'foremost concerned' is a perfectly valid phrase that can be used in written English.
It means to be primarily concerned or most worried about something. For example: "In this difficult time, I am foremost concerned about the health and safety of my family."
And DeMille, no matter what his loftier ambitions, was always first and foremost concerned with what worked.
The sale of Leopard tanks fits the growing impression in many corners of a mercantilist Germany, whose foreign policy is first and foremost concerned with its own economic interests.
Mr. Bush said he was "concerned about the deficit," an issue that has given pause to many in his own party, but he added he was "first and foremost concerned about that person looking for a job".
They were first and foremost concerned with the phenomenon of linguistic meaning, and invoked whatever entities they felt could best explain what they observed.
From his commentaries on scripture and dogma to his works of speculative theology, Abelard is first and foremost concerned to show how religious claims can be understood, and in particular how the application of dialectical methods can clarify and illuminate propositions of the faith.
According to Mr. Phillipson, Smith was, first and foremost, concerned with developing "a genuine Science of Man" — an effort that began when Smith was a student at Glasgow University.
The first concerned hypertension.
France is of foremost concern.
The king was more prudent, concerned foremost with expanding Piedmont.
A former United States congressman, Drinan is understandably concerned first and foremost with American policy.
This is why we have exercised care in our introductory characterization of the doctrine of logicism, as concerned first and foremost with the truths of arithmetic and of real analysis.
