Trends in survival from myeloma, 1990-2015: a competing risks analysis.

BACKGROUND: Myeloma survival has greatly increased over past decades. We investigated trends in survival over time in New Zealand by age, ethnicity, and geography and thus examined potential inequalities among these population subgroups. METHODS: From data supplied by the New Zealand Ministry of Health, all new diagnoses of multiple myeloma (ICD-10 code C90) between 1990 and 2016 were extracted, as well as their matched mortality data. Cox's proportional hazards regression and competing risks regression were used to estimate multivariable survival functions. RESULTS: Between 1 January 1990 and 1 December 2015, 6642 myeloma cases were registered by the New Zealand Cancer Registry. Although survival from myeloma increased substantially from 1990-1994 to 2010-2015, 5-year survival was still only about 60% in 2010-2015. The greatest improvement in survival was for people aged 60-69 years at diagnosis. Using Cox's proportional hazards regression, Maori showed an increased risk of myeloma death but this was predominantly due to differences in competing risks among ethnic groups. Competing risks analysis found the greatest improvement in myeloma survival in Pacific Islanders, and in 2010-2015 Maori had better survival than other ethnicities. Myeloma survival improved significantly over time in all regional health authorities but in all time periods the Central and Southern regions had significantly poorer survival than the Midland region. CONCLUSIONS: Improvements in myeloma survival have been unequal across subgroups and regions in New Zealand. Detailed information about utilization of chemotherapeutic agents and transplantation in New Zealand is not available. This information, as well as more detailed hematological data, is essential to further explore the relationships and reasons for differing myeloma survival in population subgroups of New Zealand.

Association of partner vasectomy, depot medroxyprogesterone acetate and intrauterine contraceptive devices with ovarian cancer.

PURPOSE: To assess the associations between ovarian cancer and depot medroxyprogesterone acetate (DMPA), intrauterine contraceptive devices (IUDs), and partner vasectomy. METHODS: We undertook a New Zealand-wide population-based case-control study. During 2013-2015, 205 eligible cases were identified from the cancer registry (152 [74%] participated) and 1,735 eligible controls were randomly selected from the electoral roll (837 [48%] participated). A postal questionnaire was used to gather information. RESULTS: Ever-use of vasectomy was inversely associated with ovarian cancer in age-adjusted analysis, but not in multivariable analysis (OR = 0.67, 95% CI = 0.46-0.96, and OR = 0.82; 95% CI = 0.54-1.23, respectively). A suggestive trend towards lower risk with longer duration of reliance on partner vasectomy was observed (P-trend = 0.08). Ever-use and duration of use of DMPA were not associated with ovarian cancer. Although ever-use of IUDs was not associated with ovarian cancer, duration of use of IUDs was associated with higher risk (P-trend = 0.04). There were also statistically significant inverse associations between ovarian cancer and use of oral contraceptives, parity, and breastfeeding. CONCLUSIONS: Prolonged use of IUDs may increase the risk of ovarian cancer. It is also possible that an inverse association exists between ovarian cancer and partner vasectomy.

Regional distribution of myeloma in New Zealand.

AIMS: To investigate regional variation in myeloma incidence in New Zealand in order to inform aetiological investigations. METHODS: All new registrations of myeloma (1991-2016) were extracted from the New Zealand Cancer Registry. Ethnic classifications used prioritised ethnicity. For geographical groupings, 74 Territorial Local Authority (TLA) categories for 2006 and population densities were used. Negative binomial regression was used to estimate incidence rate ratios, 95% confidence intervals and p-values. RESULTS: Between 1 January 1991 and 31 December 2016, 7,083 myelomas were registered. The Clutha TLA had a significantly lower incidence than the New Zealand average. Compared to Clutha, many regions had a significantly higher incidence, but there was no clear spatial pattern. The highest incidence rate was for Maori men in the North Island. Women had significantly lower incidence than men of the same ethnic group and in the same area. CONCLUSIONS: As both extremes of myeloma incidence occurred in rural areas, and as all TLAs (except one, Horowhenua) in the two lowest risk categories were rural, it seems unlikely that farming confers an increased risk. Results suggest that some other factor is driving the differences in myeloma incidence by ethnic group. We have provided a baseline of the geographical burden of myeloma in New Zealand.

The impact of primary HPV screening on the incidence of cervical cancer in New Zealand.

INTRODUCTION: Our objective was to evaluate the impact on the incidence of cervical cancer in New Zealand of 5-yearly human papillomavirus (HPV) primary screening compared with 3-yearly cytology. MATERIALS AND METHODS: Unbiased estimates of the screening test sensitivity of HPV and cytology screening, and screening coverage, were used to calculate the reduction in cervical cancer incidence obtained by current cytology screening and the new HPV screening policy. RESULTS: HPV screening in New Zealand is predicted to increase the incidence of cervical cancer in women being screened by 81.7% (95% CI: 38.9%-124.7%). The overall increase in the population incidence of cervical cancer in New Zealand was estimated to be 46.7% (95% CI 42.6%-50.8%), leading to about 57 more women developing cervical cancer each year. CONCLUSIONS: The results indicate that lengthening the screening interval concurrently with changing to HPV testing may reduce the protection from invasive cervical cancer for women. Women in New Zealand should continue to be screened by cytology every 3 years. Changes to screening policy should be carefully designed so that changes in screening effectiveness can be accurately measured.

Trends in myeloma incidence, mortality and survival in New Zealand (1985-2016).

BACKGROUND: Myeloma, one of the most common haematological malignancies worldwide arises in the bone marrow. Incidence rates vary by age and ethnicity but reasons behind these trends are unknown. Treatment of myeloma has changed significantly over recent decades, resulting in longer survival and decreased mortality. METHODS: From data supplied by the Ministry of Health, all new registrations of and deaths from myeloma between 1985 and 2016 were extracted. Trends in age-specific rates were assessed using the method of Armitage. Age-standardised rates were calculated, and trends in age-adjusted rates analysed using the Mantel-Haenszel extension chi-square test. Age-adjusted incidence and mortality rate ratios were calculated. Myeloma-specific survival was visualised using Kaplan-Meier curves and multivariable hazard ratios calculated using Cox regression. RESULTS: Between 1985 and 2016, 7826 New Zealanders were registered with myeloma. Over this time the age-specific incidence of myeloma increased significantly for men, who had higher rates than women. Myeloma mortality was highest in Maori men. Men had higher mortality rates than women in all time periods. Since 1995-1999, mortality has decreased in women whereas in men it has declined since about 2000-2004. Survival has increased significantly since 1990 but Maori still have a higher risk of death than non-Maori. CONCLUSION: The patterns of variation in myeloma incidence, mortality and survival, as well as their trends over time may be used to assist research into the causes and management of myeloma in New Zealand.

The presenting features of melanoma in New Zealand: implications for earlier detection.

OBJECTIVE: To examine the relationship between presenting features and histological characteristics of melanomas in New Zealand. METHODS: Cases were participants in a national melanoma case-control study. Histological data were extracted from a Cancer Registry download. Associations between categorical variables were assessed using the χ2 test; linear regression was used for continuous variables and multinomial logistic regression for non-binary categorical dependent variables. RESULTS: Most melanomas were self-detected. Lesions >2mm depth took longer to diagnose, predominantly due to patient delay. The commonest presenting feature was colour. After adjustment for depth, nodular melanomas were less likely than superficial spreading melanomas to present because of shape or colour, but more likely to be raised. After adjustment for subtype, thick melanomas were significantly more likely to be bigger, raised, bleeding or crusting, and inflamed, itchy or sore. CONCLUSIONS: Nodular and thick melanomas failed to fulfil the ABCDE criteria: the 'A', 'B' and 'C' discriminated poorly; and 'D' for diameter may exclude small but thick lesions. The 'E' criterion (elevation/enlargement/evolution) was perhaps best for detecting these melanomas. Implications for public health: Public education for earlier diagnosis in New Zealand needs to include the presenting features of nodular and thick melanomas and to strongly encourage seeking early physician advice.

HPV screening, invasive cervical cancer and screening policy in Australia.

INTRODUCTION: The new cervical screening policy in Australia replaces 2-yearly cytology with 5-yearly human papillomavirus (HPV) screening. However, 2 of 5 randomized trials that have reported the number of women with cervical cancer found the incidence rate of invasive cervical cancer during follow-up to be higher for HPV compared with cytology screening. Therefore, we have estimated the possible impact of the new policy on cervical cancer incidence in Australia. MATERIALS AND METHODS: Available estimates of the relative protection from cytology screening, estimates of the coverage of the 2-yearly cytology screening policy of the Australian national cervical screening program, and estimates of screening test sensitivity were used to estimate the change in the incidence of cervical cancer from the introduction of the new policy. RESULTS: HPV screening 5-yearly was predicted to increase the annual incidence of cervical cancer in women screened to 121% (95% CI: 73%-169%) of current incidence after 10 years. The overall incidence of cervical cancer in Australia was predicted to increase by 39.2% (95% CI: 34.0%-44.4%) with an additional 222 women developing cervical cancer each year after 10 years. CONCLUSIONS: Measures of the screening sensitivity of HPV testing and cervical cytology suggest the introduction of 5-yearly HPV primary screening may increase the incidence cervical cancer in Australia.

Individual risk of cutaneous melanoma in New Zealand: developing a clinical prediction aid.

BACKGROUND: New Zealand and Australia have the highest melanoma incidence rates worldwide. In New Zealand, both the incidence and thickness have been increasing. Clinical decisions require accurate risk prediction but a simple list of genetic, phenotypic and behavioural risk factors is inadequate to estimate individual risk as the risk factors for melanoma have complex interactions. In order to offer tailored clinical management strategies, we developed a New Zealand prediction model to estimate individual 5-year absolute risk of melanoma. METHODS: A population-based case-control study (368 cases and 270 controls) of melanoma risk factors provided estimates of relative risks for fair-skinned New Zealanders aged 20-79 years. Model selection techniques and multivariate logistic regression were used to determine the important predictors. The relative risks for predictors were combined with baseline melanoma incidence rates and non-melanoma mortality rates to calculate individual probabilities of developing melanoma within 5 years. RESULTS: For women, the best model included skin colour, number of moles > =5 mm on the right arm, having a 1st degree relative with large moles, and a personal history of non-melanoma skin cancer (NMSC). The model correctly classified 68% of participants; the C-statistic was 0.74. For men, the best model included age, place of occupation up to age 18 years, number of moles > =5 mm on the right arm, birthplace, and a history of NMSC. The model correctly classified 67% of cases; the C-statistic was 0.71. CONCLUSIONS: We have developed the first New Zealand risk prediction model that calculates individual absolute 5-year risk of melanoma. This model will aid physicians to identify individuals at high risk, allowing them to individually target surveillance and other management strategies, and thereby reduce the high melanoma burden in New Zealand.

A comparison of trends in melanoma mortality in New Zealand and Australia: the two countries with the highest melanoma incidence and mortality in the world.

BACKGROUND: New Zealand and Australia have the highest incidence and mortality rates from cutaneous melanoma in the world. The predominantly fair-skinned New Zealanders and Australians both enjoy sun, tanned skin and the outdoors, and differences in these activities among generations have been important determinants of trends in melanoma mortality. METHODS: Five-year age-specific and age-standardised mortality rates were calculated for each country for 5-year time periods. Tests for trends in age-specific rates were performed using the Mantel-Haenszel extension chi-square test. The age-adjusted mortality rate ratios for New Zealand/Australia were plotted against period of death to show relative changes in mortality over time. Age-specific mortality rates were plotted against period and the median year of birth to illustrate age-group and birth cohort effects. To compare the mortality of birth cohorts, age-adjusted melanoma mortality rate ratios were calculated for the birth cohorts in the quin-quennial tables of mortality rates. RESULTS: The age-standardised mortality rate for melanoma increased in both sexes in New Zealand and Australia from 1968 to 2007, but the increase was greater in New Zealanders and women in particular. There was evidence of recent significant decreases in mortality in younger Australians and less so in New Zealand women aged under 45 years. Mortality from melanoma increased in successive generations born from about 1893 to 1918. In Australia, a decline in mortality started for generations born from about 1958 but in New Zealand there is possibly a decrease only in generations born since 1968. CONCLUSIONS: Mortality trends in New Zealand and Australia are discrepant. It is too early to know if the pattern in mortality rates in New Zealand is simply a delayed response to melanoma control activities compared with Australia, whereby we can expect the same downward trend in similar age groups in the next few years. Specific research is needed to better understand and control the increases in mortality and thickness of melanoma in New Zealand.

Poorer outcome in Polynesian patients with prostate cancer treated with definitive conformational radiation therapy.

PURPOSE: To compare freedom from biochemical failure (FFBF) of French Polynesian (FP) and Native European (NE) prostate cancer patients after definitive conformal radiotherapy (RT). PATIENTS AND METHODS: Data were reviewed from medical records of 152 consecutive patients (46 FP and 106 NE) with clinically localised prostate cancer treated with definitive RT. Neoadjuvant androgen deprivation therapy (ADT) was used in 22% of cases. Definition for biochemical failure was a rise by 2 ng/mL or more above the nadir prostate-specific antigen (PSA) level. The median follow-up was 34 months. RESULTS: In comparison to NE patients, FP patients were younger (p=0.002) with a higher low-risk proportion (p=0.06). Probability of 5-year FFBF was 77% in the NE cohort and 58.0% in the FP cohort (p=0.017). Univariate analysis showed that FP ethnicity was associated with worse prognosis in high-risk tumours (p=0.004). Cox multivariate analysis showed that factors associated with FFBF were risk category (p<0.017), and FP origin (p=0.03), independently of ADT and radiation dose. CONCLUSION: FP ethnicity was an independent prognostic factor for biochemical relapse after definitive conformal RT for prostate cancer.

Clinical and histologic factors associated with melanoma thickness in New Zealand Europeans, Maori, and Pacific peoples.

BACKGROUND: Thickness is the major prognostic indicator for patients with melanoma. In many countries, the incidence of thick melanoma has not decreased. To reduce mortality, knowledge of the characteristics associated with melanoma depth is needed. METHODS: To examine the relation between melanoma thickness and other factors in Europeans, Maori, and Pacific peoples, the authors analyzed the 14,802 melanoma registrations in New Zealand between 1996 and 2006. Notifications of invasive cutaneous melanoma from 1996 to 2006 were extracted from the New Zealand Cancer Registry. Ethnicity was categorized using the Statistics New Zealand prioritization algorithm. The geometric mean tumor thickness was calculated using log-transformed Breslow depth. Multivariate linear regression was used to examine the relation of predictor variables, their interactions, and melanoma thickness. RESULTS: Melanoma thickness increased by 1% per year from 1996 to 2006. Although melanoma is rare in Maori and Pacific peoples, after adjustment, melanoma thickness was significantly greater in those populations compared with Europeans. Among Europeans, melanoma thickness was associated significantly with age at diagnosis, year of registration, sex, histology subtype, and extent of disease at diagnosis. In Maori, thick melanomas were likely to be nodular and to have regional or lymph node spread. The most important determinant of melanoma thickness in Pacific peoples was body site. CONCLUSIONS: Differences in melanoma thickness among ethnic groups were not explained fully by tumor subtype, site, or extent of disease. The current results indicated that the thicker melanomas in darker skinned populations probably can be accounted for in part by more aggressive lesions. Research is needed to identify additional characteristics to explain ethnic variations in melanoma thickness.

Meta-analysis of observational studies of serum 25-hydroxyvitamin D levels and colorectal, breast and prostate cancer and colorectal adenoma.

Epidemiological studies have suggested a reduced risk of several cancers associated with high vitamin D status. We performed a systematic review with meta-analyses of observational studies of serum 25-hydroxyvitamin D level and colorectal, breast and prostate cancer and colonic adenoma. The literature of December 2009 was searched without language restriction. The meta-regression analysis was done to compute dose-response effects. Because in case-control studies, serum 25-hydroxyvitamin D level is measured after the diagnosis of cancer, separate analyses for case-control and prospective studies were done. We identified 35 independent studies. The seven studies on colorectal adenomas were heterogeneous in terms of endpoint and control for major confounding factors, and we did not perform a meta-analysis of these data. The summary relative risk (SRR) and (95% confidence interval) for a 10 ng/ml increase in serum 25-hydroxyvitamin D was 0.85 (0.79; 0.91) for colorectal cancer (2,630 cases in 9 studies); 0.89 (0.81;0.98) for breast cancer (6,175 cases in 10 studies); and 0.99 (0.95;1.03) for prostate cancer (3,956 cases in 11 studies). For breast cancer, case-control studies (3,030 cases) had major limitations and obtained SRR of 0.83 (0.79; 0.87) whereas SRR of prospective studies (3,145 cases) was 0.97 (0.92; 1.03). For colorectal and breast cancer, differences between cases and controls in the season of blood draw or in overweight/obesity or physical inactivity could not explain the results. In conclusion, a consistent inverse relationship between serum 25-hydroxyvitamin D levels and colorectal cancer was found. No association was found for breast and prostate cancer.

Melanoma in Maori, Asian, and Pacific peoples in New Zealand.

New Zealand Maori, Pacific, and Asian people develop melanoma less frequently than New Zealand Europeans, but little is known about melanomas that develop in these people. We examined the characteristics of melanoma in these minority ethnic groups in New Zealand. In 2007, all first primary melanomas diagnosed from January 1996 to December 2006 were extracted from the New Zealand Cancer Registry database. Melanoma was more commonly diagnosed in Maori than Asian or Pacific peoples. Age-adjusted incidence rates increased annually from 1996 to 2006 by 0.37 per 100,000 in the total population and 0.20 per 100,000 in Maori, a 12% (from 30.9 to 34.6) and 90% (from 2.3 to 4.3) increase, respectively, over the 11 years. Nodular melanoma occurred more often in Maori (15.9%) and Pacific peoples (17.1%) compared with Asians (8.7%) and New Zealand Europeans (10.5%). In Pacific peoples, acral lentiginous melanoma (22.9%) was the most common subtype. The median thickness of melanoma was 0.78 mm in New Zealand Europeans, 1.2 mm in Maori, 2.5 mm in Pacific peoples, and 0.73 mm in Asians (P < 0.001, difference in medians). Thirty-seven percent of melanomas in Pacific peoples were >4 mm thick compared with 7.9% in New Zealand Europeans. About 13% of Asians and 11% of Pacific peoples, compared with 4% of New Zealand Europeans with melanoma, were diagnosed by histology of metastases rather than the primary lesion. Minority ethnicities in New Zealand have a higher than expected risk of thick and more advanced melanoma, with poorer prognosis. Melanoma campaigns should include messages that incorporate the unique features of melanoma in minorities.