The researchers behind the study – from St George’s, University of London in the UK – write about their findings in the journal EBioMedicine.
They describe how the drug artesunate – a common anti-malaria medicine – showed a promising effect in slowingtumor cell proliferation in a small group of colorectal cancer patients before they had their tumors surgically removed.
Colorectal cancer – cancer of the colon and rectum – accounts for around 10% of the annual 746,000 global cases of cancer in men per year and 614,000 cases in women. It affects all racial and ethnic groups, and is most often found in the over-50s.
Of the cancers that affect both men and women, colorectal cancer is the third most common and the second leading cause of cancer death in the US.
According to the Centers for Disease Control and Prevention (CDC), 135,260 cases of colorectal cancer were diagnosed in the US in 2011, and in that year, 51,783 Americans died of the disease.
Even best current treatments offer maximum of 60% disease-free survival after 5 years
Even with the best possible treatments, note the authors, prognosis of disease free or overall survival 5 years after diagnosis does not increase beyond 60%.
Lead author and joint study leader Sanjeev Krishna, a professor and expert in infectious diseases at St George’s, urges:
“There is therefore a continuing and urgent need to develop new, cheap, orally effective and safe colorectal cancer treatments.”
He and his colleagues decided to take a look at an existing drug – already known to have some anti-cancer effects in lab settings – and assess its safety and effectiveness in patients.
“The results have been more than encouraging and can offer hopes of finding effective treatment options that are cheaper in the future,” Prof. Krishna notes.
In total, 22 patients with colorectal cancer completed the study, which began before they had their tumors surgically removed. They were randomly assigned to two groups: one received the anti-malaria drug artesunate and the other a placebo.
The analysis was a double-blind study, which means neither the participants nor the clinicians administering the drugs knew whether they were using the anti-malaria drug or the identical-looking placebo.
The participants received a 14 days’ supply of blister-packed pills – artesunate or placebo – before undergoing surgery and receiving standard care. The patients stopped taking the oral medication 2-3 days before their operation. The dose for artesunate was 200 mg.
Results justify further studies of artesunate’s effect on colorectal cancer
At 42 months after surgery, there were six recurrences of cancer in the placebo group of 12 patients and one recurrence in the group that was given artesunate (10 patients).
Senior author and joint study leader Devinder Kumar, a professor and leading expert in colorectal cancer at St George’s notes that:
“The survival beyond 2 years in the artesunate group was estimated at 91% whilst surviving the first recurrence of cancer in the placebo group was only 57%.”
The authors note that larger clinical studies “with artesunate that aim to provide well tolerated and convenient anticancer regimens should be implemented with urgency.”
Such trials “may provide an intervention where none is currently available, as well as synergistic benefits with current treatment regimens,” they add.
Most colorectal cancer patients around the world do not have access to advanced treatments.