Dear Sarah
Based on the Oxford Collocations Dictionary, the adjective "significant" does not collocate with the word "profit". These are the most common adjectives which can be used by the word "profit":
big, fat, good, greater, handsome, healthy, high, huge, large, record, substantial, tidy | low, modest, small | excess | lost, unrealized | realized | quick | gross, pre-tax | after/post-tax, clear, net | taxable | interim, short-term | annual first-quarter, full-year, half-year, second-quarter, etc. | corporate, group | operating, trading.
Regards
Ali