Conventional

Summaries of study evidence on various conventional remedies. OBJECTIVITY zone.

May 082011
 

This post is in initial build-out status and may change.

General Information: Although typically used for headaches and cardiovascular issues, studies also continue to determine if aspirin could reduce risk of developing various types of cancer. More about aspirin in general is available at Wikipedia.

Cancer

Studied Uses: Cancer prevention and recurrence

Cancer Evidence Summary - Aspirin - https://sheet.zoho.com

Overall Cancer Score: 5.48

Behind the Score: The score for aspirin is positive, but the picture presented by studies is actually mixed, with several studies showing no effect or a negative effect, most notably for breast cancer prevention 1 but also in one study for kidney and colon cancers 2. One study even showed an increased risk for ER/PR negative breast cancer, a type viewed as aggressive. 3 (Ibuprofen also showed an increased risk of breast cancer, especially “non-localized” tumors, in that study.) That said, the picture appears to be more positive for some colorectal cancers (especially if a family history is involved 4 5 and other digestive tract cancers 6, as well as for lung cancer. 7 As noted earlier, the picture is somewhat mixed even for colorectal cancers, with an earlier randomized trial showing no benefit. 8

Notably, despite the lackluster results seen for breast cancer prevention, one prospective study reported dramatically increased survival after breast cancer among aspirin users (relative risk of death=0.29), especially for use 2 to 5 days a week, regardless of “stage, menopausal status, body mass index, or estrogen receptor status.” 9 This effect may be due to COX-2 inhibitor (anti-inflammatory) activity of aspirin.

Warnings and Special Notes: One study of elderly individuals showed an increased risk of kidney cancer corresponding with aspirin use, especially for men (although the total number of kidney cancer cases was only 35 among 22,000 study participants). That same study also showed an increased risk for both sexes of colorectal cancer corresponding with aspirin use, whereas other studies generally have shown a decreased risk. 10 A different study of women showed an increased risk for ER/PR negative breast cancer. 11

What Now? Studies continue on the effects of aspirin in cancer prevention. It should be noted that the studies showing decreased risk were mainly epidemiological/prospective studies, which rely on participant reports of use of aspirin. On the good side, these types of studies tend to involve a large number (e.g., many thousands) of participants and a long follow-up period. It is possible that there is an unidentified co-factor (such as lifestyle choices) causing the decreased risk seen in prospective trials.

What Can I Do? Aspirin is widely available over-the-counter. Bear in mind that although some studies support its use for cancer prevention, others do not and in fact show an increased risk. Use caution and make your choice based on your own individual situation and medical history.

Notes:

  1. Low-dose aspirin in the primary prevention of cancer: the Women’s Health Study: a randomized controlled trial., Journal of the American Medical Association, 2005.
  2. Aspirin use and chronic diseases: a cohort study of the elderly, British Medical Journal, 1989.
  3. Nonsteroidal Anti-Inflammatory Drug Use and Breast Cancer Risk by Stage and Hormone Receptor Status. Journal of the National Cancer Institute, 2005.
  4. A Randomized Placebo-Controlled Prevention Trial of Aspirin and/or Resistant Starch in Young People with Familial Adenomatous Polyposis. Cancer Prevention Research, 2011.
  5. Non-Steroidal Anti-Inflammatory Drugs and Colorectal Cancer Risk in a Large, Prospective Cohort. The American Journal of Gastroenterology, 2011.
  6. Aspirin, Nonsteroidal Anti-inflammatory Drugs, and the Risks of Cancers of the Esophagus. Cancer Epidemiology, Biomarkers and Prevention, 2008.
  7. Regular Adult Aspirin Use Decreases the Risk of Non-Small Cell Lung Cancer among Women. Cancer Epidemiology, Biomarkers and Prevention, 2008.
  8. Low-Dose Aspirin and Incidence of Colorectal Tumors in a Randomized Trial. Journal of the National Cancer Institute, 1993.
  9. Aspirin Intake and Survival After Breast Cancer, Journal of Clinical Oncology, 2010.
  10. Aspirin use and chronic diseases: a cohort study of the elderly, British Medical Journal, 1989.
  11. Nonsteroidal Anti-Inflammatory Drug Use and Breast Cancer Risk by Stage and Hormone Receptor Status. Journal of the National Cancer Institute, 2005.