Primary tracheal cancer is rare, with etiological factors similar to bronchogenic carcinoma. Smoking is the primary risk factor. The most common histological types are squamous cell carcinoma (41%–45%) and adenocarcinoma (36%–47%). Basal cell carcinoma accounts for approximately 12%. Cervical tracheal cancer can be classified as either primary or secondary. Secondary involvement is more common and is typically observed with local invasion from laryngeal cancer, hypopharyngeal cancer, or thyroid carcinoma. Primary cervical tracheal cancer is exceedingly rare, particularly in the upper third of the trachea.
Symptoms
Symptoms of cervical tracheal cancer are nonspecific. In the early stages, patients may experience throat itching, irritating cough, intermittent hemoptysis, and chronic shortness of breath. Tumor growth leads to tracheal narrowing, which may cause stridor. Symptoms of upper airway obstruction can occur when the tumor occupies more than one-fifth of the tracheal lumen. If the tumor extends outward and involves the recurrent laryngeal nerve, hoarseness may occur. Esophageal compression can result in progressive dysphagia.
Classification
Primary Cervical Tracheal Cancer
Primary cervical tracheal cancer is rare, with squamous cell carcinoma being the most common histological type, followed by adenoid cystic carcinoma, mucoepidermoid carcinoma, clear cell carcinoma, and neuroendocrine carcinoma. The primary symptoms include dyspnea, coughing with sputum, and hemoptysis. At initial diagnosis, it is often misdiagnosed as tracheitis, bronchitis, bronchiectasis with hemoptysis, or asthma.
Secondary Cervical Tracheal Cancer
The most common cause of secondary cervical tracheal cancer is advanced thyroid carcinoma invading the cervical trachea. Recurrence of thyroid carcinoma after surgery often involves the cervical trachea. Symptoms may include inspiratory dyspnea, hoarseness, and inspiratory stridor. If the cervical esophagus is also involved, dysphagia may occur.
Diagnosis
Flexible Laryngoscopy and Bronchoscopy:
These are key diagnostic methods for cervical tracheal cancer, allowing direct visualization of the tumor's size, shape, and location. Biopsies can also be obtained. For patients with respiratory distress, care must be taken as the examination may exacerbate upper airway obstruction.
CT or MRI
CT/MRI with contrast enhancement of the neck and upper mediastinum can reveal soft tissue opacities projecting into the tracheal lumen, defining the tumor's location and extent.
PET/CT or PET/MRI
These imaging techniques can help differentiate between benign and malignant lesions of the cervical trachea and identify distant metastases.
Exfoliative Cytology
Early diagnosis may be facilitated by exfoliative cytology using morning sputum samples or tracheal secretion washings.
Treatment
Surgery is the primary treatment for cervical tracheal cancer, focusing on complete tumor resection and subsequent reconstruction of the cervical trachea using various repair strategies. For advanced, inoperable tumors, palliative radiotherapy, chemotherapy, immunotherapy, or targeted therapy may be employed. Depending on the size of the intraluminal tumor, tracheal intubation under general anesthesia, tracheotomy under local anesthesia, or extracorporeal membrane oxygenation (ECMO) may be used.
Primary Cervical Tracheal Cancer
Resection typically involves removing 4.5–5.0 cm of the cervical trachea, followed by end-to-end anastomosis or tracheal repair, which is generally manageable surgically. Extended resection can be achieved by mobilizing the larynx and releasing the mediastinal trachea. Defects in the tracheal sidewall may be repaired using adjacent pedicled flaps such as pectoralis major musculocutaneous flaps, supraclavicular artery island flaps, thoracodorsal artery perforator flaps, or sternocleidomastoid myocutaneous flaps, as well as free flaps to reconstruct the cervical trachea.
Secondary Cervical Tracheal Cancer
For advanced thyroid carcinoma invading the trachea, resection of thyroid tissue is performed along with tracheal reconstruction, depending on the extent of invasion. Window or sleeve resection techniques may be used, with reconstruction methods similar to those for primary cervical tracheal cancer. Postoperative iodine-131 isotope therapy or radiotherapy may be employed as adjuvant treatment. For thyroid carcinoma involving the area below the clavicle, a combined cervical-thoracic incision may be required. For cases with simultaneous involvement of the larynx and trachea, partial or total laryngectomy is performed based on the extent of invasion.