Herceptin (trastuzumab) for breast cancer in men

The breast cancer cells will be tested for the HER2 protein at diagnosis. Herceptin| works by attaching to HER2 receptors (proteins) on the surface of breast cancer cells. This stops the cancer cells from dividing and growing. It may also allow the body’s defences to fight better against the cancer cells.

In men who have HER2-positive early breast cancer, Herceptin may be given to reduce the risk of cancer coming back after surgery. If chemotherapy and radiotherapy are also being given it would usually be given after these treatments. Men who have HER2-positive breast cancer that has spread (secondary breast cancer) may be given Herceptin on its own or with chemotherapy depending on what, if any, treatment they have already had. The aim of treatment will be to shrink the cancer and control it.

Herceptin is given as a ‘drip’ into a vein. This is known as an intravenous infusion. For early breast cancer, Herceptin is generally given every three weeks for a year. If it’s being used to treat secondary breast cancer, treatment will continue for as long as it is working.

Side effects are usually mild but some men may have:

• flu-like symptoms
• diarrhoea
• headaches
• an allergic reaction.

In some men, Herceptin may cause damage to the heart muscle, which could lead to heart failure. If this happens the Herceptin will be stopped. Usually, the effect on the heart is mild and reversible.

Because the long-term effect of any heart damage is not known, Herceptin is not given to men who have serious heart problems. You can discuss with your doctor whether this treatment may be suitable for you.