Breast cancer in the elderly in New Zealand – an age old issue

Project brief

Introduction

Breast cancer generally develops in older women¹ and as the population ages, the incidence of breast cancer increases alongside it². There is a tendency for under treatment of these older patients as there are concerns about the toxicities of treatment, the social implications of treatment and also the biology of the breast cancer, which may differ from breast cancer in the younger population³. There is some evidence that there is resultant poor outcomes in this group of patients3. There is also randomised evidence that in some settings treatment can be safely de-escalated⁴.

Aim

The basis of the research is to establish the patterns of care for patients diagnosed with breast cancer at age 70 or above in New Zealand and to see how these patterns compare with evidence based recommendations (where they exist) for surgery, radiation and adjuvant therapies in this age group. If possible we would also like to investigate if there have been any changes in management over the study period (although this may not be possible due to short follow-up periods). We would then wish to see if any treatment recommendations could be derived, or new study questions developed in order to optimise care for this group of patients.

This project will be in 2 phases:

Phase one

(This will constitute the summer student project)

This part of the project will refer only to patients in Christchurch. The aim of this part of the project is to update the breast cancer status for the Christchurch patients on the national breast cancer registry and report any breast cancer outcomes in the last 2 years (followup complete to 2015 in most cases). In addition for the Christchurch patients the student will list the medications and the comorbidities, living situation and use the SIOG1 tool known as G8 (Droz, 2014) to assess frailty (allowing us to classify patients as fit, vulnerable or frail)

Phase two

(This will be completed by a training radiation registrar with input from the summer student if they wish to be involved)

The Christchurch data will be merged back into the national data base and the following questions investigated from the NZ breast cancer register

1. How are elderly patients with breast cancer managed within New Zealand?
2. What are their outcomes?
3. Are the recommendations for breast cancer treatments in this group of patients (where they exist) applied within New Zealand?
4. Can recommendations be made for future management on the basis of these findings?

Method

Data from the New Zealand Breast Cancer Register will be extracted for all patients 70 years and over, diagnosed with breast cancer in the time period from January 1995 to December 2014. Patients will be identified using the four New Zealand regional breast cancer registers of prospectively collected data. Inclusion in the data registries requires written informed consent.  Data will be from registers in Waikato (established 1993), Auckland (established 2000), Christchurch (established 2009) and Wellington (since 2010).  Recently these databases have been merged and now constitute a national database.

A request is currently being considered by the clinical advisory group for extraction of the data from the NZ database. The data will be sent to our local data coordinator Valerie Davey and she will review the data, clean, merge and verify any inconsistencies by referral back to the local data coordinator at the patients centre. Valerie will then provide a supply a unique identifier to each patient. For phase one of the project, she will supply the database with an NHI of the Christchurch patients for the student to work on and subsequent to this she will add the updated followup and extra information from the Christchurch cohort to the database and supply the de-identified National database of patients to us so that we can assess the outcomes as below for the de-identified group.

Thus we would hope to review the:

1. Demographics of this population (and for the Christchurch and Waikato databases- this will include comorbidities and for Christchurch patients this may also include medication use, living conditions,  psychological disorders, geriatric syndromes and performance status).*
2. Tumour characteristics and compare this data with series of younger patients reported in the literature.*
3. Treatments delivered and where possible treatments intended and completed (surgery, radiation treatment, chemotherapy, hormonal therapy, best supportive care).*
4. Outcomes including- Local control, loco regional recurrence free survival, breast cancer specific survival, cause of death and overall survival.*
5. Any change to outcomes/management related to the time period treated by 5 year time period cohorts
6. Compare treatments/ outcomes to evidence based recommendations where these exist

For phase one of the study the information above will be gained from the electronic medical record, Mosaiq (the Christchurch oncology electronic record) and may require review of the physical notes for missing data fields. For phase 2 all data fields are as complete as possible when the data is exported to us from the national database.

Student researcher’s component of the study

Phase 1

The student will update the Christchurch patient follow-up status form the Christchurch oncology database. This will also include extraction of data on comorbidities, number of medications and frailty status at diagnosis and disease status at last follow-up. The student will use the existing data fields already provided from the national database for the Christchurch patients, and any further information required will be gained from the electronic medical record, Mosaiq (the Christchurch oncology electronic record) and may require review of the physical notes for missing data fields. The student will be involved in the analysis of this data using excel initially and then with the help of a medical statistician to draw conclusions for presentation. It is expected that the student will also be able to be involved in the initial drafts of a journal article.

Phase 2

After the Christchurch follow-up status is updated, this data will be merged with the data from the other registries and analysis of the national dataset will be performed. A training radiation oncology will be driving this part of the project. The student may wish to be involved but there would certainly we now compulsion for this.  The aim would be to present this work at department meetings, national/international meetings and to publish the conclusions in an oncology journal.

* For more detail on the actual data fields to be extracted from the national database please see the accompanying request to the clinical advisory group for the national breast cancer registry.

1. https://www.health.govt.nz/publication/cancer-new-registrations-and-deaths-2012
2. Dimitrakopoulos F-ID, Kottorou A, Antonacopoulou AG, Makatsoris T, Kalofonos HP. Early-Stage Breast Cancer in the Elderly: Confronting an Old Clinical Problem. Journal of Breast Cancer. 2015;18(3):207-217. doi:10.4048/jbc.2015.18.3.207.
3. Turner NJ, Haward RA, Mulley GP, Selby PJ. ‘Cancer in old age – is it inadequately investigated and treated?’ BMJ. 1999 319:309-12.
4. Breast-conserving surgery with or without irradiation in women aged 65 years or older with early breast cancer (PRIME II): a randomised controlled trial. Kunkler, Ian H et al. The Lancet Oncology , Volume 16 , Issue 3 , 266-273