Word for Mac Documents printed incompletely on Canon MP610 Printer

Some elements of the letter (letterhead, addressee and signatory details) are printed but not the body of the letter.

The whole letter prints satisfactorily on a brother HL-2040 Laser Printer

Could be a driver problem but also may indicate the print head is failing on the Canon or it's running out of ink. Have you tried printing from another source to the Canon? For example, print a test document from Text Edit or from Pages? The problem is not caused by Word since the document prints OK to the Brother.