Kamil Zalewski

Prognostic value of lymph node ratio and number of positive inguinal nodes in patients with vulvar cancer

OBJECTIVE To estimate the prognostic significance of lymph node ratio and number of positive nodes in vulvar cancer patients. METHODS This international multicenter retrospective study included patients diagnosed with vulvar cancer treated with inguinal lymphadenectomy. Lymph node ratio (LNR) is the ratio of the number of positive lymph nodes (LN) to the number of removed LN. Patients were stratified into risk groups according to LNR. LNR was correlated with clinical-pathological parameters. Survival analyses were performed. RESULTS This analysis included 745 patients. In total, 292 (39.2%) patients had positive inguinal LN. The mean (SD) number of resected and positive LN was 14.1 (7.6) and 3.0 (2.9), respectively. High LNR was associated with larger tumor size and higher tumor grade. Patients with LNRs 0% (N0), >0<20%, and >20% had 5-year overall survival (OS) rates of 90.9%, 70.7%, and 61.8%, respectively (P<0.001). LNR was associated with both local and distant recurrence-free survival (P<0.001). Patients with 0, 1, 2, 3 or >3 positive lymph nodes had 5-year OS rates of 90.9%, 70.8%, 67.8%, 70.8% and 63.4% respectively (P<0.001). In multivariate analysis, LNR (P=0.01) and FIGO stage (P<0.001), were associated with OS, whereas the number of positive nodes (P=0.8), age (P=0.2), and tumor grade (P=0.7), were not. In high-risk patients, adjuvant radiotherapy was associated with improved survival. CONCLUSIONS LNR provides useful prognostic information in vulvar cancer patients with inguinal LN resection in vulvar cancer. LNR allows for more accurate prognostic stratification of patients than number of positive nodes. LNR seems useful to select appropriate candidates for adjuvant radiation.

Somatic mutation profiling of vulvar cancer: Exploring therapeutic targets

BACKGROUND Vulvar squamous cell carcinoma (VSCC) constitutes over 90% of vulvar cancer. Its pathogenesis can follow two different pathways; high risk human papillomavirus (hrHPV)-dependent and HPV-independent. Due to the rarity of VSCC, molecular mechanisms underlying VSCC development remain largely unknown. The study aimed to identify pathogenic mutations implicated in the two pathways of VSCC development. METHODS Using next generation sequencing, 81 VSCC tumors, 52 hrHPV(+) and 29 hrHPV(-), were screened for hotspot mutations in 50 genes covered by the Ion AmpliSeq Cancer Hotspot Panel v2 Kit (Thermo Fisher Scientific). RESULTS Mutations of TP53 (46% and 41%, of hrHPV(+) and hrHPV(-) cases respectively) and CDKN2A (p16) (25% and 21%, of hrHPV(+) and hrHPV(-) cases respectively) were the most common genetic alterations identified in VSCC tumors. Further mutations were identified in PIK3CA, FBXW7, HRAS, FGFR3, STK11, AKT1, SMAD4, FLT3, JAK3, GNAQ, and PTEN, albeit at low frequencies. Some of the identified mutations may activate the PI3K/AKT/mTOR pathway. The activation of mTOR was confirmed in the vast majority of VSCC samples by immunohistochemical staining. CONCLUSIONS Detecting pathogenic mutations in 13/50 genes examined at comparable frequencies in hrHPV(+) and hrHPV(-) tumors suggest that genetic mechanisms of the two routes of VSCC pathogenesis may be similar, despite being initiated from different premalignant lesions. Importantly, our data provide a rationale for new anti-VSCC therapies targeting the PI3K/AKT/mTOR pathway.

Technetium-99m-based Radiopharmaceuticals in Sentinel Lymph Node Biopsy: Gynecologic Oncology Perspective

Technetium (99mTc)-radiolabeled colloids are popular tracers used to map lymphatic vessels and regional lymph nodes (LNs). The regional LN status is a significant determinant of cancer stage and patient prognosis, and strongly influences treatment. Regional LN dissection has become a part of surgical treatment. However, not all patients with LN involvement benefit from extensive lymphadenectomy in terms of prolonged survival. Moreover, overtreatment of patients with localized disease carries the unnecessary risk of complications. It is believed that sentinel LN biopsy (SLNB) allows to assess the involvement of the most representative LN of the lymphatic basin and to decide on radical LN dissection.99mTc is an easily available radionuclide emitting gamma rays. The value of 99mTc for diagnostic procedures is associated with its relatively short half-life that makes it safe both for patients and medical personnel. A colloid presenting specific physical and biological properties, including optimal particle size, is a carrier for the radionuclide. When administered at the tumor site, a radiocolloid is absorbed by the lymphatics, and the first LN that it gets trapped in is referred to as the sentinel LN (SLN). The radiopharmaceutical must reach the SLN relatively quickly, but its storage within the SLN, and the radionuclides half-life must be long enough to enable intraoperative imaging and evaluation. SLNB is currently the gold standard in breast cancer and malignant melanoma diagnosis, and is under extensive investigation in gynecological cancers. Here, we provide a historical perspective of the SLN concept and the clinical relevance of SLNB in gynecologic oncology. Moreover, we review the technical aspects of the application of 99mTc-based radiopharmaceuticals in lymphoscintigraphy and intraoperative lymphatic mapping.

Normalizers for microRNA quantification in plasma of patients with vulvar intraepithelial neoplasia lesions and vulvar carcinoma

The role of circulating microRNAs as a promising tool for diagnosing cancer and monitoring anticancer therapies has been widely studied in the past decades. To date, no suitable reference microRNAs for normalizing quantitative real-time polymerase chain reaction assays has been identified in vulvar intraepithelial neoplasia lesions and vulvar squamous cell carcinoma. The purpose of this study was to select appropriate references for gene expression studies in plasma of patients with these lesions. Expression levels of six microRNAs—hsa-miR-425-5p, hsa-miR-191-5p, hsa-miR-93-5p, hsa-miR-423-5p, hsa-miR-103a-3p, and hsa-miR-16-5p—were analyzed by quantitative reverse transcription polymerase chain reaction in plasma samples obtained from 17 patients with vulvar intraepithelial neoplasia lesion and 27 patients with vulvar squamous cell carcinoma. The expression stability of these candidate normalizers was assayed using geNorm algorithm. hsa-miR-93-5p was revealed as the most stably expressed reference in plasma samples of both vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma patients. The results pointed at hsa-miR-93-5p and hsa-miR-425-5p as microRNAs that retained the greatest robustness in plasma of vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma patients, respectively. Our work is the first report on reference microRNA selection for quantitative real-time polymerase chain reaction applications in vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma. The candidate microRNA stability values for the two types of lesions are provided and might serve for normalization of the future novel microRNA biomarkers in these rare entities.