Figure 1.

Needle biopsy of breast tumor promotes systemic dissemination

(A) Propensity-score-adjusted overall mortality risk with confidence interval (95% CI; dotted lines) plotted across the biopsy-to-surgery interval relative to the reference (30 days).

(B) Summary of hazard ratio (HR) at different biopsy-to-surgery intervals. Hazard ratios were computed with day 30 as the reference and simultaneous 95% CI; p values were adjusted for multiple comparisons using the Scheffe method.

(C) Overall mortality was plotted across the follow-up time (survival years) of patients with biopsy-to-surgery time intervals of 30, 60, 90, and 120 days.

(D) Schematic representation of biopsy-induced metastasis. Py230^mCherry or Py2T^mCherry mouse BC cells were injected into the abdominal mammary gland of B6 or FVB female mice, respectively. The tumors were biopsied once after reaching a size of 100 mm³ or left unbiopsied, and the lungs were collected 15 days later.

(E and F) Detection of metastatic BC cells in the lungs of unbiopsied and biopsied mice using flow cytometry and immunohistochemistry. The number of Py230^mCherry (E) and Py2T^mCherry (F) metastatic cells in the lungs of unbiopsied (blue circles) and biopsied (red circles) mice after enzymatic dissociation and flow-cytometric analysis. Graphs represent mean ± SEM; p values were calculated using Wilcoxon test (n = 10–13 in Py230; n = 11–12 in Py2T). Representative images of lungs immunohistochemically stained for mCherry (red) showing metastatic BC cells (black arrow) in the lung parenchyma of mice with or without biopsy are shown.