Prostate cancer patients with lymphatic node involvement detected by immunohistochemistry. Is the effort worthwhile?

INTRODUCTION: Lymph node (LN) status is one of the main prognostic factors in localized prostate cancer (CaP) patients after surgery. Examining palpable lymph nodes with hematoxylin and eosin (HE) is the most common approach in clinical practice; however, immunohistochemistry (IHC) has been reported to increase the LN detection rate. We reviewed the oncological results of patients with LN metastasis detected by IHC. METHODS: Retrospective study of CaP patients who underwent lymphadenectomy at the time of the prostatectomy. Extended lymphadenectomy was performed with complementary indocyanine green (ICG) guidance. Three groups were considered according to LN status. Definition of the pN+ group was made if LNs were detected by HE, occulted lymph node-positive (OLN+) was considered when ≥ 1 LN was identified with IHC and occulted lymph node-negative (OLN-) if no metastatic nodes were found. Oncological outcomes were reported regarding PSA kinetics, biochemical recurrence (BCR), need for secondary treatments and metastasis-free survival (MFS). RESULTS: A total of 283 patients with a median follow-up of 69 months were included in the study. Immunohistochemical assessment revealed metastatic LNs in 8.9% of patients. The rate of locally advanced disease and positive surgical margins was higher in the OLN + and pN + groups vs the OLN - group (P < 0.05). At the end of follow-up, 19%, 44% and 52% of patients from the OLN -, OLN + and pN + groups experienced BCR (P < 0.001), respectively. Additionally, 2.6%, 17% and 22% of patients developed metastatic progression from the OLN -, OLN + and pN+ group (P < 0.001), respectively. In the multivariate analysis, the OLN + group had a higher risk HR: 12 (95% CI, 2.4-56; P = 0.002) of metastatic progression in comparison with OLN - patients. This difference was not observed in the risk of biochemical recurrence HR 1.8 (95% CI, 0.9-3.8; P = 0.09). CONCLUSION: Conventional HE histological analysis underdiagnosed nearly 10% of patients. IHC-detected patients were at higher risk of metastasis development than OLN - patients. This report highlights the importance of optimizing the anatomopathological analysis properly.

Is Unilateral Lymphadenectomy an Option in Selected Patients with Prostate Cancer?

BACKGROUND: Evidence regarding the relationship between the laterality of lymph node invasion (LNI) and the prostatic lobe affected is limited. Our aim was to review our records of patients with exclusively unilateral localised prostate cancer (PCa) with metastatic LN involvement. METHODS: Between 2006 and 2023, after radical prostatectomy and extended pelvic lymphadenectomy at our centre, thirty patients with intermediate-high risk unilateral PCa and pN1 disease were identified. To perform a retrospective study, data were obtained from a prospective collected database approved by the ethical committee at the Valencian Oncology Institute Foundation. Descriptive and comparative statistical analysis was made using software R. The Fisher's Exact test was employed to analyse the categorical variables. In terms of continuous variables, both tumour volume and number of nodes retrieved exhibited normality; Hence Student's T-test was employed. Mann-Whitney U test was utilized for the number of positive nodes. RESULTS: The median age and prostate specific antigen (PSA) at diagnosis were 66 years old (interquartile range (IQR): 63.3-70.9) and 14.6 ng/mL (IQR: 7.4-21.5), respectively. Median follow-up time was 67 months (IQR: 35.9-92.9). Nineteen patients (63%) had a Gleason score of 7, and the rest had a Gleason score of 8-10. Most patients (73%) had locally advanced disease. Baseline characteristics were comparable between groups (p-value > 0.05). Twenty-two patients (73%) had concordance between the laterality of the PCa lesion and the LNI. All the patients with right prostatic cancer had exclusive ipsilateral LNI. CONCLUSIONS: In our experience, the majority of patients with unilateral PCa had exclusively ipsilateral LNI. However, sparing contralateral LN dissection in unilateral PCa should not be an option. To date, extended pelvic LN dissection remains the gold standard for N-staging and cannot be replaced yet by unilateral pelvic LN dissection until high quality evidence supports this scenario.