Detection and management of oligometastatic disease in oesophageal cancer and identification of prognostic factors: A systematic review

BACKGROUND: Oesophageal cancer is the eighth most common cancer worldwide. The prognosis of oesophageal cancer patients still remains poor. The 5-year survival rate rarely exceeds 5% in case of metastatic disease. Some patients may however present with oligometastasis which can be treated with loco-regional therapy. AIM: To assess the current practice regarding the management of patients with oligometastatic oesophageal cancer and identify prognostic factors affecting survival following treatment for oligometastasis. METHODS: A systematic search of the literature was performed in Cochrance Library, MEDLINE and EMBASE databases from September 1950 to January 2019. Relevant electronic databases were searched for studies assessing the clinical outcome of oligometastasis. RESULTS: A total of 14 publications were included, of which 12 studies assessing metachronous oligometastasis and 2 on synchronous oligometastasis. All included articles evaluated the specific outcomes of metastasis, management modality and survival outcomes. The majority of the patients presented with oesophageal squamous cell carcinoma. The median disease free interval (time to recurrence) in patients was 19.6 mo and the overall survival reached 30.8 months. Unfavourable prognostic factors were assessed in eight studies and included time to recurrence < 12 mo, large diameter pulmonary lesions (> 20 mm), disease free interval (DFI) < 12 mo, extra-pulmonary metastasis, primary tumour pathological stage III/IV. CONCLUSION: Oligometastatic oesophageal cancer in selected patients is amenable to loco-regional treatment, and the overall survival of this patient cohort may be improved with patient and tumour-specific treatments.