I heard that there are difference among "Word", "word" and "Doctrine". Please notice "Word" has a capital letter "W".
I feel that sometimes "word" and "Word" are used mixedly in the Bible.
2 Timothy 4:2 (NIV)
Preach the Word; be prepared in season and out of season; correct, rebuke and encourage--with great patience and careful instruction.
Titus 1:3 (NIV)
and at his appointed season he brought his word to light through the preaching entrusted to me by the command of God our Savior,
In above verses, one uses "Word", the other uses "word". Are they same? The second "word" might be equal to "Doctrine", just guess.