Is Grade Group 1 (Gleason score 3 + 3 = 6) adenocarcinoma of the prostate really cancer?

PURPOSE OF REVIEW Whether Grade Group 1 (GG1) prostate cancer is really cancer remains controversial. RECENT FINDINGS Favoring renaming GG1 with a noncancerous diagnosis are: fear of the term cancer, which will lead to overtreatment of GG1; and indolence of GG1. Favor designating GG1 as cancer are: morphologically, GG1 may be indistinguishable from GG2 to GG5 and GG1 is invasive (lacks basal cells), can show perineural invasion and extraprostatic extension; molecularly, GG1 has many of the hallmarks of prostate cancer; calling GG1 noncancer would lead to inconsistencies and confusion in reporting; sampling error with GG1 on biopsy can miss higher grade cancer; removing the label of cancer in men with GG1 on biopsy may make it challenging to insure follow-up during active surveillance; the prognosis of treated GG1 may not be the same if GG1 called noncancer and not treated; with Grade Group terminology, GG1 is more intuitive to patients as lowest grade cancer; and patients are increasingly adopting active surveillance, recognizing that not all prostate cancers are the same and GG1 can be followed carefully and safely on active surveillance. SUMMARY There is strong support for retaining the carcinoma designation for GG1.