| Breast cancer |
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History Epidemiologija Etiology Pathology Diagnosis Classification Differential diagnosis Treatment Prognosis Screening |
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DIAGNOSIS
Main diagnostic methods for detection of breast cancer are anamnesis, physical
examination and mammography. However, a
biopsy for pathological evaluation should be performed for exact diagnosis.
Different techniques are used to obtain
pathological material, but two of them are mostly used: 1. cytological
evaluation of the breast discharge i.e. of the aspirated material from the
breast; 2. intraoperative biopsy with histologic evaluation of the frozen
section.The first method is suitable
for diagnosis.The second method is
extremely valuable for the selection of the treatment for breast cancer
depending on histological verification of the relation of malignant cells
towards basal membrane, in other words, whether the cancer is invasive or non-invasive.
Indirect diagnostic methods are: self-examination (harmless, easy to learn, free of charge), anamnesis, physical examination, native mammography, ultrasound, and new diagnostic techniques such as MRI (Magnetic Resonance Imaging), digital mammography, CAD (computer-aided diagnosis), PET (positron emission tomography), SPECT (single photon emission imaging and computed tomography) termography, diaphanoscopy, markers (14,79).
Anamnesis is consisted of two parts:
Physical breast examination should be done with the patient in both the sitting and supine positions, and care should be taken at all times to be gentle. A thorough physical breast examination should be done to locate any lump or suspicious area. The skin of the breast and the nipples should also be carefully inspected. It is important to notice any discharge from the nipple. The lymph node under the armpit should be palpated.
Porrath’s form of physical examination of breast is shown in figure 27 (79). Although, by this exam is possible to discover only lumps which are greater than 1 cm, its importance is very emphasized, especially when combined with mammography due to its importance as a complementary examination method (4). But, sometimes ultrasound can give dubious results although mammography result is negative (80). Sensitivity of mammography, ultrasound and palpation is shown in figure 26(81).
Mammography and ultrasound of breast
Ultrasound (after physical examination) is important diagnostic technique in
the population of younger women (figure 30), due to its sensitivity and
specificity that is higher in that period compared to mammography (figure 28 and
29). The reason for that is the
fact that the largest volume of the breast in the generative age is made of
hyperechogenic gland tissue, while in the menopause gland tissue is replaced
with hypoechogenic fat tissue. In
elder population, methods are complementary, but since mammography is easier to
perform and adequately sensitive, it is the preferred method. It is important to know that these methods give us
opportunity to find out whether the change exists or not.
In order to decrease the number of unnecessary biopsies, each suspicious
change should be verified by citopunction.
Moreover, certain number of breast cancers can not be discovered by
mammography, 10-25% palpable breast cancers are not visible by mammography, and
the patients discover additional 20-25% in the period between mammographic and
clinical controls (105). The
sensitivity of those techniques is showed in figures 29 and
34 (5,12,20,82,83).
Markers of the breast cancer are the substances that exist in the
body of the patient in higher concentration than in healthy organism.
The level
of the carcinoembryonic antigen (CEA) is increased for a few percentages in I
and II stage of breast cancer.Although,
other markers, CA 15-3 and CA 549, are higher in 20% to 50% of patients with
primary breast cancer, are also higher in 20% of patients with benign breast
tumors and with gastrointestinal diseases.Katepsin D could be more important diagnostic test due to its specificity
in breast cancer.But, generally
speaking, we can not say that any of the markers separately are specific only
for breast cancer, nor any of them, even in combination could imply to early
stage of the breast cancer.In
order to propose diagnosis of breast cancer and to observe treatment success,
elementary laboratory techniques such as sedimentation, total blood exam,
biochemical examination (SGOT, SGPT, gamma GT, alcaline phosphatase with
isoenzymes, LD, LDH) are needed.X-ray
of lung is compulsory before any therapeutic treatment.
CLASSIFICATION
TNM CLASSIFICATION
Besides histopathological features, clinical stage of tumor is considered as an
important factor in order to get valid prognosis and proper treatment.Frenchman, Pierre Denoix,
in the period from 1943 to 1953 gave the basic
classification of the malign tumors according to their dissemination.
He classified tumor (T) according to tumor dissemination to regional
lymph nodes (N), or if it has already given metastasis (M).
For this reason he named this classification the TNM system.
Today, staging of cancer is determined by UICC (International Union
against Cancer).The UICC
classification is based on the TNM system and it was changed in 1987 in order to
bring closer UICC’s and AJC’s (American Joing Commission on Cancer Staging
and End Results Reporting) classifications.
It is the result of clinical, radiological and laboratory exams (table
5.) (4,65).
| Table 4. TNM breast cancer classification (65) |
| Tx Primary tumor cannot be assessed |
| T0 No evidence of primary tumor |
| TisCarcinoma in situ: intraductal carcinoma, lobular carcinoma in situ or Paget disease of the nipple with no tumor |
| T1 Tumor 2 cm or less in greatest dimension |
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T1a Tumor 0.5 cm or smaller |
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T1b More than 0.5 cm but not more than 1 cm in greatest dimension |
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T1c More than 1 cm but not more than 2 cm in greatest dimension |
| T2 Tumor more than 2 cm but not more than 5 cm in greatest dimension |
| T3 Tumor more than 5 cm in greatest dimension |
| T4 Tumor of any size with direct extension to chest wall or skin (Chest wall includes ribs, intercostal muscles and serratus anterior muscle, but not the pectoral muscles) |
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T4a Extension to chest wall |
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T4b Edema, ulceration of the skin of the breast (including peau d’orange) or satellite skin nodules confined to the same breast |
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T4c Both (T4a and T4b) |
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T4dInflammatory carcinoma |
| PNx Regional lymph node metastasis cannot be assessed |
| pN0 No regional lymph node metastasis |
| pN1 Metastasis to one or more movable ipsilateral axillary node |
| pN2 Metastasis to ipsilateral axillary lymph nodes that are fixed to one another or to other structures |
| pN3 Metastasis to one or more ipsilateral internal mammary lymph node |
| Mx Presence of distant metastases cannot be assessed |
| M0 No distant metastasis |
| M1 Distant metastasis (including metastases to one or more ipsilateral supraclavicular lymph node) |
| pN1a Micrometastasis, none larger than 0.2 cm |
| pN1b Metastasis to one or more lymph node, any of which is larger than 0.2 cm |
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pN1bI Metastases in one to three lymph nodes, any of which is larger than 0.2 cm and all of which are less than 2 cm in greatest dimension |
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pN1bIV Metastasis to a lymph node 2 cm or more in greatest dimension |
STAGING
Staging refers to the grouping of patients according to the extent of their
disease.It is important in
determining the choice of treatment for individual patients, estimating their
prognosis, and comparing the results of different treatment programs. (table 5
and figure 33) (20, 86,87).
| Table 5. Breast Cancer Stage grouping (86,87). | |||
| T(Tumor) | N(Nodes) | M(Metastasis) | |
| Stage 0 | Tis | N0 | M0 |
| Stage I | T1 | N0 | M0 |
| Stage IIA | T0 | N1 | M0 |
| T1 | N1 | M0 | |
| T2 | N0 | M0 | |
| Stage IIB | T2 | N1 | M0 |
| T3 | N0 | M0 | |
| Stage IIIA | T0 | N2 | M0 |
| T1 | N2 | M0 | |
| T2 | N2 | M0 | |
| T3 | N1,N2 | M0 | |
| Stage IIIB | T4 | Any N | M0 |
| Any T | N3 | M0 | |
| Stage IV | Any T | Any N | M1 |
DIFFERENTIAL DIAGNOSIS
There is an important principle that each suspicious change in the breast must
be considered as a malign tumor, until proved differently.
That principle imposes biopsy of all those lesions.
It is prudent to pay attention to some of the
lesions that appear more often in certain women age.Cystic hyperplasia, fibroadenoma and mastitis occur more
often before the age of 35.Between
the ages of 40 and 60, breast tumors are the most numerous. Incidence rate of breast cancer is growing with the age.
TREATMENT
Breast cancer treatment is conducted according to the protocol, depending on
histological type of tumor, stage of malign process and total physical
condition.Different combinations
are used: surgical treatment, radiotherapy, chemotherapy, hormonal therapy and
immunotherapy.In most cases
treatment begins with surgery.Today,
radical mastectomies, according to Halsted and super radical interventions with
toracotomia are mostly replaced with breast-conserving surgery like
quadrantectomia.At patients with
histological signs of invasive breast cancer, more often, besides surgery and
radiation, systematic therapy is used in order to prevent relapses.
Figure 34. shows decrease of mortality rate from breast cancer in England and Wells and that can be explained by earlier diagnosis and better treatment.
PROGNOSIS
Prognostic factors of breast cancer are
summarized in table 6.Some of them
are reliably approved, like tumor size, histological differentiation and PHD,
while reliability of other prognostic factors still needs to be approved.
The most malign development according to histological classification has ductal
invasive carcinoma, followed by invasive lobular carcinoma.
Medullary and mucinous carcinoma have better prognosis.
It is known that tumor development as well as prognosis depend on histological
differentiation. Well-differentiated
tumors have slower development and metastasize later.
Poorly differentiated tumors are more malign; the most malign tumors are
anaplastic tumors.
Good prognostic factor is inflammatory cell reaction composed of lymphocytes
and/or plasma cells in tumor stroma, and around metastases.
Medullary carcinoma in whose stroma is extensive inflammatory reaction is
taken as a model.
BCDDP (Breast Cancer Detection Demonstration Project) study showed that the
survival rate depends not only on clinical stage of disease but also on
patient’s age (figure 35,36 and
37) (92,93).
The 5-year survival rate for patients with localized breast cancer, properly
cured, is 98%, i.e. 95% after 10 years, whereas patients with metastasis have
30%, i.e. 50% after 10 years (83).
Today, breast cancer research is mainly related to molecular biology.
There are many new insights; some of them are shown in table 6.
| Table 6.Prognostic factors of breast cancer |
| Patient age (35,92,94) |
| Obesity (43,44,95,96) |
| Correlation against tumor and basal membrane (97) |
| Size of the primary tumor (98-100) |
| Histological type of tumor (10,35,94,99) |
| Histological differentiation of tumor (35,99) |
| Proliferate ability of tumor cells (mitotic index, index of signed cells with 3H timidine-LI) (35,97) |
| Characteristics of the inflammatory reactions in the tumor (97, 101) |
| Presence of blood vessels invasion (35, 97, 101) |
| Status of lymph nodes (number, localization and size of positive lymph nodes) (97, 100) |
| Metastases and their locations (102) |
| Expression of the estrogen and progesterone receptors (103, 104) |
| Ploidy (DNA index) |
| Proliferating cell nuclear antigen(PCNA) (97) |
| Proliferation marker MB-1 (97) |
| Expression of HER-2/neu oncogene (36,97) |
| Expression of tumor suppressor gene p53 (31,33,35) |
| Expression of tumor suppressor gene MMP-2 (97) |
| Expression of tumor suppressor gene nm23 (35) |
| Expression of receptors for epidermal growth factor (EGFR) (97) |
| Expression of laminin receptors (LR) (106) |
| Srp-27 protein expression (106) |
| Katepsin D expression (35,97) |
| Level of the 5-hidroksimetil-2’-deoksiuridin UDNA (107) |
SCREENING
Because of the connection between early detection
and improved outcome, proper screening method is the main aim.
Many studies have proved that screening of breast cancer is evidently
useful for women aged 50 to 74, but it is under debate for women aged 49 and
younger (5,108,109).
Methods of early detection are self-examination, physical
examination, ultrasound and mammography (19).
The best guidelines for early detection of breast
cancer are shown in figure 38.Women
aged 20 or older should perform breast self-examination every month.
Over age 35, women should have a breast exam by health professional every
year.Base line mammography, women
should have at age 40 or earlier if they are in a high-risk category (after age
35).Mammography should be repeated
every two years, i.e. every year for women aged 50 (88, 110).
Regular mammograms (figure 38) can decrease
breast cancer mortality rates for women aged 50 to 69 years by 30% (111).