Noboru Oriuchi MD, Presenter: Nothing to Disclose

Kyoichi Kaira MD, PhD, Abstract Co-Author: Nothing to Disclose

Yukiko Arisaka MD, Abstract Co-Author: Nothing to Disclose

Tetsuya Higuchi MD, PhD, Abstract Co-Author: Nothing to Disclose

Go Miyashita, Abstract Co-Author: Nothing to Disclose

Tomohiro Ishikita DDS, Abstract Co-Author: Nothing to Disclose

Keiko Koyama MD, PhD, Abstract Co-Author: Nothing to Disclose

Keigo Endo MD, Abstract Co-Author: Nothing to Disclose

L-type amino acid transporter 1 (LAT1) is highly expressed in various types of cancer cells. LAT1 transport large neutral amino acids which have critical roles in the signal pathway to control cell proliferation and metastasis. Previous study showed that [18F]-α-methyl tyrosine (FAMT) was transported through LAT1, FAMT PET could differentiate malignant tumors, and the uptake was correlated with LAT1 expression in non-small cell lung cancer (NSCLC). The present study examined prognostic significance of FAMT PET in patients with NSCLC.

The study population consisted of 88 patients with stage I to IV NSCLC (57 patients with adenocarcinoma and 31 with squamous cell carcinoma). All patients underwent PET studies with FAMT and [18F]-fluorodeoxyglucose (FDG) prior to therapy. The median follow-up duration was 17 months after therapy. Uptake of FAMT and FDG was evaluated by the maximal standardized uptake value (SUVmax). Overall survival was calculated by the Kaplan-Meier method and the prognostic significance of PET was assessed.

PET showed SUVmax of FAMT and FDG ranged from 0.6 to 5.8 (mean, 1.8±1.0), and from 0.9 to 29.6 (mean, 8.1±5.3, p<0.001), respectively. SUVmax of FAMT in adenocarcinoma was significantly lower than that in squamous cell carcinoma (p=0.0031). The SUVmax of FDG showed no significant difference between adenocarcinoma and squamous cell carcinoma. The best discriminative cutoff values of SUVmax for the FAMT and FDG in the primary tumors were 1.6 and 11.0, respectively. Univariate analysis on all patients revealed that high SUVmax of both FAMT (p=0.0129) and FDG (p=0.0481) was a significant factor to predict poor overall survival. <0> <0> In patients with adenocarcinoma, overall survival rates of patients with high SUVmax of FAMT (37.7%) was significantly lower than that with low SUVmax (81.5%, p=0.0027). Overall survival rates of patients with high SUVmax (31.7%) of FDG was also significantly lower than that with low SUV (65.8%, p=0.0185). In patients with squamous cell carcinoma, however, no significant difference in the overall survival was observed.  

Uptake of FAMT and FDG was a significant factor to predict poor overall survival in NSCLC. FAMT was more significantly correlated with survival in adenocarcinoma.

FAMT PET is a potential prognostic marker in patients with pulmonary adenocarcinoma.

Oriuchi, N, Kaira, K, Arisaka, Y, Higuchi, T, Miyashita, G, Ishikita, T, Koyama, K, Endo, K, Evaluation of LAT1 Expression with [18F]-α-methyl tyrosine PET as a Prognostic Marker of Non-Small Cell Lung Cancer.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9013907.html