Extent of positive surgical margins following radical prostatectomy: impact on biochemical recurrence with long-term follow-up

The presence of positive surgical margins (PSM) following radical prostatectomy (RP) is a worrying for surgeons and patients alike as it represents an independent biochemical recurrence (BR) risk factor [1,2,3,4,5,6,7,8]. The rate of PSM is 5-30% for organ-confined prostate cancer and 17-65% for locally-advanced cancer [9,10,11].

A PSM means incomplete cancer resection and may lead to additional treatment, such as either adjuvant radiotherapy (AR) or chemical or surgical castration. These remedial treatments display side effects and affect patient quality of life [12]. However, despite the evidence that AR significantly reduces the BR risk in locally-advanced cancers [12], the optimal approach concerning PSM remains unclear. The strategy eventually employed varies according to institution, while often left to the surgeon’s discretion or simply following each team’s habitual practice.

Moreover, there is generally no evaluation of PSM characteristics (size, number, location, and focality) regarding these additional therapeutic decisions. This can be explained by the observation that there is no consensus yet taking into account these factors for the therapeutic decision.

One reason could be the lack of standardization of anatomopathological reports regarding PSM description, and thus a potential lack of information that could be detrimental to the therapeutic decision-making process. The College of American Pathologists recommends referring to the Gleason score of the margin [13].

Nevertheless, there are still no clear recommendations, especially regarding how to act depending on the PSM (length and number) extent. Lake et al. [14] reported that the extent of the margin significantly affects BR-free survival, which is improved in cases of fPSM (length ≤ 3 mm) compared to ePSM (multifocal PSM or length > 3 mm).

In another recent study based on a median 52-month follow-up, Lee et al. [15] demonstrated that ePSM can significantly affect BR-free survival compared to fPSM. It should, however, be noted that their study included patients classified N+ and/or pT3b, which could be confounding factors in the BR assessment. Similarly, Maxeiner et al. [16] reported that multiple PSM and those > 3 mm represented an independent BR factor, whereas these authors likewise included patients with potential confounding factors (N+, PT3b, PT4, or neoadjuvant treatment).

In our study involving a median 5-year follow-up, we sought to assess the BR risk in relation with PSM extent following RP for Stage ≤PT3a patients who had not received any neoadjuvant or adjuvant treatment. We also sought to determine the influence of other BR prognostic factors, such as PSM location within the prostate.