Breast cancer susceptibility genes 1 and 2, referred to as BRCA1 and BRCA2, were discovered in 1990 and 1994 respectively. Due to the translation of academic terms, many people misunderstand that these two genes themselves are oncogenes. In fact, on the contrary, these two genes themselves are tumor suppressor genes, and perhaps should be more accurately called regulatory genes (Caretaker Gene). Its role is to repair damaged cellular DNA or promote cell destruction when DNA cannot be repaired. What really plays the role of silent female killers are mutations in BRCA1 and BRCA2. Mutations will make these two genes ineffective.
Although the initial B of BRCA1 and BRCA2 both means Breast, don’t simply think that mutations in these two genes are only related to breast cancer. In fact, their mutations also significantly increase the risk of other cancers, such as ovarian cancer.
A study published in the "Journal of Clinical Oncology" on February 24 suggested that women who carry BRCA1 choose to have their ovaries removed before the age of 35 because doing so can significantly reduce the risk of death from ovarian cancer. possibility. Women who carry BRCA1 or BRCA2 gene mutations have a lifetime risk of developing breast cancer as high as 80% (including all women with BRCA1 or 2 gene mutations and those without mutations, the lifetime risk of developing breast cancer is only about 12%), while ovaries with BRCA1 gene mutations The risk of cancer rises to 55, and BRCA2 rises to about 25 (including BRCA1 or 2 gene mutations and all women without mutations, the lifetime chance of developing ovarian cancer is only 1.4). Moreover, removal of the ovaries significantly reduces the risk of death from not only ovarian cancer and breast cancer, but also peritoneal cancer and other cancers. Ovarian cancer is extremely harmful to women's life and health, and has the highest mortality rate among the major malignant tumors suffered by women (average mortality rate within five years: ovarian cancer 55.8, cervical cancer 32.1, breast cancer 10.8 - NCI data). The reason why ovarian cancer can cause such a high mortality rate is that compared to the breast, the organ is located deeper in the human body and the early symptoms are extremely subtle. It is often not discovered until the cancer metastasizes or spreads. The National Cancer Institute predicts that 22,240 women will be diagnosed with ovarian cancer in 2013, and 14,030 of them will die from it. The study spanned 16 years (1995-2011). The scientists used international registry information to identify 5,783 women carrying BRCA gene mutations. Among them, 2,270 had not had their ovaries removed, and the other 2,123 had not had their ovaries removed at the beginning of the study. He underwent surgical resection. During these 16 years, 1,390 patients underwent surgery, and the number of deaths was only 511: 333 from breast cancer, 68 from ovarian cancer, fallopian tube cancer, and peritoneal cancer, and the rest died from other types of cancer. The researchers also observed that on average, 186 women develop ovarian, fallopian tube, and peritoneal cancer every 5-6 years.
The reason why early surgery (before the age of 35) is recommended is that if women with BRCA1 gene mutations after the age of 35 delay surgery until the age of 40, the chance of suffering from ovarian cancer will increase to 4; Delay until age 50, and the odds increase to 14.2. Therefore, as many as 70% of American women who know that they carry a BRCA1 gene mutation choose to have their ovaries removed. Relatively speaking, BRCA2 mutations are much milder. Women who only carry BRCA2 gene mutations are much less likely to develop ovarian cancer and can postpone surgery until the age of 40. Overall, removal of the ovaries significantly reduces all-cause mortality before the age of 70 years. 77 Among them, the reduction in the risk of death from cancers such as ovarian cancer, fallopian tube cancer, peritoneal cancer, and breast cancer is its greatest contribution.
After weighing the pros and cons based on the above factors, the study concluded that the benefits of preventive ovarian surgery outweigh the costs, even though ovarian removal may cause women to suffer from more intense emotional and physical problems than mastectomy.
Although the various menopausal symptoms, slightly increased risk of heart disease, and affected memory and thinking that come with the removal are distressing, hormone replacement therapy can be considered to alleviate them. Researchers also believe that removal before the age of 35 does not mean that women cannot have offspring, because women should have sufficient opportunities to start a family before that.
In addition, the research team also found that BRCA1 mutation carriers who have their ovaries removed will also have a reduced risk of breast cancer by 48.
So, Angelina Jolie is not a fool. Her well-thought-out choices are based on sufficient medical evidence. She is much more open-minded and wiser than Chen Xiaoxu, Steve Jobs, etc. Maybe you don’t know that the life of Angelina Jolie’s mother (who was also a female star) ended at the age of 56 due to ovarian cancer.
Screening for BRCA gene mutations in more women is a huge challenge. Most BRCA gene mutation carriers never realize that there is a ticking bomb hidden in their body. Generally speaking, one in 300 people may carry this genetic mutation. Dr. Andrew Menzin, associate director of gynecologic oncology at the North Shore LIJ Cancer Institute in Manhasset, N.Y., recommends that women with a family history of breast or ovarian cancer should get screened. Chinese women should not be an exception - the mutation ratio of BRCA1/2 genes in Chinese women with familial breast cancer is 12.8, while the mutation ratio of BRCA1/2 in familial breast cancer patients younger than 40 years old is as high as 27.2. As for the cost of screening, the price at Peking Union Medical College Hospital and Peking University Cancer Hospital is about 3,000 yuan; while the price in the United States ranges from a few hundred to several thousand dollars; for companies holding BRCA1 and BRCA2 gene mutation detection patents, the price is as high as 3,000 U.S. dollars.
Finally, imagine the difference in fate between Angelina Jolie and Anita Mui - basic scientific literacy is of real significance to everyone, even if you make countless people bow to you or you are rich. Superstar - Wealth and resources sometimes really don't mean everything.
PS: BRCA1 and BRCA2 gene mutations will greatly increase the probability of women suffering from malignant tumors such as breast cancer and ovarian cancer. However, the vast majority of such cancers are not caused by them. For example, only 5-10% of breast cancers and 10-15% of ovarian cancers in white American women are caused by BRCA1 or BRCA2 gene mutations.
(Author of this article: Fernshiro Frost Jiao)