Monday, March 2, 2015

Understanding Breast Cancer and Mammograms

Breast Cancer and Mammograms

What Is a Diagnostic Mammogram?
Diagnostic mammograms differ from screening mammograms in that the examination focuses specifically on an area of breast tissue that appeared abnormal in a screening mammogram. Diagnostic mammograms are also done for women who haven't had a screening mammogram but may be showing signs or symptoms of something abnormal in the breasts.

Depending on the potential abnormality, different studies may be done. In some women, only additional mammographic images are done. In other women, additional breast cancers mammographic images, an ultrasound, or a biopsy is needed.

How Does an Abnormality Appear on a Mammogram?
An abnormality on a mammogram may be called a nodule, mass, lump, density, or distortion.
  • A mass (lump) with a smooth, well-defined border is often benign. An ultrasound may be needed to characterize the inside of a mass. If the mass contains fluid, it is called a cyst.
  • A mass (lump) that has an irregular border or a star-burst appearance (spiculated) raises more concern about. A biopsy is usually recommended.
  • Calcifications (deposits of calcium) are another type of abnormality that appears as either macrocalcifications (larger deposits) or microcalcifications (smaller deposits). They can be classified as benign, suspicious, or indeterminate.  Both of these types of calicifications are often benign, however the appearance of microcalcifications may require additional studies (magnification views) and a biopsy to rule out an associated cancer.
How Effective Is Mammography in Detecting Breast Cancer?
Mammography helps diagnose about 75% to 85% of breast cancers. Mammograms have improved the ability to detect breast abnormalities before they are large enough to be felt. In addition, detection rates improve as the patient ages.

Detection rates may also improve with more widespread use of three-dimensional mammography. Initial research showed that 3D mammography, used along with standard digital mammograms , improved breast cancer detection rates and decreased the number of women who had to return for more tests because of a suspicious mammogram finding.

Source: Effective Mammography for Breast Cancer

Types of Breast Cancer: ER Positive, HER2 Positive, and Triple Negative

Types of Breast Cancer
Types of Breast Cancer

HER2-Positive Breast Cancer continued
For women with HER2-positive breast cancers, the drug Herceptin has been shown to dramatically reduce the risk of recurrence. It has now become standard treatment to give Herceptin along with adjuvant (after-surgery) chemotherapy in those with metastatic breast cancer. Another drug, Tykerb, is often given for metastatic cancer if Herceptin fails. Kadcyla is another drug that can be given after Herceptin and a class of chemotherapy drugs called taxanes, which are commonly used to treat breast cancer.

Herceptin has far fewer immediate side effects than chemotherapy, for example, there is usually no nausea or hair loss. However, there is a small but real risk of heart damage and possible lung damage. Scientists are still studying how long women should take Herceptin for the greatest benefit.
An intravenous treatment called Perjeta is also approved for late-stage HER2-positive breast cancer. In one study, Perjeta was shown to extend life when given in combination with Herceptin.

HER2 Breast Cancer


Triple-Negative Breast Cancer
Some breast cancers, estimates range between 10% and 17% -- are known as “triple negative” because they lack estrogen and progesterone receptors and do not overexpress the HER2 protein. The majority of breast cancers associated with the breast cancer gene known as BRCA1 are triple negative.

These cancers generally respond well to adjuvant chemotherapy. Overall, however, they have a poorer prognosis than other types of breast cancer. So far, no targeted therapies like tamoxifen or Herceptin have been developed to help prevent recurrence in women with triple-negative breast cancer. Cancer experts are studying several promising targeted strategies aimed at triple-negative breast cancer.

Source: Breast Cancer

Adjuvant Therapy for HER2-Positive Breast Cancer

HER2-Positive Breast Cancer
HER2-Positive Breast Cancer

Overexpression of HER2 occurs in approximately 20% of breast cancers and was correlated with a more aggressive phenotype and worse prognosis before the development of HER2-targeted therapies. The advent of trastuzumab, a monoclonal antibody (mAb) targeting the extracellular domain of the receptor, has changed the treatment paradigm for HER2-positive breast cancer. Trastuzumab has a powerful synergism with a variety of chemotherapeutics, yet lacks the side effects (with the notable exception of cardiotoxicity, which means it generally should not be given with anthracyclines).

Results are available from studies (HERA, FinHer, NSABP B-31, BCIRG006, N9831) that have demonstrated that the inclusion of trastuzumab produces roughly a 50% improvement in disease-free survival and 33% improvement in overall survival, regardless of the chemotherapy regimen or sequence of trastuzumab delivery. These trials randomized 11,650 women with early-stage HER2-positive breast cancer to trastuzumab versus non-trastuzumab-based adjuvant chemotherapy, and based on their results, trastuzumab was approved by the US Food and Drug Administration (FDA) for the treatment of HER2-positive disease in the adjuvant setting.

Another study from the BCIRG006 further established that adjuvant trastuzumab for 1 year improved disease-free and overall survival among women with early-stage HER2-positive breast cancer at 5 years, and found that a nonanthracycline regimen plus trastuzumab had a more favorable risk-benefit ratio than anthracycline-based regimens due to similar efficacy, fewer acute toxic effects, and lower risks of cardiotoxicity and leukemia.

HER2-Positive Breast Cancer
HER2-Positive Breast Cancer
A study that evaluated the efficacy of lapatinib in HER2-negative and HER2-uncharacterized metastatic breast cancer concluded that although patients with HER2-negative or HER2-untested metastatic breast cancer did not experience benefit from the addition of lapatinib to paclitaxel, first-line therapy with paclitaxel-lapatinib significantly improved clinical outcomes in patients who were HER2-positive.

Baselga et al reported that adding pertuzumab to traditional therapy with trastuzumab and docetaxel improved disease-free survival time in patients with HER2- positive metatstatic breast cancer.
Pertuzumab gained approvals for neoadjuvant treatment in combination with trastuzumab and docetaxel for patients with HER2-positive, locally advanced, inflammatory, or early stage breast cancer.

Source: HER2-Positive Breast Cancer

What the Meaning of HER2-Positive Breast Cancer?

HER2-positive breast cancer
HER2-positive breast cancer

HER2-positive breast cancer is a breast cancer that tests positive for a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. In about 1 of every 5 breast cancers, the cancer cells make an excess of HER2 due to a gene mutation. This gene mutation and the elevated levels of HER2 that it causes can occur in many types of cancer — not only breast cancer. This is a gene mutation that occurs only in the cancer cells and is not a type of mutation that you can inherit from a parent.

HER2-positive breast cancers tend to be more aggressive than other types of breast cancer. They're also less responsive to hormone treatment. However, treatments that specifically target HER2 are very effective. They include:
  • Trastuzumab (Herceptin). Trastuzumab, which specifically targets HER2, kills these cancer cells and decreases the risk of recurrence. Trastuzumab is often used with chemotherapy. But it may also be used alone or in combination with hormone-blocking medications, such as an aromatase inhibitor or tamoxifen. Trastuzumab is usually well tolerated, but it does have some potential side effects, such as congestive heart failure and allergic reaction.

  • Lapatinib (Tykerb). Like trastuzumab, lapatinib is a HER2-specific drug. Lapatinib may be effective for HER2-positive breast cancer that doesn't respond to trastuzumab. Lapatinib is used in combination with the chemotherapy drug capecitabine (Xeloda) and the aromatase inhibitor letrozole (Femara). Lapatinib is also being studied in combination with trastuzumab. Common side effects include rash, loose stools and the potential risk of congestive heart failure.
In addition, there are several new medications being developed that also target HER2 and are being tested in clinical trials.

Standard chemotherapy agents such as doxorubicin (Adriamycin) also can be effective in treating HER2-positive breast cancers, although these drugs don't specifically target the HER2 protein.

Routine testing for HER2 is recommended for most women diagnosed with invasive breast cancer because the results may affect treatment recommendations and decisions. HER2 testing is not done routinely for ductal carcinoma in situ but may be performed as part of a clinical trial. Whenever breast cancer recurs or spreads, the cancer cells should be retested for HER2 as well as for hormone receptor status, as these can change from the original cancer in up to 20 to 30 percent of cases.

Source: Answers from Sandhya Pruthi, M.D.