Parse Microsoft Office files in Node.JS
While there don't seem to be anything you can get with NPM that will do Word directly, you might be able to use a REST API to request it via another cloud service. For example Saaspose (they of the famous Aspose tools) have public API for Word, Excel, PDF, and others. They list node.js, javascript, and Heroku support on their page.
EDIT:
I see that Saaspose is now called Aspose for Cloud
Another API that claims something similar is Doxument
There doesn't seem to be any yet. See below for something that might help.