Hi, Thanks for writing in. Cancer is a challenging diagnosis and the life expectancy, survival and prognosis depends on the stage of cancer and response to treatment with chemotherapy and radiation therapy. Melanoma is an aggressive tumor and spreads to other organs even after the primary cancer is operated. Your aunt might be having spread to other organs as you have described her condition is in the final stages. She must be a strong willed person and that is the reason she is exceeding her doctors prediction of her life expectancy. It is possible that she might survive for a few weeks more. Coughing up blood is not a good sign and that itself might cause her to give up. This is causing blood loss and therefore the next symptoms might be that of severe weakness, increase in blood loss and probably she might catch an infection in her lungs, a pneumonia sort of. It is nice to know that you are spending a lot of time with your aunt in her final days. Please do not worry.