Drug combination could be less invasive treatment for breast cancer, study finds

Madam Lim Hay Eng was first diagnosed with stage three breast cancer in 2011. ST PHOTO: JASON QUAH

SINGAPORE - When Madam Lim Hay Eng experienced a relapse of her breast cancer in 2017, she was concerned about the side effects of any treatments for her condition.

She was first diagnosed with stage three breast cancer in 2011, and underwent surgery to remove cancerous tissues and lymph nodes.

She was placed on chemotherapy for about six months, which often left her weak and unwell, leading to her being sent to the intensive care unit on three separate occasions over the course of six months.

When the cancer came back five years ago, her doctor recommended that the 66-year-old retiree - now battling stage four breast cancer, which had spread to other parts of her body including her liver - try a new orally taken therapy, which was more convenient and had more manageable side effects.

Female breast cancer is the most common cancer in Singapore, affecting more than 2,000 women each year, with more than 400 dying from the disease annually, according to figures from the Singapore Cancer Registry.

Researchers from the National University Cancer Institute, Singapore (NCIS) at the National University Hospital and the Cancer Science Institute of Singapore (CSI Singapore) at the National University of Singapore found that combining two drugs - letrozole and lenvatinib - might help those with advanced stage metastatic breast cancer achieve better control of the disease.

Letrozole is an anti-hormonal drug, while lenvatinib is already approved by the United States Food and Drug Administration for use in treating cancers such as thyroid and liver.

The researchers conducted a study of 43 patients with stage four breast cancer who had failed multiple prior therapies.

Half of those given the combined therapy either saw their tumours shrink or experienced good control of the disease for more than six months, with many able to continue normal daily activities.

"There was no pain at all," Madam Lim told reporters on Friday (June 24).

Noting that the orally taken nature of the medication meant that the dosage could be adjusted to suit her, she said she could perform household chores and spend time with her grandchildren.

The treatment - which was administered to Madam Lim between January 2020 and February this year - resulted in a 7.6cm tumour in her liver shrinking by about 30 per cent to 5.5cm within the first few months, and helped control its growth for the two years that she was on the trial.

(From left) Prof Lee Soo Chin, Madam Lim Hay Eng and Asst Prof Joline Lim. ST PHOTO: JASON QUAH

The study's lead investigator, Professor Lee Soo Chin, told the media that "currently, there is an ongoing late phase trial that is running at our institution that will compare this combination directly against standard second-line treatment".

Prof Lee - who is also head of the Department of Haematology-Oncology at NCIS and senior principal investigator at CSI Singapore - hopes the study will be completed in a few years.

She expects that the treatment will be made affordable for patients, if the trial turns out successful and the treatment becomes a standard clinical option.

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