Breast Cancer
Introduction
Breast cancer is the most common type of cancer in women. It often arises in the ducts of the breast (invasive ductal carcinoma) or in the lobules (invasive lobular carcinoma). There are other less common sites of disease recurrence in the breast.
Causes
Many patients with breast cancer do not have a specific genetic or environmental cause. In a relatively small number of breast cancer cases, a patient may have and an identifiable genetic mutation which predisposes them to breast cancer. There are other unchangeable risk factors like age of menarche and menopause.
Clinical Manifestations and Diagnosis
With increased breast cancer screening with mammogram, most patients diagnosed with breast cancer are found on imaging without a palpable mass in the breast. These are often small, early stage breast cancers. Sometimes, breast cancers grow very quickly and become palpable below the skin even between regularly scheduled mammograms.
After an abnormal masses found, either by mammogram or by physical exam, he will likely undergo a needle biopsy of the suspicious area. If the biopsy reveals cancer or a precancerous condition (ductal carcinoma in situ, DCIS), you may be referred to a surgeon to discuss her surgical options.
Treatment Strategies
Surgical options sometimes include a total mastectomy or a smaller surgery sometimes called either a lumpectomy or a partial mastectomy.
The underlying features of the tumor including the estrogen receptor(ER), progesterone receptor (PR), and HER2 receptor status will help your oncology care team determine the best next steps in the treatment of your disease. Some women with ER/PR positive, HER2 negative tumors will get additional testing with molecular tests like Oncotype Dx. The results of this test will help guide decision-making for chemotherapy.
Patients who undergo a smaller surgery often benefit from radiation therapy to the breast to decrease the risk of breast cancer recurrence. Women who undergo mastectomy may not need radiation therapy unless they have higher risk features like cancer spread to lymph nodes in the axilla, a positive margin after surgery, or a very large tumor.
Speak to your oncology team about treatment decisions that will increase your chances of curing your cancer.
Prognosis and prognostic factors
Each patient has a unique cancer type and stage with different underlying risk factors. During a oncology consultation visit, your oncologist will discuss what to expect from treatment. Ask your doctor about the expected outcomes.
The 3 most common types of breast cancer are 1) ER/PR positive, HER2/neu negative invasive ductal carcinoma; 2) HER2 positive breast cancers; 3) and triple negative breast cancers. The hormone driven tumors in group 1 tend to be slower growing but can still be very serious cancers, especially if they have spread to lymph nodes or other places in the body. HER2 negative and triple negative breast cancers almost always require chemotherapy in their treatment plan.
They are typically faster growing, and if they are going to recur, they often recur soon after diagnosis and treatment. Hormone receptor positive tumors, while more slowly growing, can sometimes recur 10, 15, or even more than 20 years after their initial diagnosis and treatment.
Many things contribute to the prognosis of breast cancer including the receptor status, size of the tumor, lymph node involvement, and distant metastatic disease. Each tumor is unique at each patient's circumstance may affect prognosis. Please ask your oncology team to help you better understand what to expect during and after treatment.
Treatment Side Effects
Radiation treatment side effects tend to affect the tissues that are close to the tumor where the radiation is directed. Some side effects can be more pronounced during and shortly after radiation treatment (acute side effects). While other side effects may occur many months or years after treatment (chronic or late side effects).
For individuals undergoing breast radiation therapy, the most common side effect is skin reaction. The skin can become dry, red, or darker/tanned. It may also become itchy and irritated. The breast may also swell and feel heavier. Some women also experience fatigue during the radiation treatments and shortly thereafter. These are both typically short-term side effects that resolved within 2 to 4 weeks after completion of your radiation therapy.
More long-term side effects can include scarring of the lung just below the breast tissue and radiation to the heart can increase your risk of a cardiovascular event like arrhythmias or a heart attack. Your radiation oncologist will make sure your treatment plan has a low dose to the heart to minimize this risk.
A more common long-term side effect can be lymphedema or swelling in the arm on the side of treatment. This may be addressed with physical therapy or a compression sleeve. Risk of developing a second cancer from the radiation itself is low. The benefits of decreasing the chance of recurrence of your current cancer often outweigh this risk.