Frequency and Consequences of Cervical Lymph Node Overstaging in Head and Neck Carcinoma

Abstract

Clinical lymph node staging in head and neck carcinoma (HNC) is fraught with uncertainties. Established clinical algorithms are available for the problem of occult cervical metastases. Much less is known about clinical lymph node overstaging. We identified HNC patients clinically classified as lymph node positive (cN+), in whom surgical neck dissection (ND) specimens were histopathologically negative (pN0) and in addition the subgroup, in whom an originally planned postoperative radiotherapy (PORT) was omitted. We compared these patients with surgically treated patients with clinically and histopathologically negative neck (cN0/pN0), who had received selective ND. Using a fuzzy matching algorithm, we identified patients with closely similar patient and disease characteristics, who had received primary definitive radiotherapy (RT) with or without systemic therapy (RT ± ST). Of the 980 patients with HNC, 292 received a ND as part of primary treatment. In 128/292 patients with cN0 neck, ND was elective, and in 164 patients with clinically positive neck (cN+), ND was therapeutic. In 43/164 cN+ patients, ND was histopathologically negative (cN+/pN-). In 24 of these, initially planned PORT was omitted. Overall, survival did not differ from the cN0/pN0 and primary RT ± ST control groups. However, more RT ± ST patients had functional problems with nutrition (p = 0.002). Based on these data, it can be estimated that lymph node overstaging is 26% (95% CI: 20% to 34%). In 15% (95% CI: 10% to 21%) of surgically treated cN+ HNC patients, treatment can be de-escalated without the affection of survival.

Keywords: computed tomography; head and neck neoplasm; neck dissection; tumor staging.

Figure 1

Axial contrast-enhanced CT scans of HNC patients clinically staged as neck lymph node positive who were histopathologically negative and who could be rejected from postoperative irradiation (upper row). In the lower row, CT scans of patients who were actually histopathologically positive and who had postoperative irradiation (lower row). Red arrow indicates cervical lymph node overstaging. Green arrow indicates true positive lymph node staging: (a) A 62-year-old male patient with a cT2cN2bcM0 oropharyngeal cancer treated with lateral pharyngotomy and neck dissection; (b) A 61-year-old female patient with a cT2cN2bcM0 supraglottic laryngeal cancer treated with transoral resection and neck dissection; (c) A 54-year-old male patient with a cT2cN2bM0 (pT2pN1) oropharyngeal cancer treated with transoral resection, neck dissection and PORT; (d) A 57-year-old male patient with a cT2cN2cM0 (pT2pN2c) supraglottic laryngeal cancer treated with transoral resection, bilateral neck dissection and PORT.

Figure 2

Kaplan–Meier plots of 24 patients with originally planned surgical tumor resection, therapeutic neck dissection and PORT (red line), in whom treatment was finally de-escalated to surgery alone (cases), and patients staged as cN0 (blue line) who were a priori scheduled for primary surgical resection with elective neck dissection only (controls; n = 72; log rank p = 0.74).

Figure 3

Kaplan–Meier plots of 21 patients with originally planned surgical tumor resection, therapeutic neck dissection and PORT (red line), in whom treatment was finally de-escalated to surgery alone (cases), and matching patients with cN+ (blue line) who were admitted to definitive primary RT ± ST (controls; n = 21; log rank p = 0.18).