DreamsMaster: My approach to dreams is to consider the literal meaning first, and then to move on to the symbolism.
If you haven’t visited a doctor in a long time, maybe now is the time. Perhaps you have been noticing some odd sensations in your body that you’ve been ignoring or pushing away to the “back of your mind”, and your dreams are bringing these unconscious concerns to the forefront.
Another possibility is that the dreams could be serving as a warning. For example, if you smoke, the dream could be throwing up a red flag about the danger you’re exposing yourself to.
If a literal interpretation doesn’t fit, next look at the symbolism. If it were my dream, having cancer would symbolize something in my life is threatening to consume my life force. Along these lines, in response to a dream about lung cancer, you might ask yourself, “Where in my life do I feel like I’m unable to breathe freely, or I’m suffocating?” Similarly, dreaming about cancer in one’s legs might also represent a threat to one’s freedom, or the ability to “run away” from some perceived danger.
This is not a dream to be ignored, whether literal or symbolic. Your innermost self is sending you the message that there’s some type of malignant or negative presence threatening your well-being, and it’s up to your waking self to take action.