Could high esr an indication of cancerous growth?

Possibly: ESR in the serum is a measurment of a factor inducing increased sed rate due to inflammation. Some malignancies do have associated inflammatory conditions initiating the process. In general however the serum reflection of existing malignancy is seen in serum prealbuin which goes down and alpha 1 acid glycoprotein which goes up- the cancer serum index.

Not necessarily: High ESR is a non-specific test. It often increases due to infections or inflammation. On rare occasions it can be associated with cancer but there will be other indicators of cancer too which will show a growth before the ESR becomes too abnormal. It is not a commonly used or considered a reliable test for cancer, at least not in the us.