How long does it take for cancer to develop from metaplasia?

Not known.: This is a question with a very variable answer. Most cancer patients present with local or advanced disease, with just cancer present. This is usually something there for a long time, perhaps decades. Some tumors develop faster than others. Cervical cancer patients may have cancer in a few years, while oral cancer patients can present at over 50 years of age. Family history also plays a role.

Depends on the type: This process is quiet varied and can take mints to years and not all metaplasia will turn malignant.

No direct link: Metaplasia is the reaction of tissues, including epithelium to noxious stimuli and the change is reversible. Metalplasia by itself is not a pre-canceous condition, therefore your question cannot be answered directly.