With Ireland enjoying a significantly better points difference than the other two, with England better off than France, Lancaster will be looking for Les Bleus to do his side a favour on Saturday night.
The same XV who beat Wales at Twickenham will again step out for England in Rome with the only change coming in the replacements where Manu Tuilagi takes Alex Goode's spot, though Matt Mullan is on standby with Joe Marler's partner due to give birth.
And Lancaster, whose side's only defeat came in Paris in the opening round, admits their only focus is securing a win in Italy.
"It's great to be able to name an unchanged XV and we have been able to achieve consistency of selection from a very competitive squad this campaign," he said.
"The Wales result was very significant for us but we need to finish the tournament well in Rome. We have had a tight turnaround and the key this week has been to manage the players' recovery and get them in the best shape for what will be a tough match against Italy."