Cancer in a dream: what does it mean?
Dreams about cancer are reported by people who have it, people who have lost somebody to it, and people who are simply afraid of it, and the three are different dreams that look the same.
How do the four traditions read it?
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream. The four often disagree, and that is the point: a symbol rarely means one fixed thing, and the distance between Freud, Jung, modern research and myth tells you more than any single verdict could.
Freud
Freud would attend to what the illness was standing in for, while allowing that sometimes it stands for itself. He was clear that a bodily state or a real fear can enter a dream directly and need no translation.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
For Jung an illness dream can image something growing in a life that was not planted deliberately, and the compensatory reading would ask what the waking attitude has been refusing to look at. He would not read it as a diagnosis.
Our summary of a Jungian reading, in our own words, not Jung's. See Jung, ed., Man and His Symbols (1964).Modern
This should be said plainly and first. A dream about cancer is not evidence of cancer, and there is no reliable research showing that dreams detect illness. What the continuity view predicts is the opposite: these dreams follow waking fear, a recent scan, a friend's diagnosis, or a news story. Anybody worried about a symptom should see a doctor, and a dream is not a reason to be reassured either.
Our summary of the continuity hypothesis, named by Calvin Hall and Vernon Nordby, The Individual and His Dreams (1972). Its correct scope is disputed; see Domhoff (2017) and the replies to him.Mythological
Traditions that treat illness as an intruder or a punishment produced a great deal of cruelty toward the sick, and that history is worth recording rather than mining. The idea that a person's character caused their illness is old, persistent and wrong.
Rosmerta Publishing editorial synthesis (after Frazer; Brewer).How can writers use this symbol?
The same symbol, read as craft material rather than as a dream. What it does on the page, how genres use it differently, and what happens when you turn it inside out. Written for novelists, screenwriters and poets who need the symbol to actually work, and it ends with something to try.
In literature
Illness writing has become one of the strongest bodies of contemporary non-fiction, and what distinguishes the good work is refusal of narrative: real illness does not have acts, and the writing that admits that lands hardest.
Rosmerta Publishing editorial synthesis. Our own words; no quoted text.What it does in a story
It supplies a threat with no antagonist and an uncertain clock, which is unusually difficult to structure. Fiction tends to resolve it too neatly in either direction, and readers who have been near it can tell.
Genre conventions
Literary fiction uses the waiting for results, which is where most of the actual experience is. Memoir uses the treatment. Genre fiction tends to use it as a deadline, which is where it becomes a device rather than a subject.
How to subvert it
Write the scan that comes back clear, and the character who cannot go back to how they were beforehand.
Try this
Write a waiting room before a results appointment. Four hundred words. Nobody may say anything about why they are there.
Only the first of these names a source. What a symbol does in a story, how genres treat it, how to invert it and what to try are our editorial judgement as writers and editors, not findings from a body of research. They are offered as craft opinion and should be argued with.