Former Sen. Arlen Specter has been hospitalized with a "serious illness," friends and family of the Pennsylvania lawmaker confirmed to Philly.com on Monday.

According to the Philadelphia Daily News' Dan Gross, sources declined to comment on the nature of the 82-year-old's condition.

In 2005, Specter was diagnosed with Hodgkin's disease. The cancer returned in 2008, but was detected early. Specter returned to the Senate shortly after the cancer went into remission.

Specter, who switched party affiliation from Republican to Democrat in 2009, retired from the Senate after losing his 2010 Democratic primary to Joe Sestak. He served in the Senate for 30 years.

UPDATE 11:20 p.m. ET:

CNN reports that Specter is being treated for a "serious form of cancer" and is fighting for his life, according to a source close to the former senator. According to the source, Specter was diagnosed six weeks ago.

This is a developing story.. Check back for updates..

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  • Arlen Specter

    In this June 6, 2009 file photo, Pennsylvania Sen. Arlen Specter, D-Pa., addresses the Pennsylvania Democratic State Committee Meeting in Pittsburgh. Specter, Pennsylvania's longest serving U.S. Senator, is hosting a pilot episode of a public affairs show that airs Friday, Jan. 13, 2012 on Maryland Public Television. (AP Photo/Gene J. Puskar, File)

  • Arlen Specter

    FILE - In this June 6, 2009 file photo, Pennsylvania Sen. Arlen Specter, D-Pa., addresses the Pennsylvania Democratic State Committee Meeting in Pittsburgh. Specter, Pennsylvania's longest serving U.S. Senator, is hosting a pilot episode of a public affairs show that airs Friday, Jan. 13, 2012 on Maryland Public Television. (AP Photo/Gene J. Puskar, File)

  • Arlen Specter

    FILE - Sen. Arlen Specter, R-Pa. is seen in Philadelphia, in this Nov. 7, 2008 file photo. The longtime Pennsylvania senator performed at an open-mic night at the Helium Comedy Club in Philadelphia on Tuesday, Dec. 27, 2011 continuing a post-politics foray into standup. (AP Photo/Matt Rourke, file)

  • The 33rd Annual Kennedy Center Honors

    WASHINGTON, DC - DECEMBER 05: Arlen Specter poses for photos during the 33rd Annual Kennedy Center Honors at the Kennedy Center Hall of States on December 5, 2010 in Washington, DC. (Photo by Kris Connor/Getty Images)

  • National Museum of American Jewish History opening gala hosted by Jerry Seinfeld and Bette Midler

    PHILADELPHIA - NOVEMBER 13: Arlen Specter (R) attends the National Museum of American Jewish History opening gala hosted by Jerry Seinfeld and Bette Midler at National Museum of American Jewish History on November 13, 2010 in Philadelphia, Pennsylvania. (Photo by Mike Coppola/Getty Images for National Museum of American Jewish History)

  • Rick Santorum, Arlen Specter, Edward G. Rendell

    FILE - In this July 7, 2005 file photo, Sen. Rick Santorum, R-Pa., right, and Sen. Arlen Specter, R-Pa. , and Pennsylvania Gov. Edward G. Rendell, left, testify on Capitol Hill, Thursday in Washington. With the Iowa presidential caucuses on Tuesday, Santorum is hoping to spring a surprise showing by casting himself as the only "consistent conservative" among his GOP rivals. He's been stuck at the back of the pack for months, but he's steadily visited every Iowa county and pressed for support from Republicans with doubts about the conservative credentials of other candidates, especially Mitt Romney and Newt Gingrich. (AP Photo/Lawrence Jackson, File)

  • Senator Arlen Specter walks across the t

    Senator Arlen Specter walks across the tarmac after stepping off Air Force One on June 2, 2010 upon return to Andrews Air Force Base in Maryland. Specter was travelling with US President Barack Obama who was returing to Washington after a visit to to Pittsburgh, Pennsylvania where spoke on the economy at Carnegie Mellon University. Specter, who quit the Republican Party to become a Democrat a year ago, lost his bid for a new term last month. AFP PHOTO / Mandel NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)

  • Arlen Specter Loses Senate Bid In Democratic Primary

    PHILADELPHIA - MAY 18: (L-R) Sen. Arlen Specter (D-PA) concedes defeat at a primary night gathering of supporters and staff with his wife Joan Specter and son Shanin Specter May 18, 2009 in Philadelphia, Pennsylvania. Specter, a five-term Senator who switched his political affiliation a year ago, was defeated by Rep. Joe Sestak in the Democratic primary. (Photo by Win McNamee/Getty Images)

  • Arlen Specter Campaigns In Philadelphia On Primary Day

    PHILADELPHIA - MAY 18: Sen. Arlen Specter (D-PA) talks with reporters while touring the site of his primary night gathering for staff and supporters May 18, 2010 in Philadelphia, Pennsylvania. Specter is fighting a close campaign against Rep. Joe Sestak for the Democratic Senate nomination as voters go to the polls today. (Photo by Win McNamee/Getty Images)

  • Arlen Specter Campaigns In Philadelphia On Primary Day

    PHILADELPHIA - MAY 18: Sen. Arlen Specter (D-PA) answers questions from the press with his wife Joan while campaigning at the 4th Street Deli May 18, 2010 in Philadelphia, Pennsylvania. Specter is fighting a close campaign against Rep. Joe Sestak for the Democratic Senate nomination as voters go to the polls today. (Photo by Win McNamee/Getty Images)

  • Senate Judiciary Committee Holds Hearing On Steriods Usage

    WASHINGTON - SEPTEMBER 29: Senate Judiciary Committee's Crime and Drugs Subcommittee Chairman Arlen Specter (D-PA) delivers an opening statement during a hearing on 'Body Building Products and Hidden Steroids: Enforcement Barriers' on Capitol Hill September 29, 2009 in Washington, DC. The committee is considering drawing up legislation that would give the Food and Drug Administration the responsibility of screening dietary suppliments for illegal steroids before they can be marketed and sold. (Photo by Chip Somodevilla/Getty Images)

  • Sen. Arlen Specter Holds Health Care Town Hall Meeting

    KITTANNING, PA - AUGUST 13: Senator Arlen Specter (D-PA) speaks at at a town hall meeting on August 13, 2009 in Kittanning, Pennsylvania. Specter held the town hall meeting to speak with local residents about health care reform. (Photo by Jeff Swensen/Getty Images)

  • US Secretary of State Hillary Clinton la

    US Secretary of State Hillary Clinton laughs with Sen. Arlen Spector (D-PA) before her testimony at the Senate Appropriations Committee, on May 20, 2009 on Capitol Hill in Washington, DC. AFP PHOTO / Tim Sloan (Photo credit should read TIM SLOAN/AFP/Getty Images)

  • US Senator Arlen Specter speaks as US P

    US Senator Arlen Specter speaks as US President Barack Obama looks on April 29, 2009 in the Diplomatic Reception Room of the White House in Washington, DC. Specter, a veteran Republican senator from Pennsylvania, announced April 28, 2009 that he was switching to the Democratic party. AFP PHOTO/Mandel NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)

  • Obama Welcomes Specter to the Democratic Party

    WASHINGTON - APRIL 29: U.S. Sen. Arlen Specter (D-PA) speaks speaks during a press conference welcoming him to the Democratic Party at the White House on April 29, 2009 in Washington, DC. Obama expressed his support for Spector and his run for re-election as a democrat. (Photo by Ron Sachs-Pool/Getty Images)