Aspirin is a medication most commonly used to treat mild to moderate pain and inflammation. But new research suggests that patients who have been diagnosed with colon cancer may have better survival by taking low doses of the drug.
The research team, led by Dr. Marlies S. Reimers of Leiden University Medical Center in the Netherlands, recently published their findings in the journal JAMA Internal Medicine.
According to the American Cancer Society, there will be 96,830 new cases of colon cancer diagnosed this year.
The 5-year survival rate for those with early stage colon cancer can be as high as 90%. Unfortunately, the majority of colon cancer cases are diagnosed in the late stages, where the 5-year survival rate is as low as 12%.
Past studies have found that the use of aspirin after colon cancer diagnosis may improve survival. However, the researchers of this most recent study say the exact mechanisms behind this are unclear.
To investigate further, the team analyzed tumor tissue from 999 patients with colon cancer who had surgery between 2002 and 2008. The majority of patients were diagnosed with the cancer at stage III or lower.
The researchers assessed the tissue samples for expression of HLA (human leukocyte antigen) class I antigens and prostaglandin endoperoxide synthase 2 (PTGS2), which are types of proteins.
The team obtained information from a prescription database to determine patients' aspirin use 14 days or more after colon cancer diagnosis.
Aspirin could affect circulating tumor cells
The results of the analysis revealed that 182 patients were low-dose aspirin users. Among these patients, there were 69 deaths (37.9%) reported as a result of colon cancer. Of the 817 patients who did not use aspirin, there were 396 deaths (48.5%).
In their study, the research team says aspirin use following colon cancer diagnosis was linked with overall improved survival of colon cancer, compared with non-use of aspirin, particularly among patients whose tumors expressed HLA class I antigens.
Commenting on the findings, the study authors say:
"We found that the survival benefit associated with low-dose aspirin use after a diagnosis of colon cancer was significantly associated with HLA class I antigen-positive tumors.
In contrast, in patients whose tumors had lost their HLA class I antigen expression, aspirin use did not change the outcome."
The team says it is still unclear as to exactly how aspirin impacts colon cancer in a molecular sense, but that their findings suggest the drug affects circulating tumor cells and how they turn into metastatic deposits.
In an editorial linked to the study, Dr. Alfred I. Neugut of Columbia University in New York says that at present, he does not recommend aspirin for colon cancer patients. But he adds that these latest results could change this.
"I think based on current evidence, that if I personally had a stage III tumor, I would add aspirin to my FOLFOX (folinic acid-flourouracil-oxaliplatin) adjuvant therapy," he says. "And if I feel that way for myself, should I not convey that to my patients?"
As well as prolonging colon cancer survival, past research has shown that aspirin may help against other cancers. Medical News today recently reported on a study suggesting that daily aspirin use may reduce the risk of ovarian cancer by 20%, while other research suggests the medication could halt breast cancer.