ABSTRACT
Introduction: Tumor markers are useful means for obtaining information about some malignant tumors whilst causing minimal inconvenience and cost
Objective: The purpose of this study was to evaluate the value of CA 15-3 and CEA in patients with breast carcinoma
Materials and Methods: This retrospective study was performed on 604 patients [mean age= 47 years] who were referred for treatment to oncology departments of Ghaem and Omid hospitals of [Mashhad Iran] from 1999 to 2004. CEA [cut off, 5 ng/ml] and CA 15-3 [cut off, 40 U/ml] had been measured with radioimmunoassay method for every patient [1- 10 times]
Results: Stage I to IV were found in 25, 370, 165 and 44 patients respectively at the time of referral. With a mean follow up time of 18 months, from 560 nonmetastatic patients, 76 [13.6%] cases experienced recurrence. The sensitivity of CEA and CA 15-3 measurements in patients with overt metastasis or up to one month before the detection of recurrence were 56.4% and 90% respectively. CEA and CA 15-3 were measured 2 to 8 months before the detection of metastasis in 44 patients from which raising the levels of these markers were found in 7 [15.9%] and 23 [52.2%] cases respectively. Among 249 disease free patients who had been followed for more than 18 months, false positive levels of CEA and CA15-3 were found in 7 [2.8%] and 4 [1.7%] cases respectively
Conclusion: Considering the low number of false positive results in recurrent free patients, both CEA and CA15-3 showed good specificity. The sensitivity of CA15-3 is good for the detection of overt metastasis. However CA15-3 has a modest sensitivity in patients with minimal disease. CEA has a much lower sensitivity compared to CA15-3. However, the positive test can confirm the result of CA15-3 in metastatic setting