Medical advances have improved the outlook for relapse patients

by Eveline Gan

When Mdm Tan G E passed the five-year mark after her cancer treatment, she thought she had finally escaped the clutches of the horrifying disease.

Diagnosed with stage 2 breast cancer in 2002, the homemaker, then 53 years old, made a swift decision for a mastectomy. She removed her entire left breast - to reduce her chances of a relapse - and underwent a gruelling half year of chemo and radiation therapy.

In the following years, she lived on tenterhooks, not knowing if the treatment had worked.

"I always hear about friends getting cancer relapses. So when I went past the five-year mark, I felt so relieved because I heard that the risk of relapse is usually lower after this period." said Mdm Tan in Mandarin.

Her relief was short-lived. In the sixth year after her initial diagnosis, the cancer returned. During this time, it had spread to her liver.

When cancer relapses

For cancer patients, "relapse" is a terrifying word. "Cancer relapse refers to the cancer 'coming back', either in the same location as the initial cancer or in other parts of the body," explained Dr Yap Yoon Sim, senior consultant from National Cancer Centre Singapore's Department of Medical Oncology.

Dim Sum Dollies actress Emma Yong is in the same predicament. In December, she reportedly pulled out of a local theatre production just before the show opened because of a stomach cancer relapse.

So why does cancer, which was once thought to be eradicated with treatment, recur?

Hide-and-seek cells

An explanation could be that the cancer was never actually removed, even though it did not show up on scans, experts told TODAY.

Medical oncologist Dr Donald Poon, council member of the Singapore Cancer Society, said late-stage cancers carry a higher risk of relapse because at the time of diagnosis, "small populations of the cells may have spread to distant organs via the blood stream or areas near the primary tumour through the lymphatic vessels".

For instance, in colorectal cancer, a stage 3 diagnosis has a 40 to 80 per cent chance of relapse compared to a stage 1 diagnosis.

"Initially these cells are too small for even the most sensitive scans to detect, but when they grow big enough to appear on scans, there are at least 1 billion cancer cells in a 1-cm diameter tumour - and thereafter erroneously termed a relapse when they have, in fact, been hiding in the body all along," explained Dr Poon.

He added: "The larger the tumour and more advanced the stage of cancer, the more likely it harbours a few populations of cells that have mutated to have the ability to travel to distant sites. They are also more likely to have acquired the ability to become resistant to conventional drugs."

According to Dr Yap, cancer recurrence is more common in certain high-risk cancers including cancers that occur in various organs such as breasts, colon, stomach, et cetera. Among these cancers, the type matters too.

"Certain cancers like breast cancer have a higher risk of relapse when compared stage-for-stage with colorectal cancer. This is why, even in stage 0 or 1 breast cancer, we offer adjuvant therapy such as hormonal therapy, radiotherapy and chemotherapy to reduce the risk of relapse," explained Dr Poon.

Is it an immediate death sentence?

Recounting her relapse diagnosis, Mdm Tan said: "In my mind, I was telling myself it was doomsday. I was going to die soon because the cancer not only relapsed, but it also spread. One of the first things I asked the doctor was how long can I live for without further treatment? He said maybe a year."

Dr Poon said such cancers are tougher to treat because "generally, these cancers are not curable when they relapse".

That is why cancer prevention and screening to detect cancer at an early stage is so important, he added.

Dr Yap said although a cure is generally not possible for distant relapse of most cancers, it might be possible for certain local recurrences (a relapse in the same location as the initial diagnosis).

The good news is, recent medical advances have improved the outlook for patients with certain stage 4 cancers such that a relapse doesn't become an "automatic death sentence" even if a cure is not possible, added Dr Yap, who is treating Mdm Tan.

Mdm Tan is currently on a double-blind clinical trial targeted at recurrent and advanced-stage HER2-positive breast cancer. This type of breast cancer, which is diagnosed in about one in five cases, is typically more aggressive.

She has been in remission for three years since she enrolled in the study, dubbed the Clinical Evaluation of Pertuzumab and Trastuzumab (CLEOPATRA)

When asked what her plans are, Mdm Tan said: "I don't want to think about my future. Every day when I wake up, that is already a bonus for me. Everyone hopes for good things to happen in their lives, but even when you do meet with obstacles, one must still go ahead and tackle them full-on."

And that, is exactly what this feisty lady has done in the face of cancer.

This article was featured in Today February 7, 2012.