Is it worth fighting cancer again after multiple recurrences?

Well, tomorrow the biopsy. If it's cancer, this will be the third time. Lung cancer, then breast cancer. Lung cancer again. I almost left this world the first time. The breast cancer two years after the 1st time. My poor ol body just keeps taking the punches. But my quality of life has diminished so badly. I wonder if it's worth the fight this time.