Triple-negative breast cancer biomarker points to new cancer model

Getting the news of triple-negative breast cancer--cancer that does not have receptors for estrogen (ER), progesterone (PR) or human epidermal growth factor (HER2)--is not good. These are fast-growing tumors that often affect young women. They make up 10% to 20% of all breast cancers and are hard to treat because they don't respond to treatments targeting ER, PR or HER2. A metabolic biomarker, known as MCT4 (monocarboxylate transporter 4), spotted in these patients, could help direct treatment, but has also unlocked a new theory of cancer metabolism.

The researchers from Kimmel Cancer Center at Thomas Jefferson University looked at samples from patients with triple-negative breast cancer and spotted that high levels of MCT4 could be linked with low levels of caveolin-1, which suggests early tumor recurrence and metastasis.

This connection makes MCT4 an additional marker for breast cancer with a poor outcome. In combination with caveolin-1, it could help to select out those patients who will (and will not) respond to treatment. MCT4 could also be a target for developing new treatments. Targeting patients with an MCT4 inhibitor, or even simple antioxidants, may help treat high-risk patients who otherwise may not respond positively to conventional treatment, the researchers suggest.

In addition, the discovery of this biomarker could point to a new theory on cancer metabolism, which could change how certain types of tumors are treated.

"The whole idea is that MCT4 is a metabolic marker for a new model of tumor metabolism and that patients with this type of metabolism are feeding their cancer cells. It is lethal and resistant to current therapy," said Michael Lisanti, professor and chairman of Stem Cell Biology and Regenerative Medicine at Jefferson.

- read the press release
- see the abstract from Cell Cycle article