That theme being: humans integrated with machines, human bodies being exploited as machinery.
The Cybermen, of course, were once wholly human, gradually replacing their body parts with machinery.
In "The Girl in the Fireplace" we had robots repairing their spaceship with human body parts: the exact inverse.
Two slightly more tenuous links: in "School Reunion" we had aliens using human brains effectively as part of a giant computer to solve an equation and in "New Earth" human beings were plugged in as part of a giant medical research lab.
I can't find a connection with "Tooth and Claw", though, which is a bit of a blow to the theory.