Here's a very short story, which reflects back on some of my own experiences. Let me know what you think of it.

The woman - young, but strangely swollen and moving slowly - came to a halt at the bus stop. She swayed back to study the display of on-coming buses, sighed, and settled down to wait. She was coming back from one of her trips to the hospital. Fortunately, her treatment was drawing to a close, and so she would soon be spared these thrice-weekly visits, and she hoped she would quickly forget the wipe-down chairs in pastel green, the smell of the corridors, the agony of the needle probing ruthlessly for a vein in the back of her fist. Unconsciously, she rubbed one hand over the other, a sympathetic gesture from one limb to its fellow, made below the level of thought.
The treatment might be finishing, but there was no talk of her having been cured. That was a c-word not mentioned at all by the medical staff, and certainly not by herself. Her friends, though, her family, all happily bandied it about; it was a given, surely, that after the surgery, and after all these cycles of drugs, that the cancer was gone, banished forevermore, an inevitable conclusion like collecting three tokens from the newspaper and getting a free begonia. She leaned, tired, on the post of the bus stop. She knew better, of course, and so did the nurses and those ever-changing registrars. There was no cure, there wasn’t even proof that in her specific case the cancer had gone away. And if it had – well, there it waited, on the fringes of her mind, in the corners of every cell, just biding its time. A tiger in the undergrowth it lay, sleepy and passive for now, but who knew what unfathomable calculation of its own would lead it once again to show its teeth.
That was one of the problems of being a person with cancer, she reflected, closing her eyes and letting the light of a clear, early-Spring afternoon soak through their pallid lids in a wash of gold. Nobody wanted to hear bad news, or rather, nobody wanted to admit that sometimes cancer just killed you, no matter how many treatments you had, or how sunny you kept your attitude. People wanted to see the plucky, cheerful patient, not the exhausted, frightened, ravaged person who staggered from appointment to appointment, just wanting to endure. A man and a woman strolled past, and stared openly at her moon face and her bald head. She turned half away, and studied the pattern of tool marks on the golden stones in the wall behind her, waiting until the couple had moved on before looking round.
She often felt that perhaps she was in fact dead, that the cancer had really carried out its threat and taken her life. In this chain of half-dreamed thoughts, somehow no-one had noticed that she had died and continued to enforce treatments on her slowly-rotting frame. Or perhaps, like Lazarus, she had died and been returned to life as this half-person, not quite here and not quite elsewhere, a solid shade or a embodied ghost. Why did the skeleton not go to the ball, her ruined memory suddenly suggested, because he had no body to go with. Ha, ha. The post was cold, and she moved, shifting to the other shoulder. An old lady sitting on the bus stop’s narrow bench eyed her warily, but didn’t move.
Yes, perhaps Lazarus was the right analogy, she continued to herself. Brought back from the dead, not because he wanted to be, but because his family wept and cried and begged Jesus to do it. And the man himself? Alive, but forbidden ever to speak in case he reveal to those around him the reality of what lay beyond the grave. She felt like that. She couldn’t tell people how the chemo was dissolving her, unravelling her cells, making her a stranger in her own body; she couldn’t say, in case one day they needed chemo too and were swayed by her words to refuse its violent, drastic, last-ditch treatment. She couldn’t speak, instead she joined Lazarus in mutely looking on.

She turned to gaze up at the endless blue above the line of the buildings opposite. There was something else that she found it impossible to say to those around her: an understanding that had lain hidden in her soul, a secret line of code programed in and now revealed by the IF THEN of her weakened state. The world - that strong, fast, loud, fat, physical world - was thin, terribly thin, the merest whisper of ice on a darkened pond. All around she felt the translucency of the real, and beyond it – even she didn’t know. But there was a beyond, there was a something else, there was a place where if she didn’t hang on, if the treatment didn’t work, if she wasn’t lucky or plucky or cheerful enough, she would slip away to like an escaping balloon flitting into the afternoon sky.
Above her, she felt something change. Like plates moving smoothly across one another, like lenses focussing, she felt a transparency come into being high over her head. She looked up, and she could feel that someone was looking down, smiling down, reaching down, and her own thoughts spiralled up and up and she said in her mind:
‘Hello, Mum,’
And the gears revolved, and the gap closed over, and the bus came along the street and, moving slowly, she climbed aboard and went away.