Stem Cell. What is that?

What’s in a name? It’s a lot when it comes to stem cells, cancer and stem cell therapy.

I NEED you to pay close attention as I differentiate stem cell therapy for cancer from killing cancer stem cells in this article.

It is very important. I want you to avoid being duped or having your hopes unrealistically raised. Please read carefully and understand the difference between “stem cell therapy”, which means using stem cells to treat cancer, and “killing cancer stem cells”, which means using some form of treatment to kill an important subset of cancer cells called cancer stem cells.

If you have come so far, congratulations! It means you have in you the quest to understand more about cancer and to be careful about words and phrases that sound similar. You do not want to be taken for a ride by people with commercial interests who fudge and obfuscate issues.

“Stem cell therapy” for cancer applies only to 150 to 200 patients out of 45,000 patients diagnosed to have cancer every year in Malaysia. Almost all these 150 patients suffer from leukaemia or lymphoma.

Stem cell therapy has two purposes for such patients. The first is to repopulate the bone marrow with haematopoietic stem cells (stem cells that give rise to blood cells) after high dose chemotherapy which renders the bone marrow non-functional.

The second reason for stem cell therapy is to boost the immune system of the patient to fight cancer by enhancing the “graft vs host” reaction. In this case, stem cells are obtained from a donor (a sibling, a close relative).

Another very infrequent use of stem cell therapy in cancer is in the salvage treatment of germ cell cancer and metastatic kidney cancer. This situation occurs less than 10 times a year in our country.

The message is loud and clear: Stem cell therapy at present has absolutely no role in the treatment of 90% of cancers, and that includes breast, lung, colorectal, liver, nasopharyngeal, cervical, stomach and brain tumours. Stem cell therapy may have a role in the future (unlikely), but so do many therapies under investigation.

Let us move on to killing cancer stem cells as a cancer treatment. This could be the next big thing in cancer treatment. Or it could be a dud. It is too early to tell. We just have to be patient and let the researchers carry on with their work.

If I am still writing this column five or 10 years from now, I shall either say “killing cancer stem cells is the standard of care in cancer treatment” or “killing cancer stem cells has failed to live up to its initial promise and should be relegated to the bin of false starts!”

The point is this: cancer research starts at the “bench” (laboratory studies) and ends up at the “bed” (actual pills and injections for treating cancer patients). This process usually takes 10 to 20 years. We are just at the beginning of the research to identify and kill cancer stem cells.

A quick primer on cancer stem cells. Cancer cells are now known to be either cancer stem cells or cancer cells which are not stem cells. Perhaps it is the cancer stem cells which are the true culprits that eventually maim and kill. These cells are capable of indefinite reproduction to produce daughter cancer cells ad infinitum.

Our present ways of treating cancer €“ radiotherapy, chemotherapy, molecularly targeted therapy €“ attack all cancer cells irrespective of whether they are cancer stem cells or not. We fail to cure cancer in some cases. Is it because we did not completely eliminate all cancer stem cells?

One of the politicians I admire most is Indira Gandhi. She was the 5th (1966 to 1977) and 8th (1980 to 1984) Prime Minister of India. She was a shrewd politician whatever her detractors may say.

She was often asked what it was like to be the daughter of Mahatma Gandhi. In response she would often just smile demurely. We know of course she was not a blood relative of the Mahatma but the political mileage of this association was enormous. She was the daughter of Jawaharlal Nehru, the first Prime Minister of India. She was married to Feroze Gandhi, which of course made her Indira Gandhi.

Lesson for the week: Similar sounding names can be bewitching, confusing and misleading. Many practitioners with vested interest would neither confirm nor deny the unsuspecting public’s vague thoughts abut stem cell treatment for cancer.

The next time someone mentions something about stem cell and cancer, pin her down and ask her: is it “stem cell therapy for cancer” or “therapy to kill cancer stem cells?”

Both are not (with the exceptions mentioned) yet standard treatment for cancer.