Chemotherapy delivered through the nipple
Tests in both rats and patients have shown that chemotherapy delivered through the milk ducts of the nipple is more effective and leads to fewer side-effects than intravenous drug delivery. The technique can now be tested further in humans by increasing the dosage.
Traditionally chemotherapy is delivered intravenously into the bloodstream. This means that the medicine circulates around the whole body; requiring high doses and causing side-effects. Breast cancers often originate in the lining of the milk ducts. In theory, chemotherapy applied locally to the nipple in the early stages of the disease would require lower doses and should affect the rest of the body less.
To test this theory four standard anticancer drugs, 5-fluorouracil (5FU), carboplatin, methotrexate and paclitaxel were injected directly into the ducts of rats bred to develop breast cancer. Of these drugs, 5FU prevented the most cancers compared to no drug or to intravenous delivery. It also shrank established breast tumours with striking effectiveness, completely eliminating them in 10 of 14 treated rats.
The technique was also trialled in 12 patients to confirm safety. Very low doses were delivered into milk ducts using a small catheter. This resulted in much higher concentrations of the medicine in the breast tissue compared to patients receiving the treatment by intravenous injection. The technique only caused mild nipple pain and breast fullness, which are both experienced as a result of normal chemotherapy for breast cancer as well.
With positive results in both animal and human trials doctors will now increase the dosage and begin to test the effectiveness of the new method in more breast cancer patients.