Breast cancer staging and treatment
Once breast cancer has been confirmed, the staging process begins, which is to assess current state and extent of the breast cancer and to plan the treatment. In the initial staging process following breast cancer diagnosis, a process of dialog and cooperation is established between the patient, the oncologist, and other members of the treatment team. One of the first things that happens is the taking of a complete medical history, a more thorough clinical breast exam, and detailed review of imaging studies (with the patient).
I just want to let you know that I have created a couple new versions of this page that has more up-to-date information on Breast Cancer Stages and Breast Cancer Treatment. However, this page still has great research material, and would still use it.
A woman undergoing breast cancer staging will also likely have a full blood count, renal function, and liver test, and also levels of alkaline phosphate and calcium. It is also imperative to determine menopausal status and where there is doubt, to measure serum hormone levels. Usually, some type of surgery is required in the treatment of breast cancer, and this usually happens fairly quickly in the overall treatment scheme.
But remember that breast cancer staging classifications are only related to ‘probabilities‘ of disease outcome, and will vary considerably from patient to patient.
Traditional breast cancer staging methods are ‘anatomically’ based
For most presentations of breast tumors, the most reliable prognostic factors have been the spread or metastases of the breast cancer, and the ‘disease burden‘ (the ‘cancer load‘, or amount of cancer and cancer effects present). These ‘anatomically based‘ staging methods for breast cancer are also the main determinant for the type and intensity of treatments.
But the nuclear grading of the breast tumor and also the histological subtype, and to a certain extent patient age, is now also considered part of the staging process, as it does improve prognostic accuracy and predicted responses to treatment. The traditional/anatomical ‘TNM‘ staging method for breast cancer is most applicable when the tumor may be treated with ‘local‘ therapies, such as surgical resection and radiotherapy.
The two most common treatments for breast cancer are breast conserving surgery with radiation therapy, or mastectomy
The main goal of breast cancer surgical treatment is, basically, to remove the cancer. The two main surgical treatment options for breast cancer are ‘breast conserving surgery‘ (which removes the tumor but not the whole breast), followed by radiation therapy. Or, it may be determined that the whole breast should be surgically removed (mastectomy). So, in order to plan treatment, the regional lymph nodes also have to be assessed to check for metastasis of the breast cancer.
This is sometimes done by the less-invasive sentinel node biopsy, but surgical excision and pathological evaluation of lymph nodes might also be required. Evaluation of the lymph nodes not only allows for proper staging of the cancer (metastasis to lymph nodes indicates and advanced stage breast cancer) but also helps to inform choices in adjuvant therapy. For example, breast cancer which has already metastasized and become ‘systemic‘ needs to be treated with chemotherapy, primarily.
Stage 0-2 breast cancers are good candidates for breast conservation
A patient in which the breast tumor is a good candidate for lumpectomy will typically consult with a radiation oncologist before any surgeries are performed. Radiation therapy tends to be given five days a week for about 6 weeks. (The ten year recurrence rate for breast cancer treated by lumpectomy and radiation therapy is estimated at less than 10%).
Women with either stage 0,1, or 2 breast cancer are good candidates for lumpectomy and radiation therapy. Some patients with breast cancer at ‘stage III‘, may also be directed towards breast conserving surgery and radiation therapy, but quite often with the addition of chemotherapy prior to the surgery (‘neoadjuvant‘ chemotherapy).
Women staged with ‘high risk’ for local recurrence often have mastectomy
Mastectomy is typically indicated with breast cancer staging reveals multicentric or extensive disease, or a ‘locally advanced‘ breast cancer (meaning, the cancer is now invading the surrounding breast tissue). If a patient has received prior radiation treatments to the chest-wall region, mastectomy might also be recommended.
Also, a women with inflammatory breast cancer will usually be treated with mastectomy. And, if in the opinion of the radiologist and the surgeon it will be difficult or impossible to get wide negative margins with breast conserving surgery alone, mastectomy will be necessary.
If mastectomy is required, the women will often meet with a reconstructive plastic surgeon to discuss the cosmetic aspects and options following mastectomy. Sometimes reconstruction is done right at the same time as the mastecomy, but in other cases reconstruction may be delayed for a few months for a variety of reasons.
For women with breast cancer which is assessed at ‘high risk‘ for local recurrence, post mastectomy radiation therapy may be indicated, and this would necessitate a delay in breast reconstruction. For breast tumors graded as stage III or stage IIb tumors, (tumors larger than 5 cm, and with some positive involvement of axillary lymph nodes or skin and chest wall involvement) post mastecomy radiation therapy is usually recommended.
Staging may be imprecise for early or ‘non-palpable’ breast tumors
Sometimes the traditional staging methods are a bit imprecise, particularly with ‘non-palpable‘ breast lesions. But a breast mass or distortion detected only on mammography must be taken just as seriously as one that is clinically palpable. The presence of absence of lymph node metastasis has to be determined, even for very small or occult tumors.
Sometimes a radiologist will detect clustered microcalcifications on the mammogram (highly indicative of breast cancer) and yet the biopsy reveals no breast carcinoma. In these situations, the radiologist should not give up; the biopsy report must explain the presence of microcalcifications somehow. Perhaps another biopsy specimen must be taken in a slightly different location. This type of diagnostic investigation is really neither breast cancer screening, nor staging, at this point. It is ‘problem solving‘ of unusual cases. The possibility of ‘multifocal‘ sites of very small breast tumors has to be considered.
Staging of lubular carcinoma in situ is always a bit different
Staging of lobular carcinoma ‘in situ‘ (lobular neoplasia) is also a bit problematic with respect to the conventional staging criteria. Usually, lobular carcinoma in situ is followed-up at short intervals (4 months or so) by clinical exam and annual mammography. If lobular carcinoma seems to be growing or spreading, it then tends to be treated aggressively, with bilateral total mastecomy.
Advanced stage breast cancers may be treated with systemic therapy
In the staging process determines that the breast cancer is somewhat advanced, such as stage III A and B, then the ‘primary‘ mode of treatment may be systemic therapy rather than surgery. Inflammatory breast cancer (stage III B) might also be treated with systemic chemotherapy. And, in some cases a large early-stage tumor (I,A) might be treated with neoadjuvant chemotherapy in order to reduce the tumor size prior to surgery.
Sometimes, for large breast tumors which are positive for lymph node metastasis, the use of aromatase inhibitors is also considered to be a viable option. However, before any treatment plan with aromatase inhibitors is initiated women should have their bone mineral density assessed.
Breast cancer staging also involves a histological analysis of the tumor
Once more is understood about the individual nature and predicted behavior of a breast tumor, treatments are planned which balance an acceptable level of adverse treatment-related side effects with a significant reduction in the calculated risk of breast cancer recurrence following the initial treatment.
A biopsy and histopathological analysis of the breast tumor will be necessary in order to determine ‘predictive factors‘ of a particular breast cancer, and to target endocrine and chemotherapy as warranted. The status of hormone receptors and in particular the HER2 status are among the most relevant ‘predictive‘ factors in planning breast cancer treatments.
ER and PR positive tumors with generally respond well to endocrine therapy
Breast tumors with some or high amounts of estrogen and progesterone receptors will generally be considered to be responsive to endocrine therapy, and where these receptors are not in evidence, endocrine therapy may be foregone in favor of other types of chemotherapy. But treatments must be considered individually for each patient and each breast tumor, taking into account possible side effects, probable benefits, and to a certain extent patient preference.
A breast cancer tumor which is ER positive will generally have an improved prognosis, regardless of the stage.
HER2 positive tumors have generally been considered to have a poorer prognosis, but this can be counteracted and prognosis improved by targeted chemotherapy.
For breast tumors in which the HER2 status is positive, systemic treatment with trastuzumab is usually suggested.
Increasingly genetic markers and ‘molecular assays’ are used in the breast cancer staging process
Now, certain molecular markers and patterns of these markers are often used to divide the ‘traditional‘ breast tumor classifications into more and more subtypes, because their predicted behavior is different. And new ‘targeted‘ chemo therapies have shown promising results when certain molecular markers are expressed at high levels or have mutated.
Some breast cancers assessed as ‘high risk’ for local recurrence are treated with chemotherapy
Some kind of adjuvant chemotherapy is usually recommended for breast tumors considered at intermediate-to-high risk of local recurrence. However, for tumors smaller than 1 cm, and where staging indicates no involvement of the axillary nodes, the use of adjuvant chemotherapy is really not widely supported.
Internal mammary node metastasis is not routinely checked for
One of the things that doctors may check for during the breast cancer staging process is ‘internal mammary node‘ metastasis. Statistics vary, but between 12 % 55% (perhaps too high) of women with breast cancer will have developed internal mammary node metastasis. The spread of the breast cancer to the internal mammary nodes would seem to be related to the location and size of the primary breast tumor, and to a certain extent the histological characteristics of the tumor.
A woman’s age, and also co-involvement of the axillary lymph nodes are also factors influencing the likelihood of internal mammary node metastasis, but only about 5% of women with breast cancer will have internal mammary node metastasis without axillary node involvement. In terms of staging, this small subset of patients may be treated with radiation therapy (following surgery) and not chemotherapy.
Internal mammary node metastasis is not routinely checked for, and is sometimes detected by luck. However, it can affect how oncologists classify the stage of the breast cancer.
The use of PET scans for breast cancer staging may be useful, but is not standard procedure
The use of PET scans in breast cancer staging may be useful, but it is not a uniform and standard procedure. PET scans do illustrate the common ways that an advanced cancer will be spreading. But, they also frequently duplicate the results of other tests. Bone metastases can be detected by a bone scan, (a bone scan is a mandatory staging procedure), and metastasis to the axillary nodes can be detected by a sentinel node biopsy or axilla node dissection.
The breast cancer ‘stage‘ can be correctly determined by other means, and the PET scan is often an unnecessary expense. When applied to the whole population the extra costs ‘to society‘ of PET scans for breast cancer staging is very high with little added benefit. In the PET scan image below, one can see lots of bone metastases, and positive axilla nodes, in addition to a large, lumpy breast cancer mass in the medial left breast.
MRI is used for problem solving in unusual cases, but is not standard in breast cancer staging
Magnetic resonance imaging is often advocated for breast cancer staging purposes. There is no question that MRI imaging has the highest sensitivity and is most useful for determining the ‘extent‘ of the cancer. MRI and PET are both very effective modalities at diagnosing bifocal or multifocal breast tumors. Planning for the surgical resection of the breast tumor is also made easier through the use of MR imaging. Some breast cancer treatment research argues that up to 53% who underwent tumorectomy and still ended up with ‘positive margins‘ could have been spared a second surgical excision if MRI were used in staging.
The resection volume is somewhat easier to determine following a breast MRI. On the other hand, the use of MRI for breast cancer staging purposes has tended to lead to about double the number of mastectomies. In terms of overall survival of breast cancer, outcome for patients staged with MRI and those by conventional methods are very close, with a small 2% advantage for MRI staging. In fact, concerns over positive margins and local recurrence are generally solved through the use of radiation therapy. MRI, along with PET scanning, are basically to be used for problem solving in cases that are difficult and not as a standard staging procedure for breast cancer.
It ought to be remembered that breast cancer physicians are responsible to a population and funding that is shared amongst all diseases. Treatment of one disease, like breast cancer, cannot consume funding excessively at the detriment of other patients with other diseases.
The current ‘consensus‘ opinion in the use of MRI for breast cancer staging includes women who are either confirmed or suspected BRCA 1&2 mutation carriers not wishing to undergo a bilateral mastectomy, and patients with apparent axillary node metastasis but with no breast tumor evident on mammography. Women with Paget’s disease of the nipple and no apparent breast tumor are also typically staged with MRI. And, as mentioned, MRI is to be used for problem solving in unusual cases where there is a major discrepancy between clinical examination and the results of mammography and ultrasound.
For further reading, I suggest you visit this page which has a bunch of information on breast cancer staging, as well as this page with breast cancer treatment overviews.
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