When Is Prostate Cancer Really Cancer?

A group of 50 experts in prostate cancer, representing numerous specialty areas, met recently to address whether low-grade prostate neoplasia (Gleason 6 or Grade Group 1 [GG1]) should be called “cancer” (J Natl Cancer Inst 2025; 117:402). The participants didn't come to final conclusions, but their deliberations, including 36 commissioned presentations and discussions, should interest both specialists and primary care clinicians.

Prostate cancer is graded histologically by pathologists on a scale of 1 to 5 (from no to highly cancerous features). The scores of the primary histologic pattern and the most common secondary pattern are added together. Prostate cancer is not diagnosed when this score is ≤5, so the range of scores for a lesion labeled as “cancer” is 6 to 10. A Gleason score of 6 (i.e., 3+3) is termed GG1.

In autopsy series, GG1 lesions are so ubiquitous that many experts believe them to be a normal feature of aging. Pure GG1 lesions cause no symptoms, and, if they don't change during follow-up, they remain asymptomatic and don't metastasize. Overtreatment of persistent, but unchanging, GG1 lesions causes substantial and avoidable morbidity, without improving all-cause or cancer-specific mortality. However, GG1 lesions should not be considered “normal” by physicians nor presented as such to patients. Because they potentially can progress to more-aggressive, clinically significant disease, active surveillance should be offered. Summit participants speculated that a commitment to active surveillance by both physician and patient might be more productively discussed if GG1 lesions are renamed and not called “cancer.”

The authors also argue that enthusiasm and support among clinicians for early screening, including prostate-specific antigen (PSA) testing, might improve if a clear consensus is reached about how to discuss and manage GG1 lesions. Although a majority of GG1 cases in the U.S. now are managed with active surveillance, local variation in practice still occurs (NEJM JW Gen Med Mar 15 2023 and JAMA Netw Open 2023; 6:e231439). According to the authors, “GG1 should nearly always be managed with initial active surveillance or observation.” A marked reduction in immediate treatment of GG1 might improve patients' acceptance of more-regular screening, leading to earlier detection of aggressive lesions (J Natl Cancer Inst 2023; 115:1364).

Two concerns about a name change were expressed. First, adherence to an active-surveillance program might be low if the lesion is not labeled as “cancer.” And second, active surveillance or more-aggressive management of patients at high risk (including those with early and strong family history of cancer) might not be supported by health insurance plans if the lesion is not labeled as “cancer.”

One proposed name for GG1 lesions is “acinar neoplasm.” The renaming process could benefit from the experience of thyroid cancer experts who worked through a process of renaming one indolent variant of papillary thyroid neoplasia — previously labeled as “cancer” — to “noninvasive follicular thyroid neoplasm with papillary-like nuclear features.”

In sum, this summit conference of expert opinion has opened a critical discussion about how to name a histological abnormality of the prostate (JAMA 2025; 333:556). Patients with GG1 lesions generally are managed by urologists, but primary care clinicians are often asked by patients for their opinion about treatment alternatives and should be informed about this debate and be prepared to engage in shared decision making if requested. Similar discussions are underway regarding how to name and manage ductal carcinoma in situ (DCIS) of the breast, but that field is less developed because long-term DCIS data are scant compared with that of GG1 prostate lesions (JAMA 2025; 333:972).