Patologìâ (Dec 2019)
Frequency of metastasis in sentinel lymph node and its predictors in patients with laryngeal cancer T1-2N0M0
Abstract
The purpose of the work is to establish the frequency of metastatic lesions of the precricoid sentinel lymph node (SNL) in patients with laryngeal cancer T1-2N0M0 and to determine the predictors associated with the metastatic potential of the primary cancer tumor. Materials and methods. The study involved 61 patients with T1–2N0M0 laryngeal cancer with an average age of 57.71 ± 0.93 years; among them 56 (91.1 %) persons were male patients. Confirmed diagnosis of laryngeal cancer without clinical signs of regional metastasis was the criterion for inclusion in the study. Specialized treatment was carried out according to the protocol, with the use of larynx resections of various extents with the tumor removal in the first stage of combination treatment. The metastasis of precricoid SNL was determined histomorphologically using surgical material. The relationship between metastasis and microcirculatory indices was established by calculating the association coefficient and Fisher's exact test with the creation of a 2 × 2 table. The relative risk of metastasis was calculated. Data are presented in the form of relative risk and confidence intervals of CI. Results. It has been established that in 15 patients (26.2 %) tumor extension corresponded to the T1N0M0 criterion and in 46 (73.8 %) persons – to T2N0M0. The pathomorphological study of removed precricoid SNLs (n = 61) verified metastatic lesions (pN1sn) in 7 (11.4 %) patients with T2N0M0. Statistical analysis of the study found that there is a relationship between metastasis and the depth of invasion (association index 0.85), the degree of tumor differentiation (association index 0.66) and the bypass index (association index 0.96). It was found that when the value of the bypass index is higher than 1.63 pF units, the relative risk of metatases increases by 54 %, RR = 2.72 [1.64; 4.52] – 95 % CI, OR = 13.06 [1.39; 122.50], DI 95 %, with an invasion depth of greater than 6.28, the relative risk of metatases increases by 39 %, RR = 4.5 [1.72; 11.76], СI 95 %, OR = 8 [1.89; 33.81], СI 95 %. Conclusions. Revealed critical values of quantitative indicators of such predictors of laryngeal cancer metastasis as the extension of the process to T2N0M0, the depth of tumor invasion more than 6.28 ± 0.18 mm, the low degree of differentiation (G3), the prevalence of shunt blood flow over the nutritive one –shunt indicator is greater than 1.84 ± 0.05, can be used for intraoperative prediction of the presence of latent metastasis in the SNL and indicate the advisability of performing simultaneous sheath-fascial lymph node dissection of the neck on the side of the larynx lesion.
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