This retrospective observational study examined data before and after the 2020 BreastScreen NSW suspension to assess the impact on tumour size in breast cancer diagnoses, and volumes of mastectomy and breast-conserving surgery. It found no evidence of a substantial change in the size of tumours diagnosed by BreastScreen NSW in clients whose breast cancer screening was delayed by the suspension of service  relative to either clients who screened on-time or to the tumour size seen in the years prior to the suspension of service.

The analysis also showed that while breast-conserving surgery volumes in NSW hospitals decreased following the suspension of services in early-mid 2020, levels recovered to typical caseloads by September 2020.