Clinical

Breast cancer may change biology when it spreads to the liver

Last Updated: 2010-06-08 15:00:03 -0400 (Reuters Health)

By Fran Lowry

CHICAGO (Reuters Health) - When a primary breast cancer spreads to the liver, its biology may change, according to new research presented here today at the annual meeting of the American Society of Clinical Oncology.

In more than 12% of patients, a discordance in estrogen, progesterone, and HER2 receptor status between the primary tumor and metastatic liver lesions necessitated a change in therapy, the retrospective study showed.

Metastatic lesions might therefore need to be biopsied to reassess their biological features, Dr. Giuseppe Curigliano, from the European Institute of Oncology, Milan, told reporters at a press briefing. "Biopsy should be considered in all patients when it is safe and easy to do so, since any change is likely to impact the choice of therapy," he said.

In their study, the researchers analyzed biopsy data from primary breast tumors and liver metastases in 255 women to determine concordance of receptor status between the two lesions. The median time from primary diagnosis to liver biopsy was 3.4 years, and ranged from 0 to 18.3 years.

They found changes in estrogen receptor status in the secondary tumor in 14.5% of women, a change in progesterone status in 48.6%, and a change in HER2 status in 13.9%. This led to changes in therapy in 12.1% of the patients.

"Our study has a very simple message," Dr. Curigliano told Reuters Health. "We should reassess the biology of the disease in this era of targeted therapies, since if we do not reassess the biology and we give a targeted agent but the target is not present on the metastasis, we give a treatment that is not effective in these patients. Trastuzumab is only effective in women whose tumors overexpress HER2. Aromatase inhibitors only work in breast cancers that are estrogen-receptor positive."

Unfortunately, not all sites of the body are amenable to biopsy. "A biopsy on a liver met is very accessible, you just need an ultrasound to guide the fine needle, and you can have a tissue sampling", he said, but if you have a bone biopsy or a mediastinal lymph node, which you cannot get to easily, you may not be able to do so.