Ductal carcinoma in situ: Is core needle biopsy ever enough?

INTRODUCTION: This study investigates the rate of histological underestimation of invasive breast carcinoma following diagnosis of ductal carcinoma in situ (DCIS) on a radiologically guided core needle biopsy, and factors that may influence this upgrade rate. METHODS: A retrospective review of the results of breast core biopsies performed between 1st January, 2005 and 2nd July, 2014 was conducted, and those with a diagnosis of DCIS were identified. Data including final excision pathology, lesion size, performing radiologist, core biopsy system and guidance method used were collected and included in the analysis. RESULTS: We report an overall upgrade rate to invasive cancer of 20.5% (95% CI = 16.1-24.9%). No statistically significant relationship was identified between biopsy systems used or clinicians performing the biopsies and the rate of upgrade to invasive cancer. Initially a statistically significant relationship was demonstrated between upgrade rates and lesion size, DCIS grade, as well as guidance method. Subsequent multivariable analysis showed no statistically significant relationship between guidance method and upgrade rates but a trend towards statistical significance (P < 0.1). CONCLUSION: Our recommendation is to inform women diagnosed with DCIS preoperatively in our programme, that there is a one in five chance the diagnosis will prove to be invasive cancer on definitive surgery. This is particularly important for women contemplating whether or not to undergo surgery for DCIS. Additionally, as the most significant predictor of upgrade rate demonstrated in this study is increasing lesion size, consideration should be given to increasing the number of core samples taken of larger lesions.

Breast cancer screening for women aged 40 to 49 years--what does the evidence mean for New Zealand?

AIM: To review the evidence on the benefits, harms and costs of breast cancer screening for women aged 40 to 49 years in New Zealand. METHODS: A review of the two most recently published meta-analyses of breast cancer screening, combined with a web-based literature search and review. RESULTS: The meta-analyses demonstrated that mammography reduces breast cancer mortality among women aged 40 to 74 years. Benefit is greatest, and harms are lowest, for women aged over 50. Cost-effectiveness is also greater for women aged over 50. CONCLUSION: The risks of developing and dying of breast cancer are continuous variables that increase with age. The United Kingdom Age Trial will provide further important evidence to guide policy on breast screening for women aged 40 to 49. The most recent reports of this trial suggest a smaller reduction in predicted deaths than observed in many other studies that included women below the age of 50, and less than in either of the meta-analyses reported in this article. Any further lowering of the age range of BSA should be informed by the results of this trial as well as other high quality studies that examine both the benefits and harms of breast screening for women aged 40 to 44.

What is the most appropriate breast-cancer screening interval for women aged 45 to 49 years in New Zealand?

AIM: To review the international evidence on the benefits and harms of different screening intervals for women aged 45 to 49 years, and to inform the development of a national policy. METHODS: A systematic search and review of the literature, up to March 2005. RESULTS: There is no robust trial evidence on which to base a decision on the most appropriate breast-cancer screening interval for women aged 45 to 49 years, and it is unlikely that definitive trial evidence will ever emerge. Evidence from less robust studies is equivocal. CONCLUSION: In the absence of definitive evidence, those charged with determining the screening interval for women aged 45 to 49 years in a breast-cancer screening programme have to weigh up the available evidence, and consider it alongside other relevant factors. A two-yearly screening interval for women aged 45 to 49 was decided upon, and became policy in New Zealand.

The epidemiology of breast cancer in Maori women in Aotearoa New Zealand: implications for screening and treatment.

AIM: To describe the epidemiology of breast cancer in Maori and non-Maori women in New Zealand, and to identify the implications for breast cancer screening and treatment policy and practice. METHODS: New Zealand Census Mortality Study (NZCMS)-adjusted age-specific incidence and mortality rates for breast cancer in total and sole Maori and non-Maori women were calculated using registration and mortality data obtained from New Zealand Health Information Service for 1996-2000. RESULTS: Despite similar age-specific incidence rates of breast cancer in total Maori and non-Maori women under 50 years of age, total Maori women aged 25-59 years had higher age-specific mortality from breast cancer than non-Maori. A similar pattern is seen for sole Maori age-specific rates; however, the rates are even higher than total Maori rates. DISCUSSION: Possible drivers of ethnic disparities in breast cancer mortality require investigation--particularly the role of access to breast cancer screening and treatment for Maori women compared to non-Maori. Specific initiatives are continually needed to ensure that Maori women are able to access breast cancer screening--otherwise ethnic inequalities in mortality will persist. The interaction between deprivation and ethnicity in breast cancer incidence and mortality analyses should be investigated in future analyses.

The epidemiology of breast cancer in Maori women in Aotearoa New Zealand: implications for ethnicity data analysis.

AIM: To describe the methods used to estimate breast cancer incidence and mortality in Maori and non-Maori women using multiple adjustors to assign ethnicity. METHODS: Age-specific incidence and mortality rates for breast cancer in Maori and non-Maori were calculated using registration and deaths data obtained from New Zealand Health Information Service (NZHIS) for 1996-2000. Four different methods were used to assign total and sole ethnicity: New Zealand Census Mortality Study (NZCMS)-adjusted, ever Maori-adjusted, National Health Index (NHI)-adjusted, and unadjusted source information. RESULTS: Unadjusted and NHI-adjusted estimates were least similar to the NZCMS-adjusted estimate used as the 'gold standard' in this study. Ever Maori-adjusted results closely approximated NZCMS-adjusted results in both incidence and mortality data. Sole Maori breast cancer incidence and mortality estimates were generally higher than total Maori estimates. DISCUSSION: Using four different estimates to assign ethnicity confirms previous findings showing poor quality of ethnicity data in routinely collected datasets. Future calculations of breast cancer incidence and mortality rates should assign total and sole ethnicity and reduce ethnicity misclassification by using NZCMS or ever Maori-adjusted estimates. This paper supports the need to collect better quality ethnicity data in order to identify and monitor Maori vs non-Maori cancer inequalities.