There are several different types of lung cancer, and the protective fish effect appeared to be the strongest for a type called adenocarcinoma - about 5% of all cases.
The researchers also found that aspirin reduced the risk of adenocarcinoma with metastasis at initial diagnosis by almost a third (31%), and risk of metastasis on subsequent follow-up in patients without metastasis initially (by 55%), particularly in patients with colorectal cancer(by 74%), and in patients who remained on trial treatment up to or after diagnosis (by 69%).