Age- and Comorbidity- Adjusted Optimal Radiotherapy Utilisation Rate for Women with Breast Cancer
Penny Mackenzie,
Australia
OC-0921
Abstract
Age- and Comorbidity- Adjusted Optimal Radiotherapy Utilisation Rate for Women with Breast Cancer
Authors: Penny Mackenzie1, Claire Vajdic2, Geoff Delaney3, Tracy Comans4, Meera Agar5, Gabriel Gabriel6, Michael Barton3
1The University of New South Wales, South West Sydney Clinical School, Sydney, Australia; 2 The University of New South Wales, Centre for BIG Data Research in Health, Sydney, Australia; 3The University of New South Wales, Collaboration for Cancer Outcomes Research and Evaluation (CCORE), Sydney, Australia; 4The University of Queensland, Centre for Health Services Research, Brisbane, Australia; 5The University of Technology, Centre for Improving Palliative, Aged and Chronic Care through Clinical Research and Translation (IMPACCT), Sydney, Australia; 6The University of New South Wales, Collaboration for Cancer Outcomes, Research and Evaluation (CCORE), Sydney, Australia
Show Affiliations
Hide Affiliations
Purpose or Objective
Optimal radiotherapy utilisation (RTU) modelling estimates the proportion of people with cancer who would benefit from radiotherapy. Older adults with cancer may have comorbidities which impact on physiological reserve and affect radiotherapy recommendations. These have not been considered in previous models. We aimed to develop an age- and comorbidity- adjusted optimal RTU model for breast cancer.
Material and Methods
NSW Cancer Registry data (2010-2014) linked to radiotherapy and hospitalisation data (2008-2015) was used to determine the number of women diagnosed with invasive breast cancer in four pre-specified age groups (<60, 60-69, 70-79 and 80+ years). The Charlson Comorbidity Index (CCI), Cancer Specific C3 ‘all sites’ index and the Hospital Frailty Risk Score (HFRS) were derived for each woman from diagnostic codes in hospital records. Women were deemed unfit, and thus unsuitable candidates for radiotherapy, if the comorbidity indices were as follows: CCI ≥2; C3 score≥3; and HFRS ≥5. The proportions of women suitable for radiotherapy in each age group were then incorporated into a breast cancer decision tree model. The actual RTU was also calculated using the linked datasets.
Results
23601 women were diagnosed with breast cancer in NSW from 2010-2014 and 2526 were aged 80+ years. The overall comorbidity adjusted- RTU for women of all ages was 86% (CCI), 84% (C3) and 82% (HFRS). The optimal comorbidity adjusted- RTU for women aged 80+ was 76% (CCI), 70% (C3) and 62% (HFRS). The actual RTU for women aged 80+ years was 25%.
Conclusion
The vast majority of older Australian women with breast cancer are fit for radiotherapy. The overall optimal RTU is only slightly reduced when adjusted for age and comorbidities and was similar using each of the three indices. Our data suggests radiotherapy is underutilised for older women with breast cancer.