Introduction We aimed to evaluate, in a large database of patients with vulvar cancer, the incidence of positive lymph nodes with relation to known pathological risk factors, and specifically among those with apparent low grade, small size tumors.

Methods We used the Surveillance, Epidemiology and End Results (SEER) database to identify vulvar squamous cell cancer (SCC) patients, with known tumor size and regional lymph nodes examined. A comparison between patients who had positive and negative lymph nodes was conducted, with relation to survival. Subgroup analysis was conducted in patients diagnosed with grade 1 vulvar SCC and tumor size up to 2 cm according to the status of lymph nodes.

Results Multivariate analysis found that both grade of disease and tumor size were significant factors in predicting lymph nodes status. Among those with tumors of low grade, small size tumors up to 2 cm, the odds ratio for positive lymph nodes was found to be 2.5 for those with tumor size more than 1 cm. In a multivariate survival analysis older age, larger tumor size and positive lymph nodes were independently associated with decreased survival.

Conclusion/Implications Our study confirmed that among small size tumors, those above 1 cm size have a significantly increased risk for positive nodes compared to those under the size of than 1 cm, and among this specific group, patients with nodes positive have decreased survival. Future studies are needed to answer the question, if in the era of sentinel node procedure, it is safe to omit lymph node evaluation all together.