The impact of 18-fluorodeoxyglucose positron emission tomography on the staging, management and outcome of anal cancer

• Published in: British journal of cancer Vol. 100; no. 5; pp. 693 - 700
• Main Authors: Winton, E de, Heriot, A G, Ng, M, Hicks, R J, Hogg, A, Milner, A, Leong, T, Fay, M, MacKay, J, Drummond, E, Ngan, S Y
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10-03-2009; Nature Publishing Group
• Subjects: Adult; Aged; Aged, 80 and over; Anus Neoplasms - diagnosis; Anus Neoplasms - pathology; Anus Neoplasms - therapy; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cancer Research; Cancer therapies; Carcinoma, Squamous Cell - diagnosis; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - therapy; Clinical Study; Drug Resistance; Epidemiology; Female; Fluorodeoxyglucose F18; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Lymphatic system; Male; Medical prognosis; Medical research; Medical sciences; Metastasis; Middle Aged; Molecular Medicine; Neoplasm Staging; Oncology; Patients; Planning; Positron-Emission Tomography - methods; Prognosis; Radiation therapy; Sensitivity and Specificity; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Survival analysis; Tomography; Tumors; Australia; Victoria Australia; radiotherapy; PET CT; anal cancer; staging; Radionuclide study; 2-deoxy-2-fluoroglucose; Prognosis; Radiodiagnosis; Staging; Anal cancer; Stage classification; Malignant tumor; Radiotherapy; Cancerology; Clinical management; Treatment; Medical imagery; Digestive diseases; Intestinal disease; Computerized axial tomography; Positron emission tomography; Anorectal disease; Cancer; Emission tomography
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/sj.bjc.6604897

Accurate inguinal and pelvic nodal staging in anal cancer is important for the prognosis and planning of radiation fields. There is evidence for the role of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) in the staging and management of cancer, with early reports of an increasing role in outcome prognostication in a number of tumours. We aimed to determine the effect of FDG-PET on the nodal staging, radiotherapy planning and prognostication of patients with primary anal cancer. Sixty-one consecutive patients with anal cancer who were referred to a tertiary centre between August 1997 and November 2005 were staged with conventional imaging (CIm) (including computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound and chest X-ray) and by FDG-PET. The stage determined by CIm and the proposed management plan were prospectively recorded and changes in stage and management as a result of FDG-PET assessed. Patients were treated with a uniform radiotherapy technique and dose. The accuracy of changes and prognostication of FDG-PET were validated by subsequent clinical follow-up. Kaplan–Meier survival analysis was used to estimate survival for the whole cohort and by FDG-PET and CIm stage. The tumour-stage group was changed in 23% (14 out of 61) as a result of FDG-PET (15% up-staged, 8% down-staged). Fourteen percent of T1 patients (3 out of 22), 42% of T2 patients (10 out of 24) and 40% of T3–4 patients (6 out of 15) assessed using CIm, had a change in their nodal or metastatic stage following FDG-PET. Sensitivity for nodal regional disease by FDG-PET and CIm was 89% and 62%, respectively. The staging FDG-PET scan altered management intent in 3% (2 out of 61) and radiotherapy fields in 13% (8 out of 61). The estimated 5-year overall survival (OS) and progression-free survival (PFS) for the cohort were 77.3% (95% confidence interval (CI): 55.3–90.4%) and 72.2% (95% CI: 51.5–86.4%), respectively. The estimated 5-year PFS for FDG-PET and CIm staged N2-3 disease was 70% (95% CI: 42.8–87.9%) and 55.3% (95% CI: 23.3–83.4%), respectively. FDG-PET shows increased sensitivity over CIm for staging nodal disease in anal cancer and changes treatment intent or radiotherapy prescription in a significant proportion of patients.