This time I decided against surgery since the cancer was spreading and Sappho was an old cat with several other medical problems (which were being managed). For several more months I kept an eye, or rather a finger, on their progress at the same time as watching Sappho's general condition and demeanor. The spread of cancer was one of the contributing factors to Sappho's eventual euthanasia (the others were Inflammatory Bowel Disease - probably one reason she loved a belly rub - and senility); but I'd given her two more years than she might have had.
All my feline family love her their massage session, blissfully unaware of its diagnostic aspect. So go on; spoil your cats with a weekly rub down!