Laser vermilionectomy has been used for premalignant lesions of the lower lip [3] (Fig. 5.2), and other studies have examined its use for early invasive carcinoma. In one report of 46 patients with T1 SCC of the lip with a minimal follow-up of 5 years, disease-free survival (DFS) was 82.6 % following the use of Nd:YAG laser ablation [4]. Although the authors concluded that these results support the use of the Nd:YAG laser for stage 1 cancers of the lip, the literature generally reports a survival of >90 % in stage 1 disease. It should also be noted that 6 patients in the above cohort of 46 required repeat laser ablation.

Squamous cell carcinoma of the lips behaves more like skin cancer than mucosal oral cavity epithelial malignancy, and Mohs surgery has been used for these cancers. In a large series of 1,119 patients with stage I (983 %) and stage II (1.7 %) SCC of the lower lip, local recurrence was only 1.5 % [5]. Another paper analyzing Mohs surgery found a 91 %, 5-year cure rate in 45 patients with early stage SCC of the lower lip [6].

In larger lesions and lesions thicker than 2–3 mm, full-thickness excision is utilized (Fig. 5.3). There are few good trials to assess the margins necessary for excision of SCC of the lip. Older studies advocate 8–10 mm as for mucosal SCC of the oral cavity [7]. However, it is difficult to reconcile the removal of such a margin with the excellent results for microscopic margins reported for Mohs. De Visscher et al. [8] reported a more conservative approach in a clinical trial of 72 patients with SCC of the lower lip, where 3 mm margins controlled by intraoperative frozen sections were used. They found 89.9 % of margins were initially clinically free and a false-positive result of 1.4 % for frozen section. Local recurrence was 2.8 % with a minimum 2-year follow-up. They advocated a 3 mm margin with frozen sections and a 6 mm margin if frozen sections were not used [8]. Brotland and Zitelli [9] in a prospective study of cutaneous SCC not specifically located to the lip advocated 4 mm margins. However, in high-risk lesions, i.e., 2 cm or more in size, histologic grade 2 or higher, invasion of the subcutaneous tissues, and location in high-risk areas, these authors prefer 6 mm margins[9]. In the absence of prospective trials, it appears that early stage I SCC of the lip may be managed with margins 3–5 mm. However, when the size of the primary tumor is >2 cm, there is an increased rate of local recurrence [10–12] and margins of at least 10 mm are required. Resection can be undertaken with a V- or shield-shaped full-thickness excision especially in small tumors. In larger thicker tumors extending below the skin-vermilion border, these tapering excisions may compromise margins and a vertical incision such as a W or rhomboid is preferred (Fig. 5.4). Where the whole vermilion has premalignant changes, a vermilionectomy can be incorporated with the excision.

As the tumor increases in size, adjacent structures to the lip may become invaded by direct extension and both the mandible and inferior alveolar nerve may require management. In cancers of the lower lip, the mandible will be managed as for intraoral SCC. If the tumor is close to the bone but not fixed to it and the periosteum can be stripped without evidence of perforation or invasion, then the mandible can be left intact. When the tumor is stuck to the periosteum or is eroding/invading the cortical bone, only then a marginal resection with preservation of mandibular continuity is indicated (Fig. 5.5). In more advanced cases where invasion through the cortical bone into the medullary bone is present, then a segmental resection of the involved bone is the safest oncologic procedure.

The mental nerve may be involved by tumor invasion and the SCC can spread in theory along the nerve to the foramen ovale with intracranial involvement [13]. Patients have symptoms of sensory disturbance of the lip, and the panoramic radiograph may show widening of the mental foramen or mandibular canal [14]. If sensory changes are diagnosed preoperatively, resection of the nerve with frozen section control should be planned. Magnetic resonance imaging may be the most accurate way of defining the extent of perineural involvement, but it is reported that usually only 10–15 mm of nerve is involved in lip cancer [15]. However, if the nerve is involved within the mandible, the surgeon may need to remove the entire nerve bearing segment of the mandible.

Adjuvant radiation therapy (RT) is usually given for T3–4 tumors, and if the final margins are positive, either re-resection or chemo/radiation is recommended. Perineural invasion is also believed to be an indication for postoperative RT.