Exhibit 99.1 EXACT SCIENCES CORPORATION 63 Great Road Maynard, MA 07154 LETTER TO COMMISSION PURSUANT TO TEMPORARY NOTE 3T March 26, 2002 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549-0408 Ladies and Gentlemen: Pursuant to Temporary Note 3T to Article 3 of Regulation S-X, Exact Sciences Corporation has obtained a letter of representation from Arthur Andersen LLP ("Andersen") stating that the December 31, 2001 audit was subject to their quality control system for the U.S. accounting and auditing practice to provide reasonable assurance that the engagement was conducted in compliance with professional standards, that there was appropriate continuity of Andersen personnel working on the audit and availability of national office consultation. Availability of personnel at foreign affiliates of Andersen is not relevant to this audit. Very truly yours, By: /s/ John A. McCarthy, Jr. ----------------------------- John A. McCarthy, Jr. Executive Vice President, Chief Operating Officer, Chief Financial Officer and Treasurer