In addition to contesting d4 immediately with 2.c3, White has a number of "closed" setups that more or less ignore Black's control of d4 for the time being. White can play the Closed Sicilian, Grand Prix, "Big Clamp", 2.Na3!?, or King's Indian systems. One of the more radical options is 2.a4!?!? which must be proof that being White means being able to get away with virtually anything short of losing material. It appears the basic idea of 2.a4 is to meet any a7-a6 with a4-a5 to clamp down on b6, and to meet Nc6 or d6 with Bb5 in order to direct play into Rossolimo channels where the a4-pawn, by defending White's bishop, is not so ridiculous.
FM Stefan Buecker has published an interesting article featuring 2.a4!?!?, and started a messageboard discussion including a commented PGN of the following game. I am sure that after skimming the linked sources, you will "know" more about this quirky opening than any Sicilian player in a 100 mile radius.