Cell kinetics and tumor regression during radiotherapy in head and neck squamous-cell carcinomas.
Head and neck squamous-cell carcinoma (HN-SCC) patient management is mainly based on TNM classification and needs be improved by considering other potentially useful prognostic factors. We examined the pre-radiotherapy tumor potential doubling time (Tpot) evaluated after in vivo infusion of bromodeoxyuridine and flow-cytometric analysis and the early clinical tumor regression after 40 Gy (40 Gy-TR). Tpot values and clinical 40 Gy-TR classes (minor and major) were available for 82 HN-SCC patients. Radiation therapy completion was done either with 1 dose per day (conventional regimen) or 2 doses per day (accelerated regimen). Local control was also available for follow-up times above 4 years. We found that major 40 Gy-TR was strongly correlated with fast tumor growth, characterized by Tpot values below 5 days, and that patients with major 40 Gy-TR showed better local control than those with minor 40 Gy-TR, independently from the radiotherapy regimen type. We also found that treatment completion with accelerated radiotherapy gave better local control for patients with major 40 Gy-TR and fast tumor growth than conventional radiotherapy. Multivariate analysis, performed on all patients, assigned an independent prognostic value to Tpot, tumor classification and 40 Gy-TR.
Department of Radiotherapy, National Institute for Cancer Research, Genova, Italy.
R
R
Corvò
W
W
Giaretti
E
E
Geido
G
G
Sanguineti
R
R
Orecchia
M
M
Scala
G
G
Garaventa
E
E
Mora
V
V
Vitale
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005434:Flow Cytometry; D006258:Head and Neck Neoplasms / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011879:Radiotherapy Dosage
D004273:DNA, Neoplasm