Management of oligometastatic head and neck squamous cell carcinoma: A systematic review

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common type of cancer worldwide. It is mainly discovered in a locally advanced stage, but it is estimated that 40% of recurrences after the treatment of the primary disease will be in a metastatic form, with one third being oligometastatic. There is no clear consensus regarding the treatment of oligometastatic HNSCC, whether it being local treatment, systemic treatment or a combination of both. We put together a systematic review using the Preferred Reporting Item for Systematic review and Meta-Analysis (PRISMA) method to gather all pertinent articles approaching the therapeutic management of oligometastatic HNSCC, especially in the metachronous setting. Out of 344 articles, 21 articles fit our inclusion criteria and were deemed pertinent to help answer the question of our review. Eight studies included only head and neck cancers (HNC) and the other 13 tackled multiple histologies including HNC. Stereotactic body radiotherapy (SBRT) was the treatment of choice for oligometastatic HNSCC with good local control rates and manageable toxicity. Most included studies were retrospective and not randomized. The association of local treatment and systemic treatment was difficult to assess as treatment protocols were not always standardized. There is crucial need for more prospective randomized trials that compare all treatments and sequences as some patients with a high risk of developing polymetastatic disease could derive benefit form a more intensified approach.