Wiktionary
precancerous
a. (context oncology English) Of or pertaining to growth that is likely to develop into cancer. alt. (context oncology English) Of or pertaining to growth that is likely to develop into cancer.
WordNet
precancerous
adj. of or relating to a growth that is not malignant but is likely to become so if not treated
Usage examples of "precancerous".
A 1998 landmark study found that the use of tamoxifen in such women, who have no cancer but a family history of cancer or precancerous lesions, reduces the rate of expected breast cancers by 45 percent.