Assessing the prognostic significance and predictive features of cervical occult metastasis in glottic laryngeal squamous cell carcinoma.

Background: Cervical lymph node metastasis in glottic laryngeal squamous cell carcinoma (LSCC) increases the chance of tumor recurrence and significantly impacts the prognosis. This scenario is worse when the cervical metastasis is not identified in the clinical evaluation, resulting in cervical occult metastasis. Therefore, it is necessary to explore the oncological outcome related to cervical occult metastasis in glottic LSCC and describe features associated with this aggressiveness marker.

Methods: Retrospective study with glottic LSCC patients without cervical metastasis at the clinical evaluation (cN0), surgically treated with cervical dissection in the Instituto Nacional de Câncer (Brazil). cT1 samples were excluded because none of them presented cervical occult metastasis.

Results: Cervical occult metastasis was observed in 39 (23.78 %) of 164 cN0 glottic LSCC patients. Regarding their neck levels, 2.7 % of patients had cervical metastasis in neck level I, 22 in neck level II, 16 in neck level III, 15 in neck level IV, and four in neck level VI. Cervical occult metastasis was associated with lymphovascular involvement (OR = 9.41), subglottic involvement (OR = 4.48), thyroid involvement (OR = 8.53), and tobacco smoking (OR = 5.70). Finally, cervical occult metastasis was an independent prognostic factor for overall (HR = 7.40), disease-specific (HR = 11.90), and disease-free (HR = 9.07) survivals.

Conclusions: We observed a significant frequency of cervical occult metastasis in glottic LSCC, negatively impacting the prognosis. Cervical occult metastasis was associated with a history of cigarette smoking, subglottic invasion, and lymphovascular and thyroid involvement. Consequently, the surgical planning for neck dissection in patients exhibiting these characteristics could be adjusted to enhance the effectiveness of oncological treatment.