[Impact of precariousness on breast cancer care in the Île-de-France region: Results of the DESSEIN study].

Introduction: Precariousness has been associated with an increase in breast cancer mortality, but the links between precariousness, stage at diagnosis and care pathways are little explored. The objective of the DESSEIN study was to assess the impact of precariousness on disease and care pathways.

Methods: Prospective observational study in Île-de-France comparing precarious and non-precarious patients consulting for breast cancer and followed for 1 year.

Results: In total, 875 patients were included between 2016 and 2019 in 19 institutions: 543 non-precarious patients and 332 precarious patients. Precarious patients had a more advanced stage at diagnosis (55% T1 vs. 63%, 30% N+ vs 19%, P=0.0006), had a higher risk of not receiving initially planned treatment (4 vs. 1%, P=0.004), and participated less in clinical trials (5 vs. 9%, P=0.03). Non-use of supportive oncology care was 2 times more frequent among patients in precarious situations (P<0.001). During treatment, 33% of deprived patients reported a loss of income, compared with 24% of non-deprived patients (P<0.001). At 12 months from diagnosis, lay-offs were 2 times more frequent in precarious patients (P=0.0001).

Discussion: Precariousness affects all stages of the cancer history and care pathway. Particular attention needs to be paid to vulnerable populations, considering issues of accessibility and affordability of care, health literacy and possible implicit bias from the care providers.