  The medium modified hadron properties are studied by using the scale-chiral
perturbation theory $\chi$PT$_\sigma$ in which the lightest scalar meson
$f_0(500)$ is included as an explicit degree of freedom by regarding it as the
Nambu-Goldstone boson of scale symmetry both spontaneously broken and
explicitly broken by the QCD trace anomaly. We derive Brown-Rho scaling at the
leading order of scale symmetry from $\chi$PT$_\sigma$ and formulate how to
make higher-order scale-chiral corrections going beyond the leading order of
scale symmetry. By taking into account the intrinsic density dependence given
by the dilaton condensate in the "bare" parameters of the Lagrangian, the
medium modified hadron properties are investigated. Relying on available
experimental information and certain reasonable assumptions, we arrive at the
leading order scale symmetric effective theory that can be confronted with
nature .
