Without Bitcoin starting a bull run again and getting to new all time highs, it is quite unlikely, that Litecoin will get to over $5000 in this year, even though it might be possible in the long run sometime in the future.
You are right, every altcoin increase means that bitcoin needs to start a bull run. If we see Bitcoin above 20,000 dollar then we can speak about big increasing of Litecoin. For 2018 is it very hard to believe that Litecoin hit 5000 dollar.