A team of 14 researchers at University of Oxford has recently published a report saying that a drug previously used in malaria research could be a potent mix in the treatment for cancer. The group is hopeful that atovaquone can be used to vitally make cells more radiosensitive prior to radiotherapy. The drug is expected to alleviate the state of hypoxia among cancer cells, thereby increasing their radiosenstivity.
The study published in the journal Nature conducted numerous tests among different cancer cell lines, spheroids from solid tumor cells and xenografts from mice. Scientists were effectively looking for a drug that could reduce hypoxia until they found the candidate atovaquone. Their aim is very clear; to get the oxygen consumption rate of cancer cells low, thereby increasing the overall levels of oxygen in the tumors high enough for therapy to be effective.
Even though the experiments have been conducted only in vitro yet, a rapid 80% decrease in the oxygen consumption rate in various cancer cell lines is very encouraging. The paper concludes: “We are now initiating a proof of principle, ‘window of opportunity’ clinical trial to investigate whether atovaquone reduces tumour hypoxia in lung cancer patients prior to surgical resection”.
The drug atovaquone which is already being used for medication in multiple conditions like malaria and pneumocystis pneumonia (a type of pneumonia), is sure to be a safe bet for doctors, as it’s already in use because of its relatively mild side effects. It is expected to work by preventing oxygen consumption in cells of the tumor by interfering with their respiration i.e., the process that utilizes oxygen to ‘burn’ glucose for energy. Exactly how elevated levels of oxygen aid therapy remains known.
Emma Smith, the science information manager at Cancer Research UK, has remarked, “The types of cancer that tend to have oxygen deprived regions are often more difficult to treat — such as lung, bowel, brain and head and neck cancers,” she continued, “Looking at the cancer-fighting properties of existing medicines is a very important area of research where medical charities can make a big impact and is a priority for Cancer Research UK. Clinical trials will tell us whether this drug could help improve treatment options for patients with these types of tumor.”
They study has successfully shown that atovaquone works as an adjunct to radiotherapy. Although at first it was predicted that to get the desired result, a pharmacological concentration of the drug won’t work, the results have surprised scientists for the better.
Re-oxygenation of cancer cells comes with its risks. Scientists argue that increased quantity oxygen might cause the cancer cells to enter metastasis and thus invade other parts of the body. Studies, however, have weighed the potential hazards and benefits. They conclude that the benefits of decrease in hypoxia in therapy outweigh the possible threats.
According to WHO, cancer has been assessed to take 8.2 million lives each year. In fact, it accounts for 13% of deaths globally. Since cancer is an age onset disease, the number of cancer cases is expected to increase as the average life span increases and large populations of middle aged individuals’ age further. Dreadfully, the number of cancer cases is expected to increase by a mammoth 70% in the following two decades. Although there is a range of different types of cancers (more than 100), the options for treatment are rather limited to mainly surgery, chemotherapy and radiotherapy.
During radiotherapy in particular, the fact that cancer cells are deprived of oxygen (the aforementioned hypoxia) is problematic as the therapy needs the presence of oxygen to be effective. Hypoxia is prevalent among cancer cells because the outer layer of a tumor uses up all of the oxygen from the incoming blood to grow rapidly, making the mass of tumor cells inside oxygen starved.
Since cancer research is often overhyped, any situation where the researchers of preclinical studies themselves hold prospect for clinical trials is a good indication for the effectiveness of the therapeutic agent in consideration.
The survival rate of this horrendous ailment is depressingly low. Mayo Clinic states that in the case of a lung cancer, the survival rate is 52% for early stage patients and a mere 4% for late stage cancer (metastasized). And these percentages are projections for only the next five years.
Fortunately for prospect patients, the production of the drug atovaquone is no longer tangled under any copyright law, its patent has expired. Hence, the drug is going to be cheap. If this drug proves to be effective in ridding cancer cells of hypoxia, patients will benefit from this low cost drug into the resources for combating cancer.