Postoperative radiation therapy for cervical lymph node metastases from an occult squamous cell carcinoma

Abstract

One hundred thirteen patients with cervical metastases from a squamous cell carcinoma and no evidence of the primary tumor were treated for cure by surgery and routine large-field postoperative irradiation. Patients were staged according to the 1987 American Joint Committee on Cancer (AJCC) classification. There were 24 N1, 54 N2, 29 N3, and 6 Nx lesions. One hundred four patients underwent cervical lymph node dissection and 9 had adenectomy. All patients received postoperative external beam therapy to the entire naso-oro-pharyngo-larynx and all cervical lymphatics. The overall nodal failure rate was 13.7%. Nodal failure was significantly correlated with N staging (P = .01) and with the number of histologically involved nodes (P = .05). NOdal failure was 21% when nodes were initially fixed versus 7.5% when they were not (P = .07) and 18% when there was extracapsular spread versus 4.3% when the capsule was intact (P = .11). Eleven patients (9.7%) developed a subsequent primary lesion. In 3 patients (2.6%), this primary was located in the previously irradiated area and, in 2 cases, under the anterior block of lateral fields. Metastases occurred in 18 patients (16%). The five-year overall survival rate was 38%. Survival was correlated with N staging (P less than .02), nodal fixation (P = .05), extracapsular spread (P = .01) and loosely with the number of histologically involved nodes (P = .08). On the contrary, histological differentiation did not influence the local control rate, nor the development of metastases or subsequent primary lesions. Large-field prophylactic radiation therapy appears to be effective in preventing the emergence of initially occult primary lesions. However, control of disease in the neck and survival remain disappointing in patients with advanced nodal disease, even after combined surgery and radiation therapy.

Cervical lymph node metastases from occult squamous cell carcinoma

“…Strojan and Anicin [21] also reported a mucosal primary emergence rate of 9%, a neck relapse rate of 18%, a distant metastases rate of 11%, and a 5-year survival rate of 52% in a series of 56 patients treated with nodal resection and radiotherapy (given through extended portals in 48 patients). The data of six earlier reported series [22][23][24][25][26] combined are consistent with these findings. Of 389 patients, 370 received postoperative and 19 received preoperative radiotherapy, delivered to large-volume areas, including pharyngeal axis in virtually all patients.…”

Occult primary head and neck carcinoma

“…The stage of the neck disease dictates the overall prognosis for patients with carcinoma of the cervical lymph nodes in the absence of a known primary tumor site. Multiple retrospective studies have demonstrated better 5-year survival for N1 (65%-80%) versus N2 (40%-60%) and N3 disease (15%-30%) [16][17][18]. Traditionally, treatment of the N1 neck consists of a modified radical neck dissection followed by postoperative radiotherapy to the neck and to potential primary tumor sites (Waldeyer's ring).…”

Neck Lymph Node Metastases from an Unknown Primary Tumor

“…In the literature, 5-year appearance rates of subsequent head and neck primary tumors vary from 2% to 54% (Table 3). Therefore, some authors advise an extended irradiation including prophylactic therapy of potential primary mucosal sites and both sides of the neck to minimize the risk of subsequent appearance of a primary tumor [2,6,15,24,30,35,38]. On the other hand, this treatment strategy is associated with side effects (especially chronic xerostomia) due to the increased irradiated volume [23].…”

“…Several prognostic factors in neck metastases from a CUP have been described: extracapsular extension [6,24,35], surgery/resection status [10,21,23,30], nodal status [5,6,12,15,23,24,33], histological grading [12,33], appearance of a subsequent primary tumor [5,12,23], nodal fixation [24], tumor localization [21], and pretherapeutic hemoglobin level [15].…”