How long does it take for esophageal cancer to grow so much that it's inoperable?

Depends on the stage. There are 4 stages of esophageal cancer. Stage i-iii can be considered operable if the patient is of good physical condition. Tumor growing through the esophagus and into surrounding lymph nodes (regional) would be stage iii and still potentially operable. Tumor involving unresectable structures like the heart or bone, or that have metastastasized to distant organs (like brain) are inoperable.
This varies. Esophageal cancer is inoperable when it spreads through the layers of the esophagus to the surrounding tissues and lymph nodes. I should redefine inoperable, because frequently one may recieve a "palliative" operation, one that doesn't necessarily cure it but in conjunction with radiation and/or chemo, they may live longer than otherwise. The time for this cancer to do this varies-a few months t.