I know I'm late is responding to this but I will update this thread, and hopefully others can benefit from it.
When an application is withdrawn, the E-CAS status will change to "Withdrawn". It takes about 2 weeks to withdraw an application. According to my lawyer, you cannot send a new application and withdraw letter at the same time IF your file has been transferred to local office.
My wife had to withdraw her application. So she sent the letter to her local office first; it took about 2 weeks for the status to get updated on e-cas. Once the application was withdrawn, she re-applied again.
For those who need to know why her application was withdrawn:
She had a typo in her entry date to Canada and she was short few days. That triggered the RQ after test, even the officer didn't notice that mistake during the interview or maybe she did and decided not to mention it to my wife. In any case, she applied again in Aug 2014 and got the email confirmation last week.
Will she be RQed again or will it have any impact on her application the second time? I have no clue... I guess we will find out soon.
Good Luck All.