PERSPECTIVE, PATTERNS OF SPREAD, AND PATHOLOGY
Cancers of the mammary gland predominate among tumors of the chest wall, and their oncoanatomy emphasizes their rich lymphatics and microvasculature.
PERSPECTIVE AND PATTERNS OF SPREAD
Breast cancer is the most prevalent female malignancy and exceeds the incidence of the next two common cancers of lung and colorectal areas combined. At an annual rate of 215,000 new patients and a death rate of 40,000, virtually everyone has a family member or friend who has encountered or experienced breast cancer. With the widespread use of mammography, most cancers are detected in early stages that often are not palpable. Especially important is the ability to identify preinvasive carcinomas in situ.
The patterns of spread account for the physical signs associated with breast cancer (Fig. 20.2; Table 20.2). Most commonly, a small palpable nodule, often without tenderness, appears to be a thickening or swelling, which is freely movable. If the lesion causes skin wrinkling with positional changes, Cooper's suspensory ligaments are involved. Lactiferous ductal invasion can result in expression of a bloody secretion from the nipple or even nipple inversion. Loss of mobility strongly suggests invasion of the pectoralis major or chest wall. When loss of mobility occurs with muscle flexion, it is due to muscle invasion; chest wall infiltration leads to a permanent loss of mobility (Fig. 20.2; Table 20.2).
PATHOLOGY
The majority (85%) are ductal carcinomas in situ and the rest are lobular cancer in situ, which run a more benign course. The histopathologic varieties of breast cancer are tabulated in Table 20.1; Figure 20.1. It is recommended that all invasive breast cancers be graded utilizing the Nottingham system, in which point scores based on specific features are equated with grades 1 to 3. A comprehensive review of the literature of histologic grade and outcome in early stage breast cancer in the current American Joint Committee on Cancer (AJCC) sixth edition indicates its robustness as a prognostic factor. It seems certain that emerging data will support its incorporation into staging in the future editions, similar to the Gleason grade for prostate cancer staging.
Figure 20.1| A: Carcinoma of the breast. Ductal carcinoma cells invading stroma showing irregular cords and nests of invasive. B: Lobular carcinoma. Invasive lobular carcinoma. In contrast to invasive ductal carcinoma, the cells of lobular carcinoma tend to form single strands that invade between collagen fibers in a single pattern. The tumor cells are similar to those seen in lobular carcinoma in situ.
Figure 20.2 | Patterns of spread. The primary cancer (breast cancer) invades in various directions, which are color-coded vectors (arrows) representing stage of progression: Tis, yellow; T1, green; T2, blue; T3, purple; T4, red; and metastatic, black. The concept of visualizing patterns of spread to appreciate the surrounding anatomy is well demonstrated by the six-directional pattern i.e. SIMLAP Table 20.2.
TNM STAGING CRITERIA
TNM STAGING CRITERIA
Breast cancer has been among the earliest cancers staged utilizing the TNM system and was proposed in 1954 by the International Union Against Cancer (UICC). Agreement by both UICC/AJCC (the first joint publication in 1968) has enabled the staging criteria to remain constant over the past three decades. The modifications relate to the frequent use of surgical findings and their histopathologic examination. The clinical basis for primary breast cancer staging is size: T1, less than 2 cm; T2, 2 to 5 cm; and T3, greater than 5 cm in any dimension. Evidence of fixation to the chest wall appeared as a modifier in each stage, that is, A or B. The lymph node staging applied to axillary nodes mainly.
In the fourth edition (1992), the impact of mammography was acknowledged and tumor size was so noted and used to create subcategories for stage I: T1A, 0.5 cm; T1B, 0.5 to 1 cm; T1C, 1 to 2 cm; and extension to skin or chest wall is applied to T4 cancers only.
In the fifth edition (1997), clinical measurement of size applied to both physical examination and mammography, and pathologic tumor size for T applied “only to the invasive component.” Cellular and molecular markers were tabulated, acknowledging that 80 putative variables were reported in the literature. Although three prognostic groupings were noted, no specific incorporation of biomarkers was made by the American College of Pathologists. In the sixth edition (2003), microinvasion is defined at the primary site and regional nodes. The use of scintigraphy for determining the sentinel node(s) has been allowed. More subcategories exist for the primary and regional nodes, but the general parameters of size have remained stable. There have been considerable new data presented for the interested investigator in the latest AJCC 7th edition for evidence-based changes. These are covered in the rules for classification section. Histopathologic evaluation of surgical specimens can yield a long list of histopathologic types.
The importance of specific imaging modalities to estimate tumor size includes mammograms, sonograms, and magnetic resonance imaging (MRI), as noted at the beginning of the seventh edition summary of changes. Most of the changes relate to microinvasive disease and identifying the invasive components, mostly for accurate pathologic stages. An increasing array of categories and definitions include (Fig. 20.3B):
• DIN: ductal intraepithelial neoplasia
• DCIS: ductal cancer in situ
• LIN: lobular neoplasia
• LCIS: lobular cancer in situ
• Paget's disease
The TNM staging matrix is color coded for identification of stage group once T and N stages are determined (Table 20.3)
SUMMARY OF CHANGES SEVENTH EDITION AJCC
Tumor (T)
• Identified specific imaging modalities that can be used to estimate clinical tumor size, including mammography, ultrasound, and MRI (Fig. 20.3A).
• Made specific recommendations that (i) microscopic measurement is the most accurate and preferred method to determine pathologic staging (pT) with a small invasive cancer that can be entirely submitted in one paraffin block, and (ii) the gross measurement is the most accurate and preferred method to determine pT with larger invasive cancers that must be submitted in multiple paraffin blocks.
• Made the specific recommendation to use the clinical measurement thought to be most accurate to determine the clinical T of breast cancers treated with neoadjuvant therapy. Pathologic (posttreatment) size should be estimated based on the best combination of gross and microscopic histological findings.
• Made the specific recommendation to estimate the size of invasive cancers that are unapparent to any clinical modalities or gross pathologic examination by carefully measuring and recording the relative positions of tissue samples submitted for microscopic evaluation and determining which of these contain tumor.
Stage Summary Matrix TABLE 20.3
BREAST CANCER
Figure 20.3A | TNM staging diagram. Breast cancers are mammary gland cancers, and because of the effectiveness of mammography screening the classification has become more of a pathologic staging system for both primary and lymph nodes. Note stage III is divided into A/B/C as distinct from stage IV. Vertical presentation of stage groupings, which follows the same color code for cancer advancement, are organized in horizontal lanes: Stage 0, yellow; I, green; II, blue; IIIA, purple; IIIB, red; and metastatic stage IIIC and IV, black. Definitions of TN are on the left and stage groupings are on the right.
• Acknowledged DIN as uncommon, and still not widely accepted, terminology encompassing both DCIS and atypical ductal hyperplasia (ADH), and clarification that only cases referred to as DIN containing DCIS (+/− ALH) are classified as Tis (DCIS) (Fig. 20.3B).
• Acknowledged LIN as uncommon, and still not widely accepted, terminology encompassing both LCIS and atypical lobular hyperplasia (ALH), and clarification that only cases referred to as LIN containing LCIS (+/− ALH) are classified as Tis (LCIS).
• Clarification that only Paget's disease not associated with an underlying noninvasive (i.e., DCIS or LCIS) or invasive breast cancer should be classified as Tis (Paget's) and that Paget's disease associated with an underlying cancer be classified according to the underlying cancer (Tis, T1, etc.).
• Made the recommendation to estimate the size of noninvasive carcinomas (DCIS and LCIS), even though it does not currently change their T classification, because noninvasive cancer size may influence therapeutic decisions, acknowledging that providing a precise size for LCIS may be difficult.
• Acknowledged that the prognosis of microinvasive carcinoma is generally thought to be quite favorable, although the clinical impact of multifocal microinvasive disease is not well understood at this time.
• Acknowledged that it is not necessary for tumors to be in separate quadrants to be classified as multiple simultaneous ipsi-lateral carcinomas, providing that they can be unambiguously demonstrated to be macroscopically distinct and measurable using available clinical and pathologic techniques.
• Maintained that the term “inflammatory carcinoma” be restricted to cases with typical skin changes involving a third or more of the skin of the breast. While the histologic presence of invasive carcinoma invading dermal lymphatic is supportive of the diagnosis, it is not required, nor is dermal lymphatic invasion without typical clinical findings sufficient for a diagnosis of inflammatory breast cancer.
• Recommended that all invasive cancer should be graded using the Nottingham combined histologic grade (Elston-Ellis modification of Scarff-Bloom-Richardson grading system).
Nodes (N)
• Classification of isolated tumor cell clusters and single cells is more stringent. Small clusters of cells not greater than 0.2 mm, or nonconfluent or nearly confluent clusters of cells not exceeding 200 cells in a single histologic lymph node cross-section are classified as isolated tumor cells.
• Use of the (sn) modifier has been clarified and restricted. When six or more sentinel nodes are identified on gross examination of pathology specimens the (sn) modifier should be omitted.
• Stage I breast tumors have been subdivided into stage IA and stage IB; stage ID includes small tumors (T1) with exclusively micrometastases in lymph nodes (N1mi).
Metastases (M)
• Created new M0 (i+) category, defined by presence of either disseminated tumor cells detectable in bone marrow or circulating tumor cells or found incidentally in other tissues (such as ovaries removed prophylactically) if not exceeding 0.2 mm. However, this category does not change the stage grouping. Assuming that they do not have clinically or radiographically detectable metastases, patients with M0 (i+) are staged according to T and N.
Postneoadjuvant Therapy (yc or ypTNM)
• In the setting of patients who received neoadjuvant therapy, pretreatment clinical T (cT) should be based on clinical or imaging findings.
• Postneoadjuvant therapy T should be based on clinical or imaging (ycT) or pathologic findings (ypT).
• A subscript will be added to the clinical N for both node negative and node positive patients to indicate whether the N was derived from clinical examination, fine-needle aspiration, core needle biopsy, or sentinel lymph node biopsy.
• The posttreatment ypT will be defined as the largest contiguous focus of invasive cancer as defined histopathologically with a subscript to indicate the presence of multiple tumor foci. Note: Definition of posttreatment ypT remains controversial and an area in transition.
• Posttreatment nodal metastases no greater than 0.2 mm are classified as ypN0 (i+) as in patients who have not received neoadjuvant systemic therapy. However, patients with this finding are not considered to have achieved a pathologic complete response (pCR).
• A description of the degree of response to neoadjuvant therapy (complete, partial, no response) will be collected by the registrar with the posttreatment ypTNM. The registrars are requested to describe how they defined response (by physical examination, imaging techniques—mammograms, ultrasound, MRI—or pathologically).
• Patients will be considered to have M1 (and therefore stage IV) breast cancer if they have had clinically or radiographically detectable metastases, with or without biopsy, prior to neoadjuvant systemic therapy, regardless of their status after neoadjuvant systemic therapy.
Breast cancer staging is equally weighted more to lymph node progression and the primary tumor (Fig. 20.2). This is evident in stage I N0, stage II N1, stage IIIA N2, and stage IIIC N3. The pathologic staging is more detailed with each N category being further subdivided into N1a/b/c based mainly on the number of nodes microscopically involved and the number of locations (i.e., axillary and internal mammary).
There are a number of important and interesting definitions for a lymph node to be considered positive. Definitions of microdeposits began in breast cancer staging:
• ITC: isolated tumor cell clusters in lymph nodes less than 0.2 mm (approximately 1,000 cells).
• Micromets: greater than 0.2 mm to less than or equal to 2.0 mm deposits in nodes
• NB: size of largest deposit, not sum of deposits
• pNo (mol+): refers to use of molecular markers (reverse transcription-polymerase chain reaction [RT-PCR])
• SN: refers to sentinel nodes
• yP: prefix refers to posttreatment assessment of disease
• c Mo (i+): refers to molecular or microdeposits of circulating tumor cells (CTC) or in bone marrow.
Although histopathologic grading systems are discussed, they are to be noted but not included in staging as in prostate cancer. The Nottingham combined histologic grade is recommended (Table 20.4).
Figure 20.3B | The Wellings-Jensen model of breast cancer evolution proposes that the cellular origin of breast cancers occurs in the normal terminal duct lobular unit (TDLU) and that the putative precursors represent a nonobligatory series of increasingly abnormal stages that progress to cancer over long periods of time, probably decades in most cases. Briefly, the key stages in the so-called ductal lineage (representing about 80% of all breast cancers) are referred to as columnar cell hyperplasia (CCH) or hyperplastic enlarged lobular units (HELUs), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC). The stages in the so-called lobular lineage (representing the remaining 20% of carcinomas) are referred to as atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), and invasive lobular carcinoma (ILC).
T-ONCOANATOMY
ORIENTATION OF THREE-PLANAR ONCOANATOMY
The isocenter for the breast three-planar anatomy is customarily at the thoracic T8-9 level. The planes for regional lymph nodes are midaxillary, midclavicular, and parasternal (Fig. 20.4).
T-Oncoanatomy
The mammary gland consists of 15 to 20 lobes of glandular tissue with varying amounts of fat in a dense fibroareolar stroma and is attached to the anterior chest wall by pectoral fascia. In cross-sections starting from the nipple, there are openings of the lactiferous ducts and their lactiferous sinuses, which are the conduits for the secretions of the hormonally stimulated breast glands. These ducts are distinct and individual for each lobule; they first run dorsally from the nipple and then spread radially into the glandular tissue.
The three-planar views illustrate the breast three-dimensionally in terms of its anatomic relationships to other structures (Fig. 20.5). As a superficial structure, the mammary gland is covered by skin. Posteriorly, the underlying pectoral muscles bind the breast to the chest wall. Deep to the glandular tissue, there is usually a small amount of fat, which, along with the breast proper, is bounded by a deeper layer of superficial fascia. This layer can usually be dissected free from the deep fascia invaginating the pectoralis major muscle. Connective tissue septa called the suspensory ligaments (of Cooper) form subdivisions of the breast, dividing the breast into lobes.
The pectoralis major, the muscle underlying the breast, consists of two heads that arise from the clavicle, sternum, and cartilages of the first six ribs, and it inserts as a bilaminar structure on the anterolateral aspect of the humeral shaft.
The entire chest and breast must be considered as an anatomic unit. This requires knowledge of the underlying bony architecture, the muscles, as well as the nerves and vessels of the region.
• Coronal: As a superficial appendage of the chest wall, the mammary gland is covered by skin, and its glandular structures are compartmentalized between connective tissue septa—15 to 20 lobes that have their own lacunae and duct opening on the alveolar area of the nipple. Note the axillary tail (of Spence) of the breast.
• Sagittal: Most of the breast consists of fat; a region of loose connective tissue between the pectoral fascia muscle and breast—the retromammary space—permits mobility because the suspensory ligaments of Cooper allow alteration of shape with movement.
• Axial: The T8-9 level demonstrates the relationship of the breast to chest wall. The diagram is simplified by showing nerves on the right and arteries on the left. The three musculomembranous layers are the external intercostals muscle and membrane, internal intercostals muscle and membrane, and the innermost intercostals, transverse thoracic muscle, and the membrane connecting them. The inter-costal nerves are the anterior rami of spinal nerves T1 to T11; the anterior ramus of T12 is the subcostal nerve.
Figure 20.4 | Orientation of T-oncoanatomy. The anatomic isocenter for three-planar oncoanatomy in the coronal view is placed lateral to midline over the breast and in the sagittal view anterior to the chest wall with the transverse view at the T8-9 level.
Figure 20.5 | T-oncoanatomy. Connecting the dots: Structures are color coded for cancer stage progression. The color code for the anatomic sites correlates with the color code for the stage group (Fig. 20.3) and patterns of spread (Fig. 20.2) and SIMLAP table (Table 20.2). Connecting the dots in similar colors will provide an appreciation for the 3D Oncoanatomy.
N-ONCOANATOMY AND M-ONCOANATOMY
N-ONCOANATOMY
The breast lymphatics drain via four major routes—axillary, transpectoral, internal thoracic parasternal (mammary) trunks, and intercostal into numerous surrounding regional nodes, such as axillary (low, middle), axillary apex, supraclavicular, internal thoracic parasternal, interpectoral, and subclavicular nodes. Other pathways include crossover lymphatic channels to the opposite breast and inferior drainage into diaphragmatic and subdiaphragmatic channels. (Note: Subclavicular nodes are considered juxtaregional on the ipsi-lateral side.) Disease involvement in all other nodes—cervical, contralateral, supraclavicular, and contralateral internal thoracic, and mammary nodes—is equivalent to distant metastases (Fig. 20.6; Table 20.4).
The axilla is a crucial area to multidisciplinary oncologic decision making. Thorough knowledge of the axillary nodal status requires surgical sampling or dissection by the surgical oncologist. The presence of positive axillary nodes often determines the use of adjuvant chemotherapy. And, if the axilla is to be treated by radiation therapy, it needs to be encompassed in its entirety.
The axillary contents consist of a variety of important structures. Damage to vessels can occur if they are injured during dissection. The major vessels include axillary veins, the cephalic vein and its branches, and the axillary artery and its branches. There is a close association between the brachial plexus and these vessels. Although perineural invasion by tumor is uncommon, it can occur.
Although anatomic knowledge of the region of the mammary nodes is quite important in oncologic decision making, internal thoracic (mammary or parasternal) nodes are most commonly identified in the first three intercostal spaces or the xiphisternal angle. These nodes lie laterally to the sternum in an approximately 1- to 2-cm-wide strip and are 3 cm deep to the chest wall. The deeper lymphatics within the thoracic cavity and mediastinum are important pathways for dissemination. They include the pleural, vertebral, and mediastinal nodes and the thoracic duct. Of equal importance clinically are the major lymphatic routes. The lymphatic circulation empties into the general circulation at the junction of the internal jugular and subclavian veins. Therefore, lymphatic metastases often become blood borne metastases, as if direct vascular invasion occurred.
REGIONAL LYMPH NODES
The breast lymphatics drain by way of three major routes: axillary, transpectoral, and internal mammary (Fig. 20.6). Intramammary lymph nodes reside within breast tissue and are coded as axillary lymph nodes for staging purposes. Supraclavicular lymph nodes are classified as regional lymph nodes for staging purposes. Metastases to any other lymph node, including cervical or contralateral internal mammary or axillary lymph nodes, are classified as distant (M1). The regional lymph nodes are as follows:
1. Axillary (ipsilateral): interpectoral (Rotter's) nodes and lymph nodes along the axillary vein and its tributaries that may be (but are not required to be) divided into the following levels:
a. Level I (low-axilla): lymph nodes lateral to the lateral border of pectoralis minor muscle.
b. Level II (mid-axilla): lymph nodes between the medial and lateral borders of the pectoralis minor muscle and the interpectoral (Rotter's) lymph nodes.
c. Level III (apical axilla): lymph nodes medial to the medial margin of the pectoralis minor muscle and inferior to the clavicle. These are also known as apical or infraclavicular nodes. Metastases to these nodes portend a worse prognosis. Therefore, the infraclavicular designations will be used hereafter to differentiate these nodes from the remaining (level I, II) axillary nodes.
2. Internal thoracic (mammary) (ipsilateral): lymph nodes in the intercostal spaces along the edge of the sternum in the endothoracic fascia.
3. Supraclavicular: lymph nodes in the supraclavicular fossa, a triangle defined by the omohyoid muscle and tendon (lateral and superior border), the internal jugular vein (lower border). Adjacent lymph nodes outside of this triangle are considered to be lower cervical nodes (M1).
4. Intramammary: lymph nodes within the breast; these are considered axillary lymph nodes for purposes of N classification and staging.*
M-ONCOANATOMY
The rich plexus of veins parallel the lymphatics, with the outer quadrants draining into the axillary veins and the inner quadrants draining into the internal thoracic (mammary) veins. The axillary veins enter the subclavian, and the internal thoracic veins enter the brachiocephalic veins, which form the superior vena cava (Fig. 20.7). Metastatic breast cancer will result in an estimated death toll of almost 40,000 patients. The identification of circulating cancer cells for disseminated cancer cells in the blood or bone marrow has been designated M0(i+) in the 7th edition as a precursor state for metastases, but does not change the stage group. Monoclonal antibodies to epithelial cytokeratine or membrane glycoproteins can be used to detect bone marrow spread. Micro metastases are detected in 30% of patients, most often with negative prognostic factors as ERCS, PRC-S, HER-2(+). If micro metastases are detected survival is poorer in multivariate outcome.
*Preceding passage from Edge SB, Byrd DR, and Compton CC, et al. AJCC Cancer Staging Manual, 7th edition. New York: Springer, 2010, pp. 352.
Figure 20.6 | N-oncoanatomy. Lymph drained from the upper limb and breast passes through nodes arranged irregularly in groups. Pectoral, along the inferior border of the pectoralis muscle. Subscapular, along the subscapular artery and veins. Brachial, along the distal part of the axillary vein. Central, at the base of the axilla embedded in axillary fat. Apical, along the axillary vein between the clavicle and the pectoralis minor muscle.
Figure 20.7 | M-oncoanatomy. The basilic vein joins the accompanying veins of the brachial artery to become the axillary vein at the inferior border of teres major, the axillary vein becomes the subclavian vein at the lateral border of the first rib, and the subclavian joins the internal jugular to become the brachiocephalic vein posterior to the sternal end of the clavicle. Observe the three suprascapular veins: One entering the axillary vein and two entering the external jugular vein.
STAGING WORKUP
RULES FOR CLASSIFICATION AND STAGING
Clinical Staging
With early and subclinical detection of breast cancer by screening mammography and further evaluation by MRI, the clinical staging that relied on physical examination, consisting of careful palpation and inspection of the mammary glands and draining lymph nodes, has been supplemented by image-guided biopsy of the breast and suspicious nodes. The key feature in staging is in determining the size of the invasive component within 4 months of diagnosis and in the absence of disease progression (Table 20.5; Fig. 20.8).
Pathologic Staging
The importance of pathologic staging (pT) is in its ability to truly assess the invasive component of a nodule and evaluate lymph node involvement, often as sentinel nodes determined by scintigraphy. The nodule needs to be completely excised for pT, only microscopic positive margins are allowed, not macroscopic. The intraductal component is not added to the invasive component. Microinvasion is defined as extension beyond the basement membrane, with no focus more than 0.1 cm in diameter. When multiple foci exist, the size of the largest is used to classify microinvasion. Similarly, for multiple primaries only the largest is given a T stage, no stage is assigned to smaller cancers.
• T1a is greater than 1 mm and less than or equal to 5 mm in greatest dimension;
• T1b is greater than 5 mm and less than or equal to 10 mm in greatest dimension; and
• T1c is greater than 10 mm and less than or equal to 20 mm in greatest dimension.
Curiously, microinvasion first defined in cervical uterine cancers is noted differently: T1a1 is stromal invasion 3 mm in depth 7 mm horizontally and T1a2 is greater than 3 mm × less than or equal to 7 mm, respectively.
The pN categories are the most detailed in the AJCC manual, noting both the size of micrometastases in nodes, as pN1Mi is greater than 0.2 mm to less than or 2 mm, and the number of nodes involved as well as their geographic location. Each pN stage is modified into three subcategories, creating 9 to 12 possibilities. At issue awaiting more data and analysis are:
• Isolated tumor cells (ITCs) detected by immunohistochemical techniques may be as small as 1 mm or 500,000 cells; however, confirmatory hematoxylin and eosin stains are advised.
• ITC is defined as less than or 0.2 mm and micrometastases as greater than 0.2 mm but less than or 2 mm.
• RT-PCR can identify isolated cancer cells, but pN0 is advised with an appended designation of (mol+) or (mol−) as appropriate.
• The number of positive nodes is well supported by large series: 1 to 3 positive, 4 to 10 positive, and 10 positive show a progressive decline in survival as a function of the number of positive nodes.
• Supraclavicular lymph nodes (SCLN) are considered N3 and not M1 because survival is better with isolated SCLN without disseminated metastatic foci.
• Maturation of 80 potential prognostic variables remains under study, namely, p53, HER2/neu, and Ki-67.
Oncoimaging Annotations
• There are no pathognomonic mammographic signs that a lesion is either benign or malignant. The more irregular a mass is, the greater the likelihood of malignancy. Spiculated masses, however, can be caused by radial scars, postoperative scars, fat necrosis, desmoid tumors, hemorrhage, or abscesses.
• Approximately 10% of breast cancers are not mammographically visible. Only about two thirds of recurrent cancers in the treated breast are visible mammographically.
• On ultrasound, malignancies are typically ill defined, irregular, hypoechoic, taller than wide, and have posterior acoustic shadowing.
• MRI is the most reliable imaging study for assessing the presence of cancer. Contrast enhancement is not needed for this study. Dynamic contrast enhancement is, however, critical in the MRI evaluation of breast masses.
• Calcification per se is not a sign of malignancy and may be associated with firm adenomas, fibrocystic processes, and sclerosing adenosis.
• Highly suspicious calcifications are divided into two groups: pleomorphic or heterogeneous (granular) similar to a crushed stone pattern.
• Fine linear or branching in a discontinuous dot dash pattern are suspicious.
• Branching points in a duct produce Y-shaped patterns that can appear bizarre and are the most suspicious types seen on mammography.
Figure 20.8 | Axial CTs of T8 and T9 level correlate with the T-oncoanatomy transverse section (Fig. 20.5C). Oncoanatomy with CT is commonly applied to staging cancers, often combined with PET to determine true extent of primary cancer and involved lymph nodes. A. Mediastinal window. 1, ascending aorta; 2, descending aorta; 3, right ventricle; 4, right atrium; 5, left atrium; 6, left atrial appendage; 7, inferior pulmonary vein; 8, segmental lower lobe artery; 9, left anterior descending coronary artery; 10, circumflex coronary artery. B. Lung window . 1, inferior pulmonary vein; 2, anteromedial segment LLL bronchus; 3, lateral segment LLL bronchus; 4, post segment LLL bronchus; 5, post segment RLL bronchus; 6, lateral segment RLL bronchus; 7, antior segment RLL bronchus; 8, segmental pulmonary artery.
PROGNOSIS
The limited number of prognostic factors are listed in Table 20.6.
PROGNOSIS AND CANCER SURVIVAL
CANCER STATISTICS AND SURVIVAL
Breast cancer death rates have been decreasing since 1990, after 5 decades with minimal change. The dramatic improvement in breast cancer survival is due to multiple factors including early detection and improved multimodal treatments, often with breast conservation. There are more than 200,000 new cases of breast cancer diagnosed in the USA, which constitutes 28% of all female cancers and is the most common female cancer. Nevertheless, breast cancer accounts for approximately 40,000 deaths, 15% of all cancer deaths in females, and are the second most common female death exceeded only by lung cancer.
Early detection, by mammography on average will detect 80 to 90% of breast cancers in women without symptoms. MRI is recommended for women at high risk, i.e., family history of breast cancer, have BRAC1 and BRAC2 gene expression, use of combined estrogen and progesterone, and high radiation dose in young women survivors with Hodgkin's disease.
The five year survival rates have improved from 60% in the 1950’s to 90% currently. Also, five year survival for Stage I cancer is 98%, decreases with regional node involvement to 84%, and decrements with metastases to 23%. All stages combined are 82% at ten years, and 75% at 15 years. The observed survival rates of breast cancer based on the National Cancer Database (271,645 cases) as shown in Figure 20.10, which is presented at 5 year rates.
Figure 20.9 | Trajectory for breast cancer curability.
The impact of two important prognostic factors are:
• Diameter of primary tumor (cm) 2 cm − >5 cm.
• Nodal involvement 1−3+ nodes, and 4+ nodes (Fig. 20.11).
Figure 20.10 | Observed survival rates for carcinoma of the breast. Data from the National Cancer Data Base (Commission on Cancer of the American College of Surgeons and the American Cancer Society). Diagnosed in years 2001–2002.
Figure 20.11 | Impact of tumor diameter and nodal involvement on breast cancer survival.