RESUMO
BACKGROUND AND PURPOSE: The aim of our prospective study was to assess the prognostic value of 18F-FDG PET/CT performed two months post treatment for anal canal neoplasm. POPULATION AND METHODS: Consecutive patients with histologically proved anal cancer, with 18F-FDG PET/CT pre and two months post treatment were included. Patients were not previously treated for this neoplasm and then received radiotherapy ± chemotherapy. Clinical and pathologic data were collected and for 18F-FDG PET/CT visual and quantitative analysis (standardized uptake value, metabolic volume) were performed; response was classified according to EORTC and PERCIST criteria. The results were assessed for disease free survival and local recurrence free survival using the log-Rank test RESULTS: From December 2014 to September 2019, 94 consecutive patients were screened and 78 were included in this study. Median follow-up was 51 months. Two months post treatment, 37 patients (47.4%) had a complete radiological response according to both EORTC and PERCIST criteria, 66 patients (84.6%) had a clinical complete response. For disease free survival, the prognostic value of complete response was statistically significant (p=0.02) with 18F-FDG PET/CT and with clinical examination (p<0.001). For local recurrence free survival, the prognostic value with 18F-FDG PET/CT was lower (p=0.04) than clinical examination (p < 0.007). CONCLUSION: While clinical examination remains the gold standard for post treatment evaluation in anal cancer, 18F-FDG PET/CT has a statistically significant prognostic value. These two assessments could be combined to improve early evaluation.
RESUMO
In squamous cell anal canal neoplasms, persistent disease or recurrence after initial chemoradiotherapy are not the rule, yet their occurrence deserves to be analyzed to better identify prognostics factors. The aim of our study was to describe the patterns of failures of the initial treatment, their subsequent evolution and to identify prognostic factors in these relapsed patients. All patients with non-metastatic anal squamous cell carcinoma initially treated with curative intent at the Centre Antoine Lacassagne between 1999 and 2019, and who presented persistent disease or recurrence were analyzed. The median follow-up was 44 months. Univariate and multivariate analyses were performed to identify prognostic factors. From our database of 528 patients, 77 patients were eligible: 25 with persistent disease and 52 with recurrence after complete response. The median overall survival was 39 months (95% CI: 25.5-52.3 months) from the date of treatment failure. In univariate analysis, prognostic factors were gender, initial lymph node status, type of failure, response to treatment's failure. In multivariate analysis, only female gender remained statistically significant (HR 0.43- P=0.016). 32% of patients with persistent disease had metastatic status. 17.3% and 5.8% of recurrences respectively occurred after three and five years of follow-up. Systematic imaging could be performed after initial treatment because of distant lesions in one third of patients with persistent disease. The follow-up should not be interrupted before five years, given the significant frequency of late recurrences. In multivariate analysis, only female gender was statistically significant. Stratified treatment based on prognostic factors could be envisaged, the details of which remain to be defined.
