking in some instances, and further research is needed in this arena and in potential solutions.

Dynamic ctDNA Mutational Complexity in Patients with Melanoma Receiving Immunotherapy

BACKGROUND

Circulating tumour DNA (ctDNA) analysis promises to improve the clinical care of people with cancer, address health inequities and guide translational research. This observational cohort study used ctDNA to follow 29 patients with advanced-stage cutaneous melanoma through multiple cycles of immunotherapy.

METHOD

A melanoma-specific ctDNA next-generation sequencing (NGS) panel, droplet digital polymerase chain reaction (ddPCR) and mass spectrometry analysis were used to identify ctDNA mutations in longitudinal blood plasma samples from Aotearoa New Zealand (NZ) patients receiving immunotherapy for melanoma. These technologies were used in conjunction to identify the breadth and complexity of tumour genomic information that ctDNA analysis can reliably report.

RESULTS

During the course of immunotherapy treatment, a high level of dynamic mutational complexity was identified in blood plasma, including multiple BRAF mutations in the same patient, clinically relevant BRAF mutations emerging through therapy and co-occurring sub-clonal BRAF and NRAS mutations. The technical validity of this ctDNA analysis was supported by high sample analysis-reanalysis concordance, as well as concordance between different ctDNA measurement technologies. In addition, we observed > 90% concordance in the detection of ctDNA when using cell-stabilising collection tubes followed by 7-day delayed processing, compared with standard EDTA blood collection protocols with rapid processing. We also found that the undetectability of ctDNA at a proportion of treatment cycles was associated with durable clinical benefit (DCB).

CONCLUSION

We found that multiple ctDNA processing and analysis methods consistently identified complex longitudinal patterns of clinically relevant mutations, adding support for expanded clinical trials of this technology in a variety of oncology settings.

Equity of Cancer and Diabetes Co-Occurrence: A National Study With 44 Million Person-Years of Follow-Up

PURPOSE

The co-occurrence of diabetes and cancer is becoming increasingly common, and this is likely to compound existing inequities in outcomes from both conditions within populations.

METHODS

In this study, we investigate the co-occurrence of cancer and diabetes by ethnic groups in New Zealand. National-level diabetes and cancer data on nearly five million individuals over 44 million person-years were used to describe the rate of cancer in a national prevalent cohort of peoples with diabetes versus those without diabetes, by ethnic group (Māori, Pacific, South Asian, Other Asian, and European peoples).

RESULTS

The rate of cancer was greater for those with diabetes regardless of ethnic group (age-adjusted rate ratios, Māori, 1.37; 95% CI, 1.33 to 1.42; Pacific, 1.35; 95% CI, 1.28 to 1.43; South Asian, 1.23; 95% CI, 1.12 to 1.36; Other Asian, 1.31; 95% CI, 1.21 to 1.43; European, 1.29; 95% CI, 1.27 to 1.31). Māori had the highest rate of diabetes and cancer co-occurrence. Rates of GI, endocrine, and obesity-related cancers comprised a bulk of the excess cancers occurring among Māori and Pacific peoples with diabetes.

CONCLUSION

Our observations reinforce the need for the primordial prevention of risk factors that are shared between diabetes and cancer. Also, the commonality of diabetes and cancer co-occurrence, particularly for Māori, reinforces the need for a multidisciplinary, joined-up approach to the detection and care of both conditions. Given the disproportionate burden of diabetes and those cancers that share risk factors with diabetes, action in these areas is likely to reduce ethnic inequities in outcomes from both conditions.

Ethnic Differences in Cancer Rates Among Adults With Type 2 Diabetes in New Zealand From 1994 to 2018

IMPORTANCE

People with type 2 diabetes have greater risk for some site-specific cancers, and risks of cancers differ among racial and ethnic groups in the general population of Aotearoa New Zealand. The extent of ethnic disparities in cancer risks among people with type 2 diabetes in New Zealand is unclear.

OBJECTIVE

To compare the risks of 21 common adult cancers among Māori, Pasifika, and New Zealand European individuals with type 2 diabetes in New Zealand from 1994 to 2018.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, matched cohort study used data from the primary care audit program in Auckland, New Zealand, linked with national cancer, death, and hospitalization registration databases, collected from January 1, 1994, to July 31, 2018, with follow-up data obtained through December 31, 2019. Using a tapered matching method to balance potential confounders (sociodemographic characteristics, lifestyle, anthropometric and clinical measurements, treatments [antidiabetes, antihypertensive, lipid-lowering, and anticoagulant], period effects, and recorded duration of diabetes), comparative cohorts were formed between New Zealand European and Māori and New Zealand European and Pasifika individuals aged 18 years or older with type 2 diabetes. Sex-specific matched cohorts were formed for sex-specific cancers.

EXPOSURES

Māori, Pasifika, and New Zealand European (reference group) ethnicity.

MAIN OUTCOMES AND MEASURES

The incidence rates of 21 common cancers recorded in nationally linked databases between 1994 and 2018 were the main outcomes. Weighted Cox proportional hazards regression was used to assess ethnic differences in risk of each cancer.

RESULTS

A total of 33 524 adults were included: 15 469 New Zealand European (mean [SD] age, 61.6 [13.2] years; 8522 [55.1%] male), 6656 Māori (mean [SD] age, 51.2 [12.4] years; 3345 [50.3%] female), and 11 399 Pasifika (mean [SD] age, 52.8 [12.7] years; 5994 [52.6%] female) individuals. In the matched New Zealand European and Māori cohort (New Zealand European: 8361 individuals; mean [SD] age, 58.9 [12.9] years; 4595 [55.0%] male; Māori: 5039 individuals; mean [SD] age, 51.4 [12.3] years; 2542 [50.5%] male), significant differences between New Zealand European and Māori individuals were identified in the risk for 7 cancers. Compared with New Zealand European individuals, the hazard ratios (HRs) among Māori individuals were 15.36 (95% CI, 4.50-52.34) for thyroid cancer, 7.94 (95% CI, 1.57-40.24) for gallbladder cancer, 4.81 (95% CI, 1.08-21.42) for cervical cancer (females only), 1.97 (95% CI, 1.30-2.99) for lung cancer, 1.81 (95% CI, 1.08-3.03) for liver cancer, 0.56 (95% CI, 0.35-0.90) for colon cancer, and 0.11 (95% CI, 0.04-0.27) for malignant melanoma. In the matched New Zealand European and Pasifika cohort (New Zealand European: 9340 individuals; mean [SD] age, 60.6 [13.1] years; 4885 [52.3%] male; Pasifika: 8828 individuals; mean [SD] age, 53.1 [12.6] years; 4612 [52.2%] female), significant differences between New Zealand European and Pasifika individuals were identified for 6 cancers. Compared with New Zealand European individuals, HRs among Pasifika individuals were 25.10 (95% CI, 3.14-200.63) for gallbladder cancer, 4.47 (95% CI, 1.25-16.03) for thyroid cancer, 0.48 (95% CI, 0.30-0.78) for colon cancer, 0.21 (95% CI, 0.09-0.48) for rectal cancer, 0.21 (95% CI, 0.07-0.65) for malignant melanoma, and 0.01 (95% CI, 0.01-0.10) for bladder cancer.

CONCLUSIONS AND RELEVANCE

In this cohort study, differences in the risk of 21 common cancers were found between New Zealand European, Māori, and Pasifika groups of adults with type 2 diabetes in New Zealand from 1994 to 2018. Research into the mechanisms underlying these differences as well as additional screening strategies (eg, for thyroid and gallbladder cancers) appear to be warranted.

Risk factors at five-year survival in grade 3 breast cancer: a retrospective observational study of the New Zealand population

BACKGROUND

Breast cancer is the most common cancer in New Zealand, with approximately 3000 new registrations annually, affecting one in nine women and resulting in more than 600 deaths. This study analyzed data of patients with selected prognostic factors of Nottingham grade 3 tumors over a specified five-year period. The study aimed to identify factors that result in differential survival in the female, New Zealand population.

METHOD

This is an observational, retrospective cohort study of prospectively collected data from New Zealand Breast Cancer Register. The selected period of 1st January 2011 to 31st, December 2015 allowed a consistent overlap for a national five-year data of grade 3 breast cancer in New Zealand. Mortality was carried out using univariate Fine-Gray competing risk statistical models.

RESULTS

This study showed that women in the older age group (> 70 years) had higher five-year mortality risk (HR: 1.7, 95% CI: 0.9-3.0, p = 0.053). Hormonal receptor analysis showed that ER positive, PR negative, and ER negative, PR negative subjects were at increased risk (HR = 3.5, 95% CI 2.3-5.4, p < 0.001) and (HR = 2.6, 95% CI, 1.8-3.9, p < 0.001) respectively. Molecular subtypes Triple Negative Breast Cancer and Luminal B subjects were at increased risk (HR = 3.0, 95% CI, 1.8-4.7, p < 0.001 and (HR = 3.3, 95% CI, 1.7-6.3, p < 0.001) respectively. HER2 enriched subjects were at a higher, but not significant, risk of five-year mortality compared to luminal A (HR = 1.6, 95% CI, 0.8-3.0, p = 0.10). NZ Europeans were at increased risk (HR = 1.7, 95% CI, 0.8-3.2, p = 0.11), with the highest Cumulative Incidence Function CIF, the largest proportion of HER2 enriched and TNBC across ethnicities.; however, Pacific Islanders experienced the highest HER2 CIF.

CONCLUSION

The survival rates for grade 3 breast cancer vary across the selected prognostic factors and ethnicity. The results of this study make an initial contribution to the understanding of grade 3 breast cancer in the New Zealand population.

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.

The Prevalence, Impact, and Risk Factors for Persistent Pain After Breast Cancer Surgery in a New Zealand Population

OBJECTIVE

Few Australasian studies have assessed persistent pain after breast cancer surgery. This study aims to evaluate the prevalence, impact, and risk factors of moderate to severe persistent pain after breast cancer surgery in a New Zealand population.

METHODS

Retrospective cross-sectional study of patients who underwent breast cancer surgery between six and 48 months previously. Validated questionnaires were used to assess pain prevalence and impact, psychological distress, and upper limb function. Patients' clinical records were assessed for potential risk factors.

RESULTS

Of the 375 patients who were sent questionnaires, 201 were included in the study. More than half of the patients (N = 111, 55%) reported breast surgery related-persistent pain, with 46 (23%) rating the pain as moderate to severe. Neuropathic pain was reported by 21 (46%) patients with moderate to severe pain. Pain interference, upper limb dysfunction, and psychological distress were significantly higher in patients with moderate to severe pain (P < 0.001). Non-European ethnicity (odds ratio [OR] = 5.02, 95% confidence interval [CI] = 2.05-12.25, P < 0.001), reconstruction surgery (OR = 4.10, 95% CI = 1.30-13.00, P = 0.02), and axillary node dissection (OR = 4.33, 95% CI = 1.19-15.73, P < 0.03) were identified as risk factors for moderate to severe pain by multivariate logistic regression analysis.

CONCLUSIONS

Moderate to severe persistent pain after breast cancer surgery affects many New Zealand patients, and is associated with impaired daily life activities, physical disability, and psychological distress. Large numbers of patients undergo breast cancer surgery annually. This study emphasizes the importance of identification and management of these patients perioperatively.

Disease Burden of Hepatocellular Carcinoma: A Global Perspective

Liver cancer is one of the leading causes of cancer-related mortality around the world. Hepatocellular carcinoma (HCC) is the primary cancer of the liver, accounting for the majority of liver cancers. The risk factors associated with HCC include chronic infections with HBV and HCV, alcoholic liver disease, and nonalcoholic fatty liver disease. Additionally, male patients have higher risk for than females, and the risk increases with older age. Mortality rates for HCC parallel its increasing incidence rates. In this context, incidence rate for HCC shows geographic variations in different parts of the world and is heavily affected by regional differences in risk factor for liver disease. The highest incidence rates for HCC are observed in Asia and Africa, while Europe and North America have lower rates. In fact, HBV is still regarded as the leading cause of HCC globally, while HCV is the most common cause of HCC in the USA. Recently, it has been suggested that HCC cases related to nonalcoholic fatty liver disease is on the rise, while the proportion of HCC attributed to alcoholic liver disease remains stable.

Risk factors for breast cancer in the breast cancer risk model study of Guam and Saipan

BACKGROUND

Chamorro Pacific Islanders in the Mariana Islands have breast cancer incidence rates similar to, but mortality rates higher than, those of U.S. women. As breast cancer risk factors of women of the Mariana Islands may be unique because of ethnic and cultural differences, we studied established and suspected risk factors for breast cancer in this unstudied population.

METHODS

From 2010-2013, we conducted retrospective case-control study of female breast cancer (104 cases and 185 controls) among women in the Mariana Islands. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each of various lifestyle-related factors from logistic regression of breast cancer, in all women and in pre- and postmenopausal women separately. Tests for interaction of risk factors with ethnicity were based on the Wald statistics for cross-product terms.

RESULTS

Of the medical and reproductive factors considered - age at menarche, breastfeeding, number of live births, age at first live birth, hormone use, and menopause - only age at first live birth was confirmed. Age at first live birth, among parous women, was higher among cases (mean 24.9 years) than controls (mean 23.2 years); with increased breast cancer risk (OR=2.53; 95% CI, 1.04-6.19 for age≥30y compared to <20y, P for trend=0.01). Of the lifestyle factors -body mass index, waist circumference, physical activity, alcohol and betel-nut intake, and education - only waist circumference (OR=1.65; 95% CI 0.87-3.14 for the highest tertile group compared to the lowest, P for trend=0.04) was significantly associated with breast cancer risk and only in Filipino women. The association with many other established risk factors, such as BMI, hormone use and physical activity, were in the expected direction but were not significant. Associations for family history of breast cancer and alcohol intake were not evident CONCLUSIONS: The results provide a basis for cancer prevention guidance for women in the Mariana Islands.

Epidemiology of Hepatocellular Carcinoma in the Asia-Pacific Region

Hepatocellular carcinoma (HCC) is the predominant primary liver cancer in many countries and is the third most common cause of cancer-related death in the Asia-Pacific region. The incidence of HCC is higher in men and in those over 40 years old. In the Asia-Pacific region, chronic hepatitis B virus and hepatitis C virus infections are the main etiological agents; in particular, chronic hepatitis B infection (CHB) is still the major cause in all Asia-Pacific countries except for Japan. Over the past two decades, the incidence of HCC has remained stable in countries in the region except for Singapore and Hong Kong, where the incidence for both sexes is currently decreasing. Chronic hepatitis C infection (CHC) is an important cause of HCC in Japan, representing 70% of HCCs. Over the past several decades, the prevalence of CHC has been increasing in many Asia-Pacific countries, including Australia, New Zealand, and India. Despite advancements in treatment, HCC is still an important health problem because of the associated substantial mortality. An effective surveillance program could offer early diagnosis and hence better treatment options. Antiviral treatment for both CHB and CHC is effective in reducing the incidence of HCC.

Asia-Pacific clinical practice guidelines on the management of hepatocellular carcinoma: a 2017 update

There is great geographical variation in the distribution of hepatocellular carcinoma (HCC), with the majority of all cases worldwide found in the Asia–Pacific region, where HCC is one of the leading public health problems. Since the “Toward Revision of the Asian Pacific Association for the Study of the Liver (APASL) HCC Guidelines” meeting held at the 25th annual conference of the APASL in Tokyo, the newest guidelines for the treatment of HCC published by the APASL has been discussed. This latest guidelines recommend evidence-based management of HCC and are considered suitable for universal use in the Asia–Pacific region, which has a diversity of medical environments.

Kavalactone yangonin induces autophagy and sensitizes bladder cancer cells to flavokawain A and docetaxel via inhibition of the mTOR pathway

Consumption of kava (Piper methysticum Forst) has been linked to reduced cancer risk in the South Pacific Islands. Kavalactones are major bioactive components in kava root extracts, which have recently demonstrated anti-cancer activities. However, molecular mechanisms of kavalactones' anti-cancer action remain largely unknown. We have identified two kavalactones, yangonin and 5′ 6'-dehydrokawain, as potent inducers of autophagic cell death in bladder cancer cells. The effect of yangonin inducing autophagy is associated with increased expression of beclin and ATG5. In addition, yangonin increases the expression of LKB1 and decreases the phosphorylation of Akt, PRAS40, rpS6, p70S6K and 4E-BP1, leading to increased binding of 4E-BP1 to m7 GTP. The growth inhibitory effects of yangonin were attenuated inTSC1 or LKB1 knockout mouse embryonic fibroblasts, suggesting that TSC1 and LKB1 expression may contribute to optimal growth inhibition by yangonin. Furthermore, yangonin reduces the viability of bladder cancer cell lines derived from different stages of human bladder cancer, and acts synergistically with apoptosis-inducing agents such as docetaxel and flavokawain A. Our results support a novel anti-bladder cancer mechanism by yangonin and further studies are needed to assess the potential use of yangonin for bladder cancer prevention and treatment

Risk of cancer in Asian Americans: a Kaiser Permanente cohort study

PURPOSE

To supplement published cohort data about incident cancer in Asian Americans (Asians) including risk of specific Asian ethnic groups.

METHODS

A cohort study in 124,193 persons (13,344 Asians) with baseline examination data in 1978-1985 used Cox proportional hazards models with seven covariates to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs).

RESULTS

Through 2012 cancer was diagnosed in 18,687 persons including 1,522 Asians. Compared to Whites, the HR (CIs) for any cancer in Asians was 0.8 (0.7-0.9, p < 0.001). Lower Asian risk was stronger for men (HR = 0.7, p < 0.001) than for women (HR = 0.9, p = 0.003). Lower Asian vs. White risks with p < 0.05 were found for cancers of the upper airway digestive area, hematologic malignancies, melanoma, and cancers of the prostate, bladder, and brain. Melanoma contributed substantially to lower Asian risk, especially in women. HRs for specific Asian groups versus Whites follow: Chinese = 0.9 (p < 0.001), Japanese = 0.9 (p = 0.01), Filipinos = 0.8 (p < 0.001), South Asians = 0.5 (p < 0.001), and Other Asians = 0.7 (p = 0.006). Both South Asian men and women had lower risk than Whites, and South Asians had lower risk than any other racial/ethnic group.

CONCLUSIONS

Asians had lower cancer risk than Whites, due to lower risk of several cancer types. Each Asian ethnic group had lower risk than Whites with South Asians at the lowest risk.

Treatment delay for Māori women with breast cancer in New Zealand

OBJECTIVES

To identify differences in delay for surgical treatment of breast cancer between ethnic groups and to evaluate the role of health system, sociodemographic and tumour factors in ethnic inequities in breast cancer treatment.

METHODS

A retrospective analysis of prospectively collected data from the Waikato Breast Cancer Register for cancers diagnosed in the Waikato region in New Zealand (NZ) from 1 January 2005 to 31 December 2010.

RESULTS

Approximately 95% (1449 out of 1514) of women with breast cancer diagnosed in the Waikato over the study period were included. Of women undergoing primary surgery (n = 1264), 59.6% and 98.2% underwent surgery within 31 and 90 days of diagnosis, respectively. Compared with NZ European women (mean 30.4 days), significantly longer delays for surgical treatment were observed among Māori (mean = 37.1 days, p = 0.005) and Pacific women (mean = 42.8 days, p = 0.005). Māori women were more likely to experience delays longer than 31 (p = 0.048) and 90 days (p = 0.286) compared with NZ European women. Factors predicting delays longer than 31 and 90 days in the multivariable model included public sector treatment (OR 5.93, 8.14), DCIS (OR 1.53, 3.17), mastectomy (OR 1.75, 6.60), higher co-morbidity score (OR 2.02, 1.02) and earlier year of diagnosis (OR 1.21, 1.03). Inequities in delay between Māori and NZ European women were greatest for women under 50 years and those older than 70 years.

CONCLUSION

This study shows that significant inequities in timely access to surgical treatment for breast cancer exist in NZ, with Māori and Pacific women having to wait longer to access treatment than NZ European women. Overall, a high proportion of women did not receive surgical treatment for breast cancer within the guideline limit of 31 days. Urgent steps are needed to reduce ethnic inequities in timely access to breast cancer treatment, and to shorten treatment delays in the public sector for all women.