Getting multiple checkboxes from FormCollection element

Given multiple HTML checkboxes:

<input type="checkbox" name="catIDs" value="1" />
<input type="checkbox" name="catIDs" value="2" />
...
<input type="checkbox" name="catIDs" value="100" />

How do I retrive an array of integers from a FormCollection in an action:

public ActionResult Edit(FormCollection form)
{
    int [] catIDs = (IEnumerable<int>)form["catIDs"]; // ???

    // alternatively:
    foreach (int catID in form["catIDs"] as *SOME CAST*)
    {
        // ...
    }

    return View();
}

Note: I read the related questions and I don't want to change my action parameters, eg. Edit(int [] catIDs).