Clinical impact of radiographic carotid artery involvement in neck metastases from head and neck cancer

Abstract

The treatment of lymph node metastases involving the carotid artery is controversial. The aim of the present study was to determine the outcomes of head and neck cancer patients with radiographic carotid artery involvement in neck metastases. A total of 27 patients with head and neck cancer and radiologically diagnosed advanced metastases involving the common carotid artery or internal carotid artery were enrolled. All patients underwent a primary or salvage neck dissection and surgical carotid peeling. The oncological outcome and survival of all patients were analyzed. Loco-regional control was observed in 13 of the 27 patients (48.1%). During follow-up, five patients (18.5%) developed second primaries and 11 (40.7%) developed distant metastases. The survival time was poor independent of regional control. The median overall survival was 1.55 years and disease-free survival was 0.71 year. Radiographic carotid artery involvement in neck metastases in head and neck cancer appears to correlate with a poor long-term prognosis, with a high rate of distant metastases despite loco-regional control.

Lymphogenic metastasis represents the most important independent prognostic factor for squamous cell carcinoma of the upper aerodigestive tract. The presence of lymph node metastases is associated with a reduction in the survival rate of approximately 50%. The different pathological characteristics of lymph node metastases are also of prognostic relevance. These include the size, number, and location of the lymph node metastases. In this context the presence of extracapsular spread of the cervical metastasis represents the most important prognostic factor and is associated with a significantly higher loco-regional recurrence rate and with distant metastases.

Neck dissection is an important treatment for metastases of upper aerodigestive tract carcinoma. A review of the literature showed that a significant number of studies on neck dissection concern the N0 neck. These studies have discussed the value and extent of neck dissection especially in the clinically N0 neck. However, bulky metastatic neck disease is the surgical and clinical challenge. Radiographic carotid artery involvement in neck lymph node metastases has been described in a small group of patients with head and neck cancer. The invasion of the carotid artery by neck metastases adjacent to the artery is a rare situation. The carotid sheath acts as a barrier against metastases. In addition, pulsation and dislocation of the artery may delay the invasion. In a retrospective study, the records of 508 patients who had undergone radical neck dissection were evaluated. The presence of tumour attached to the carotid arterial system was found in 28 of these patients (5.5%).

Invasion of the external carotid artery by neck metastases has a low clinical impact since this can usually be resected without relevant side effects. However, invasion of the internal or common carotid artery is particularly challenging and its management is unclear. The modalities for the treatment of carotid involvement in metastases reported in the literature are controversial. The management strategies discussed have included carotid resection with reconstruction, surgical carotid peeling, radiotherapy and chemotherapy, and finally no treatment and the provision of the best supportive care.

The aim of the present study was to determine the outcome of head and neck cancer patients with radiographic carotid artery involvement in neck metastases, with and without loco-regional control. The relationship of the neck metastases to the carotid artery was considered.

Patients and methods

Patient selection and clinical data

The clinical data of 27 patients with squamous cell carcinoma of the head and neck were included in the present study; four were female and 23 were male (average age 58.7 years, range 29–77 years). The clinical data of all patients, including tumour site, stage, loco-regional control, second primary, and distant metastases, are summarized in Table 1 .

Table 1
Oncological characteristics of the patients with squamous cell carcinoma of the head and neck and the clinical impact of radiographic carotid artery involvement in neck metastases ( n = 27).
Characteristics No. of patients (%)
Sex
Male 23 (85.2)
Female 4 (14.8)
Age, years
Median 58.7
(Range) (29–77)
Primary site
Oral cavity 7 (25.9)
Oropharynx 11 (40.7)
Hypopharynx 3 (11.1)
Larynx 4 (14.8)
CUP 2 (7.4)
T classification
T1 5 (18.5)
T2 7 (25.9)
T3 5 (18.5)
T4 8 (29.6)
Tx 2 (7.4)
N classification a
N0 2 (7.4)
N1 1 (3.7)
N2a 3 (11.1)
N2b 8 (29.6)
N2c 9 (33.3)
N3 4 (14.8)
Loco-regional control
Yes 13 (48.1)
No 14 (51.9)
Second primary
Yes 5 (18.5)
No 22 (81.5)
Distant metastases
Yes 11 (40.7)
No 16 (59.3)

CUP, carcinoma of unknown primary.

a Patients with N0, N1, and N2a necks developed late metastases with carotid involvement after initial treatment.

Clinical examination revealed fixed nodal metastases by palpation in all cases. Advanced neck metastasis involving the common carotid artery or internal carotid artery was demonstrated by computed tomography (CT) or magnetic resonance imaging (MRI). A segmental obliteration of the fat between the metastases and the carotid artery or deformity of the carotid artery, representing a sign of radiological cancer involvement in the vascular wall, was identified in all of the cases studied. Patients with histology other than squamous cell carcinoma, with carotid involvement by the primary, and also patients with distant metastases at diagnosis were excluded from the study.

Relationship between lymph node metastases and the carotid artery

The relationship between the metastases and the carotid artery was classified in terms of the encasement of 50% of the circumference of the carotid artery by the metastases, i.e. ≥180° vs. <180°. The maximum length of the carotid contact with the metastases was assessed using a selected cut-off value of 30 mm, i.e. ≥30 mm vs. <30 mm. According to the literature, a length >30 mm and a circumference >180° suggests tumour invasion. In addition, the localization of the metastases in relation to the carotid bifurcation (above or below) was noted.

Treatment procedures and outcomes

The treatment concept was implemented with curative surgical intention in all patients. Surgical resection of the primary and neck dissection in combination with adjuvant radiochemotherapy was performed in 13 cases (48.1%) (in two patients with carcinoma of unknown primary, only a neck dissection was performed). Six patients (22.2%) underwent primary radiochemotherapy in combination with a salvage neck dissection for residual neck disease. Eight patients (29.6%) underwent neck dissection for delayed metastases after primary surgery and adjuvant radiochemotherapy. In all patients, the resection of metastases involving the carotid artery was performed by surgical carotid peeling.

Loco-regional control, distant control, and the prognosis were evaluated for all patients. The median follow-up time was 26.3 months (range 3–80 months). Survival rates were calculated by Kaplan–Meier method with regard to the time period from the first consultation to the last consultation or death. Disease-free survival was defined as the time period between the operation and the occurrence of local or regional recurrence, distant metastases, or second primary.

Results

Characteristics of metastases in relation to the carotid artery

The maximum length of carotid contact was ≥30 mm in 14 patients (51.9%) and <30 mm in 13 patients (48.1%). The median maximum length of carotid contact was 36.4 mm (range 10–105 mm). The circumference of the contact area of the neck metastases and carotid artery was ≥180° in 16 patients (59.3%) and <180° in 11 patients (40.7%) ( Fig. 1 , Table 2 ). The carotid contact was at level II in 14 cases, levels III and IV in six cases, and levels II–IV in seven cases. Carotid involvement in lymph node metastases was identified at first diagnosis in 19 cases, and the carotid involvement was due to delayed metastases in eight cases.

Fig. 1
CT scans of three representative cases showing lymph node metastases involving the carotid artery. (A) Axial image showing 360° of encasement of the common carotid artery by the lymph node mass (black arrow). The internal jugular vein is not visible due to compression. (B) Axial image showing <180° of encasement of the internal carotid artery (white arrow) and ≥180° of encasement of the external carotid artery (black arrow). The internal jugular vein is not visible due to compression. (C) Coronal image showing the length of internal carotid involvement, measuring 38.5 mm.
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Jan 16, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Clinical impact of radiographic carotid artery involvement in neck metastases from head and neck cancer
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