Treatment of Precancerous Lesions in Breast Duct Can Eliminate All Signs of Early Breast Cancer

Breast cancer can be treated in several ways depending on its kind and how far it has already spread. According to the Centers for Disease Control and Prevention (CDC), breast cancer could be treated with chemotherapy, radiation, hormonal, biological, and surgery.

Recently, scientists have found a new way to target precancerous lesions in breast ducts to eliminate any early signs of breast cancer. They performed the experiments on mice, which yielded positive results.

What is Stage 0 Breast Cancer?

Stage 0 breast cancer or DCIS is characterized by the presence of precancerous lesions inside the breast ducts and affects 69,000 women each year in the US.

According to Mayo Clinic, DCIS is the earliest form of breast cancer. Although it is noninvasive, which means it has not spread through the milk duct of the breast yet and has low chances of becoming invasive, it is still best to consult a professional immediately to have it checked and get treated.

DCIS can be easily spotted using a mammogram during breast cancer screening or when a woman feels a lump in her breast. They look like small clusters of calcifications that have irregular shapes and sizes.

Aside from a lump, other symptoms of DCIS also include unusual skin or thickened region under the skin and a bloody nipple discharge. It is usually treated with surgery combined with radiation or chemotherapy to remove the affected breast tissue. Scientists have found a better way to address early breast cancer.

Breast Duct Treatment for DCIS

Senior study author Saraswati Sukumar, Ph.D., a professor of oncology and pathology at Johns Hopkins, and his team proposed an alternative treatment to DCIS by injecting immunotoxin through the breast duct to eliminate precancerous lesions.

In their study titled "Intraductal Administration of Transferrin Receptor-Targeted Immunotoxin Clears Ductal Carcinoma in Situ in Mouse Models of Breast Cancer-a Preclinical Study," published in the Proceedings of the National Academy of Sciences (PNAS), the team explained how the targeted immunotoxin HB21(Fv)-PE40 affected four cell lines in different molecular subtypes of breast cancer.

According to Medical Xpress, the immunotoxin contains the monoclonal antibody HB21 that can bind to a specific target and is used to fuse to PE40, a fragment of bacterial toxin responsible for stopping protein production in cells that leads to cell death.

Experiments showed that the treatment had a strong cancer-killing effect in all four cell lines when administered to 10 mice. When they tested their subjects for toxins in their blood, they found no toxins after five to 30 minutes after the injection.

They then tested the immunotoxin on two mouse models with DCIS. The first mouse MCF7 was injected once per week for three weeks, while the second mouse SUMM225 received the pilot toxin treatment for two weeks. Treatments were followed by noninvasive imaging.

The MCF7 mouse who received the treatment in the body had slower tumor growth, but it recurred after day 26 when the treatment was stopped. On the other hand, tumors disappeared in SUM225 who received the treatment via breast ducts after two weeks of completing two of the three treatments and there was no recurrence detected even after 61 days since the last injection.

Therefore, the study suggests intraductal injection of immunotoxin as it would be most beneficial for larger and higher-grade DCIS as it allows the immunotoxin to directly reach all cancer lesions, eliminating even those not visible in the imaging.

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