Partial laryngectomy has developed as one of the main surgical treatments for T3 hilar laryngeal cancer. According to the UICC (2002) definition of TNM staging of laryngeal cancer, T3 glottic laryngeal cancer is defined as a tumor originating in the glottis region, confined to the larynx, with vocal cord fixation and/or invasion of the paravocal fold, and/or accompanied by localized destruction of the thyroid cartilage. Depending on the specific situation of laryngeal cancer patients and the different local infiltration extent of T3 vocal fold laryngeal cancer, as well as the indications for different surgical procedures for laryngeal cancer, stage T3 vocal fold laryngeal cancer can be treated with either total laryngectomy or different partial laryngectomy.
Surgery alone and radiotherapy are both effective treatments for laryngeal cancer, and surgery plus radiotherapy is the main mode of treatment for advanced laryngeal cancer at present. In this paper, we only analyzed the clinical data of 57 patients with stage T3 acoustic laryngeal cancer who underwent surgery alone, in order to explore the ideal surgical approach for stage T3 acoustic laryngeal cancer.
Data and Methods
I. General information
In this paper, we collected data of 57 patients with T3 stage vocal hilar laryngeal carcinoma who were treated by surgery alone between 1997.1 and 2006.6 in our hospital. N17 cases, N23 cases; 54 males, 3 females, age 36 – 85 years, mean 60.6 ± 10.3 years, 10 cases greater than or equal to 70 years, 47 cases less than 70 years. Due to the complications of radiotherapy and the economic status of the patients, radiotherapy was not performed in all of these patients.
General principles of surgical modality selection
For T3 laryngeal carcinoma with local involvement of ipsilateral vocal cord, anterior commissure, and/or invasion of contralateral vocal cord, supra-cricoid laryngeal partial excision is preferred; for local involvement of ipsilateral vocal cord and para-acoustic space, enlarged vertical partial excision or supra-cricoid laryngeal partial excision is considered first; for local involvement of ipsilateral vocal cord, posterior commissure, and/or invasion of interarytenoid space, supra-cricoid laryngeal partial excision is preferred;
and/or invasion of the cricoarytenoid joint preserving the contralateral cricoarytenoid joint cannot guarantee the safe first cutting edge, and the invasion of the subglottis is more than 1.0 cm, consider choosing total laryngectomy; the local infiltration of laryngeal cancer is already an indication for total laryngectomy, but the residual normal mucosa in the laryngeal cavity can still be sutured into an articulatory tube of about 0.5 cm in diameter, so you can choose to perform near-total laryngectomy. In addition, those who are older than 70 years old and have poor lung function are considered to choose total laryngectomy. Before surgery, the specific surgical approach is decided by combining the patient’s local lesion and systemic condition.
III. Follow-up and statistical analysis
All of the data in this group were followed up for more than 3 years, and 7 cases were lost. Survival analysis was performed using the 3-year tumor-free survival rate, and postoperative follow-up cases with tumor recurrence and lost cases were calculated by death. Data were analyzed by statistical software SPSS 16.0, and the 3-year tumor-free survival rate of patients was analyzed by Kaplan-Meier method with chi-square test.
Results
The 3-year tumor-free survival rate of our data was 63.2% (see Table 1). 57 patients with T3 hilar laryngeal cancer were all treated surgically, and the survival curves of different procedures are shown in Figure 1. the 3-year tumor-free survival rate of total laryngectomy was 66.7% (16/24), the survival rate of near-total laryngectomy was 50% (4/8), and the survival rate of partial laryngectomy was 64.0% (16/25), and the statistical test P>0.05, and there was no significant difference in the survival rate between the different procedures. The 3-year tumor-free survival rates were 60% (12/20) and 80% (4/5) for partial laryngectomy with enlarged vertical partial laryngectomy and supracondylaryngeal cricoid cartilage resection, respectively.
Partial laryngectomy preserved the laryngeal function of the patients and significantly improved the quality of their survival. Three cases of pharyngeal fistula occurred after total laryngectomy, which healed in 10-40 days with drug replacement; one case of articulation failure after near-total laryngectomy; one case of laryngeal stenosis after partial laryngectomy, which was treated with tracheostomy.
In our data, there were 10 patients ≥70 years old, 7 cases of total laryngectomy and 3 cases of partial laryngectomy. The total laryngectomy patients included one 74-year-old patient who was given a total laryngectomy 4 months after partial laryngectomy because he could not overcome choking. There were 47 patients <70 years old, 17 cases of total laryngectomy, 8 cases of near-total laryngectomy and 22 cases of partial laryngectomy, and the survival rates are shown in the table and the survival curves are shown in Figure 2. There were 7 lost cases in this group, and the lost rate was 12.3%. This had an impact on the statistics of survival rate.
Among the 57 patients in this group, 36 cases had cervical lymph node dissection, including 2 cases of total cervical lymph node dissection, 6 cases of modified cervical lymph node dissection, 28 cases of zoned cervical lymph node dissection, 9 cases of positive postoperative pathological lymph nodes, 1 new case of recurrence of cervical lymph node metastasis was found in the postoperative follow-up, and the distribution of metastatic lymph nodes was 7 times in zone II, 5 times in zone III, and 2 times in zone IV, with the rate of cervical lymph node metastasis of 17.5%; ≥ 70 years of age group and <70 years of age group, the rate of cervical lymph node metastasis was 10% (1/10) and 19.1% (9/47), respectively.
Discussion
The main features of T3 glottic laryngeal cancer are tumor originated in the vocal cord, confined to the larynx, and fixed in the vocal cord. With the development of laryngeal function preserving surgery, partial laryngectomy for T3 laryngeal carcinoma has been gradually recognized and accepted. In fact, the definition of T3 laryngeal carcinoma by UICC is not unchanging.
The UICC (1997) defines the TNM stage of laryngeal cancer: T3 laryngeal cancer is defined as a tumor originating in the vocal fold area, confined to the larynx, with fixed vocal folds, while the UICC (2002) defines a tumor originating in the vocal fold area, confined to the larynx, with fixed vocal folds and/or invasion of the paravocal fold, and/or with local destruction of the thyroid cartilage. The latter is more specific about the extent of tumor involvement, so that a more reasonable surgical approach can be targeted according to the different extent of tumor invasion and the indications for different surgical approaches.
Unlike transglottic carcinoma, due to the barrier effect of the laryngeal tissue structure, the lesion of glottic carcinoma is limited to the glottic region within a certain period of time, which is the anatomical basis for partial laryngectomy for some T3 glottic carcinomas.
The cricoarytenoid joint is the hub of laryngeal function. The bottom line of partial laryngectomy for laryngeal cancer is to ensure at least one normal cricoarytenoid joint unit. According to the definition of TNM stage of laryngeal cancer by UICC (2002), if the lesion site is near the anterior commissure, because there is little submucosal tissue there, the tumor is easy to invade the thyroid cartilage, then even if the vocal cord is not fixed, it should be diagnosed as T3 lesion, and this T3 vocal fold type laryngeal cancer is undoubtedly an indication for partial laryngectomy on the cricoarytenoid cartilage.
Invasion of the paravocalicular space, intralaryngeal muscle and cricoarytenoid joint can lead to vocal fold fixation. If the lesion is posterior to the vocal cord, invades the cricoarytenoid joint, and involves the interarytenoid, contralateral phial and vocal cord, it is an indication for total laryngectomy. t3 glottic laryngeal carcinoma tends to invade the subglottic region through the parglottic space, and when the subglottic invasion is large, glottic laryngeal carcinoma may show the characteristics of subglottic laryngeal carcinoma: localized circumferential infiltration. Therefore, total laryngectomy should be considered when the subglottis invasion is more than 1.0 cm.
The prognosis of subglottic laryngeal carcinoma is better. According to the data of Li Qinghong’s group, the survival rate of subglottic laryngeal carcinoma by surgery alone is 84.4%. The 3-year tumor-free survival rate of T3 vocal hilar laryngeal cancer in our group was 63.2%. 24 cases of total laryngectomy, 8 cases of near-total laryngectomy and 25 cases of partial laryngectomy were performed among 57 patients. The results showed no statistical difference in postoperative survival between total laryngectomy and partial laryngectomy.
The patients’ general condition, especially lung function, was also an influential factor in deciding the surgical approach for laryngeal cancer. Due to the effect of surgery on the structure and function of the larynx, patients will experience transient choking back on food after partial laryngectomy, and the new larynx re-establishes a normal swallowing reflex. Poor lung function in patients can lead to recurrent unresolved lung infections due to choking back and eventually respiratory failure may occur. Some studies have shown that changes in lung function are more pronounced in older adults as they enter their 70s.
The risk of surgical complications in lung cancer patients over 70 years of age is significantly increased [15]. Therefore, age is also one of the factors that should be considered when deciding on laryngeal cancer surgery. In our data, one patient aged 74 years was given another total laryngectomy 4 months after partial laryngectomy because he could not overcome choking. The data of this group were divided into the ≥70 years old group and the <70 years old group for analysis, and the survival rates of the two groups were 70% and 61.7%, respectively, and there was no statistical difference between the two groups, so it can be seen that advanced age is not a risk factor for the survival rate after T3 acoustic laryngeal cancer.
The number of total laryngectomy cases was dominant in the ≥70-year-old group, with a total laryngectomy rate of 70%; the number of partial laryngectomy cases was dominant in the <70-year-old group, with a total laryngectomy rate of 36.2%. The different composition ratios of surgical modalities in the two groups may be one of the factors contributing to the difference in survival rates between the two. Old age alone is not an absolute contraindication to partial laryngectomy, and if the patient's general condition is good, partial laryngectomy can achieve a good outcome.
Cervical lymph node metastasis is an important factor affecting the survival rate of laryngeal cancer after surgery. Many scholars believe that cT3N0 acoustic hilar laryngeal cancer should undergo cervical lymph node dissection in zones II-IV. In our group, the rate of cervical lymph node metastasis was 17.5%. 36 of 57 patients underwent cervical lymph node dissection, and among 21 N0 patients who did not undergo cervical lymph node dissection, only one patient was found to have an ipsilateral neck mass six months after surgery, and the postoperative pathology confirmed that it was a lymph node metastatic squamous carcinoma.
The rate of cervical lymph node metastasis in acoustic laryngeal carcinoma is low, and there should be more evidence-based basis for whether cT3N0 acoustic laryngeal carcinoma should undergo cervical lymph node dissection in zones II-IV. In addition, the cervical lymph node metastasis rates of patients in the ≥70-year-old group and the <70-year-old group were 10% and 19.1%, respectively, which is a small number of cases and cannot indicate that the older the age, the lower the cervical lymph node metastasis rate of vocal hilar laryngeal cancer.
T3 glottic laryngeal cancer often invades the anterior commissure, paravocalicular space, subglottic area, and cricoarytenoid joint, and partial laryngectomy often cannot ensure sufficient safety boundary, which may lead to local recurrence of the tumor. Some literature shows that the local recurrence rate of vertical partial laryngectomy for T3 laryngeal cancer is more than 30%. The local recurrence rate of 28% in our data is similar to that reported in the literature.
Therefore, the extent of tumor infiltration should be fully evaluated during preoperative surgery, and if there are indications for partial laryngectomy, sufficient safety boundaries should be ensured during surgery, and intraoperative margin freezing pathological examination should be performed if necessary to reduce the local recurrence rate of T3 hilar laryngeal cancer after surgery.
Both partial laryngectomy and total laryngectomy are the main surgical methods for T3 hilar laryngeal cancer. In addition to local factors such as the site and extent of tumor, systemic factors such as patient’s age and lung function are also important factors in deciding the surgical approach for laryngeal cancer. For patients with T3 hilar laryngeal cancer, appropriate individualized surgical methods should be selected based on the patient’s specific conditions to ensure the survival rate and improve the quality of survival as much as possible.