Rep. Eric Massa (D-N.Y.) announced Wednesday that he would not run for re-election, citing a recurrence of cancer, while also angrily denouncing unsubstantiated reports that he was being investigated by the House ethics committee.In a conference call with reporters, Massa said he was hospitalized in December with a recurrence of cancer, and that doctors have told him he would no longer be able to function at full speed all the time. I run at about a hundred miles an hour. And my doctors have made it clear to me that I can no longer do that, Massa said.Politico reported earlier Wednesday that the ethics committee had been alerted to a sexual harassment allegation against the freshman Congressman.Massa acknowledged to reporters that Im a salty guy and he has used salty language with staff, particularly when angry and in private. Massa said he has apologized to anyone he has offended. But he said those kinds of articles unsubstantiated without fact or backing are a symptom of whats wrong with this city.He did not directly address the allegations in the Politico story and he did not take questions from reporters.Massa was first elected in 2008, when he defeated then-Rep. Randy Kuhl (R) in the Republican-leaning 29th district.The GOP had been targeting Massa for defeat in November, and the race to succeed him will likely be competitive.He is the 15th Democrat to announce plans to leave the House at the end of this year.