讀後心得

In Taiwan, breast cancer is the most common cancer among women, and the treatment of "triple-negative breast cancer" is particularly challenging because this type of cancer lacks available hormone therapies and targeted treatments. Recently, an associate professor from Stanford University shared a study published in *Science*, indicating that a diet rich in ω-6 linoleic acid may promote the growth of triple-negative breast cancer, as it can activate the key signaling pathway mTORC1. The research found that triple-negative breast cancer cells have high levels of FABP5, making them sensitive to ω-6, which increases the risk of tumor growth. Therefore, adjusting the dietary structure to reduce the intake of ω-6 may help lower the risk of this type of cancer.

Among women in Taiwan, the most common cancer is breast cancer, and the most troublesome type within breast cancer is "triple-negative breast cancer." The treatment options for this cancer are relatively limited.

According to research, triple-negative breast cancer (TNBC) often faces treatment challenges because this type of cancer cell lacks three hormone receptors: estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). As a result, most patients can only rely on chemotherapy, without access to hormone therapy and targeted therapy, leading to limited treatment options. Additionally, the genetic variability of triple-negative breast cancer is extremely high, causing patients to frequently encounter poor prognosis, high recurrence rates, and an increased likelihood of tumor metastasis to the brain, resulting in a higher mortality rate.

Recent studies indicate that fat intake from diet may be closely related to cancer growth. Research shows that the level of FABP5 is relatively high in triple-negative breast cancer cells, making it easier for omega-6 linoleic acid to promote tumor growth. When omega-6 linoleic acid activates the mTORC1 signaling pathway, it promotes the growth of certain breast cancer cells. Therefore, lipids in the diet may become an important signal for cancer progression.

Specifically, the research found:

• FABP5 acts as a "guiding molecule" for lipids, binding with high affinity to omega-6 linoleic acid and directly interacting with the regulatory protein Raptor of mTORC1, promoting the proliferation of triple-negative breast cancer cells.
• Even in environments lacking amino acids and growth factors, omega-6 linoleic acid can independently promote cell growth, indicating that lipids play a significant role in cancer progression.
• The concentrations of FABP5 and omega-6 linoleic acid are both higher in tumors and serum of triple-negative breast cancer patients, suggesting that FABP5 may serve as a novel tumor biomarker to help identify breast cancer patients sensitive to specific dietary lipids.
• In experiments feeding mice a high omega-6 linoleic acid diet, the growth of triple-negative breast cancer tumors accelerated, and the mTORC1 signaling within tumors was significantly enhanced, further confirming the direct correlation between dietary fat and cancer growth.

This research challenges traditional notions of "healthy fats," as previous associations between omega-6 linoleic acid intake and breast cancer risk remain inconclusive. However, the study results indicate that triple-negative breast cancer cells with high FABP5 expression are more sensitive to omega-6 linoleic acid, which may explain why certain types of breast cancer particularly rely on high-fat diets.

When discussing the impact of diet, the professor mentioned the differences between Western diets and traditional Asian diets. The Western diet is characterized by processed foods, high-fat meats, and fast food, with most cooking oils being soybean oil, corn oil, and other high omega-6 fats, whereas the Mediterranean diet or traditional Asian diet places more emphasis on balanced intake of olive oil, fish, and nuts. The research suggests that limiting omega-6 linoleic acid intake may be beneficial for patients with higher FABP5 levels, while also helping to balance the intake of omega-6 and omega-3 fatty acids, thereby reducing the dietary influence on tumor growth.

Finally, linoleic acid is an omega-6 polyunsaturated fatty acid that the human body cannot synthesize on its own and must be obtained through diet. It is widely found in our everyday cooking oils, nuts, and certain animal meats.