I was diagnosed with stage IV acral lentiginous melanoma in August 2014. The year before, I had bumped my thumb against the side of a pool. When the injury didn’t heal with antibiotics, my doctor scheduled a tissue biopsy.

After I found out I had melanoma, my biggest worry was what life would be like for my wife and four sons if I were not around. The thought of my wife raising our 15-year-old son and 13-year-old triplets alone...