Samsung Medical Center Research Team has found a characteristic of “young breast cancer patients”

The molecular biological characteristics of premenopausal breast cancer patients, that is, young breast cancer patients, among Asian women, including Koreans, have been identified by Korean researchers.

Breast cancer is known to occur mainly after menopause, and in fact, for women in the western part of the world, the post-menopause occurrence rate accounts to up to 85%. However, for Korean and Asian women,  the pre-menopause occurrence rate is at 50%, which shows a significant difference.
Breast cancer that occurs in young women, 40 years old and below, is mostly pre-menopausal, and the biological activity that goes with it is very aggressive. The progression of cancer is also rapid, as it does not respond to various types of treatment, thereby causing a severe long-term prognosis.
 The Samsung Comprehensive Cancer Center’s research team, led by Nam Seok Jin, MD, PhD (Division of Breast Surgery), Park Yeon Hee, MD, PhD (Division of Hematology-Oncology), and Park Woon Yang, MD, PhD, from the Samsung Genome Institute, with Dr. Zhengyan Kan, a precision oncology scientist at a global pharmaceutical company (Pfizer), has revealed characteristics of breast cancer in Asian women through DNA sequencing, which was different from that of Western women. This research was recently published in Nature Communications.

The researchers conducted a prospective genomic analysis of the cancer tissue from 187 breast cancer patients, who have received treatment at the Samsung Medical Center, and compared the results with TCGA1) and looked for differences.

For the clinical type of breast cancer, the Asian patients showed a comparably high rate of ER+/HER2+. This rate accounted for 16.1% of the patients checked by Samsung Medical Center, which was almost three times the TCGA report (5.4%).

Considering that this type of patients has faster-growing cancer and worse prognosis, this result reflects the characteristics of young breast cancer patients.
Moreover, the research team found differences in the breast cancer-affecting gene mutation for Asian women. When the team assessed the degree of mutation for BRCA2), which has been confirmed to affect breast cancer, the Asian patients showed 10.8%, whereas the Western patients showed 4.7%, which is a significant difference.

Another cancer-related gene, TP53, was also found in 47.9% of Asian patients, whereas it was found in only 32% of Western patients. Moreover, Asian patients had an increased number of TIL, an immune cell, when compared to Western patients, and there was a decrease in the secretion level of TGF-β, an inhibitor of breast cancer cell growth.
Professor Park Yeon Hee said that “for Asian women, the onset of breast cancer is comparably early, stripping their life apart” and "this study has deepened our understanding of young Asian breast cancer patients at a molecular biological level, and it will act as a stepping stone for future development of new treatments.”

1) The Cance Genome Atlas
2) BReast CAncer gene