What are signs of vocal cord and esophageal cancer?

My brother-in-law just had his voice box removed last month. He had stage 4 cancer. He had hoarseness, only being able to speak in whispers, for several months. No pain at all. When he woke up in the middle of the night and could not breathe, he finally took our advice and went to the doctor. The doctor said the tumor would suffocate him if he chose to do nothing.