Is body mass index a risk factor for lymphnode metastasis in penile cancer?

Introduction: Obese patients with penile cancer may have more advanced disease. This study evaluated the association of obesity with penile cancer and the risk of lymph node metastases in patients who underwent inguinal lymphadenectomy.

Methods: We retrospectively reviewed the charts of 197 penile cancer (PC) patients from January 2000 to December 2011. Seventy underwent inguinal lymphadenectomy. For this subgroup, chi-square analysis evaluated the correlations of sociodemographic, clinical, and pathological variables with the presence of positive inguinal lymph nodes. Patients were divided into normal weight, overweight, and obese categories according to body mass index (BMI). The mean numbers of positive and resected lymph nodes were compared for each BMI category.

Results: The percentage of overweight men in the Brazilian population and among patients with PC was 52.6% and 42.8%, respectively. For patients who underwent lymphadenectomy, the mean BMIs were 25.9 ± 6. Most patients were white, married, had a lower education level, and had no history of smoking. Partial penectomy was the most frequently performed surgery; lymphovascular invasion occurred in 45.7%, and lymph node metastasis occurred in 52.9% of cases. The mean numbers of resected and positive lymph nodes for normal weight, overweight, and obesity were 21.1 and 2.2, 23.3 and 2.2, and 16.8 and 1.5, respectively.

Conclusion: Overweight and obesity were less frequently seen in patients with PC than in the Brazilian population. BMI was not a risk factor for developing lymph node metastasis; the only predictive factor for lymph node metastasis was the presence of lymphovascular invasion.