Standard of care would recommend needle core biopsy as the best method to evaluate a breast mass, abnormal mammogram/ultrasound/MRI. There are many types of breast pathologies, which can be confusing. Understanding a pathology report is the key to understanding treatment options.
It is very important to understand your pathology report; even when the results are benign. Upstaging occurs when a needle biopsy underestimates the presence of a cancer. Surgical excision may be necessary to further evaluate a finding on breast imaging.
Pathology | Upstage Rate | |
HIGH RISK | Atypcial Ductal Hyperplasia (ADH)
Atypical Lobular Hyperplasia (ALH) Flat Epithelial Atypic (FEA) Papillary Lesions |
10-20%
<5-50% 10-15% 10-35% |
LOW RISK | Fibrocystic Changes
Usual Duct Hyperplasia Duct Ectasia Stromal Fibrosis |
0%
0% 0% 0% |
Can Surgical Excision Be Avoided?
Avoid Excision if:
Why Should These Lesions Be Excised
Breasts are composed of lobules, which make milk, and ducts, which carry the milk to the nipple. The lobules and ducts are both lined by two layers of cells. When the cells lining the lobules or ducts grow, the collection of cells is called hyperplasia. Usual hyperplasia poses no risk, but when the cells grow in an irregular pattern, they can become problematic. This irregular pattern is known as atypia. Atypical cells are not pre-cancer cells, but they will increase a patient’s lifetime risk for developing breast cancer.
Atypical hyperplasia is found in approximately 10% of all benign breast biopsies. There are two types of atypical hyperplasia based on microscopic appearance: Atypical ductal hyperplasia, also known as ADH, involves the ducts of the breast tissue and atypical lobular hyperplasia, also known as ALH, involves the lobules of the breast tissue. They are considered to be high-risk breast lesions. Other forms of abnormal cells include lobular neoplasia, also called LIN, and lobular carcinoma in-situ, as called LCIS. Collectively, all of these cellular abnormalities are considered high risk lesions.
When high risk lesions are seen by the pathologist on a core needle biopsy performed for an abnormal mammogram or ultrasound, an open surgical biopsy may be recommended. The reason for this recommendation is that core needle biopsy samples can potentially miss a breast cancer 10-20% of the time. Atypia found on an open surgical biopsy does not require another operation but will be helpful in assessing for cancer and in calculating a patient’s risk for developing breast cancer in the future. The purpose of surgical biopsy is not to remove all of the atypical cells but rather to rule out a nearby cancer that the needle biopsy may have missed.
Once a woman is diagnosed with a high risk lesion, she has a cumulative incidence of breast cancer (either ductal carcinoma in situ or invasive cancer) of 30% over the next 25 years. The risk of breast cancer is higher in those diagnosed with high risk lesions at a younger age, and the cumulative incidence of breast cancer appears to increase linearly overtime. However, if women with high risk lesions take medication to prevent breast cancer, their risk of developing breast cancer may be reduced by over 40% and up to approximately 80%.
Clinical trials have shown pharmacologic risk reduction (taking medication to prevent cancer) to be effective in women with high risk lesions. Approximately 97% of atypical ductal hyperplasia and 88% of atypical lobular hyperplasia has estrogen receptor staining, meaning it is stimulated by estrogen. Because of this, medications called selective estrogen receptor modulators (tamoxifen and raloxifene) and aromatase inhibitors (exemestane, anastrozole, and letrozole) have been shown in clinical trials to effectively and significantly reduce the risk of breast cancer associated with these lesions.
Despite the evidence that chemoprevention medications work, MOST patients are reluctant to take them due to fear of side effects. Vasomotor symptoms (hot flashes, night sweats) are not uncommon; they occurred in 60-120 per 1000 high-risk women on tamoxifen. The serious risks associated with tamoxifen and raloxifene are related to thromboembolic (clotting) events, including deep venous thromboses (blood clots in the legs) and pulmonary emboli (blood clots in the lungs), and are very infrequent. The risk of developing clots while taking these medications ranges from 5.9 to 14 per 1000 women. Tamoxifen (but not raloxifene or the aromatase inhibitors) is also associated with an increased incidence of endometrial (uterine) cancer of 5.5 per 1000 women, mainly in those who are postmenopausal, but the risk is still quite low overall.
For individuals who have an elevated risk of getting breast cancer, enhanced screening with breast MRI is often considered. An MRI is performed in addition to an annual mammogram, not instead of a mammogram.