Invasive ductal carcinoma: Clinical sciences

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Introduction0:00–0:32

Invasive ductal carcinoma is the most common form of breast cancer, and occurs when malignant epithelial cells from ductal tissue infiltrate through their basement membrane.
Treatment of invasive breast cancer is based on the stage of cancer. Patients are roughly classified as early-stage, locally advanced, or metastatic disease.
When a patient presents with a new breast lump or abnormal screening mammogram, you should consider an invasive ductal carcinoma.

Initial assessment0:32–2:02

The first step is to obtain a focused history and physical exam. History may include changes in the breast or nipple appearance, nipple discharge, and the presence of swollen lymph nodes.
You should also ask about common risk factors, such as a personal or family history of breast or ovarian cancer; early menarche or late menopause; nulliparity; first birth after 30 years of age; being older than 40; dense breast tissue; chest radiation; exogenous hormone use; and family or personal history of deleterious cancer gene mutations like BRCA.On the flip side, a physical exam might reveal a palpable breast lump, which could be fixed and is more concerning for malignancy.
There may also be skin changes; or nipple changes, like flattening or inversion. Some patients even have lymphadenopathy, which can be above and below the clavicle, and in the axilla.Your next step will be to obtain some labs, including baseline CBC and CMP.
Labs might show elevated transaminases or alkaline phosphatase.Alright, these findings should prompt you to get imaging with a diagnostic mammogram and an ultrasound.

Imaging/alternative diagnoses2:02–3:45

Here’s a clinical pearl! Breast findings on imaging can be categorized with a standardized system called BI-RADS, which stands for Breast Imaging-Reporting and Data System.
The imaging findings are assigned into categories labeled as 0 to 6. First, 0 means incomplete, which needs additional imaging or comparison with previous images if available.
Next, 1 is negative, meaning that mammography is normal, with no findings like masses or calcification; while 2 indicates findings are completely benign, meaning that mammography reveals findings with no probability of malignancy; a category of 0, 1, and 2 can only be used when undergoing routine screening.
On the other hand, 3 is probably benign, meaning that mammography may reveal a finding with minimal malignant potential of less than 2%, so these patients should get follow-up imaging.
Next, 4 is suspicious for malignancy, meaning that mammography may reveal a finding with malignant potential between 2 to 94%, where biopsy will likely be indicated.
Then, a category of 5 is highly suspicious of malignancy, with malignant potential over 95%. Lastly, 6 is known malignancy that has been proven with biopsy, and requires definitive management with surgery, chemotherapy, or radiation.
Now, let’s talk about imaging findings that are suspicious for invasive ductal carcinoma. A diagnostic mammogram might show a spiculated or irregular soft tissue mass.

Invasive ductal carcinoma3:45–4:45

You may also see microcalcifications, which should raise suspicion for an underlying malignancy. On ultrasound, you might see an irregularly shaped soft tissue mass that can be taller than it is wide, with a hypoechoic appearance and posterior acoustic shadowing.
If your imaging does not have these findings, you should consider an alternative diagnosis. However, if imaging has any of these signs, you should suspect invasive ductal carcinoma.
Here’s a clinical pearl! If your initial imaging isn’t concerning, but you still have high suspicion for breast cancer, you can obtain an MRI for better visualization.
Okay, now that we suspect invasive ductal carcinoma, our next step is to get a core needle biopsy. If the core needle biopsy does not show any malignant cells, you’ll again need to consider an alternative diagnosis.

Core needle biopsy4:45–5:16

However, if the biopsy shows malignant epithelial cells that arise from ductal tissue, and they invade through the surrounding basement membrane, you can confirm your diagnosis of invasive ductal carcinoma.
After confirming the diagnosis, it's time to consider TNM staging. First, evaluate the tumor based on size and invasion into surrounding structures like the skin or chest wall.
Then, you want to evaluate lymph nodes. If the patient has any clinically palpable or suspicious lymph nodes on ultrasound, perform a fine needle aspiration biopsy of the node.

TNM staging5:16–6:47

Next assess for distant metastasis, often by using the patient’s other symptoms, in conjunction with imaging. For example, if your patient has a cough or hemoptysis, get a chest CT.
If they have localized bone pain or an elevated alkaline phosphatase, obtain a bone scan. Patients with elevated transaminases or abdominal pain should have a CT scan of the abdomen and pelvis.
Next, it is important to establish whether the tumor expresses hormone receptors, like estrogen and progesterone; and HER2, also called HER2/neu, receptors.
Breast cancers that express these receptors can be treated with hormone therapies and immunotherapies. Finally, some patients should also meet with a genetic counselor and consider genetic testing.
Okay, once you have your staging, you can broadly classify patients into three groups, Early Stage, Locally Advanced, and Metastatic disease.
Alright, let’s start with patients who have Early Stage disease. These patients have T1 or T2 tumors, which means that tumors are less than five centimeters in size; N0 or N1 nodal status, meaning that zero to three lymph nodes are involved; and are M0, which means that there is no evidence of distant metastasis.

Early stage6:47–8:58

Okay, treatment for patients who are Early Stage typically includes surgery, may include radiation therapy, hormone therapy, and immunotherapy.
For surgery, patients may have breast-conserving therapy, usually as a partial mastectomy, or lumpectomy. Contraindications for breast conserving therapy include multicentric disease, a large tumor size in relation to the size of the breast, diffuse calcifications, prior radiation therapy of the chest, and pregnancy.
Another option is total mastectomy, with or without breast reconstruction. In addition, patients should undergo sentinel node biopsy to look for nodal metastasis.
If more than 3 nodes are positive, patients should undergo axillary node dissection. Post-operatively, you need to consider additional treatments, such as radiation therapy.
This includes all patients who had a partial mastectomy, and those who had a total mastectomy with either positive margins on biopsy or a very large preoperative tumor.
Lastly, axillary radiation is necessary for all patients who get either partial or total mastectomy and have malignant cells on lymph node biopsy.
You should also consider hormone therapies, according to their tumor receptor status, such as a Selective Estrogen Receptor Modulator, or SERM, like Tamoxifen; or consider an immunotherapy, like Trastuzumab, if the patient is HER2 positive.
Now, let’s backtrack and discuss managing patients with Locally Advanced disease. These patients have T3 or T4 tumors, meaning that it is greater than five centimeters; N2 or N3 nodal status, which means greater than four lymph are nodes involved; and are M0, so have no evidence of distant metastasis.

Locally advanced8:58–10:48

Just as before, you will base your search for distant metastasis on the patient’s symptoms. However, in the case of Locally Advanced disease, you should also consider a PET/CT scan and a brain MRI.
For therapy, you want to start with a multidisciplinary team that includes an oncologist, a radiation oncologist, and a surgical team.
This multidisciplinary team works together to create a treatment plan and timeline. Typically, patients will start with neoadjuvant chemotherapy.
You will then re-evaluate the primary tumor and regional lymph nodes for ongoing involvement. The next step is typically a surgical option, including partial or total mastectomy, as well as axillary lymph node dissection.
As before, once the surgery is done, you need to consider if the patient needs radiation therapy. These include patients who have a tumor with a high risk of recurrence, such as the ones larger than five centimeters, with positive or indeterminate margins on biopsy, or extensive nodal involvement.
Some patients may also require postoperative chemotherapy. Finally, you will want to consider hormone therapy and immunotherapies.
Okay, the final group of patients we’re going to discuss are those with Metastatic disease.. On TNM staging, these patients can have any T or N status but are M1, which means they have distant metastases on imaging.

Metastatic10:48–11:49

Start with a biopsy of the metastatic lesion, if possible, to assess for the pathologic origin of the lesion to breast cancer.
If the patient has hormone-sensitive breast cancer, whenever possible, you will want to start with hormone therapy. If the patient relapses, or if the patient has breast cancer that is not sensitive to hormones, you should give chemotherapy, as well as immunotherapy.
As for surgical options, there is mixed and unclear data regarding the benefit of resection. Finally, all patients with metastatic breast cancer should be offered expert palliative care, as improving quality of life, like by controlling pain, should be a priority.
Alright, as a quick recap… Patients with invasive ductal carcinoma commonly present after an abnormal screening mammogram or detection of a breast lump.
Start your diagnostic work up with a diagnostic mammogram and ultrasound, and proceed with a core needle biopsy if you see suspicious findings on imaging that’s considered a BI-RADS 4 or 5.
Then, assess for clinically suspicious lymph nodes and obtain additional labs and imaging to determine the TNM staging. Next, establish the hormone and HER2 receptor status of the tumor.

Review11:49–12:31

Finally, surgical, radiation, or systemic therapy depends on whether the patient has early-stage, locally advanced, or metastatic disease.
considered a BIRADS four or five then assess for clinically suspicious lymph nodes and obtain additional labs and imaging to determine the TNM staging Next establish the hormone and her two receptor status of the tumor Finally surgical radiation or systemic therapy depends on whether the patient has early stage