Carcinoma in situ of the breast refers to the histological concept of early carcinoma occurring in the ducts or lobules of the breast, called intraductal carcinoma in situ and lobular carcinoma in situ, respectively.
I. Incidence
Carcinoma in situ of the breast is a special type of breast cancer that is relatively rare in clinical practice. It is well known that the growth and expansion of carcinoma are from in situ to early infiltration and then to extensive diffuse infiltration. Therefore, it is not difficult to understand that breast cancer is also a kind of infiltrating cancer that starts from in situ hug and gradually develops into a clinically common one. Therefore, it is not true that the prevalence of breast carcinoma in situ is low, but the clinical diagnosis rate is low and clinically rare. The literature reports that the incidence of breast carcinoma in situ accounts for 3.3c,to of breast cancer in the same period
~5.6%. Among them, intraductal carcinoma in situ is predominant and lobular carcinoma in situ is relatively rare.
Pathological characteristics
Breast carcinoma in situ is divided into two categories according to its different sources and histological features: intraductal carcinoma in situ and lobular carcinoma in situ. They are generally considered as different and independent diseases.
1. Lobular carcinoma in situ is characterized pathologically by the filling of normal glandular follicles with hyperplastic cells, and the boundaries of the hyperplastic cells are unclear. Individually, the proliferating cells are larger, but the normal nuclear plasma ratio is maintained, and nuclear division is relatively rare. The lesions are polycentric or occur in both breasts at the same time, which can be as high as 70% to 80%.
2. Histological features of intraductal carcinoma in situ are malignant proliferation of ductal epithelium, but it does not infiltrate the surrounding normal stroma. There are three types of pathology: acne type, papillary type and sieve type. The acanthotic type of intraductal carcinoma in situ has a large infiltration, while the papillary and sieve mesh types of ductal carcinoma in situ have a relatively small infiltration. Ductal carcinoma in situ often occurs singly, but it can also occur in multiple centers individually.
Clinical manifestations
Ductal carcinoma in situ often has no obvious positive signs clinically, and most of them have no obvious breast lumps. However, the following signs related to carcinoma in situ can be seen clinically: localized glandular thickening of breast with rapid development; nipple overflow, often fresh or old bloody overflow from a single fixed duct; eczema-like changes of nipple, often recurrent and with a long history; limited and nodular hyperplasia of breast gland with the tendency of mass formation, etc.
IV. Diagnosis
Any middle-aged woman who is clinically found to have some positive signs related to carcinoma in situ as mentioned above should be alerted to the possibility of carcinoma in situ of the breast. The following auxiliary examinations are helpful for the early detection and diagnosis of in situ breast cancer.
1.Mammography, which is the main means to detect breast cancer in situ. Its main X-ray features are tiny calcification foci. These calcifications are characterized by large number, cluster shape, variable size and shape, and may also appear as linear or branching calcifications. There are also x-ray presentations without calcification, showing only disorganized glandular structure and asymmetric glandular density, with one or more newly emerging large ductal lesions visible against the original x-ray. Among the X-ray examinations, some scholars also reported that full digital mammography has some clinical value in the diagnosis of carcinoma in situ of the breast.
The role of this technique in the early diagnosis of breast cancer has been confirmed. This method is relatively safe, less invasive and has a high diagnosis rate, so it has been widely used in clinical practice. If microcalcifications or irregular glandular density are found in x-ray examination, a fine needle can be punctured to the suspected area under x-ray stereoscopic positioning, and then an excisional biopsy can be performed along the area guided by the needle for pathological examination, which can often lead to a more satisfactory diagnosis. This method should be used to pay attention to the accuracy of the fine needle puncture positioning, the scope of excisional tissue should be appropriately expanded to avoid missed diagnosis.
3, needle aspiration cytology examination this method is easy to operate, the patient pain is small, the results are more reliable. For the clinical breast can be palpable suspicious lamellar thickening needle aspiration, the aspirated exfoliated cells smear for pathological examination, can often obtain a high diagnostic rate. If the diagnosis is difficult, immunopathological staining of these exfoliated cells with monoclonal antibodies can improve the detection rate of malignant cells. The method can be operated in the lesion site multi-point, multi-directional puncture, in order to improve the positive rate of the purpose.
4.Near infrared scan In recent years, many scholars have studied the early diagnosis of breast cancer with near infrared scan and achieved certain results. Especially in the screening of breast cancer, it has shown some superiority.
5.Ductal endoscopy This method was invented by Japanese scholar Okazaki in 1990s, and is the latest detection means for the diagnosis of the cause of nipple discharge. Endoscopy can visually examine the micro-J lesions in the milk ducts, which has the advantages of high diagnostic rate and repeatable examination.
6.Other tests such as LCD thermogram diagnosis, B-ultrasound diagnosis, pathological examination of nipple overflow smear, CT and MRI breast scan are all valuable for the diagnosis of breast cancer in situ.
V. Treatment
The treatment of breast carcinoma in situ is mainly based on surgery. Whether chemotherapy, radiotherapy and endocrine treatment are also needed after surgery is still somewhat different. Surgical treatment mainly includes the following ways.
1.Simple mastectomy can cure nearly 100% of patients, and it is the traditional operation for treating breast carcinoma in situ. However, this method is relatively traumatic and brings certain WJ psychological burden to patients. Currently, there is a trend to replace simple mastectomy with breast-conserving surgery to treat breast cancer in situ in foreign countries. However, due to the different national conditions and people’s ideology, simple mastectomy is still the preferred treatment for breast cancer in situ in China, and axillary lymph node removal is generally not required. This procedure is more suitable for lobular carcinoma in situ because of its multifocal characteristics.
2.Mastectomy with breast preservation, i.e. 1/4 mastectomy or partial mastectomy with removal of normal glands more than 1 cm away from the tumor margin. This procedure is accepted by most beauty-loving women because it preserves the general shape of the breast and is relatively aesthetic. In recent years, breast-conserving surgery has become more and more common in the treatment of carcinoma in situ of the breast. The rationale for this procedure is that although there is a certain recurrence rate after breast-conserving surgery, there is no significant difference in the overall survival rate between patients who undergo local recurrence followed by local excision and radiation therapy or mastectomy and those who undergo mastectomy initially. The best indications for breast-conserving surgery are patients whose x-rays show microcalcifications in the arc.
Breast-conserving surgery is contraindicated in the following cases.
(1) The lesion is located in the central region of the breast, especially near the nipple.
(2) If there are two or more primary lesions, especially in different quadrants.
(3) Mammograms showing extensive sandy calcifications.
(4) Pathological examination showing extensive intraductal carcinoma lesions.
(5) Pre-pregnancy, post-operative radiotherapy is required.
(6) Small breasts, who have difficulty in maintaining perfect breast appearance after surgery.
Data show that invasive carcinoma after local excision of ductal carcinoma in situ mainly occurs in the primary site of the affected side. The chance of anterior lymph node metastasis in ductal carcinoma in situ is very small, only 3%, so generally, anterior lymph node biopsy may not be considered. However, when histologic features suggest the possibility of invasive metastasis, patients should also be considered for sentinel lymph node biopsy after mastectomy. Paul et al. reported that in 4853 patients with lobular carcinoma in situ, the incidence of invasive carcinoma in the breast 10 years after resection of lobular carcinoma in situ was 0.i% ± 0.5%, which is much higher than that in the general population. These diffuse invasive carcinomas do not necessarily occur at the original site of resection, but can occur anywhere on the affected or contralateral side. Although lobular carcinoma in situ is treated surgically, the possibility of invasive carcinoma in this patient is still higher than that in the general population, and lobular carcinoma in situ is one of the high-grade factors for the development of invasive breast cancer. Therefore, some scholars believe that lobular carcinoma in situ is a precancerous lesion of invasive carcinoma and should be followed up regularly after surgery.
VI. Prognosis
The prognosis of breast carcinoma in situ is much better than that of invasive carcinoma. The cure rate of in situ cancer treated by mastectomy can reach 98% to 100%, and the local recurrence rate is very low. The literature reports that the recurrence rate after total mastectomy is less than 0.75%, and the mortality rate related to primary cancer is only l_ 7%. There is a certain recurrence rate when treated with breast-conserving surgery, and regular follow-up should be performed and the development of the contralateral breast should be noted.