In vivo cell kinetics in elderly patients affected by squamous cell carcinoma of the head and neck.

The purpose of the study was to determine whether pretreatment tumor cell kinetics can predict local control in elderly patients affected by squamous cell carcinoma of the head and neck (SCC-HN) and help guide different therapeutic modalities. Over a 6-year period, 52 patients with stage II to IV SCC-HN and aged more than 70 years were given an infusion of bromodeoxyuridine (BrdUrd) 6 hours prior to tumor biopsy sampling. The simultaneous labeling S phase fraction (LI) and duration (Ts) as well as potential doubling time (Tpot) were measured with flow cytometric analysis of BrdUrd and DNA content. Patients were then treated as follows: 14 with conventional radiotherapy; 13 with partly accelerated radiotherapy; 11 with chemoradiotherapy; 14 with surgery plus adjuvant radiotherapy. Univariate analysis showed that, independently of treatment type, patients with fast growing SCCs-HN characterized by Tpot value < or = 5 days had a lower three-year local control than patients with slow growing tumors with Tpot value > 5 days. Our results also demonstrated that surgery or chemoradiotherapy were effective treatments for fast growing tumors. Radiotherapy alone, instead, was more effective for slow growing tumors. Our data suggest that in vivo cell kinetics may play a role as additional prognostic factor for elderly patients with SCC-HN and predict the outcome of different treatments.