Prognostic value of baseline 18F-FDG-PET (PET) in anal cancer (AC) patients (pts): A Bologna Multidisciplinary Rectal Cancer Group analysis (BMRCG-AC01)

• Published in: Journal of clinical oncology Vol. 31; no. 15_suppl; p. e15154
• Main Authors: Pini, Sara, Di Fabio, Francesca, Iacopino, Bruno, Guido, Alessandra, Castellucci, Paolo, Cuicchi, Dajana, Fanti, Stefano, Lecce, Ferdinando, Rojas Llimpe, Fabiola Lorena, Giaquinta, Stefania, Adua, Daniela, Mazzarotto, Renzo, Pinto, Carmine
• Format: Journal Article
• Language: English
• Published: 20.05.2013
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2013.31.15_suppl.e15154

Abstract only e15154 Background: The incidence of AC has increased. In locally advanced disease treatment is curative radio-chemotherapy (RCT) followed by brachytherapy boost (BRT) or external beam radiotherapy (EBR). The aim of this analysis is to evaluate prognostic factors in predicting disease recurrence. Methods: We retrospectively evaluated pts with diagnosis of T2-3-4, N-/+ AC. External RT was delivered up to a dose of 4,500 cGy in 25 fr and CT consisted in 5-fluorouracil CI day 1-4 and Mitomicin-C bolus day 1 in the first and fifth weeks of radiotherapy as per Nigroregimen. BRT or EBR were performed at the end of RCT. A PET scan was performed at diagnosis before starting treatment. The standard uptake value (SUV) was determined from the most active tumor site. Results: Between March 2006 and August 2012, 50 pts with AC accessed the BMRCG. In this analysis we considered 29 pts evaluated by PET. The pt characteristics were: 8(27.6%) men, 21(72.4%) women; median age 63 (42-89) years; 17(58.6%) squamous cell carcinoma (scc), 12(41.4%) basaloid carcinoma (bc); 6(20.7%) cT2N0, 5(17.2%) cT3N0, 7(24.1%) cT3N+, 2(6.9%) cT4N0, 9(31.1%) cT4N+. Twenty-six (90%) pts received full-dose standard protocol RCT and subsequent radiotherapy boost. After a median follow-up of 25 months we observed 4 (13.8%) recurrences: 3 local and 1 lung metastasis. No disease-related death occurred. Stage at diagnosis (T2-3N0 vs T3N+T4N+/-) and tumor histotype (scc vs bc) did not relate to DFS (p=0.67 and p=0.86 respectively). ROC analysis identified a SUV cut-off of 12.5 at the baseline PET related to recurrence. In 15(51.7%) pts the baseline SUV was ≤12.5 (low SUV) and in 14 (48.3%) it was >12.5 (high SUV). Pts with high SUV had significantly worse DFS than those with low SUV (p=0.02). Multivariate Cox regression did not confirm any SUV prognostic value (p=0.95). Conclusions: These results suggest that high SUV could predict relapse in AC pts treated with curative RCT. The small number of pts rules out any definitive conclusion; a controlled trial should be conducted to explore the prognostic role of SUV to define good prognosis pts for “tailored” treatment and reduce therapy-related toxicities.