Adenocarcinoma with BAC features corresponds to the World Health Organization (WHO) classification of adenocarcinoma, mixed subtype with a BAC component.
Erlotinib was given under a similar clinical trial where patients were preselected on the basis of histology, which had to include BAC, BAC with focal invasion, or adenocarcinoma with BAC features.
The tumors were initially classified on tissue as pure BAC, mucinous, nonmucinous, or mixed; BAC with invasion (BAC-I) where the invasive component of the tumor was less than 15%; adenocarcinoma with BAC features when an adenocarcinoma with a prominent (at least 15%) BAC growth pattern was present; and adenocarcinoma without evidence of BAC.
The tumors were initially classified into the categories of BAC, BAC-I, and adenocarcinoma with BAC features as described above.
As with the group of responders, the tumors were initially classified as BAC, BAC-I, and adenocarcinoma with BAC features, and then reclassified.
In our responder group, well to moderately differentiated adenocarcinoma and adenocarcinoma with BAC features (specifically acinar and BAC mixed subtype by the 2004 World Health Organization classification) predominated.