Introduction

Cancer of the tongue is most common in 60- to 70-year-old male drinkers and smokers but is also encountered in much younger and older individuals without a history of smoking or ethanol use. Most cancers of the tongue are squamous cell carcinomas, which arise on the lateral aspect of the tongue and exhibit a propensity for early spread to the lymph nodes of the neck. Early stage cancers (stages 1 and 2) are equally well controlled with surgery or radiation; however, surgery is associated with less long-term side effects. For advanced cancer, multiple treatment modalities, most commonly surgery followed by radiation, are usually necessary.

In evaluating a patient with a newly diagnosed cancer of the tongue, several questions must be addressed prior to surgery: (1) How extensive is the cancer, and can it be removed through the mouth? (2) Has the cancer spread to the lymph nodes of the neck, and what type of neck dissection, if any, should be undertaken? (3) After the cancer is removed, should the defect be reconstructed?

The office examination and selected radiographic studies are important in assigning an initial tumor stage. The physical examination provides important information regarding the local extent of the cancer, both in its size and depth. Lymph node metastases can often be detected by careful palpation of the neck. Imaging studies such as computed tomography (CT) scans or magnetic resonance imaging (MRI) may identify invasion of the deep muscles of the tongue and small cervical lymph node metastases not appreciated on office examination alone, improve the accuracy of the initial tumor staging, and facilitate the development of a treatment plan.

Most early stage cancers of the tongue can be managed by means of a partial glossectomy and a neck dissection ( Fig. 28.1A and B ). A larger, deeply infiltrating cancer may require greater exposure than that achieved through the mouth alone. A transcervical delivery or mandibulotomy may be necessary for an oncologically sound extirpation. Larger resections are also more likely to require surgical reconstruction, most often with microvascular transfer of soft tissue from the forearm or thigh to enhance healing and postoperative function. A neck dissection may be omitted in small tongue cancers with minimal invasion but is recommended for thicker cancers even in the absence of clinical or radiographic evidence of lymph node metastases, due to the high frequency of micrometastatic disease. In a large randomized study, patients without detectable metastases prior to surgery who underwent elective neck dissection at the time of the surgery for cancer of the tongue had improved overall and cancer-related survival than those who waited until signs of metastatic disease became clinically evident. Neck dissection is more effective earlier in the course of the disease. Additional treatment such as radiation and chemotherapy is added based on the final pathologic review of the resected surgical specimen. Lymphoscintigraphy with sentinel lymph node biopsy effectively identifies micrometastases when performed by experienced surgeons and may be considered as an alternative to a selective neck dissection for cN0 oral cancer in some cases. However, while the survival benefit of selective neck dissection in this setting has been confirmed in a randomized clinical trial, the equivalence of sentinel lymph node biopsy to neck dissection has not.

A, Irregular plaque with raised edges suggests the depth of invasion is at least 2 to 3 mm. Palpation provides additional information regarding the depth of invasion. B, A partial glossectomy involves removing an adequate margin of mucosa and muscle. A partial glossectomy of the posterior oral tongue frequently does not require a formal reconstruction.

The overall recurrence rate and survival after surgery for early stage cancer are favorable, with 85% to 90% 5-year rates of cancer-free survival reported. The presence of metastasis to lymph nodes in the neck decreases cancer-free survival rate by 50%, providing justification for additional treatment to improve outcome.

Key Operative Learning Points

• 1.
  

  Preoperative staging helps in developing a suitable surgical treatment plan. Patients with stage 1 to 2 cancer of the tongue are usually managed with a partial glossectomy and selective neck dissection, including levels I, II, III, and possibly IV. Sentinel lymph node biopsy may be considered as an alternative in select cases, as noted previously.

  
  
• 2.
  

  Inspection and palpation usually differentiate thin, minimally invasive cancers of the tongue (and those less than 2 to 3 mm thick) from more deeply infiltrating cancers that are associated with higher rates of cervical lymph node metastases.

  
  
• 3.
  

  Locally advanced cancers, particularly those classified as T4, with deep muscle invasion often require greater exposure than that afforded by a transoral approach. Transcervical delivery or manibulotomy may be needed. Bone invasion by cancer is an indication for a segmental mandibulectomy.

  
  
• 4.
  

  Imaging with CT or MRI scan confirms deep infiltration of tongue muscles ( Fig. 28.2B ) and is more accurate than clinical examination alone in identifying cervical metastases. The presence of metastatic cancer on imaging clinically upstages the cancer and requires a comprehensive rather than a selective neck dissection.

  
  

  
  

  
  

  

  
  

  
  

  A, Deviation of the tongue should raise concerns about deep infiltration of the cancer into the muscles of the tongue. B, CT scan confirms extension to involve the deep muscles of the tongue.

  
  
  
  
• 5.
  

  Infiltrative cancers may be more extensive than appreciated on inspection alone. Intraoperatively, the use of palpation to define the clinical extent of the cancer is critical in achieving an adequate resection margin and preventing incising into the cancer and a positive margin.

  
  
• 6.
  

  Most T1 and many T2 cancers of the oral tongue may be left open to heal without specific reconstruction (see Fig. 28.1B ). Significant extension onto the ventral tongue and floor of the mouth suggests the need for reconstruction with a radial forearm fasciocutaneous flap or a split-thickness skin graft. For larger cancers requiring a hemiglossectomy or a subtotal glossectomy, microvascular soft tissue transfer is usually employed to enhance long-term function.

  
  
• 7.
  

  A close or positive margin is best managed if identified at the time of the initial surgery. Suspicion of a close or positive margin should prompt a complete, circumferential, peripheral, and deep margin assessment. Blue dye is used to ink the surgical defect on the patient side. An additional layer of soft tissue measuring 2 to 4 mm thick is excised and oriented, representing the new margin. A complete margin assessment will diminish the likelihood of a false negative margin and improve local control.

  
  
• 8.
  

  Careful ligation of the lingual artery at the posterior lateral glossectomy wound site may diminish the likelihood of a severe postoperative hemorrhage.

Preoperative Period