Excisional biopsies may remove the tumor, but further surgery is often necessary to reduce the risk of recurrence. Complete surgical excision with adequate surgical margins and assessment for the presence of detectable metastatic disease along with short- and long-term followup is standard. Often this is done by a wide local excision (WLE) with margins. Melanoma-in-situ and lentigo malignas are treated with narrower surgical margins, usually . Many surgeons consider the standard of care for standard excision of melanoma-in-situ, but margin might be acceptable for margin controlled surgery (Mohs surgery, or the double-bladed technique with margin control). The wide excision aims to reduce the rate of tumor recurrence at the site of the original lesion. This is a common pattern of treatment failure in melanoma. Considerable research has aimed to elucidate appropriate margins for excision with a general trend toward less aggressive treatment during the last decades. A 2009 meta-analysis of randomized controlled trials found a small difference in survival rates favoring wide excision of primary cutaneous melanomas, but these results were not statistically significant.