From untreatable to curable? The evolution of cancer treatment

Humankind has been trying to find a cure for cancer for thousands of years. Today, we may have reached a point where we know enough to develop an effective cancer cure and the question remains, where will science take us next?

To get a better understanding of cancer therapies, and where this industry is headed today, let’s look at where we’ve come from. 

In ancient civilisations, surgical removal of the visible growth was the only treatment available, but it was very risky. And, as the Roman physician Celsus wrote, “After excision, even when a scar has formed, none the less the disease has returned.” Source: Cancer.org

The disease remained effectively incurable (except rare successful attempts at surgical removal) until anesthesia was discovered in 1846 which cleared the path for better and more efficient cancer removal surgery. And a the end of the nineteenth century Professor William Stewart Halsted developed the radical mastectomy for breast cancer. 

But surgery didn’t do much for the underlying understanding of how cancer worked. It didn’t help control the disease or prevent reoccurence. More often than not the cancer would simply return after the primary tumour had been removed. 

Stephen Paget, an English Surgeon and Halsted’s contemporary, challenged the belief that cancer could not spread and that, once a tumour was removed, the disease was cured. He hypothesised that cancer spreads through the bloodstream. He compared the process with seeds that ‘are carried in all directions, but they can only live and grow if they fall on congenial soil.’ Source: Cancer.org

Almost a hundred years later, Paget’s hypothesis of metastasis – the concept that cells from a primary tumour can spread through the bloodstream – was confirmed by modern methods based on cellular and molecular biology. 

The nineteenth century saw a growing interest in cancer cures, not just surgery, but other methods as well. The pursuit to understand how cancer spread kindled the interest of many scientists. Thomas Beatson was one. He found that oophorectomy (removal of the ovaries) often resulted in improvement for breast cancer patients, laying the groundwork for hormonal cancer therapy. Meanwhile, the x-ray was discovered in 1896 by the German physics professor Wilhelm Conrad Roentgen. Within three years, it was used for cancer treatment and was found to effectively treat small growths that could not be surgically removed.

During World War II, the US army studied chemical compounds for war, and in the process a compound called nitrogen mustard was found to be effective against a type of cancer called lymphoma. This created the basis of cancer-killing alkylating agents which in turn lead to the discovery of several chemicals that worked by destroying DNA, inhibiting cell growth or blocking chemical reactions needed for DNA’s replication, including aminopterin, the predecessor of methotexate, a cancer drug used commonly today. Chemotherapy successfully treated a rare tumour called choriocarcinoma in 1956, and treated cancers such as Hodgkin disease and ALL (acute lymphoblastic leukemia) in the 1960s. A combination of chemotherapy drugs were eventually found to make treatment much more effective, and it’s this type of treatment – combination chemotherapy – which is used to cure many cancers today. 

Chemotherapy was a leap forward, so much so that it remains one of the best-known therapies today. Unlike radiation, it could treat larger cancer growth.  

Unfortunately traditional chemotherapy as we know it today can’t always treat cancer. The drugs aren’t sufficiently targeted to avoid damage on healthy tissue causing adverse effects such as hair loss, weight loss and nausea. 

Cancer survival rates also remain lower than desirable. Prognosis varies, but to take a few common examples, lung cancer only has an 18% five year survival rate in the US, while bone cancer has a 67.7% and breast cancer a 91.7% five year survival rate. Thyroid cancer has one of the best prognoses at 98.2% survival rate, while brain stem cancer has less than 1%.

So what is the next step? What is the missing piece that will make cancer treatment better and more efficient? An 18% survival rate for lung cancer is hardly a cure. 

New research suggests targeted medicine might be the answer. 

Traditional cancer medicine works by destroying everything in its path. Much like spreading weed-killer, it kills the weeds but also destroys the rest of your lawn. Most cancer drugs only work on some people, while having no effect (or even adverse effects) on others. The more efficient method would be to spot treat the weeds. It’s this idea that has led cancer treatment research in the direction of more targeted therapies. 

This is an exciting area that has shown promising results in clinical trials that has been made possible by years of cancer research and refined modern technology. With new knowledge and technology on hand, the goalposts of medicine may be changing from aiming to treat the specific disease, to deciding the best possible treatment path, and ultimately, cure, for each human being.

We may be moving towards bespoke treatment of cancer, which would be ultra precise and much more effective than previous non targeted treatments.

 

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