Prognostic significance of lymphovascular invasion in radical prostatectomy specimens

Abstract

Study Type - Prognosis (case series).

Level of evidence: 4. What's known on the subject? and What does the study add? The reported incidence of lymphovascular invasion (LVI) in radical prostatectomy specimens ranges from 5% to 53%. Although LVI has a strong and significant association with adverse clinicopathologic features, it has almost uniformly not been found to be a predictor of biochemical recurrence (BR) on multivariate analysis. This study confirms that LVI is associated with features of aggressive disease and is an independent predictor of BCR. Given that LVI may play a role in the metastatic process, it may be useful in clinical decision-making regarding adjuvant therapy for patients treated with RP.

Objectives: To determine whether lymphovascular invasion (LVI) in radical prostatectomy (RP) specimens has prognostic significance. The study examined whether LVI is associated with clinicopathological characteristics and biochemical recurrence (BCR).

Patients and methods: LVI was evaluated based on routine pathology reports on 1298 patients treated with RP for clinically localized prostate cancer between 2004 and 2007. LVI was defined as the unequivocal presence of tumour cells within an endothelium-lined space. The association between LVI and clinicopathological features was assessed with univariate logistic regression. Cox regression was used to test the association between LVI and BCR.

Results: LVI was identified in 10% (129/1298) of patients. The presence of LVI increased with advancing pathological stage: 2% (20/820) in pT2N0 patients, 16% (58/363) in pT3N0 patients and 17% (2/12) in pT4N0 patients; and was highest in patients with pN1 disease (52%; 49/94). Univariate analysis showed an association between LVI and higher preoperative prostate-specific antigen levels and Gleason scores, and a greater likelihood of extraprostatic extension, seminal vesicle invasion, lymph node metastasis and positive surgical margins (all P < 0.001). With a median follow-up of 27 months, LVI was significantly associated with an increased risk of BCR after RP on univariate (P < 0.001) and multivariate analysis (hazard ratio, 1.77; 95% confidence interval, 1.11-2.82; P = 0.017). As a result of the relatively short follow-up, the predictive accuracy of the standard clinicopathological features was high (concordance index, 0.880), and inclusion of LVI only marginally improved the predictive accuracy (0.884).

Conclusions: Although associated with features of aggressive disease and BCR, LVI added minimally to established predictors on short follow-up. Further study of cohorts with longer follow-up is warranted to help determine its prognostic significance.