Some MSK departments/divisions have editors to assist researchers with the manuscript submission process. The easiest way to find out if you have access to a department editor is to ask your departmental admin.
If your department does not have an editor, many journal publishers offer services for authors, including Elsevier, Sage, Springer Nature, Taylor & Francis, Wiley, and Wolters Kluwer.
You can also search for a freelance medical communication professional from the Scientific Editors Network and the American Medical Writers Association's online directory.