Recurrent cancer

Recurrent cancer is a form of cancer that has returned or recurred when a fraction of primary tumor cells evade the effects of treatment and survive in small spaces that are undetectable by diagnostic tests. The initial tumor may become the site of cancer’s return or it may spread to another part of the body. These surviving cells accumulate various genetic changes over time, eventually producing a new tumor cell. It can take up to weeks, months, or even years for cancer to return. Following surgery and/or chemotherapy or radiotherapy, certain tumor cells may persist and develop resistance to treatment and eventually develop into new tumors. Age, sex, cancer type, treatment duration, stage of advancement, and grade of original tumor are some of the factors that determine the rate of cancer recurrence. If recurrent cancer has already moved to other body parts or has developed chemo-resistance then it may be more aggressive than original cancer. In general, the severity of cancer increases with a shorter duration of time between initial treatment and its return.

Cancers with the highest recurrence rates include Glioblastoma with a recurrence rate of almost 100%,  Epithelial ovarian cancer with a recurrence rate of 85%, and Bladder cancer with a recurrence rate of 30-54%