Understanding and Management of Cancer Recurrence

Abstract

Cancer recurrence is defined as the re-establishment of tumor burden following previous eradication of primary cancer by various treatments. Once this event takes place, the prognosis of the patient often becomes grim, signaling the end of life. Compared to the management of initially diagnosed cases, clinical dealing of recurred cancer has been in a state of chaos without consensus and guidelines. The reason for this lack of consensus in dealing with recurred cancer comes from highly variable outcomes to the same treatment in individual case, thus no defined treatments can be planned in advance. Why is recurred cancer more deadly than primary cancer? Why do some cancer cases recur while others don’t? Why is it more difficult to deal with recurred cancer than primary cancer? These are challenging clinically relevant questions, the answer to which may help us to understand the mechanism behind tumor recurrence and provide strategy to deal with this deadly event more efficiently. Here, using a few cases, we present our analyses on this issue with focus on the status of antitumor immunity, the most critical factor influencing the outcome of each recurrence. Our analyses and experiences with cancer recurrence indicate that although appearing complicated than initially diagnosed cancer, recurred cancer could be reasonably managed like initially diagnosed cancer as long as its reason for recurrence is clearly identified.