Key points

Introduction

The incidence of larynx cancer in the United States for the year 2014 was estimated to be 12,630 cases, accounting for 3610 deaths, with a male/female ratio of 4:1. Despite improvements in diagnostic and therapeutic techniques, the overall survival rate has not improved substantially during the past 25 years.

Introduction

The incidence of larynx cancer in the United States for the year 2014 was estimated to be 12,630 cases, accounting for 3610 deaths, with a male/female ratio of 4:1. Despite improvements in diagnostic and therapeutic techniques, the overall survival rate has not improved substantially during the past 25 years.

What is conservation laryngeal surgery?

CLS encompasses open surgical techniques such as laryngofissure with cordectomy and SCPLs; it also includes transoral endoscopic head and neck surgical techniques. The cornerstone of CLS rests on these fundamental principles that optimize both oncologic and functional outcomes. The surgeon should consider CLS when the proposed surgery should have a high probability of achieving local control in the larynx and preserve at least 1 cricoarytenoid unit, which serves as the basic functional unit of the larynx. The cricoarytenoid unit includes 1 functioning arytenoid, an intact cricoid cartilage, associated laryngeal musculature, and corresponding innervation by the superior and recurrent laryngeal nerves. The conservation laryngeal surgeon must have carefully examined the extent of the patient’s tumor to provide the patient with a high probability of completing the resection without requiring total laryngectomy. The conservation laryngeal surgeon must also understand that the resection of normal tissue may be necessary to achieve consistent functional outcomes. Finally, the patient and surgeon must understand and accept that a successful functional outcome after CLS following RT may take much longer to achieve than after primary CLS.

Laryngofissure with cordectomy is best suited for small, mid–vocal fold lesions not reaching the anterior commissure or the vocal process with no impairment of vocal fold mobility in patients in whom endoscopic exposure is inadequate. This approach involves splitting of the thyroid cartilage to gain access to the endolarynx and excise the affected vocal fold. Although this procedure was previously characterized by the need for a perioperative tracheotomy, Muscatello and colleagues reported a series of 33 cases in which no tracheotomies were needed. In this cohort, the local control rate was 100%, the 5-year survival rate was 97%, and the laryngeal preservation rate was 100%. Danilidis and colleagues observed similar results in a cohort of 94 patients with a 5-year survival rate of 93% but acknowledged that the survival rates were significantly poorer in patients who were treated with a laryngofissure and cordectomy for local recurrence after RT. Only 2 of the 5 patients treated with a salvage procedure survived for more than 5 years; the remainder died from another recurrence.

Vertical partial laryngectomy (VPL) or vertical hemilaryngectomy entails extending a laryngofissure with cordectomy to include resection of the corresponding thyroid ala with the affected vocal fold, sparing the ipsilateral arytenoid and, if needed, the anterior commissure or the anterior one-third of the contralateral vocal fold. For T1 lesions treated with VPL, local control rates are 89% to 100%. Involvement of the anterior commissure decreases local control; one study reported that anterior commissure involvement decreased local control from 93% to 75%. The same study found that local recurrence decreased the 10-year survival rate from 63% to 31%. T2 tumors treated with VPL have local control rates of 74% to 86%. One meta-analysis review found better rates of local control in select patients without impairment of vocal fold immobility or significant extension to the subglottis or supraglottis. VPL as salvage surgery for early-stage glottic cancers that recur after RT has been shown to have rates of local control ranging from 55% to 100%, without significantly different functional outcomes from those who had VPL as the primary surgery. Laccourreye and colleagues observed a 78.1% laryngeal preservation rate for VPL in the salvage setting, strictly in patients in whom the tumor has not enlarged. In a study comparing 21 patients who had prior RT with 41 previously untreated patients, Lydiatt and colleagues determined that there was no significant difference in 5-year survival (79% vs 95%, P = NS), although survival was clearly better when CLS was performed in previously untreated patients. Moreover, functional outcomes, such as time to tracheotomy decannulation and swallowing function at the time of discharge, were not significantly different between the irradiated group and the previously untreated group.

In a supraglottic laryngectomy (SGL), or horizontal partial laryngectomy, the larynx is resected between the pre-epiglottic space and the ventricles, with preservation of both true vocal folds, both arytenoids, and the hyoid bone. Extended procedures may include resection of the tongue base, arytenoids, aryepiglottic fold, or superior medial pyriform wall. Contraindications to SGL are involvement of the glottis, thyroid or cricoid cartilage invasion, tongue base involvement within 1 cm of the circumvallate papillae, major pre-epiglottic space invasion, and deep musculature involvement in the tongue base. Local control rates after SGL are 92% to 100% for T1 lesions and 85% to 100% for T2 tumors. DeSanto and colleagues underscored that, although 80% (24 of 30) of patients with supraglottic carcinoma who underwent RT and failed would have been theoretically amenable to SGL before RT, only 30% (9 of 30) underwent CLS for failure after RT. Sørensen and colleagues noted poor oncologic and functional results after SGL for RT failure and advocated total laryngectomy in these patients. Yiotakis and colleagues examined 9 patients who had SGL after RT failure and found that 4 of the 9 had recurrent disease within 2 years and the overall survival rate was 67%.

SCPLs involve the resection of both true and false vocal folds, the thyroid cartilage, both paraglottic spaces, and 1 partial or full arytenoid. The epiglottis and pre-epiglottic space may or may not be included according to the tumor origin and extent. This procedure is reconstructed with either a cricohyoidoepiglottopexy in glottis cancer or a cricohyoidopexy in supraglottic and transglottic ones. SCPLs are used for T1b and T2 carcinomas and selected T3 cancer (pre-epiglottic space invasion, thyroid cartilage, and true vocal cord fixation). Contraindications to SCPL include arytenoid cartilage fixation, invasion of the cricoid or posterior commissure, subglottic extension to level of the cricoid, and extension to or beyond the outer perichondrium of the thyroid cartilage. For T1 and T2 lesions, the 5-year actuarial estimate of local control is as high as 98% ; another study reported rates of 96% and 91% for T1 and T2 tumors, respectively. Overall, local control rates range from 87% to 98%, and overall 5-year actuarial estimates of survival range from 73% to 79%, with disease-specific survival estimated at 94%. The mortality rate for SCPL is low (1%–2%), with a 9.6% to 11% postoperative morbidity rate. Laccourreye and colleagues evaluated the role of SCPLs as a salvage technique after failed laryngeal RT in 12 cases and determined a 3-year actuarial survival and local control rate of 83%. The time to tracheotomy decannulation was twice as long in these patients (average of 15 days) than in cases of SCPLs in patients who have not received RT, likely due to significant postoperative edema in the arytenoid cartilages and the delayed healing present in irradiated tissues. A more recent multi-institutional study by Pellini and colleagues of 78 patients who received SCPLs in the salvage setting observed 3- and 5-year disease-free survival rates of 96% and 3- and 5-year overall survival rates of 85% and 82%, respectively. Within 1 year, most cases were able to be decannulated and achieve adequate swallowing (97%). Laryngeal preservation rates for SCPL in the salvage setting have been shown to be around 90%.

TLM is well established in the primary management of early-stage larynx cancer. The 5-year disease-free survival rate in early-stage glottic cancer treated primarily by TLM is 81% to 93%. However, the usage of TLM for recurrent larynx cancer often requires repeat surgery. In patients with recurrent disease after RT, Steiner and colleagues reported that only 38% achieved local control after the first TLM and 6% of patients required 4 procedures. A meta-analysis reported that the pooled outcome for local control in radio recurrent disease with the first TLM is 56.9% and 63.8% with repeat TLM. The pooled laryngeal preservation rate was 72.3%. Even when repeat TLM is taken into account, the oncologic outcomes of TLM for recurrent laryngeal cancer are inferior to those of open CLS techniques. The postoperative complication rate and recovery rate are less in TLM compared with open CLS techniques. Steiner and colleagues observed that 9% had glottic synechia and 3% had laryngeal stenosis after repeated TLM procedures. The average hospital stay was 9 days.

Strategy of conservation laryngeal surgery after radiation therapy failure: when, for which tumors, and why?

Local failure rates for RT for early-stage larynx cancer have been estimated to be 5% to 10% for T1 lesions and 20% to 40% for T2 lesions. RT failures in limited disease are often caused by errors in initial staging based on clinical criteria; hence, it is important to perform careful staging after a thorough endoscopic examination aided by computed tomographic (CT) findings. It is important to understand the pattern and spread of recurrent early larynx cancer to select patients who would be best suited for salvage CLS. Although most primary larynx cancers demonstrate concentric tumor growth (77%), only a fifth of recurrent cancers presented in that manner (19%). Recurrent larynx cancer more commonly presents with multifocal tumor nests (86%), dissociated tumor cells (76%), and perineural spread (81%). Viani and colleagues observed that in patients with T1–3N0 glottic cancer, more than 80% of the recurrent tumors were pT3–4. De Vincentiis and colleagues reviewed 68 patients with recurrent larynx cancer who underwent salvage by either total laryngectomy or SCPL and determined that the method of salvage was not associated with overall survival but positive margins were independently associated with decreased survival (hazard ratio, 11.3; P = .02). Toma and colleagues observed that patients with margins less than 1 mm had significantly higher recurrence rates after salvage CLS than those with margins of 1 mm or more.

Radiation treatment induces inflammatory and fibrotic changes in tissue that makes the clinical assessment of the extent of recurrent disease more difficult because of posttherapeutic edema, erythema, and changes in laryngeal mobilities. Consequently, the clinical assessment of recurrence by endoscopic examination and imaging has a diagnostic accuracy of 38%, with 10% of the tumors overstaged and 52% understaged. Diagnosis of recurrent disease is based on clinical suspicion, follow-up CT findings, and direct endoscopy with biopsy, although caution should be maintained when taking a biopsy from a post-RT larynx because of the risk of chondritis. All this often leads to late discovery of the recurrence, leaving many patients who are eligible for surgical salvage needing to undergo total laryngectomy.

Som was the first to publish results on CLS as salvage therapy after RT in 1951. More recently, Ganly and colleagues noted that local control rates for salvage total laryngectomy were 65% to 85% for T1 and T2 glottic tumors, whereas local control rates for salvage CLS range from 66% to 96%. Although CLS can be an effective salvage therapy, most patients with recurrent or persistent disease after RT end up with a total laryngectomy because they often present with advanced disease. Because recurrent tumors can be unpredictable and have adverse features, patients should be informed about the possible need for a total laryngectomy during preoperative planning for CLS. In 1990, Shah and colleagues recommended excluding patients from CLS if recurrent disease extends beyond the original site. One year later, Lavey and Calcaterra stated, after a review of the literature, that vertical hemilaryngectomy should be contraindicated in the RT failure case if the tumor involved the arytenoids, there was more than 10 mm of subglottic extension anteriorly and 5 mm posteriorly, and cartilage invasion into the thyroid or the cricoid was demonstrated to be present. For supraglottic cancer, Shaw stated that SGL is contraindicated in the post-RT failure setting unless the primary tumor was small, the recurrence was located anteriorly, and the carcinoma never involved the anterior commissure. However, these indications were made at a time when quality CT laryngeal scan evaluation was not widely diffused and only VPL and SGPL were the CLS techniques available because neither TLM nor SCPL was widely known and used. Institutional studies have demonstrated that 32% to 52% of patients with early-stage recurrent cancer after RT are candidates for salvage with CLS.

Even in the N0 recurrent laryngeal cancer, prophylactic neck dissection should be considered, although this procedure should be considered individually across the laryngeal subsites. A retrospective review reported a 0% incidence of occult cervical metastases with T1 and T2 glottic cancer. Deganello and colleagues examined 26 patients with N0 cancer with recurrent disease after RT managed with SCPLs and determined a 19% rate of occult neck metastasis. All of the patients with occult neck metastases had clinically T1 disease that was upstaged to T2–3, and the investigators suggested the use of ipsilateral elective neck dissections in these select patients. Supraglottic cancers present with a higher incidence of cervical metastasis; up to 30% of patients with N0 cancer have occult lymph node metastases. It is therefore recommended that the levels II–IV of the neck be addressed bilaterally for all supraglottic tumors, either surgically or with radiotherapy, whereas treatment of the neck may not be indicated for early recurrent glottic cancer with N0 disease. Yao and colleagues observed a 20% rate of occult metastases in patients with T3–T4 recurrent glottic cancer and in patients with supraglottic cancer and recommended bilateral elective neck dissections in these cohorts.