Capitalizing a word mid-sentence

Solution 1:

I'm afraid not. In standard English a capitalisation is only permitted under the following conditions (according to GrammarBook.com):

1. The first word of a document and the first word after a period.
2. Proper nouns and adjectives derived from proper nouns.
3. Titles when they are used before names, unless the title is followed by a comma. Do not capitalize the title if it is used after a name or instead of a name.

Your audience has a high probability of misinterpreting the capitalisation as an error and read the advertisement with a furrowed brow.

Alternatively, use FULL CAPITALISATION or other tricks if possible, such as italicising or emboldening, or any other formatting option available.

You may instead want to ask this question over on the Writing Stack Exchange

Solution 2:

Capitalization serves to elevate the word, in addition to its grammatical uses, when used sparingly. I'm thinking of Terry Pratchett and P.G. Wodehouse, who, when they say something like "this young man has Got Above Himself" it allows the reader to more accurately and dynamically hear the dialog, and to feel the disdain being applied to the poor lad. It also allows a colloquialism to be used without quotations within another piece of dialog.

Does this make it appropriate for marketing? Probably, because ads are stylized text as much as they are grammatical text, I would think.

Solution 3:

What you are looking for here is what is called "Title Case", a perfectly standard way of capitalising English sentences under specific conditions.

Under standard use of title case (such as outlined in this document), your capitalisation would be widely considered as being incorrect, and should instead be "CRC Is Preventable!" (the "Is" being capitalised).

What vexes me slightly, tho', is that you say "in the middle of a sentence"; is "CRC is Preventable!" not the entire sentence?

Because if the sentence is something like "CRC is Preventable! using technique XYZ." then stylistically, the use of an exclamation point (and to a lesser extent capitalisation) is out-and-out nonstandard.