Specimen Information

Type

Gold, SST

Volume

1.0 ml

Transport Info

Centrifuge and immediately transfer serum to separate plastic tube
Frozen

Fasting Required?

False

Clinical Significance

An aid in the management of breast cancer patients with metastatic disease by monitoring the progression or regression of disease in response to treatment.

Breast cancer is the most common cancer among women in the United States. The vast majority of breast cancer deaths are from advanced disseminated disease. Although many therapeutic modalities exist for the treatment for metastatic disease, most breast cancers usually become refractory to specific drugs and require second and third line regimens. A circulating tumor marker, such as CA 27.29, which can monitor response to therapy and can indicate disease status is a valuable tool in the management of these patients.CA 27.29 is a highly polymorphic glycoprotein belonging to the mucin family and is the product of the MUC-1 gene. It is most useful using serial measurements to monitor both the course of disease and response to therapy because of the direct correlation of changing levels of CA 27.29 with clinical status. In patients with known metastases, a reduction in levels of this marker indicates a good response to treatment while increasing levels indicate resistance to therapy and progressive disease and justify further clinical evaluation and regular monitoring. It has also recently been shown that an elevation of CA 27.29 levels above the upper limit of normal in patients with no clinical evidence of disease is an early indicator of recurrence. An elevated serum CA 27.29 level in patients in remission of Stage II or III breast cancer provided a positive predictive value of 83.3% for recurrent disease, with an average lead time of 5.3 months before recurrence was clinically established.