A Brief Guide to Breast Cancer Pathology and Second Opinions
A breast cancer diagnosis often starts when a change is found during a breast exam or mammogram. That is usually followed by a breast core biopsy, in which a small sample of the breast tissue is taken and given to a pathologist. A pathologist is a doctor who specializes in diagnosing cancer and other diseases by examining tissue samples using a microscope.
Zueslabolt, May 19, 2025
How often do you give a second opinion that substantially changes a diagnosis?
n most instances, a second opinion will confirm the original diagnosis, with only minor changes of no substantial impact for that person.
But about 1 to 10% of the time, a second opinion can translate into a substantial change in treatment. For example, take a woman who has been diagnosed with the noninvasive breast cancer ductal carcinoma in situ (DCIS). Sometimes when we’re asked for a second opinion on DCIS, we find microscopic evidence of a small invasive cancer. That finding may require a more aggressive approach, such as a biopsy of the axillary lymph nodes to make sure the cancer hasn’t spread from the breast.
Occasionally the diagnosis will dramatically change the other way. For example, recently I was asked for a second opinion for someone who had been diagnosed with DCIS. When I did my review, I found that no DCIS was present, but instead there was lobular carcinoma in situ (LCIS).
That is great news for the patient because, despite its name, LCIS is not regarded or treated as a real breast cancer. The person did not need to have radiotherapy, which is part of the standard treatment of DCIS but can have major side effects. The patient initiated this request for a second opinion. People often have an instinct to ask for a second opinion and that sometimes can be a very healthy impulse.
What new developments in breast cancer pathology should people know about?
Many people are familiar with drugs like tamoxifen (Nolvadex®, Soltamox®) and aromatase inhibitors. These are effective in treating breast cancers with specific hormone receptors.
We are currently learning more about another hormone receptor, the androgen receptor (AR). Androgen is actually a male hormone, but the AR is expressed in many breast cancers. This finding is particularly significant for people with triple-negative breast cancer. This aggressive breast cancer does not respond to treatments targeting the other hormones often found in breast cancer cells.
In clinical trials, some people with metastatic triple-negative breast cancer that has come back showed a good response or no disease progression with androgen-targeted treatments, such as enzalutamide (Xtandi®) and bicalutamide (Casodex®). At MSK, we test the expression of the androgen receptor in all triple-negative breast cancer. There is still a lot of research to be done. But there is reason for hope.
When should people get a second opinion? Should they worry that it could delay treatment?
If someone receives a diagnosis of breast cancer and wants to ask for a second opinion, the sooner the better. Certainly a second opinion should be obtained before any definitive surgery, like a mastectomy, or a treatment with substantial side effects, such as radiation therapy or chemotherapy.
People should not worry too much that a second opinion on their breast pathology will delay treatment. A second opinion usually takes a few days or a week. A difficult case may take longer, but that probably really needs a second opinion. In the big scheme of things, that kind of delay has no substantial impact in terms of outcome. It is more important to have the right diagnosis so that the right treatment is given rather than being treated quickly. Think quality over speed.
How does breast pathology work at MSK?
People can call our consultation office, which can tell them what materials and papers they need to submit. Most insurers will cover a second opinion, although people should always check first. Anyone requesting a second opinion needs to tell us the name and contact information of the doctor to be notified. We give our second opinion to that doctor because doctor-to-doctor communication helps ensure that the appropriate treatment is pursued. If a woman has questions about her diagnosis, she can speak with her doctor, but she can also reach out to the pathologist.
Should all people diagnosed with breast cancer consider getting a second opinion?
People can call our consultation office, which can tell them what materials and papers they need to submit. Most insurers will cover a second opinion, although people should always check first. Anyone requesting a second opinion needs to tell us the name and contact information of the doctor to be notified. We give our second opinion to that doctor because doctor-to-doctor communication helps ensure that the appropriate treatment is pursued. If a woman has questions about her diagnosis, she can speak with her doctor, but she can also reach out to the pathologist.