Introduction
There were 584 new laryngeal cancers and 247 laryngeal cancer deaths in Australia in 2001.1 Early laryngeal squamous cell carcinoma (SCC) may be treated with surgery, open laryngeal conservation surgery or transoral laser microsurgery or definitive radiotherapy. A review of over 17 000 laryngeal cancers treated in the United States between 1986 and 1992 showed that most (54 per cent) stage I glottic cancers received initial definitive treatment with radiotherapy. The five-year relative survival rate was comparable between radiotherapy (73 per cent) and surgery (81 per cent). The five-year survival rate for stage II glottic cancer treated initially with surgery alone was 57 per cent where radiation had a five-year survival of 69 per cent (and 70 per cent for the combination). However, the lower surgical survival rate may reflect a selection bias as cancers staged T2 on the basis of impaired fold mobility are treated preferentially with surgery in many centres and have a poorer prognosis.Reference Hoffman, Karnell, Steele, Jessup, Winchester, Menck and Murphy2 A recent meta-analysis concluded that ‘there is no good evidence available from randomised controlled trials to guide treatment choice for patients with early stage glottic cancer’.Reference Dey, Arnold, Wight, MacKenzie, Kelly and Wilson3
Strong and Jako first described use of the CO2 laser to endoscopically resect laryngeal cancers.Reference Strong and Jako4 Strong showed that in up to 20 per cent of cases, no residual SCC remained after the initial diagnostic biopsy often making radiotherapy unnecessary. Steiner showed six local recurrences and only one laryngectomy in 159 patients followed for at least five years using transoral laser microsurgery techniques.Reference Steiner5 Since then, transoral laser microsurgery has been widely adopted as an alternative to definitive radiotherapy in the treatment of early laryngeal cancer.Reference Shah, Karnell, Hoffman, Ariyan, Brown and Fee6
If local control and survival are comparable the choice between surgery and radiotherapy for early laryngeal cancer is determined by patient preference after discussion of risks, benefits and likely functional outcomes. Steiner showed that most transoral laser microsurgery cases could be done as day cases with modest pain for a few days. Patients must be warned that approximately one-third of patients require a second procedure, often to biopsy suspicious granulation tissue. Most radiation protocols take six weeks, cause painful mucositis lasting a further two to four weeks and carry the small but real risk of causing a radiation induced tumour (estimated at 1/300).Reference Parson, Greene, Speer, Kirkpatrick, Barhorst and Yanckowitz7
Materials and methods
Transoral laser microsurgery became a treatment option at St Vincent's Hospital in 1997. All patients with early (T1/T2) glottic cancer electing to undergo transoral laser microsurgery between July 1997 and December 2004 had their patient demographics and tumour maps recorded. Patients who had a second primary tumour or who had received previous treatment (other than a biopsy) were excluded.
Details of the surgery were prospectively recorded as cordectomy (level I–IV according to depth of invasion), vertical hemilaryngectomy or extended hemilaryngectomy as defined by the European Laryngological Society.Reference Remacle, Eckel, Antonelli, Brasnu, Chevalier and Friedrich8
All patients who elected to receive transoral laser microsurgery had a voice recording taken pre-operatively and 12 weeks post-operatively. The voice recordings were independently analysed by two independent speech therapists against the Oates Russell Voice Profile.Reference Oates and Russell9 This gives a grade of 0 (normal) to 5 (severe dysphonia).
Patients were reviewed six weekly for the first six months then three monthly for two years then four to six monthly until five years. All patients were followed for a minimum of two years.
Results and analysis
There were 53 patients who underwent transoral laser microsurgery for early glottic SCC from July 1997 to December 2004. Thirty-six (67.9 per cent) patients were male and 17 (32.1 per cent) were female. The mean age of patients was 56 years (range 37 to 83 years). The mean follow up was 47 months (range 24 to 111 months) excluding two patients who died before 24 months follow up (at nine and 13 months after treatment).
Nineteen patients were staged T1 and underwent cordectomy (six cordectomy level II, six cordectomy level III and seven patients cordectomy level IV). Fifteen (78.9 per cent) patients staged T1 underwent a single procedure, three (15.8 per cent) a second procedure to biopsy granulations and one (5.3 per cent) a third procedure after the second biopsy showed SCC in situ. No patients required a laryngectomy for salvage for T1 cancer. Two patients (10.6 per cent) staged T1 died in the follow-up time, one of a second primary lung cancer at 45 months following his surgery and the other of acute myocardial infarction at 25 months following his surgery.
The mean Oates Russell Voice Profile following cordectomy was 2.37 (range 1 to 4) indicating a mild (Reference Hoffman, Karnell, Steele, Jessup, Winchester, Menck and Murphy2) to moderate (Reference Dey, Arnold, Wight, MacKenzie, Kelly and Wilson3) degree of voice impairment. A typical scoring chart for a patient scoring 2 can be seen in Figure 1. The Oates Russell Voice Profiles for different cordectomies (depth of resection) can be seen in Figure 2.
Fig. 1 Typical Oates Russell Voice Profile scoring 2.
Fig. 2 Oates Russell Voice Profile for T1 cancers treated by transoral laser microsurgery cordectomy (level II-IV).
Thirty-four patients were staged T2. Twenty (58.8 per cent) patients underwent a single transoral laser microsurgery procedure, eight (23.5 per cent) two transoral laser microsurgery procedures, three (8.8 per cent) required three transoral laser microsurgery operations and three (8.8 per cent) required salvage laryngectomy following local recurrence at six, nine and eleven months post initial transoral laser microsurgery. Five patients (14.7 per cent) died during the follow-up period. One patient developed unresectable neck recurrence and died nine months post treatment, one patient died with lung metastases after 31 months. Three patients (8.8 per cent) died of unrelated causes at 13, 28 and 41 months following treatment.
Twenty-one (61.8 per cent) T2 staged patients underwent initial transoral laser microsurgery hemilaryngectomy and their Oates Russell Voice Profiles are seen in Figure 3. The mean score for transoral laser microsurgery hemilaryngectomy was 2.75 (range 1 to 4) indicating a moderate (Reference Dey, Arnold, Wight, MacKenzie, Kelly and Wilson3) impairment. One patient (voice outcome not included in chart) undergoing initial hemilaryngectomy required a total laryngectomy for local recurrence and uses a Blom–Singer prosthesis for voicing.
Fig. 3 Oates Russell Voice Profiles for patients undergoing transoral laser microsurgery hemilaryngectomy.
Thirteen (38.2 per cent) T2 staged patients underwent initial transoral laser microsurgery extended hemilaryngectomy including resection of the anterior commissure and contralateral vocal cord. The Oates Russell Voice Profiles are seen in Figure 4. The mean score for transoral laser microsurgery extended hemilaryngectomy was 2.56 (range 1 to 4) indicating mild (Reference Hoffman, Karnell, Steele, Jessup, Winchester, Menck and Murphy2) to moderate (Reference Dey, Arnold, Wight, MacKenzie, Kelly and Wilson3) impairment. Two patients (not included in chart) required total laryngectomy for salvage following local recurrence and both use oesophageal speech.
Fig. 4 Oates Russell Voice Profile for transoral laser microsurgery extended hemilaryngectomy.
Discussion
Survival outcomes following transoral laser microsurgery or primary radiotherapy for early glottic cancer are comparable. The absolute survival in this series was excellent: T1 89.4 per cent and T2 85.3 per cent after a mean follow up of 47 months. Consequently, voice outcomes and laryngeal preservation are central issues that must be discussed in guiding the treatment choice of patients with early glottic cancer.
This series demonstrates that voice impairment is usually mild to moderate following transoral laser microsurgery for early glottic cancer. Voice impairment is similar for T1 or T2 cancers although more extensive resections (deeper cordectomy or hemilaryngectomy) will tend to cause more impairment. The most impaired patients in this series have a moderate to severe impairment with no patients being aphonic.
Cragle and Brandenburg reported that surgical treatment of early glottic cancers may produce a vocal result that is equivalent to that following irradiation.Reference Cragle and Brandenburg10 They showed similar voice profiles characterised by decreased maximum phonation times and increased jitter, shimmer, and signal-to-noise ratios in 11 patients treated with transoral laser microsurgery and 20 patients treated with irradiation. Most investigators, however, contend that a better voice more reliably follows treatment with radiotherapy rather than transoral laser microsurgery.Reference Casiano, Cooper, Lundy and Chandler11–Reference Rydell, Schalen, Fex and Elner14 Unlike surgery, radiotherapy does not require removal of adjacent healthy tissue to provide a clear margin around a cancer. However, vocal deterioration may result from radiotherapy and may be significant if loss of vocal fold bulk results from tumour necrosis or if fibrosis develops.
This series demonstrates mild or moderate voice impairment and a high degree of laryngeal preservation. Schuller and others used interviews and questionnaires to evaluate 75 patients treated with transoral laser microsurgery for early laryngeal cancers. They found that 88 per cent of the respondents were content with the post-operative voice.Reference Schuller, Trudeau, Bistline and LaFace15 The absolute quality of their voice may not be as important a consideration for many patients in selecting treatment as is their general ability to communicate and satisfaction with the treatment modality.
This series shows that total laryngectomy is rarely required for T1 glottic cancers (0 per cent) and unusual in T2 cancers (8.8 per cent). Ton-Van et al. evaluated 356 patients with early glottic cancer and determined that the quality of voice after treatment with radiotherapy is ‘indisputably superior to that after conservation surgery’.Reference Ton-Van, Stern, Buisset, Coche-Dequeant and Vankemmel16 However, these investigators pointed out that a functional larynx was preserved in 92 per cent of patients treated surgically compared with 81 per cent initially treated with radiotherapy. As a result, Ton-Van et al. advocate the use of surgery as a primary mode of therapy in patients who can tolerate general anaesthesia. Exceptions include patients who are willing to accept a greater risk of total loss of the larynx in the effort to preserve the highest quality voice.
One of the key differences between transoral laser microsurgery and radiation is the ability to repeat transoral laser microsurgery in the event of local failure whereas radiation failures are most commonly treated with total laryngectomy.Reference Howell-Burke, Peters, Goepfert and Oswald17 In this series 21.1 per cent of T1 tumours and 41.2 per cent of T2 tumours underwent a second procedure (to biopsy granulations, treat local recurrence or salvage with laryngectomy). Consequently final laryngeal conservation is probably higher for T2 tumours using transoral laser microsurgery.Reference DeSanto18 Morris et al. carried out an intensive literature review and identified an overall 8.6 per cent failure rate at the primary site for T1 glottic cancers managed surgically compared with a 16.7 per cent failure rate among similarly staged cancers managed with radiotherapy.Reference Morris, Canonico and Blank19
• Radiation has been the gold standard treatment of early glottic cancer
• Pioneers such as Steiner have shown transoral laser microsurgery to be a viable alternative for early glottic cancer
• Debate has surrounded the reproducibility of such results and functional outcomes following transoral laser microsurgery compared with radiotherapy
• This series shows excellent functional and survival outcomes following the first 10 years of transoral laser microsurgery in an Australian centre
• Due to repeatability, the need for salvage laryngectomy may be reduced with transoral laser microsurgery compared with radiotherapy
One of the advocates for radiation, Jorgensen and others, described 1005 Danish patients treated at a single referral centre between 1965 and 1998.Reference Jorgensen, Godballe and Hansen20 All early glottic cancers (99 per cent) within a catchment area of 1.33 million people received primary radiotherapy and follow up was excellent (only three patients were lost to follow up). Three hundred and twenty-one T1 glottic cancers were treated with irradiation with a five-year local control of 88 per cent and 233 T2 glottic cancers were treated with irradiation with a five-year local control of 67.4 per cent. These investigators identify that this high recurrence rate (one out of three) for T2 glottic cancers resulted in an overall laryngeal preservation of 80 per cent. This is substantially lower than the 95 per cent organ preservation reported by Chevalier's group using organ preservation surgeryReference Chevalier, Laccourreye, Brasnu, Laccourreye and Piquet21 and the 91.2 per cent in this series.
Jorgensen and others argued that part of the excellent results reported by Chevalier and others reflected a selection bias. Jorgensen and others additionally pointed out that the voice quality is better after irradiation than after supracricoid laryngectomy. For these reasons, they have not altered their standard approach to managing T2 glottic cancers with irradiation. Jorgensen observed that improved radiotherapy techniques, as well as the capacity to salvage irradiation failures with supracricoid laryngectomyReference Shah, Loree and Kowalski22 will likely decrease the ultimate need for total laryngectomy. Undoubtedly the salvage rate of transoral laser microsurgery for local recurrences is highReference Eckel23 as is confirmed in this series. More recently, Steiner has shown that radiotherapy failures may also be salvaged by transoral laser microsurgery in many cases.Reference Steiner, Vogt, Ambrosch and Kron24
In conclusion, patients choosing transoral laser microsurgery for early glottic cancer have satisfactory voice outcomes. Although voice outcomes are probably better following radiation, very few patients require total laryngectomy despite local recurrences compared with radiotherapy, resulting in overall good functional outcomes. These issues are central to the choice of treatment for early glottic cancer.
