Correlation between computed tomographic density of lymph node metastases and response to cisplatin-based chemotherapy in patients with head and neck squamous cell carcinoma in an area in which betel quid chewing is prevalent.

ABSTRACT

BACKGROUND: Identifying the factors predicting response to chemotherapy is important for patients with head and neck squamous cell carcinoma (HNSCC). It allows more rational selection of subsets of patients who may benefit from multidisciplinary treatment. Correlation of lymph node density in contrast-enhanced computed tomographic (CT) scans of HNSCC with response to chemotherapy was observed in the recent literature. This prospective study was designed to validate this clinical issue. METHODS: From January 1992 to March 1995, 71 patients with untreated HNSCC were included in this study in which the following criteria were met 1) a lymph node > 3 cm by physical examination or > or = 2 cm by scanographic examination; 2) clinically evaluable disease treated by cisplatin-based neoadjuvant chemotherapy; and 3) availability of a pretherapeutic contrast-enhanced CT scan showing the cross-sections of relevant lymph node metastases. The density of the largest lymph node was compared with that of the nuchal muscles by a radiologist blinded to the patient's therapeutic outcome. A lymph node was classified as hypodense if more than 33% of the lymph node surface area was comprised of a hypodense zone, and isodense if less than a third of the lymph node surface area was comprised of a hypodense zone. RESULTS: Fifty-one patients (72%) had the largest lymph node classified as hypodense, and 63 patients (89%) were found to have extranodal spread (ENS) in the relevant lymph nodes. Fifty-nine patients were betel quid chewers. Lymph node density was not related to T classification, primary site, or histologic differentiation of the primary tumor. There was also no correlation between lymph node density and lymph node N classification. The lymph node chemotherapy response rate was 35% (7 of 20) of the isodense group and 47.1% (24 of 51) of the hypodense group (P = 0.36). ENS was found to have no impact on the chemotherapy response. CONCLUSIONS: Computed tomographic density of lymph node metastases did predict chemotherapy response in the HNSCC patients in the current study from an area in which betel quid chewing is prevalent.