FDG-PET metabolic response predicts outcomes in anal cancer managed with chemoradiotherapy

Br J Cancer. 2011 Aug 9;105(4):498-504. doi: 10.1038/bjc.2011.274. Epub 2011 Jul 26.


Background: The aim was to investigate the correlation between (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) metabolic response to chemoradiotherapy and clinical outcomes in squamous cell carcinoma (SCC) of the anus.

Methods: A total of 48 patients with biopsy-proven anal SCC underwent FDG-PET scans at baseline and post chemoradiotherapy (54 Gy, concurrent 5-FU/mitomycin). Kaplan-Meier analysis was used to determine survival outcomes according to FDG-PET metabolic response.

Results: In all, 79% patients (n=38) had a complete metabolic response (CMR) at all sites of disease, 15% (n=7) had a CMR in regional nodes but only partial response in the primary tumour (overall partial metabolic response (PMR)) and 6% (n=3) had progressive distant disease despite CMR locoregionally (overall no response (NR)). The 2-year progression-free survival (PFS) was 95% for patients with a CMR, 71% for PMR and 0% for NR (P<0.0001). The 5-year overall survival (OS) was 88% in CMR, 69% in PMR and 0% in NR (P<0.0001). Cox proportional hazards regression analyses for PFS and OS found significant associations for incomplete (PMR+NR) vs complete FDG-PET response to treatment only, (HR 4.1 (95% CI: 1.5-11.5, P=0.013) and 6.7 (95% CI: 2.1-21.6, P=0.002), respectively).

Conclusion: FDG-PET metabolic response to chemoradiotherapy in anal cancer is significantly associated with PFS and OS, and in this cohort incomplete FDG-PET response was a stronger predictor than T or N stage.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Anus Neoplasms / diagnostic imaging
  • Anus Neoplasms / drug therapy*
  • Anus Neoplasms / metabolism
  • Anus Neoplasms / mortality
  • Anus Neoplasms / radiotherapy*
  • Australia / epidemiology
  • Carcinoma, Squamous Cell / diagnostic imaging
  • Carcinoma, Squamous Cell / drug therapy*
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / mortality
  • Carcinoma, Squamous Cell / radiotherapy*
  • Chemotherapy, Adjuvant
  • Confounding Factors, Epidemiologic
  • Disease-Free Survival
  • Dose Fractionation, Radiation
  • Female
  • Fluorodeoxyglucose F18 / metabolism*
  • Follow-Up Studies
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Positron-Emission Tomography* / methods
  • Proportional Hazards Models
  • Radiopharmaceuticals / metabolism
  • Radiotherapy, Adjuvant
  • Retrospective Studies
  • Treatment Outcome


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18