WASHINGTON  Senator John McCain is set to release 400 pages of medical records, including documents related to his melanoma surgery in August 2000, to a tightly controlled group of reporters on the Friday before Memorial Day weekend.

Mr. McCain said late last week that he had nothing to hide. Campaign officials have nonetheless said that even if nothing in the records suggests a problem with his health, a rush of news media reports focusing on the cancer surgery was not politically helpful and that they wanted to play down the information as much as possible  something that the timing of the release would seem to accomplish.

“There are going to be no surprises,” Mr. McCain, 71, told reporters last Friday aboard his campaign bus on a trip to West Virginia. His doctors, he added, “have told me that everything’s fine.”

In an unforeseen bit of timing, the release of the records, which cover 2000 to 2008, will follow by three days the disclosure that Edward M. Kennedy, Democrat of Massachusetts, who is Mr. McCain’s good friend in the Senate, has a malignant brain tumor.