Dear EBP: The use of CA27.29 to detect breast cancer recurrence at present is controversial. When other alternative causes of elevated CA 27.29 have been eliminated, an abnormal test result may indicate recurrent disease. However, there has been no evidence to date that treatment based solely on CA27.29 elevation significantly improves overall survival rates. The American Society of Clinical Oncologists (last update in 1997) guidelines state that at present the data are insufficient to recommend routine use of CA27.29 for screening, diagnosis, staging or surveillance following primary treatment. Although an increasing CA 27.29 can detect recurrence following primary treatment, the clinical benefit is not established. When discussing clinical benefit they are talking about will this have an effect on disease free or overall survival? Will the benefit of early treatment outweigh the risks of treatment side effects? The answers or evidence in regards to these questions is not currently available.
Elevated levels may be found in-patients with other diseases such as ovarian cysts, uterine fibroids, intestinal or colonic problems, medication; Paxil, hepatitis, tuberculosis, systemic lupus.
In many clinical settings, this test is not done because it is too difficult to interpret results. In the absence of other information that would confirm disease progression, it makes sense to stick with the current plan. The CA27.29 may not be a reliable enough test on which to base independent clinical decisions.
In other words, we would only change the treatment plan if there was clear evidence of disease progression. This would be confirmed through bone scans or CT. When to do these exams is somewhat individual but definitely should be done if there are new symptoms.