  It is shown that the square-root Van Hove singularity in the density of
states (DOS), associated with extended saddle-point features in the electronic
spectra of cuprates, leads to a nonmonotonic dependence of Tc on the position
of the Fermi level. As the result of cancellation of the DOS divergence in the
electron-electron coupling constant, renormalized due to the account of
strong-coupling effects, Tc approaches zero when Fermi level touches the bottom
of the saddle. The Tc dependence on the doped holes' concentration, obtained in
the strong coupling approximation, agrees with experimental data for the
overdoped cuprate metal-oxides.
