In response to news about about my mother's cancer, occasionally I am asked if she smoked. (I'm certain this is a common occurance with other head and neck and lung cancer patients.)

Everyone these days is aware of the hazards of smoking, but many, many factors contribute to causing cancer. My family is wrestling with the news of my mother's cancer, the treatment and the inevitable outcome... to hear the question about smoking, as if that assigns blame or minimizes the severity of the diagnosis; well, it just sort of ticks me off.
I suppose I look at is as medical professionals deserve to know a person's history, but not nosey co-workers and acquaintances! Not sure why the question offends me, but it certainly does.

Simply, my question is this: what is an easy response to this question, without erupting on the inquirer?