When Kate Middleton, the princess of Wales, announced in March 2024 that she was receiving “preventive chemotherapy” following abdominal surgery, many wondered what that entails. Formally known as adjuvant therapy, administering chemotherapy or other treatments after surgery is a common approach to treating certain types of cancer and is not necessarily intended to prevent cancer.
Oncologist Alexander Olawaiye of the University of Pittsburgh explains what factors doctors take into account when devising a cancer treatment plan.
Why are some cancers treated with surgery but not others?
There are many types of cancer treatment, including surgery, chemotherapy, radiotherapy, immunotherapy and hormonal therapy, among others. Sometimes doctors combine multiple types of treatment. Which is the best treatment approach depends on which organ the tumor originated from and how much the tumor has spread at the time of diagnosis.
Broadly speaking, there are two types of cancers: solid tumors – or visible tumors that can be seen by the naked eye or through imaging – and liquid tumors, such as blood cancers. The primary treatment for solid cancers is surgery to physically remove the tumor, with the goal of getting rid of all tissues involved with the tumor.
For example, in ovarian cancer, surgery often includes removing the ovaries, fallopian tubes and the uterus, along with any visible cancer tissue in the rest of the belly. Sometimes this requires removing the spleen or part of the small intestine or liver.
For some cancer patients, systemic treatment such as chemotherapy may be a better option than surgery.
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For skin cancers such as melanoma, surgery involves removing both the tumor and a good margin of normal-looking skin with it to capture any remaining cancer cells that may not be visible in the surrounding healthy skin. Likewise, a surgeon may also remove nearby lymph nodes.
When solid cancer is diagnosed early, the success of treatment following surgery is typically high. For example, an estimated 91% of cervical cancer patients who are diagnosed early are still alive at least five years after diagnosis. Endometrial cancer patients who are diagnosed early have an estimated five-year survival rate of 95%.
Why do some cancers recur?
Despite surgical removal, many tumors come back. Researchers don’t fully understand why cancers recur, but there are certain red flags that indicate the potential for recurrence.
One is how different the cancer cells look compared with healthy cells. The more different, the more aggressive the tumor. When a tumor is more aggressive, it’s more likely to invade neighboring tissues and spread to other parts of the body.
Another is the extent the cancer has spread at the time of diagnosis. This is what determines the stage of the cancer. For example, stage 1 cancer refers to a tumor that is confined to the organ it…