According to the results of a study conducted in Korea, breast cancer patients under the age of 35 have a worse prognosis than patients between the ages of 35 and 50, and may also be less responsive to tamoxifen (Nolvadex®). These results were published in the Journal of Clinical Oncology.
Breast cancer is uncommon in very young women (those under the age of 35), and when breast cancer occurs it may have different characteristics or responsiveness to treatment than breast cancer in older women. Understanding the unique aspects of breast cancer in very young women is important to meeting the treatment needs of these patients.
To describe breast cancer outcomes in younger and older women, researchers in Korea conducted a study among 9,885 breast cancer patients age 50 or younger. Roughly 15% of these patients were under the age of 35.
- Compared to women between the ages of 35 and 50, women under the age of 35 tended to have larger tumors, a higher likelihood of positive lymph nodes, and a higher likelihood of hormone receptor-negative cancer.
- Regardless of tumor size or lymph node status, younger women had worse survival than older women. This difference in survival by age was only apparent among women with hormone receptor-positive breast cancer. Among women with hormone receptor-negative cancer, there was no significant difference in survival between younger and older women.
- Among women with hormone receptor-positive breast cancer, adjuvant (post-surgery) tamoxifen appeared to be less effective among women under the age of 35 than among older women.
The researchers conclude that very young women with hormone receptor-positive breast cancer tend to have worse breast cancer outcomes than older women with hormone receptor-positive breast cancer. Some of this difference may be explained by younger women having less of a response to adjuvant tamoxifen.
The researchers note that because this study was conducted in Korea, in an ethnically homogenous population of women, the results may not be generalizable to other populations.
Reference: Ahn SH, Son BH, Kim SW et al. Poor outcome of hormone receptor-positive breast cancer at very young age is due to tamoxifen resistance: national survival data in Korea-a report from the Korean Breast Cancer Society. Journal of Clinical Oncology. 2007;25:2360-2368.