What is metastatic breast cancer?
Metastatic breast cancer is breast cancer that spreads to other parts of the body. It normally affects one or more of the following body parts:
In rare cases, breast cancer does spread to the colon.
Just a little above 12 out of every 100 women will have cancer of the breast in their lifetime. Of these cases, studies have shown that just about 20 to 30 percent will develop into a metastatic form.
If breast cancer metastasizes, the treatment becomes targeted at preserving your quality of life and slowing the spread of cancer. There is no cure for metastatic breast cancer, but advancements in medical science have helped patients to live longer and more fulfilling lives.
What are the symptoms of colon metastasis?
Symptoms of metastatic breast cancer in the colon include:
A review of metastatic breast cancers treated at the Mayo Clinic found that no less than 26% of patients who had metastases of the colon had blockage of the intestines.
It is important to note that in the Mayo review, colon metastases are sub-divided to cover 8 other sites, including:
- Small bowel
This implies that this percentage covers more than just women experiencing colon metastasis.
What causes metastatic breast cancer in the colon?
Breast cancer starts in the lobular cells. The lobules are glands that produce milk. Breast cancer can also start in the ducts that transport milk to the nipple. If breast cancer is restricted to these areas, it is considered non-invasive.
Metastatic breast cancer occurs when breast cancer cells detach from the original tumor and travel through the lymphatic system or the blood to other parts of the body.
When cancer cells travel from the breast to the bones or the lungs and form tumors, these tumors are still considered breast cancer cells and not bone or lung cancer.
All cancers have the potential to spread to any part of the body. however, some cancers move through a certain path to specific body organs. Medical researchers have no clue as to why this happens.
Cancer of the breast can spread to the colon, but it is rare. The spread of breast cancer to the digestive tract is very uncommon.
If it happens, the cancer is more likely to be found in the peritoneal tissue lining the small intestine, or the small intestine, but not the large intestine of which the colon is a part.
A study of metastatic breast cancer cases highlights potential sites to which cancer may spread.
This study also highlights the major locations to which breast cancer spreads:
- 41% of the time, it spreads to the bone
- 22.4% of the time, it spreads to the lungs
- 7.3% of the time, it spreads to the liver and the brain
Colon metastases are not so common, so they’re not included in the list.
When cancer gets to the colon, it does so as invasive lobular carcinoma. Invasive lobular carcinoma is a form of cancer that originates from the lobes that produce breast milk.
Diagnosis of metastasis to the colon
If you are experiencing any of the symptoms listed above, especially if you have a history of breast cancer, then speak with your healthcare provider.
Your doctor may ask you to undergo one or two tests to determine whether cancer has spread to the colon or not.
During the examination of your colon, your doctor will specifically search for polyps. They are small abnormal overgrowths that may form in the colon. Most polyps are harmless, but some can become cancerous.
When you have a sigmoidoscopy or a colonoscopy, your doctor will cut off any existing polyps. They will then be tested for cancer.
If it happens to be cancerous, the testing will show whether it is breast cancer or a new one that originates in the colon.
This is a test that lets your doctor view the interior of your large intestine (which includes your colon and rectum).
During a colonoscopy, your doctor will use a thin tube, usually flexible, with a camera attached at the end. The tube is called a colonoscope. It is inserted into your anus and then up your colon.
With a colonoscopy, your doctor can check if you have:
- Colon polyps
- Bleeding areas
The images captured by the camera are then transmitted to a video screen, which will allow your doctor to make a diagnosis. Medication is usually given before the exam so you can sleep while it is being done.
This procedure is almost the same as a colonoscopy. However, the tube used in a sigmoidoscopy is not as long as a colonoscopy. Only the lower part of the colon and the rectum are examined.
No medication is needed for flexible sigmoidoscopy.
It is also referred to as a virtual colonoscopy. CT colonoscopy uses advanced X-ray technology to create two-dimensional images of your colon. It is a painless procedure, and also non-invasive.
How is metastatic breast cancer treated?
If you are diagnosed with metastatic breast cancer to the colon, your healthcare provider will order more tests to verify whether cancer has spread to other areas of your body.
Once the picture is clear, your doctor will share the treatment options. You can then discuss with him or her which is most suitable for you. This may include one or more of the following:
Most metastatic breast cancers to the colon are estrogen receptor-positive. This implies that estrogen plays a role in the growth of these breast cancer cells.
Hormone therapy reduces estrogen concentration in your body or prevents it from binding to the breast cancer cells and enhancing their growth.
Doctors use hormone therapy to reduce the spread of the cancer cells after it has been treated with radiation, surgery, or chemotherapy.
Side effects of hormone therapy include:
- Vaginal dryness
- Hot flashes
- Blood clots
- Mood changes
- Thinning of the bones in women approaching menopause
- High risk of uterine cancer for postmenopausal women
Drugs used in chemotherapy kills cancer cells, especially the ones that reproduce quickly. Chemotherapy has some side effects including:
- Loss of hair
- Mouth sores
- Increased risk of infection
People respond differently to chemotherapy. Many people can manage their side effects.
It is also called molecular therapy. Targeted therapy uses medications to inhibit the growth of cancer cells.
It is important to note that some of the medications used in molecular therapy can damage your heart, distort immune system function, or damage other parts of the body seriously. But your doctor will keep a tab on you to avoid any complications.
Surgery is done to remove cancerous parts of the colon or bowel obstructions.
Radiation therapy can treat abdominal bleeding (for those who experience it). Radiation therapy uses gamma rays, X-rays, or charged particles to kill cancer cells or shrink tumors. Side effects of radiation therapy include:
- Skin changes at the radiation site
The prognosis for metastatic breast cancer
Metastasized cancer cannot be cured. However, advancements in medical science help people with this condition to live longer and more fulfilled lives.
A study by the American Cancer Society shows that metastatic breast cancer patients have a 27% chance of living no for at least five years after receiving their diagnosis.
Note that this is a general figure and varies according to individual circumstances. Your doctor will share with you your most accurate prognosis based on your medical history, diagnosis, and treatment plan.