Complex sentence: It was stated by the government that he had what turned out to be a large, cancerous tumor in his abdomen, but Glushko later reported that he actually died due to a poorly performed operation for hemorrhoids.
Split into simpler sentences: It was stated by the government that he had what turned out to be a large, cancerous tumor in his abdomen. But Glushko later reported that he actually died due to a poorly performed operation for hemorrhoids.