Differences in breast cancer treatment pathways for women participating in screening through BreastScreen New South Wales

Abstract

Background Previous studies have shown that mammographic screening is associated with earlier stage diagnosis of breast cancer and use of breast conserving surgery. Aims The current study aimed to quantify and validate these associations in multivariate analysis and investigate surgery type, adjuvant radiotherapy and immediate breast reconstruction (IBR) for invasive breast cancer or ductal carcinoma in situ (DCIS) by participation in BreastScreen NSW mammographic screening. Methods A data linkage study of 10,931 women aged 40+ years surgically treated for breast cancers diagnosed in 2009-2011 using registry and routinely-collected data. Multivariable logistic regression was used to adjust treatment outcomes for patient and tumour characteristics. Results A third of women undergoing surgery had never screened, 46 per cent had screened recently (within 24 months) through BreastScreen NSW. Breast-conserving surgery (BCS) and use of adjuvant radiotherapy following BCS were more common among recently screened compared with never screened women. Differences in treatment outcomes remained after adjusting for patient and tumour characteristics. There were no significant differences in use of IBR with mastectomy by screening participation, with 9 per cent and 33 per cent of women receiving IBR for invasive cancer and DCIS respectively. Conclusion Treatments received by women with invasive breast cancer and DCIS varied by mammographic screening history. This may be due to differences in treatment referral pathways or patient engagement in healthcare.