How to edit breadcrumb in drupal 7?
Check the menu_get_active_trail() and menu_set_active_trail() functions. They should be of use for what you want (retreiving and changing your breadcrumb).

Try the following in your template.php in your theme :

/**
 * Implementing theme_preprocess_html
 */
function YOURTHEME_preprocess_html(&amp;$vars) {
    $crumbs = menu_get_active_trail();
    $count = count($crumbs);
    // dpm($crumbs);
    unset($crumbs[$count - 1]);
    menu_set_active_trail($crumbs);
}


See how it goes.