Mode of diagnosis of metastatic breast cancer recurrence and survival: a retrospective study

Abstract

Randomized studies failed to show a survival benefit for screening asymptomatic breast cancer (BC) survivors for metastases, however, their relevance to the era of modern systemic therapies is unknown. Socioeconomic status (SES) may confound the association between mode of diagnosis and prognosis. The aim of this study was to evaluate whether mode of metastatic detection is associated with survival outcomes in patients with metastatic BC treated with contemporary systemic therapies, accounting for clinical characteristics and SES. A retrospective study of patients diagnosed with metastatic BC after curative therapy for localized BC treated with systemic therapy between 2015 and 2023. The primary endpoint was overall survival (OS) from metastatic diagnosis. Secondary endpoints included OS from initial diagnosis and progression-free survival (PFS) on first-line therapy. Multivariable Cox regression models were used to adjust for SES and relevant clinical prognostic factors. A total of 220 patients were included; median age was 52.4 years, and 55% were diagnosed with metastatic disease following symptoms. Patients in the screening group had higher SES than those diagnosed following symptoms (32.7% vs 19.2% in the high SES category; p = 0.010). Mode of metastatic detection was not associated with OS from metastatic diagnosis (HR 1.15, 95% CI 0.78–1.69; p = 0.473) or with OS from initial diagnosis (HR 1.15, 95% CI 0.77–1.71; p = 0.493), but there was a trend for improved 1st line PFS in patients diagnosed by screening (HR 1.37, 95% CI 0.98–1.90; p = 0.065). Liver metastases (HR 1.70, 95% CI 1.00–2.89; p = 0.051), brain metastases (HR 2.61, 95% CI 1.32–5.17; p = 0.06), greater metastatic burden (HR 1.57 per additional metastatic site; p = 0.007), and triple-negative breast cancer (HR 2.39, 95% CI 1.20–4.80; p = 0.014) were associated with shorter survival. A longer interval between localized diagnosis and metastatic recurrence was associated with improved survival (HR 0.97 per month; p < 0.001). SES was not independently associated with survival after adjustment for clinical factors. In this cohort, diagnosis of metastatic BC by screening was not associated with improved survival. Our results support current guidelines emphasizing clinical surveillance and prompt symptom assessment.