Invasive Carcinoma 70–85

No special type carcinoma ("ductal") 79

Lobular carcinoma 10

Tubular/cribriform carcinoma 6

Mucinous (colloid) carcinoma 2

Medullary carcinoma 2

Papillary carcinoma 1

Metaplastic carcinoma <1

The data on invasive carcinomas are modified from Dixon JM, et al: Long-term survivors after breast cancer. Br J Surg 72:445, 1985.

*The proportion of in situ carcinomas detected depends on the number of women undergoing mammographic screening and ranges from less than 5% in unscreened populations to

almost 50% in patients with screen-detected cancers. Current observed numbers are between these two extremes.

typically express hormone receptors and do not overexpress HER2/neu. Others are composed of anastomosing sheets of pleomorphic cells ( Fig. 23-22B ) and are less likely to express

hormone receptors and more likely to overexpress HER2/neu. The majority of invasive ductal carcinomas lie between these two extremes. Most carcinomas induce a marked increase in

dense, fibrous desmoplastic stroma, giving the tumor a hard consistency on palpation and replace fat, resulting in a mammographic density (scirrhous carcinoma).

Carcinomas of NST are accompanied by varying amounts of DCIS. The grade of the DCIS usually correlates with the grade of the invasive carcinoma. For example, comedo DCIS is

usually associated with poorly differentiated carcinomas, and low-grade DCIS is usually associated with well-differentiated carcinomas. Carcinomas associated with a large amount of

DCIS require large excisions with wide margins to reduce local recurrences.

Morphologic analysis of this large group of carcinomas has not identified tumor types of significant clinical relevance beyond the specialized types to be described below. Recent studies

using microarrays to analyze the transcriptional profile of these cancers have identified additional subgroups. ( Box 23-1 )[41] [56] [57] The challenge of future studies will be to show the

clinical relevance of subtypes identified by gene expression profiling (e.g., with respect to etiology, presentation, prognosis, or response to treatment) and, if found, to determine whether

these carcinomas can be recognized by more widely

Figure 23-22 A, Well-differentiated invasive carcinoma of no special type. Well-formed tubules and nests of cells with small monomorphic nuclei invade into the stroma with a

surrounding desmoplastic response. B, Poorly differentiated invasive carcinoma of no special type. Ragged sheets of pleomorphic cells without tubule formation infiltrate into the

adjacent stroma.

Figure 23-23Invasive lobular carcinoma. Parallel arrays of small, regular cells with scant cytoplasm infiltrate singly in linear arrays or as small clusters of cells. There is often

associated LCIS.

Figure 23-24Medullary carcinoma. The cells are highly pleomorphic with frequent mitoses and grow as sheets of cohesive cells. A lymphoplasmacytic infiltrate is prominent.

Figure 23-25Mucinous (colloid) carcinoma. The tumor cells are present as small clusters within large pools of mucin. The borders are typically well circumscribed, and these cancers

often mimic benign masses.

Figure 23-26Tubular carcinoma. The carcinoma must be completely composed of well-formed tubules lined by a single layer of well-differentiated cells.

With no involvement, the 10-year disease-free survival rate is close to 70% to 80%; the rate falls to 35% to 40%

with one to three positive nodes and 10% to 15% in the presence of more than 10 positive nodes.

Most breast carcinomas drain to one or two sentinel nodes that can be identified by radiotracer, colored dye, or both. The sentinel node is highly predictive of the status of the remaining

nodes. Sentinel node biopsy can spare women the increased morbidity of a complete axillary dissection. In some women, particularly those with medial tumors, the sentinel node may be

an internal mammary node. These nodes are generally not biopsied owing to the morbidity associated with the procedure.

Macrometastases (>0.2 cm) are of proven prognostic importance. Because sentinel nodes often undergo more intense scrutiny with additional sections through the tissue, and

immunohistochemistry or reverse transcriptase-polymerase chain reaction (RT-PCR) to detect rare tumor cells, increased numbers of women with minute metastatic deposits in lymph

nodes are being identified. The clinical significance of small micrometastases is unclear and is being addressed by current clinical trials.

l Tumor size.The size of the carcinoma is the second most important prognostic factor and is independent from lymph node status. However, the risk of axillary lymph node

metastases does increase with the size of the carcinoma. Women with node-negative carcinomas under 1 cm in diameter have a prognosis approaching that of women without breast

cancer. The 10-year survival rate of such women without treatment is approximately 90%. On the other hand, over half of women with cancers over 2 cm in diameter present with lymph

node metastases, and many of these women will eventually succumb to breast cancer.

l Locally advanced disease.Tumors invading into skin or skeletal muscle are frequently associated with concurrent or subsequent distant disease. With increased awareness of breast

cancer detection, such cases have fortunately decreased in frequency and are now rare at initial presentation.

l Inflammatory carcinoma.Women presenting with the clinical appearance of breast swelling and skin thickening have a particularly poor prognosis with a 3-year survival rate of

only 3% to 10%.

The major prognostic factors are used by the American Joint Committee on Cancer to divide breast carcinomas into clinical stages as follows:[70]

• Stage 0. DCIS or LCIS (5-year survival rate: 92%).

• Stage I. Invasive carcinoma 2 cm or less in diameter (including carcinoma in situ with microinvasion) without nodal involvement (or only metastases < 0.02 cm diameter) (5-

year survival rate: 87%).

• Stage II. Invasive carcinoma 5 cm or less in diameter with up to three involved axillary nodes or invasive carcinoma greater than 5 cm without nodal involvement (5-year

survival rate: 75%).

• Stage III. Invasive carcinoma 5 cm or less in diameter with four or more involved axillary nodes; invasive carcinoma greater than 5 cm in diameter with nodal involvement;

invasive carcinoma with 10 or more involved axillary nodes; invasive carcinoma with involvement of the ipsilateral internal mammary lymph nodes; or invasive carcinoma with

skin involvement (edema, ulceration, or satellite skin nodules), chest wall fixation, or clinical inflammatory carcinoma (5-year survival rate: 46%).

• Stage IV. Any breast cancer with distant metastases (5-year survival rate: 13%).

Date: 2016-04-22; view: 664