In clinical practice, we often encounter breast cancer patients and their family members asking about the severity of the disease and how long they will survive, which is actually a very complicated issue. In clinical practice, the treatment plan and prognosis should be determined by combining various classification methods and making an overall assessment.
I. Classical TNM staging.
The basic structure is based on the size of the tumor (referred to as T), whether the lymph nodes are metastatic and the number of metastases (referred to as N), and whether there are distant organ metastases (referred to as M), etc. The value of TNM as an anatomic pathological stage for predicting tumor recurrence and metastasis cannot be underestimated and is a more mature risk assessment index in clinical practice.
Primary tumor (T) staging: Tx Primary tumor status unknown (resected). t0 Primary tumor not retrieved. tis Carcinoma in situ (including lobular carcinoma in situ and intraductal carcinoma), Paget’s disease confined to the nipple, no masses retrieved in the breast. t1 Tumor maximum diameter less than 2Cm. t2 Tumor maximum diameter 2-5crn. t3 Tumor maximum diameter more than 125px. t4 Tumor of any size. Direct invasion of chest wall and skin (including inflammatory breast cancer).
Regional lymph node (N) staging: N0 regional lymph nodes are not found; Nx regional lymph nodes are unknown (previously removed); N1 ipsilateral axillary lymph nodes are enlarged and mobile; N2 ipsilateral axillary lymph nodes are enlarged, fused with each other, or adherent to other tissues; N3 ipsilateral internal breast lymph nodes are metastatic; ipsilateral subclavian and supraclavicular lymph nodes are metastatic.
Distant metastasis (M) staging: Mx with or without distant metastasis is unknown. m0 without distant metastasis. m1 with distant metastasis.
Second, practical clinical staging.
Different clinical stages can be composed according to different TNM, which is also the most common stage used by clinicians to explain the disease to patients and families.
Pathological classification and histological grading.
The histological pattern of breast cancer is complex and there are many types, and more than two types can exist simultaneously in the same piece of cancer tissue or even in the same section. Each type of breast cancer has different treatment methods and prognosis, and the clinical treatment plan should be combined with the pathological type and histological classification. At present, the international and domestic pathological classification of breast cancer is still not uniform in practice.
(a) At present, the following pathological classifications are mostly used in China.
1. Non-invasive carcinoma.
① intraductal carcinoma (cancer cells do not break through the basement membrane of ductal wall).
② lobular carcinoma in situ (cancer cells do not break through the basement membrane of terminal milk duct or alveoli).
③ Intraductal papillary carcinoma.
④Papillary eczema-like breast cancer. This type is early stage and has better prognosis.
2.Early invasive carcinoma.
Early invasive ductal carcinoma (cancer cells break through the basement membrane of the duct wall and start to infiltrate into the interstitium).
Early invasive lobular carcinoma (cancer cells break through the basement membrane of terminal milk duct or alveoli and start to infiltrate into the interstitium, but still confined to the lobules). This type is still in early stage and has better prognosis. (Early infiltration means that the infiltrative component of the cancer is less than l0%).
3.Infiltrative carcinoma.
(1) Infiltrative special carcinoma: papillary carcinoma, medullary carcinoma (with large number of lymphocyte infiltration), tubular carcinoma (highly differentiated adenocarcinoma), adenoid cystic carcinoma, mucinous adenocarcinoma, sweat gland-like carcinoma, squamous cell carcinoma, etc. The differentiation of this type is generally higher and the prognosis is still good.
(2) Invasive non-specific carcinoma: including invasive ductal carcinoma (the most common type in clinical practice), invasive lobular carcinoma, sclerosing carcinoma, medullary carcinoma (without massive lymphocytic infiltration), simple carcinoma, adenocarcinoma, and so on. This type has low differentiation and poor prognosis compared with the above types, and it is the most common type of breast cancer, accounting for 80%.
4. Other rare cancers.
(B) Histological grading criteria.
The relationship between histological grading of tumors and patient prognosis has long attracted the attention of oncologists. The degree of differentiation of breast cancer is very closely related to the prognosis, but the various grading criteria are quite different. The histological grading of breast cancer is mainly evaluated from the following 3 aspects.
1. the degree of glandular duct formation.
2. The polymorphism of the nucleus.
3.Nuclear division count.
The grading criteria of our common malignant tumor diagnosis and treatment standard.
1. Glandular duct formation: 1) 1 point for having most obvious glandular ducts. ② moderately differentiated glandular ducts for 2 points. (3) Solid lamellae or cords of cells are 3 points.
2. Irregularity of nucleus size, shape and chromatin ① 1 point for consistent nucleus size, shape and chromatin. ②Moderate irregularity of nucleus is 2 points. 3 points for obvious polymorphism of the nucleus.
3, chromatin increase and nuclear division phase (×400) ①1/10HPF is 1 point. ②2～3/10HPF is 2 points. ③3 points for >3/10HPF.
The scores determined by the three indicators of each criterion were summed, and 3-5 were classified as grade I (well differentiated), 6-7 as grade II (moderately differentiated), and 8-9 as grade III (poorly differentiated).
Fourth, molecular typing (new classification based on the genetic level).
In recent years, molecular typing of breast cancer based on DNA microarray technology and quantitative multigene RT-PCR assays to predict the risk of recurrence and metastasis of breast cancer and its response to treatment is often combined with molecular subtyping by gene microarray technology and immunohistochemistry, and breast cancer can be clinically classified into four categories [55-57]: Luminal A type (ER+/PR+, HER-2-), Luminal B (ER+/PR+, HER-2+), HER-2+ (ER-/PR-/HER-2+) and Basal-like (ER-/PR-/HER-2-). The clinical response and survival of different molecular subtypes of breast cancer are different, and are now receiving increasing clinical attention.
V. Risk grading (2007 St, Gallen consensus).
According to patient’s age, tumor size, hormone receptor status, tumor cell grading, vascular tumor embolism, HER2 status, and lymph node status, the 2007 St, Gallen expert consensus classifies them into low, intermediate, and high-risk recurrence risk groups, which provides a basis for clinicians to choose the appropriate treatment plan.