Malignant lung nodules - How long have they been there?

5-year life survival information is not very helpful if you don't have a starting point. In January, 2022, several lung nodules appeared on a CT scan that was ordered for another medical issue. The largest nodule was about 5mm. The 5-year survival rate for metastatic, follicular thyroid cancer is 67%. But I don't know how long those nodules were there before being discovered, so I don't know the starting point for the 5-year timeline.