Breast cancer "screened out"

Author: Yuanli Beijing Boai Hospital

Reviewer: Xu Qing, Chief Physician, Beijing Boai Hospital

Breast cancer is one of the common malignant tumors in women, and its incidence and mortality rate rank first and fourth among malignant tumors in women in my country, respectively. According to the World Health Organization (WHO), in 2020, breast cancer has surpassed lung cancer to become the world's number one cancer worldwide, and 18.4% of new breast cancer cases are in China. With the increase in prevalence, the mortality rate of breast cancer in my country has also increased year by year, from 4.87/100,000 in 2003 to 6.67/100,000 in 2015, and rose to 9.50/100,000 in 2020. As medical staff and the general public have a deeper understanding of breast cancer, they are increasingly aware of the importance of early detection, early diagnosis, and early treatment. So, how to "screen" out breast cancer is crucial!

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1. What is breast cancer screening?

Breast cancer screening refers to screening asymptomatic women through effective, simple and economical breast examination methods, in order to detect breast cancer or precancerous lesions as early as possible, achieve early detection, early diagnosis and early treatment of tumors, and ultimately reduce the mortality rate of breast cancer. It is an early diagnosis measure for asymptomatic patients.

Breast cancer screening is divided into opportunistic screening and group screening.

(1) Opportunistic screening : refers to breast cancer screening conducted by healthcare institutions on women of appropriate age who come to the institution for treatment for various reasons, or breast cancer screening conducted by individual women who take the initiative to go to healthcare institutions.

(2) Group screening : Breast cancer screening is provided in an organized manner by the community or unit for all eligible women in the community with the help of equipment, technology and personnel from medical and health institutions.

As people's health awareness increases, many patients visiting outpatient clinics are transitioning from group screening to opportunistic screening, or alternating between the two.

2. Why should we conduct breast cancer screening?

At present, the diagnosis and treatment of breast cancer has become quite standardized, and the treatment level of breast cancer in my country, especially in first-tier cities, has surpassed the world level. As we all know, the earlier the disease is discovered and the more timely the treatment, the higher the cure rate. For early breast cancer, the cure rate has reached more than 95%. Breast cancer screening is an important means of detecting breast cancer.

3. What are the screening methods for breast cancer?

(1) Self-examination : refers to an individual examining himself or herself, generally recommended once a month.

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(2) Professional examination : refers to the examination conducted by professional doctors and/or professional equipment when patients undergo opportunistic screening or group screening. Examination methods include physical examination by doctors, breast ultrasound, breast X-ray examination, special optical examination of the breast and breast magnetic resonance imaging (MRI) examination. Different examination methods have their own advantages, and generally professional doctors choose the examination method according to the patient's condition.

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(3) Genetic testing : It is the most advanced screening method at present, but it is often expensive. It is generally recommended that people with high-risk factors take the test voluntarily.

4. How do different groups of people conduct breast cancer screening?

The breast cancer screening population is divided into general risk population and high risk population.

1. Screening of general risk population

The general risk population refers to people with an average or low risk of cancer. Most guidelines use the lifetime risk of breast cancer as an important indicator for determining the degree of risk. For the general risk population, breast cancer screening is recommended starting at age 45. The recommended screening frequency is once every 1 to 2 years.

Depending on the situation, breast X-ray examination or breast color ultrasound examination can be performed alone, or the two examinations can be combined. In my country, breast color ultrasound examination is more widely used.

2. Screening of high-risk groups

Definition of high-risk population: ① There is a clear genetic tendency for breast cancer, that is, a first-degree relative has breast cancer or ovarian cancer before the age of 50, and ≥2 second-degree relatives have breast cancer or ovarian cancer; a first-degree relative carries a BRCA mutant gene; ② Patients with atypical hyperplasia or lobular carcinoma in situ confirmed by breast biopsy; ③ A history of chest radiotherapy before the age of 30; ④ A high-risk population assessed by the Gail model (≥1.67%).

(1) Screening start age and screening method for patients with gene mutations: ① Start self-examination of the breast with self-awareness at the age of 18. ② For patients aged 25 to 29, perform breast ultrasound examination once a year on the basis of self-examination and physical examination by a doctor (once every 6 to 12 months); ③ For patients aged 30 to 75, perform breast ultrasound examination once every 6 months on the basis of self-examination and physical examination by a doctor (once every 6 to 12 months), and perform breast X-ray (except for TP53 harmful mutations) or breast nuclear X-ray and MRI examination alternately once a year; ④ Consider individualized screening plans for people over 75 years old. ⑤ Patients can be screened for high-risk genes for breast cancer based on their conditions, professional doctor's advice and patient wishes.

(2) Other high-risk groups who do not carry breast cancer susceptibility genes: ① Start to have a self-conscious regular breast self-examination at the age of 18; ② From the time they are determined to be at high risk, they should have a physical examination by a doctor every 6 to 12 months on the basis of self-examination; ③ 10 years before the youngest age of breast cancer in the family or from the time they are determined to be at high risk, but ≥ 25 years old, on the basis of self-examination and physical examination by a doctor (once every 6 to 12 months), they should have a breast ultrasound examination once a year. After the age of 50, they should have a mammogram once a year, and if necessary, a breast MRI examination.

5. What does the grade in breast cancer screening results mean?

In clinical work, many patients are confused about the BI-RADS classification in the report. They don't know what the BI-RADS classification is, nor do they know the significance of the classification. In fact, the full name of BI-RADS is "Breast Imaging Reporting and Data System". Proposed by the American College of Radiology in 1992, this classification method is convenient for clinical application and communication, and with the continuous development of medical imaging technology. At present, BI-RADS classification is not only used to guide breast X-ray diagnosis, but also widely used in breast ultrasound and MRI diagnosis.

BI-RADS classification is divided into 6 levels.

BI-RADS level 0: means that the existing images cannot complete the assessment and need to be combined with previous or supplemented with other imaging examinations.

BI-RADS grade 1: negative, possibility of malignancy is 0.

BI-RADS grade 2: benign finding, zero possibility of malignancy.

BI-RADS grade 3: The possibility of benignity is high, and the possibility of malignancy is 0-2%.

BI-RADS grade 4: It is divided into 4a, 4b and 4c, among which 4a has a malignancy possibility of 2% to 10%, 4b has a malignancy possibility of 10% to 50%, and 4c has a malignancy possibility of 50% to 95%.

BI-RADS level 5: highly suspected of malignancy, with a malignancy probability ≥ 95%.

BI-RADS grade 6: confirmed to be malignant.

Breast cancer is a malignant tumor that can be diagnosed and treated. Breast cancer screening is of great significance for early detection of breast lesions. As doctors, we hope that breast cancer screening can attract enough attention from the general public, especially female friends, and not be afraid to seek medical treatment. I hope everyone is healthy and happy!

References

1. He Jie, Chen Wanqing, Li Ni, et al. Guidelines for screening, early diagnosis and early treatment of breast cancer in Chinese women (2021)[J]. Chinese Journal of Oncology, 2021, 30(3): 161-191.

2. Shen Songjie, Sun Qiang. Chinese female breast cancer screening guidelines (2022 edition)[J]. Chinese Research Hospital, 2022, 9(2): 6-13.

3. Zhang Xiaohui, Sun Qiang. Expert consensus on breast cancer prevention in Chinese women[J]. Chinese Research Hospital, 2022, 9(4): 5-13.