- For more than a century the Halstedian hypothesis of contiguous metastasis from the primary tumor through the lymphatics to distant sites shaped lymph node surgery for melanoma. We challenge this dogma of serial metastatic dissemination. A single-center series of 2,299 patients with cutaneous metastatic melanoma was investigated to analyze overall survival and distant metastasis-free survival of stage IV patients with or without primary lymphatic metastasis. Results were then compared with those of 2,134 patients from three independent centers of the German Central Malignant Melanoma Registry.
- Obesity is a known risk factor for cancer development (Arnold et al., 2016; Basen-Engquist and Chang, 2011; Renehan et al., 2015) and death (Calle et al., 2003). Obesity has been associated with an increased risk of developing melanoma in men (Sergentanis et al., 2013) and with thicker primary melanomas (Skowron et al., 2015). The inflammatory adipokine leptin promotes melanoma progression in mice (Amjadi et al., 2011; Brandon et al., 2009; Gogas et al., 2008); elevated leptin levels may predict melanoma sentinel node metastasis (Oba et al., 2016).