Anal cancer maximum F-18 fluorodeoxyglucose uptake on positron emission tomography is correlated with prognosis.
OBJECTIVE
To evaluate anal cancer uptake of F-18 fluorodeoxyglucose (FDG) measured as the maximum standardized uptake value (SUV(max)) by positron emission tomography (PET) and its correlation with prognostic factors.


METHODS
The study population consisted of 77 patients with stages 0-IIIB anal cancer who underwent pre-treatment FDG-PET. Tumor histology included 65 squamous cell, 11 basaloid, and 1 small cell cancers. SUV(max) and sites of lymph node metastasis were recorded. We analyzed the association between SUV(max) and prognostic factors.


RESULTS
The mean SUV(max) was 10.0 (range 1.0-43.1). The stage distribution included: 2 stage 0, 7 stage I, 49 stage II, 10 stage IIIA, 9 stage IIIB. SUV(max) and clinical tumor size were not associated (R(2)=0.338). Histology did not significantly influence SUV(max) (mean SUV(max) 10.0 for squamous versus 9.90 for basaloid). Higher SUV(max) was associated with an increased risk of nodal metastasis at diagnosis (p<0.0001). Higher SUV(max) was associated with worse disease-free survival (p=0.05). Patients with high anal tumor SUV(max) at diagnosis were at an increased risk of persistent or recurrent disease on post-therapy FDG-PET performed less than 4months after completing therapy (p=0.0402).


CONCLUSIONS
SUV(max) is a valuable biomarker of anal cancer prognosis, predicting increased risk of lymph node metastasis and worse disease-free survival.
Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Elizabeth A
EA
Kidd
Farrokh
F
Dehdashti
Barry A
BA
Siegel
Perry W
PW
Grigsby
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001005:Anus Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18