Death thumb|right|280px|President Richard Nixon paying his last tributes to Senator Dirksen in 1969. Dirksen was a heavy smoker. In August 1969, chest X-rays disclosed an asymptomatic peripherally located mass in the upper lobe of the right lung. Dirksen entered Walter Reed Army Hospital for surgery, which was undertaken on September 2. A right upper lobectomy removed what proved to be lung cancer (adenocarcinoma). Dirksen initially did well, but progressive complications developed into bronchopneumonia. He suffered a cardiopulmonary arrest and died on September 7, 1969, at age 73.
Death thumb|right|280px|President Richard Nixon paying his last tributes to Senator Dirksen in 1969. Dirksen was a heavy smoker. In August 1969 chest X-rays disclosed an asymptomatic peripherally located mass in the upper lobe of the right lung. Dirksen entered Walter Reed Army Hospital for surgery, which was undertaken on September 2. A right upper lobectomy removed what proved to be lung cancer (adenocarcinoma). Dirksen initially did well, but progressive complications developed into bronchopneumonia. He suffered a cardiopulmonary arrest and died on September 7, 1969, at age 73.