Sen. Edward Kennedy (D-Mass.), who has been battling brain cancer, will remain in Massachusetts this week as the Health, Education, Labor and Pensions Committee continues slogging through its markup of comprehensive health care legislation.“Sen. Kennedy is at home in Massachusetts and continues to balance his work on health care with his treatment,— spokesman Anthony Coley said Monday, adding, “He spoke with President [Barack] Obama a couple times last week.—Kennedy has largely been absent from the Senate since January, when he suffered a seizure on Inauguration Day that sent him to the emergency room. Kennedy was diagnosed with brain cancer in May 2008.Meanwhile, it remains unclear whether Sen. Robert Byrd (D-W.Va.) will return to the Senate this week. Byrd, 91, was released from the hospital on June 30 after a six-and-a-half-week stay. His office has not released an update on his status since his release from the hospital. Byrd was first admitted to the hospital on May 15 for what was then described as a mild infection. His office later said Byrd had developed a staph infection.