Do No Harm: Stories of Life, Death and Brain Surgery by Henry Marsh is one of the best books I've ever read, the last time a book made me cry I was a kid. I was in tears several times, including on a flight from London to Helsinki, no holding back, pure emotional roller-coaster.
As a cancer research scientist (genomics core facility head in a cancer research institute) I rarely see or talk to cancer patients; we do have tours a few times a year and speaking to people living, and dying, with cancer brings home the real reason we're all doing our jobs.
Dr Henry Marsh is a Neurosurgeon and this book describes his career through the lives of patients he has operated on; some are cured, some die and some are unlucky - they live but with terrible repercussions of treatment gone wrong. When something goes wrong in my lab I might get tied up in knots about the loss of an £11,000 Illumina PE125bp run, who's going to pay, were the samples irreplaceable, etc; but when surgery goes wrong for Dr Marsh the results are catastrophic. He discusses the good and bad of his career with unflinching honesty and genuine emotion.