Prognostication of vulvar cancer based on p14ARF status: molecular assessment of transcript and protein.

PURPOSE: This study was designed to determine the prognostic role of p14ARF in vulvar squamous cell carcinoma (VSCC). METHODS: Immunohistochemistry for p14ARF and p53 and fluorescent in situ hybridization (FISH) for TP53 were performed in 139 cases of VSCC. Human papillomavirus (HPV) genotyping by hybridization was employed in 100 cases. qRT-PCR for p14ARF and p53 transcript assessment was performed in 16 cases. All results were correlated with clinicopathological variables. RESULTS: Immunohistochemistry analysis showed p14ARF and p53 positivity in 16.4% and 53% cases respectively. Positive p14ARF expression was significantly associated with the following variables: shorter cancer-specific survival (P=0.04) and shorter disease-free survival (P=0.02), presence of perineural invasion (P=0.037), vascular invasion (P=0.047), and node metastasis (P=0.031). Also, p14ARF-positive HPV-negative cases had the shortest cancer-specific survival (P=0.03) and disease-free survival (P=0.04). HPV infection was detected in 32.8% of the cases; HPV16 was the most prevalent type. Viral infection was more common in poorly differentiated tumors (P=0.032). qRT-PCR demonstrated that CDKN2A (p14ARF) had higher expression in tumor samples compared with paired noncancerous samples (P<0.001). The opposite relationship was seen in TP53 expression evaluation (P<0.001). FISH demonstrated 4 cases with deleted TP53 (6.3%). CONCLUSIONS: p14ARF represents an important marker of poor prognosis in VSCC. p53 and HPV infection did not show any prognostic importance. Further clinical trials concerning p14ARF positivity may result in important contributions due to its relationship with poor outcome. Mainly due to the relationship of p14ARF with lymph node metastasis, the immunohistochemistry evaluation of this marker may help to identify a subset of patients more suitable to less radical procedures.

Prognostic significance of c-KIT in vulvar cancer: bringing this molecular marker from bench to bedside.

BACKGROUND: Vulvar carcinomas are rare tumors, and there is limited data regarding molecular alterations. To our knowledge there are no published studies on c-KIT and squamous cell carcinomas of the vulva (VSCC). Although there are a significant number of other tumor types which express c-KIT, there remains controversy as to its relationship to patient outcome. Thus, we wished to investigate such controversial findings to determine the prognostic importance of c-KIT by evaluating its protein and mRNA expression in VSCCs, correlating these findings with clinicopathological features and Human Papillomavirus (HPV) infection. METHODS: c-KIT expression was scored by immunohistochemistry (IHC) as positive or negative in 139 formalin-fixed paraffin-embedded (FFPE) cases of vulvar carcinomas arrayed in a tissue microarray (TMA) using the DAKO A4502 rabbit polyclonal c-KIT antibody (diluted 1:100). c-KIT mRNA was evaluated by qRT-PCR in 34 frozen samples from AC Camargo Hospital Biobank (17 tumoral and 17 non-tumoral samples) using TaqMan probes-Applied Biosystems [Hs00174029_m1]. HPV genotyping was assessed in 103 samples using Linear Array® HPV Genotyping Test kit (Roche Molecular Diagnostics, Basel, Switzerland). All results obtained were correlated with clinical and pathological data of the patients. RESULTS: c-KIT protein was positive by immunohistochemistry in 70.5% of the cases and this was associated with a higher global survival (p = 0.007), a higher recurrence-free survival (p < 0.0001), an absence of associated lesions (p = 0.001), lymph node metastasis (p = 0.0053), and HPV infection (p = 0.034). Furthermore, c-KIT mRNA quantitation revealed higher levels of transcripts in normal samples compared to tumor samples (p = 0,0009). CONCLUSIONS: Our findings indicate that those vulvar tumors staining positively for c-KIT present better prognosis. Thus, positivity of c-KIT as evaluated by IHC may be a good predictor for use of more conservative surgery techniques and lymph node dissection in vulvar cancer. So part of the essence of our study is to see the possibility of translating our current results from the bench to the bedside. This will help provide patients a more appropriate, less mutilating treatment, in order to keep the maximum physical and psychic quality as possible to these women.