Vulvar cancer is the fourth most common gynecologic cancer. Regarding invasive squamous cell carcinoma (SCC), two independent pathways have been described: one related with HPV infection affecting young patients and the other in older age with non-neoplastic vulvar epithelial disorders. In Europe, the prevalence of HPV associated with vulvar cancer is 34.7% [1], although a wide geographic variation has been described [2]. Invasive carcinomas harboring HPV DNA have been associated with better prognosis [3,4]. Our aim was to evaluate the prevalence of HPV in a single center in Portugal and to make a correlation with clinical data, namely age of patient at diagnosis and prognosis.
We evaluated the presence of HPV DNA in 84 women with SCC treated in our institution between 2008 and 2015. HPV DNA was evaluated with an In House assay: after DNA extraction (QIAamp MinElute Vírus Kit, QIAGEN), a 75 bp amplicon (SPF10 primers) was amplified using Real Time PCR (SYBR Green dye). Samples with a positive result were genotyped using HPV INNO-LIPA.
Patients median age is 74, ranging from 36 to 92. HPV DNA is present in 26 SCC (31%) being 20 (23%) for HR HPV, 3 (4%) for LR HPV and 3 (4%) for HPV X. The most prevalent genotypes are HPV16 (38.5%) and HPV 39 (12.5%). Regarding Low Risk genotypes, we detected HPV 6 (n=2) and 42 (n=1); 17% (n=4) had multiple infections, mainly with HPV 16 (n=3). The overall survival rate in patients with HPV was 71%; in patients without HPV infection the survival was only 62%.
Our detection of HPVDNA in squamous cell carcinoma of the vulva (31%) is in agreement with the prevalence of HPV in vulvar cancer in European countries (34.7%). We did not found an association between SCC of vulva with HPV DNA with patient age, and survival.
[1] De Vuyst et al, Int. J. Cancer: 124, 1626-1639 (2009)
[2] Sanjose S et al, Eur J Cancer 49:3450-61 (2013)
[3] Lindell G et al. Gynecol Oncol 117: 312–316 (2010).
[4] Alonso I et al, Gynecol Oncol 122: 509-14 (2011).