Malignant Tonsil Tumor Surgery Treatment & Management

Updated: Aug 06, 2018
  • Author: Niels Kokot, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Treatment

Medical Therapy

Non-surgical therapy of tonsil carcinoma consists of radiation therapy to the primary site and neck for early stage T1-2N0 tumors. For advanced stage tumors T3-4N+, non-surgical therapy consists of organ-preservation concurrent chemoradiation. This article focuses on surgical treatment, and therefore these therapies will not be discussed in detail.

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Preoperative Details

When evaluating a patient with tonsil carcinoma for surgery, one must determine the optimal surgical approach. For most early stage tumors and select late-stage tumors, a transoral approach may be appropriate. Transoral approaches include using a standard mouth gag and headlight as performing a standard tonsillectomy, transoral laser microsurgery (TLM), or a new technique, transoral robotic surgery (TORS). [9]

However, for most advanced stage tumors, the standard open approaches are typically appropriate. Open approaches may include a lip-splitting mandibulotomy or a lateral pharyngotomy to achieve access to the tumor. Typically in these open approaches, reconstruction with either a local, regional, or free tissue flap is needed to close the surgical defect. When deciding upon an approach, the surgeon must carefully assess the extent of the tumor, and when considering a transoral approach, the surgeon must determine if transoral access is possible.

Factors preventing transoral access include trismus, large teeth, small transverse mandibular dimensions, mandibular tori, large tongue, poor atlanto-occipital extension, and prior radiation that may obscure tissue planes or determination of resection margin. Furthermore, if the tumor has significant lateral extension, transoral resection may put the carotid artery at risk, making this approach unsafe.

In addition, if transoral resection may leave a positive margin (such as with skull base extension), then an open approach should be chosen. Finally, the experience of the surgeon must be considered. Transoral resection tonsil carcinoma approaches the anatomy from “inside-out” in a way that may not be familiar to many surgeons. This can make transoral surgery difficult and compromise the resection margin.

When the tumor has significant involvement of adjacent sites such as the soft palate, tongue base, or nasopharynx, a transoral resection may not be appropriate due to the need for reconstruction. When more than half the soft palate or tongue base is resected, these patients may benefit from reconstruction with a flap, and an open surgical approach may be more appropriate. Most of these factors can be accurately assessed prior to taking the patient to the operating room for definitive treatment. Physical examination in the office or during operative endoscopy can accurately map out the extent of the tumor. Careful examination of preoperative imaging can determine the proximity of the carotid artery to the tumor.

A retrospective study by Spellman et al indicated that in patients with palatine tonsil SCC, staging of the malignancy can determine candidates for primary TORS. The investigators found that in patients with early stage (T1/2) tonsillar SCC, definitive treatment with TORS in those who had pathologically confirmed N0/N1 necks without extracapsular extension resulted in clear margins in all patients. No significant intraoperative or postoperative complications occurred in these cases, and no recurrences of the cancer were found in mean and median 28-month follow-up. [10]

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Intraoperative Details

If the patient is deemed a candidate for transoral resection, the surgeon must then decide how to resect the tumor. Options include the using standard mouthgags and a headlight, TLM, or TORS. Holsinger et al described their approach to transoral lateral oropharyngectomy for removal of tonsil carcinomas using standard mouthgags and a headlight. [7] This approach involves incising the superior constrictor muscle at the pterygomandibular raphe, and then reflecting the constrictor muscle from lateral to medial. This approach takes the superior constrictor muscle as the lateral margin of resection.

Transoral laser microsurgery techniques have been described in detail by Steiner and Ambrosch. [11] The standard approach is to gain exposure via standard mouthgags or distending oropharyngoscopes. The operating microscope and a CO2 laser is then used to remove the tumor piecemeal. Using the enhanced visualization of the microscope and the differential cutting of the laser through normal tissue versus tumor allows the surgeon to follow the tumor and preserve the maximal amount of normal tissue. Because the tumor is removed piecemeal, it is imperative that the surgeon communicate effectively with the pathologist to ensure a true negative margin. [12]

Transoral Robotic Surgery is new technique pioneered by Weinstein et al. [9] TORS achieves exposure of the tumor using standard mouthgags. The robotic endoscope and operating instruments are then inserted into the mouth and used to resect the tumor in a modified fashion described by Holsinger et al. Advantages of TORS include enhanced 3-D visualization and use of wristed instruments and angled endoscopes that allow the surgeon to achieve access to the tumor that are otherwise difficult with the standard transoral approach or TLM. [11]

In all cases of transoral resection, the surgeon must be able to control bleeding from branches of the carotid arterial system. This is achieved either by electrocautery or through the use of surgical hemoclips. Typically, the surgical bed is left to heal by secondary intention. This makes protecting the carotid artery critical, to prevent erosion of the vessel wall by exposure to saliva.

In cases in which an open approach is needed, exposure of the tumor may be through a lip-splitting mandibulotomy, a lateral pharyngotomy, or a combination of transoral exposure and lateral pharyngotomy. This leaves the patient with an open communication between the neck and the pharynx, necessitating a reconstruction with a soft tissue flap. Common options for reconstruction include a pectoralis major myocutaneous flap, radial forearm fasciocutaneous free flap, or anterolateral thigh fasciocutaneous or myocutaneous free flap. Advantages of open approaches include direct access to the tumor while providing maximal control of the great vessels. However, patients are subjected to longer operative times, the need for reconstruction, and longer time for recovery of swallowing.

Treatment of tonsillar carcinoma requires management of the regional lymphatics. Selective neck dissection to include levels I-IV is the standard operation. In open approaches, neck dissection is performed with the resection of the primary tumor. In transoral approaches, neck dissection can be performed concomitantly, or it may be staged to avoid the risk of a salivary fistula. In addition, the retropharyngeal nodes may be at risk. These can be removed at the time of primary tumor resection.

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Postoperative Details

Patients undergoing surgery for tonsillar carcinoma must be monitored carefully in the postoperative period. Issues that are critical to consider include airway management, potential for bleeding, and diet. Airway management is dependent on the approach used and the extent of resection. When a transoral approach is utilized, patients may remain intubated following surgery, depending on the extent of resection, the potential risk for bleeding, or the preference of the surgeon. In most cases, patients undergoing transoral resection will not need a tracheostomy, as swelling is generally less than in open resections.

In the case of open resections, edema is usually significant, especially with flap reconstruction, and most patients will require a tracheostomy. The tracheostomy is temporary in most cases. Bleeding following resection of tonsillar carcinoma can be significant and life-threatening. Most cases of transoral resection allow the wound to heal by secondary intention. As a result, branches of the external carotid artery that have been ligated during surgery are at risk for bleeding. Bleeding can be brisk, and due to the proximity to the airway, aspiration of blood can be a significant problem. Rich et al reported a 3.6% bleeding rate in a large series of oropharyngeal carcinomas treated with TLM. [12]

Resumption of an oral diet is also an important consideration following surgical treatment of tonsillar carcinoma. Nearly all patients will have some level of dysphagia that can interfere with resumption of a normal diet. Transoral resections typically have less dysphagia, although many patients will require a temporary feeding tube. Timing of feeding tube removal can be dictated by a clinical examination, with or without a modified barium swallow. Long-term percutaneous gastrostomy (PEG) tube requirement is rare with transoral resections. Weinstein et al reported a 3.7% PEG tube rate in their initial study of TORS radical tonsillectomy. [9] This is similar to the rate (4%) reported by Moore et al in their study of transoral resection of tonsil carcinomas. [13]

Adjuvant treatment with radiation therapy or chemoradiation is frequently indicated following surgery, and is dictated by the final pathology. Indications for postoperative radiotherapy include perineural or lymphovascular invasion, multiple positive nodes, close margins, and T4 disease. Indications for postoperative chemoradiation include positive margins and extracapsular spread in the lymph nodes. [14]

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Follow-up

Routine follow-up care of patients with tonsil cancer is important, particularly because the risk of developing a second primary tumor is highest in this group. Patients with head and neck cancers have a 20% overall risk of developing a second primary tumor, while patients with tonsil cancer have as high as a 30% risk.

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Complications

Complications of the various forms of current therapy include the following:

  • Pain

  • Xerostomia

  • Infections

  • Poor wound healing

  • Dysphagia

  • Fistula formation

  • Trismus

  • Potential disfigurement

  • Fatigue

The family and patient should understand all of these in advance before committing to any therapy.

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Outcome and Prognosis

The prognosis as determined by 5-year survival rate of treated squamous cell carcinoma of the tonsillar region is as follows:

  • Stage I - 80%

  • Stage II - 70%

  • Stage III - 40%

  • Stage IV - 30%

The survival from tonsillar carcinoma has historically been considered poor, especially for late stage (III and IV) disease. However, more recent literature has shown promising results with surgical therapy for tonsillar carcinoma, even for advanced stage disease. A study by Rahmati et al of patients who had undergone a combination of surgery and postoperative radiotherapy for tonsillar SCC found the 5-year rates of overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) to be 66%, 82%, and 80%, respectively. The study involved 88 patients, 48% of whom had T3-T4 tumors and 75% of whom had neck lymph node metastases. The study results indicated that neck metastases were not predictive of survival, with DSS being 80% for patients without such metastases and 82% for those with metastases, but that lymphovascular invasion was predictive of OS, DSS, and RFS. [15]

Rich et al reported 2- and 5-year disease-specific survival rates of 96% and 92% for stage III and IV oropharyngeal carcinoma treated with transoral laser microsurgery (TLM) and adjuvant therapy. [12] Likewise, Moore et al reported 94% disease-specific survival in stage III and IV tonsillar carcinomas treated with transoral resection and adjuvant therapy. The results of these studies indicate that select patients, when treated appropriately, can have excellent survival outcomes despite historically poor outcomes.

The safety and feasibility of transoral robotic surgery (TORS) as a minimally invasive treatment alternative for malignancies of the head and neck was established by investigators at the University of Pennsylvania, University of Alabama-Birmingham, and the Mayo Clinic. This resulted in TORS being approved by the US Food and Drug Administration (FDA) in 2009 for transoral otolaryngology surgical procedures in adults restricted to benign and malignant tumors classified as T1 and T2. Advanced T-stage tumors were not approved since these studies only had a small number of advanced-stage tumors. While these initial studies reported their oncologic outcomes, the follow-up was short due to the relative infancy of the procedure. However, the oncologic data for TORS are beginning to mature and longer-term follow-up data are being reported.

The University of Pennsylvania reported the results of 47 consecutive patients with advanced-stage oropharyngeal squamous cell carcinoma (OPSCC) and a minimum of 18 months follow-up who were treated with primary TORS, staged neck dissection, and adjuvant radiation or chemoradiation as indicated. [16] Seventy-seven percent of patients had T1 and T2 tumors, while 51% of patients had N1 disease and 49% of patients had N2 disease.

Negative margins were achieved in 98% of patients. Five patients avoided radiotherapy altogether, while 13 patients received radiotherapy only, 2 received chemotherapy only, and 27 received concurrent chemoradiation. Local control and regional control were 98% and 96%, respectively. Actuarial 1- and 2-year overall survival was 96% and 82%, respectively. Actuarial disease-specific survival at 1 year and 2 years was 98% and 90%, respectively. Disease-free survival was 96% at 1 year and 79% at 2 years. When compared with similar organ-preservation chemoradiation trials, oncologic control was similar. [17, 18]

With the changing landscape of OPSCC and more tumors caused by human papillomavirus (HPV) infection, the same authors analyzed the oncologic outcomes of a cohort of TORS patients with respect to HPV status. [19] In 50 patients treated with TORS, staged neck dissection, and adjuvant radiation or chemoradiation as indicated, 37 patients (74%) had HPV-positive tumors and 13 patients (26%) had HPV-negative tumors. There was no statistical difference between the 2 groups with respect to the margin status, presence of cervical metastases, recurrence, or survival curves. Many HPV-induced tumors are presenting with smaller tumors at the primary site but with advanced-stage neck disease.

To determine the rates of regional recurrence in their patients, the authors examined 31 patients, all with negative-margin TORS who underwent selective neck dissection and adjuvant therapy, and they found only one regional recurrence. Examination of the pathological specimens in the neck showed that 33% and 43% of the clinical N0 and N1 patients, respectively, were pathologically upstaged, while 4 of the 14 clinical N1 patients had negative pathological necks. Pathological staging of the necks allowed the authors to selectively administer adjuvant therapy and to deintensify therapy in some cases. [20]

The University of Alabama-Birmingham (UAB) and the Mayo Clinic pooled their data to report their 2-year survival analysis in a cohort of 89 patients with carcinoma of the oral cavity, oropharynx, and supraglottic larynx. [21] Seventy-nine percent of patients were stage T1 and T2, and negative margins were achieved in all patients. Seventy-six percent of patients underwent staged or concomitant neck dissection. Of the patients who underwent TORS as primary treatment, 63% received adjuvant radiation therapy and 48% had chemotherapy either before or after surgical treatment. Two-year recurrence-free survival in patients who underwent TORS as primary treatment was 89.3%.

Genden et al reported 18-month survival data in 30 patients with head and neck squamous cell carcinoma, the majority of who had OPSCC. [22] All patients underwent TORS, concomitant neck dissection, and adjuvant therapy as indicated. Because all patients were pathologically staged, adjuvant therapy was deintensified in 4 patients, while it was escalated in 5 patients. Eighteen-month locoregional control, distant control, disease-free survival, and overall survival rates were 91%, 93%, 78%, and 90%, respectively. Comparison with a matched group of patients undergoing primary chemoradiation showed no statistically significant survival differences.

In addition to excellent oncologic outcomes, patients treated with TORS have shown excellent functional outcomes with longer follow-up. The University of Pennsylvania reported a 2.4% (one patient) gastrostomy tube dependency rate at a minimum of 1-year follow-up, while the rate of feeding tube dependency in the combined UAB and Mayo Clinic, as well as the Mt. Sinai study, was 0%. [16, 21] In addition to gastrostomy tube dependency rate, quality-of-life data are now available in patients undergoing TORS.

Leonhardt et al found that in 38 patients with OPSCC undergoing TORS, staged neck dissection, and adjuvant therapy, declines in the eating and diet domains on the Performance Status Scale that were seen at 6 months returned to baseline at 12 months. [23] Declines in the speech domain remained significantly decreased at 6 and 12 months. Patients receiving adjuvant chemoradiation had significantly lower diet domain scores at 6 and 12 months compared with those who underwent surgery only.

Hurtuketal et al used the Head and Neck Cancer Inventory to show that speech, aesthetics, attitude, and overall quality of life remained in the high domain at 12 months, while the eating domain dropped to the intermediate level at 12 months in 18 of 64 patients who underwent TORS and adjuvant therapy for head and neck squamous cell carcinoma at all sites. [24]

Genden et al compared TORS patients with a similar cohort of patients treated with primary chemoradiation and found that all TORS patients returned to baseline in the eating, speech, and diet domains on the Performance Status Scale for Head and Neck, as well as the Functional Oral Intake Score. In contrast, patients treated with chemoradiation had a lower-than-baseline diet score and lower Functional Oral Intake Score. [22]

Since its inception, TORS has proven to be a safe and efficacious, minimally invasive means of achieving an en bloc resection of head and neck malignancies. Functional outcomes have been excellent, and as the data mature, the oncologic outcomes appear to be equivalent to those with achieved with standard open surgery or organ-preservation chemoradiation protocols. By surgically staging patients with TORS and neck dissection, adjuvant therapy can be tailored to the individual patient and can be deintensified in some cases of low-risk disease. TORS offers the potential to maximize oncologic control while maximizing functional outcomes. This approach is in stark contrast to chemoradiation protocols in which all patients receive identical therapy. More studies are necessary to validate long-term outcomes.

It is becoming apparent that survival for tonsil cancer correlates with HPV status. There has been recent evidence from both the surgical and nonsurgical literature that patients with HPV-positive tumors have improved survival. [25] Several retrospective case series have shown that patients with HPV-positive oropharyngeal tumors have a better prognosis than patients with HPV-negative tumors. [26] Similar findings were reported in a prospective analysis of data from a small clinical trial. [27]

More recently, Ang et al analyzed the HPV status in a large number of patients randomized to receive either standard fractionated chemoradiation or accelerated fractionation chemoradiation for stage III-IV OPSCC. [28] Patients with HPV-positive tumors had improved 3-year overall survival (82.4% vs 57.1%, P< .001) and 58% risk-of-death reduction compared with patients with HPV-negative tumors.

Furthermore, these authors found that patients could be risk stratified according to HPV status and smoking history. Low-risk patients had HPV-positive tumors and less than 10 pack years smoking history or had HPV-positive tumors, more than 10 pack years smoking history, but had N0-N2a neck disease. Intermediate-risk patients had HPV-positive tumors with more than 10 pack years smoking history and advanced neck disease or they had HPV-negative tumors with less than 10 pack years smoking history and T2-T3 tumors. The high-risk group had HPV-negative tumors with less than 10 pack years smoking history and T4 tumors or they had HPV-negative tumors and more than 10 pack years smoking history. Three-year overall survival in the low-, intermediate-, and high-risk groups was 93%, 70.8%, and 46.2%, respectively.

In the surgical literature, HPV tumor status is proving to affect prognosis as well. Rich et al reported improved overall survival (HR = 0.04) and disease-specific survival (HR = 0.10) in patients with p16-positive tumors compared with p16-negative tumors. [12] While p16 serves as a biomarker for HPV positivity, the authors did not, however, find that HPV positivity affected survival. This may be related to discrepancies between the different detection techniques.

Results of the above studies, and others, indicate that HPV-positive tumors have improved outcomes compared with HPV-negative tumors. Knowledge of the HPV status of the tumor is important for prognosis and risk stratification of patients and should be included in the pathologic analysis of tumor specimens.

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Future and Controversies

The largest controversy regarding the treatment of tonsillar carcinoma surrounds whether this cancer should be treated primarily with surgery or with organ-preservation chemoradiation. Each treatment is not without its own risks, and the decision regarding treatment should be made in conjunction with the recommendations of the multidisciplinary team and the preferences of the patient.

Recent surgical literature has been extremely promising in the treatment of tonsillar carcinoma. Minimally invasive techniques such as transoral robotic surgery and transoral laser microsurgery offer patients an excellent option for treatment both from a functional and an oncologic standpoint.

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