Kate Middleton is in remission from cancer. This does not always mean that the disease is cured.

Princess Catherine, wife of Prince William, announced on Tuesday that her cancer was in remission. But what does it mean to be in cancer remission?

Doctors unexpectedly discovered she had cancer in March last year, when she underwent abdominal surgery. She did not reveal what type of cancer she had or how advanced it was when detected.

However, she said she underwent chemotherapy, which she said ended in September. She told British news agency PA Media that she had a port, a miniature device implanted under the skin and attached to a catheter inserted into a huge vein. It allows drugs, such as chemotherapy drugs, to be delivered directly into the veins in the chest, avoiding needle sticks.

Catherine told PA Media that chemotherapy was “really challenging”.

“It’s a relief to be in remission and continuing to focus on recovery,” she wrote on Instagram.

Her announcement “is certainly good news and uplifting,” said Dr. Kimmie Ng, deputy chief of the division of gastrointestinal oncology at Dana-Farber Cancer Institute in Boston.

However, cancer experts like Dr. Ng say what remission means to a patient can vary.

Generally, when doctors and patients talk about remission, they mean there is no evidence of cancer in blood tests or scans.

The problem is that complete remission does not mean that the cancer is gone. Even if cancer is “cured” – which is defined as no signs of cancer for five years – it may not be defeated.

This makes life challenging for patients who must visit oncologists frequently for physical examinations, blood tests and imaging tests.

“It’s really scary,” Dr. Ng said. “The amount of uncertainty is very, very high,” she added.

However, this constant supervision is necessary, despite the sacrifices it makes for patients.

“Different cancers have different propensities for recurrence or failure to recur,” said Dr. Elena Ratner, a gynecologic oncologist at Yale Cancer Center.

She noted that as many as 75 to 80 percent of ovarian cancer cases may recur an average of 14 to 16 months after remission, depending on the stage of the cancer when detected and its biology.

“Once cancer returns, it becomes a chronic disease,” Dr. Ratner said. He tells his patients: “You will live with this cancer. You will be on and off chemotherapy for the rest of your life.

Dr. Ratner’s gynecologic cancer patients must return for CT scans every three months to watch for evidence of the cancer returning.

“Women live from CT scan to CT scan,” she said. “They say they have a wonderful life for two and a half months, but then, before the next CT scan, the fear returns.”

“It costs them, a lot,” she said.

“It’s terrible, but every day I’m amazed by their strength,” she said of her patients.