Posted on Apr 10, 2013 Last Updated Sep 17, 2013
Source: Straits Times (09 August 2012)
A NEW treatment could offer hope for breast cancer patients whose tumours remain too large to remove via surgery despite undergoing chemotherapy.
Taking a drug called sunitinib one week before chemotherapy helps shrink the tumours so they get a better shot at going under the knife safely if the need arises, doctors at the National University Cancer Institute have found. Preliminary results of 24 patients show that the new method shrank tumours by one quarter after just one cycle of chemotherapy. In contrast, patients who took the only-chemotherapy route saw minimal tumour reduction after the first cycle. Typically, one has to complete four cycles.
Patients recruited under this study have advanced breast cancer, with tumours measuring an average of 8cm across. Treatment involves long periods of chemotherapy and even radiation therapy to shrink the tumours.
Dr Lee Soo Chin, associate director of research at the institute, said there remains a small proportion of patients who do not respond well to the chemotherapy.
“Usually, they need surgery for better chances of survival,” said Dr Lee, who led this research that started in 2010. But the tumour has to have shrunk enough to allow for an operation.
Sunitinib works by destroying vessels that supply blood to the tumour which fuels its growth.
The tumour blood vessels are usually leaky, explained Dr Lee. “The chemotherapy doesn’t work as well because the drug may be leaking out,” she said. With sunitinib, however, the vessels are repaired briefly before being destroyed. This means chemotherapy delivered during this window can be more effective than usual. That is how the drug is able to shrink the tumour more drastically, said Dr Lee. “This treatment means patients have higher chances of successful or less extensive surgery so they are more likely to be cured,” she added.
Researchers found that a daily dose of 12.5mg of the drug, taken one week before chemotherapy starts, is more effective than the usual regimen.
No traces of cancer were found in about 9 per cent of patients after four cycles of chemotherapy coupled with the drug. None of the patients who had only chemotherapy achieved this.
Sunitinib’s side effects include low blood count, nausea and diar- rhoea, but they are uncommon among the patients in this study.
The findings of Dr Lee’s team were presented at the prestigious American Society of Clinical On- cology conference in June.
Sunitinib is currently approved by the US Food and Drug Administration for other cancers like kid- ney. Each tablet costs about $100. The study is expected to rope in 50 patients in all and take another year to complete.
Whether the treatment will become available to patients hinges on the results of this ongoing study. If they are good enough, re- searchers can proceed to the next phase of clinical trials. This is expected to take another few years.
Breast cancer is the top cancer in women here, with 1,556 new cases yearly. Less than 10 per cent end up unsuitable for surgery to remove the tumour, even after a standard round of chemotherapy.