“Smart” drugs get smarter

Many people know the name of the breast cancer drug Herceptin, also known as trastuzumab, most famous for causing controversy over its availability in different parts of the UK. The treatment is a so-called “smart” or targeted therapy, designed to lock on to molecules on the surface of some breast cancers. Now researchers in Japan think that trastuzumab, and a similar drug called cetuximab, might also have a use for treating a different disease – cancer of the oesophagus.

Within our bodies, there are many chemical signals that tell our cells to grow and multiply. These are very important at certain times in our lives – for example, when we grow into a baby in the womb, when wounds heal, or simply to replace cells that have died through normal wear and tear. But some cancer cells are super-sensitive to these signals, and grow out of control in response to them.

Two of the receptors for certain signalling molecules are EGFR and HER-2. EGFR is found on the surface of some bowel cancer cells, which can be targeted with cetuximab (also known as Erbitux). And HER-2 is found in around a fifth of all breast cancers, which can be treated with trastuzumab (Herceptin).

Led by Dr Koji Kono, the Japanese team have previously found that oesophageal cancer cells also bear EGFR and HER-2. Specifically, they looked at a type of cancer called squamous cell carcinoma (SCC) – the most common form of oesophageal cancer in Japan. The scientists have now tested whether cetuximab and trastuzumab might work to treat this type of cancer.

Working with cancer cells grown in the lab, they found that a combination of the two drugs could slow down the growth of many (but not all) of the cell lines they tested. And when they looked at patients with oesophageal SCC, they found that around a fifth of them had EGFR and HER-2 on their cancer cells.

Although the two drugs haven’t yet been tested for treating people with this type of cancer, these results, published this month in the British Journal of Cancer, suggest that the combination might prove useful. The next step would be to carry out clinical trials to see if this is really the case.