My otherwise very healthy 70-year-old mother has been diagnosed with lung cancer. It is at an early stage, has not spread, and she has undergone an aggressive course of radiotherapy. She has accepted my family's invitation to move in with us as we want to look after her. However, I struggle both with the smell of her cigarette smoke and her refusal to contemplate the prospect that stopping smoking might increase her longevity, just as the radiotherapy might. How should I deal with this?

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