Could an aspirin a day keep cancer away?

Those who take aspirin daily in order to lower the risk of heart attack and stroke may also be preventing cancer. Who knew that such an accessible and cheap drug could have so much potential in healthcare?

Scientists from The City College of New York have developed a new aspirin that inhibited the growth of 11 types of human cancer cells in culture without harming any normal cells. It also shrank human colon cancer tumors by 85 percent in animals. No adverse effects were observed. Called the NOSH-aspirin, the compound is derived from the typical aspirin used for headaches and minor aches and pain. This new aspirin, if found to be just as effective for humans as for animals, could be used along with other drugs to shrink tumors before performing invasive treatment like chemotherapy and surgery.

Aspirin works by inhibiting the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes that produce prostaglandins, molecules that trigger processes in the body, including inflammation. COX-1 enzymes are involved in the production of prostaglandins called thromboxanes that contribute to normal functions in the body, like protecting the stomach lining and helping blood clots form. COX-2 enzymes produce prostaglandins when pain and inflammation occur. Aspirin inhibits by splitting and latching one part onto the enzyme, preventing the reaction that would convert arachadonic acid to prostaglandin. It blocks a tunnel-like molecular structure through which the acid flows so that the acid cannot be converted into prostaglandins.

Past studies have monitored the regular use of aspirin and other non-steroidal anti-inflammatory drugs like ibuprofen and naproxen, discovering the drugs’ ability to inhibit the growth of cancer. In a study conducted by John Burns and his colleagues at Newcastle University, 861 people with Lynch syndrome, a genetic condition linked to a range of cancers, began a two-year program of either 600 milligrams a day of aspirin or a placebo between 1999 and 2005. An analysis in 2007 found no difference in cancer rates between the two groups. But in 2010, 19 patients who took aspirin had bowel cancers as opposed to 34 in the placebo regimen. The study showed regular aspirin’s effect on cancer takes a few years to materialize. 

However, taking aspirin frequently causes side effects such as bleeding ulcers and kidney failure. The Newcastle University study suggests that for every 10,000 cancers prevented, 1,000 ulcers result from taking aspirin. Although the benefits of cancer prevention may outweigh the side effects of aspirin, the increase of ulcers is great enough to be a concern.

The NOSH-aspirin resolves these issues, increasing the drug’s safety and strength while keeping the dosage level low. One arm of this new aspirin releases nitric oxide (NO), helping to protect the stomach lining, and as a result, preventing ulcers and consequently, targeting the primary side effect of taking aspirin. The other arm releases hydrogen sulfide (H2S), which has been shown to enhance aspirin’s cancer-fighting abilities. According to City College’s Associate Professor Khosrow Kashfi, the primary investigator of the hybrid aspirin, the NOSH-aspirin is much more potent compared to regular aspirin for treating cancer. Just after 24 hours of treating a culture of cancer cells, the NOSH-aspirin showed 100,000 times more potency than traditional aspirin alone.

The new aspirin was 15,000 times more potent than existing NO-aspirins and 80 times more than those that incorporate just H2S. The resulting benefit of this drug is that it would require lower doses in order to be effective, lowering the chance of any side effects like ulcer. It is also more potent, aiding those who are prone or subject to aspirin resistance. The effects on cancer cells from using the NOSH-aspirin are almost immediate, compared to the 2010 study by Burns using regular aspirin. Also, because this new drug is based off of the regular aspirin found in drugstores, the cost to distribute the NOSH-aspirin, when ready for patients, would be cheaper than the drugs currently used for cancer treatment.