Also called: Ductal Carcinoma in Situ, Infiltrating Ductal Carcinoma, DCIS, Comedo Carcinoma, Intraductal Carcinoma, Invasive Ductal Carcinoma
Ductal carcinoma is a form of breast cancer where cancerous cells grow in breast ducts, the tubes that carry breast milk from the breast lobules, where it is secreted to the nipple. Ductal carcinoma is the most common form of breast cancer, accounting for about 80 percent of diagnoses in the United States, according the American Cancer Society (ACS). Ductal carcinoma is usually diagnosed in women, although it is also the most common type of breast cancer diagnosed in men.
- There are two main types of ductal carcinoma:
Ductal carcinoma in situ (also called DCIS or intraductal carcinoma). Typically, a noninvasive form of ductal carcinoma, in which the disease does not spread outside the duct where it began. Although it can sometimes become invasive and spread outside the duct, DCIS may be considered a precancerous condition.
- Invasive ductal carcinoma (also called infiltrating carcinoma). This type of ductal carcinoma develops when abnormal cells grow within the breast duct and then spread through the membrane that lines the bottom of the cells to tissue outside the duct. Left untreated, invasive ductal carcinoma can spread to other parts of the body.
DCIS is usually diagnosed during regularly scheduled mammograms. Invasive ductal carcinoma often forms a hard lump. It can sometimes be found during monthly breast self-examinations, a breast examination by a physician or other healthcare provider, or during a mammogram, which frequently can detect cancers too small to be felt.
To diagnose breast cancer, a biopsy is performed in which part or all of the abnormal mass is removed and analyzed by a pathologist who views the specimen under a microscope. If a pathologist finds the tumor to be malignant (cancerous), additional tests may be ordered to provide additional information about the tumor.
To determine the stage of cancer, an oncologist will consider the size of the malignant tumor, and any possible spread of the cancer to the lymph nodes and to other organs or tissues. Staging cancer helps an oncologist identify the best treatment options for ductal carcinoma. This may include surgery, radiation therapy, chemotherapy, therapy to block the actions of certain hormones and biological therapy.
Overall survival rates for breast cancer are quite high when the disease is detected and treated in its earliest stages. When breast cancer progresses undetected to later stages, the survival rates drop and the treatments are more aggressive. Survival rates for breast cancer have improved over the past two decades. The increased survival rates are related to the earlier detection and treatment of breast cancer, and increased awareness of the issue in the general population.
About ductal carcinoma
Ductal carcinoma is a type of breast cancer that involves the growth of cancerous cells in the lining of breast ducts. Most cases of breast cancer in women are some form of ductal carcinoma.
Breasts are composed of lymph vessels, blood vessels and fatty and connective tissue, as well as ducts and lobules, which are glands capable of producing breast milk. The ducts transport milk from the lobules to the nipple. Breast cancer typically occurs in the ducts or lobules.
Most forms of ductal carcinoma start in the lining of the breast ducts. When ductal carcinoma is identified just in the ducts, it is known as ductal carcinoma in situ (DCIS). In situ is a Latin term meaning “in place,” and indicates the cancer has not spread from the duct lining, through the basement membrane that separates the breast cells from surrounding tissues. DCIS cells have typical features of cancer, but usually remain within the confines of the breast ducts.
If cancer cells in the breast ducts spread through the duct walls and penetrate the basement membrane, the condition is known as invasive, or infiltrating, ductal carcinoma (IDC). From there, the cancer cells can spread, or metastasize, to other parts of the breast and other parts of the body through the lymphatic system, the bloodstream or directly into adjacent tissues.
Although the overwhelming majority of breast cancers occur in women, men can also develop breast cancer. The male breast contains ducts but few lobules. In men, breast cancer may occur within the ducts, but the cancer does not spread to fatty breast tissue or tissues outside of the breast. Most cases of breast cancer in men are invasive ductal carcinomas. DCIS occurs rarely in men.
While some specialists consider DCIS precancerous, others consider it the earliest stage of breast cancer. With the use of mammograms, DCIS is detected much more readily than in previous years. Regardless of the scientific perspective on this issue, DCIS is a condition that requires medical attention.
Overall, the American Cancer Society (ACS) estimates that more than 178,000 women will be diagnosed with invasive breast cancer in 2007, which includes invasive ductal carcinoma. In addition, the ACS estimates that more than 62,000 women will be diagnosed with in situ carcinomas, of which about 85 percent will be DCIS. Most of the 2,030 cases of breast cancer diagnosed in men in 2007 will be ductal carcinomas. After nonmelanoma skin cancers, breast cancer is the most common form of cancer in women. The ACS estimates that more than 40,000 women and 450 men will die from breast cancer in 2007.
Types and differences of ductal carcinoma
Ductal carcinomas are breast cancers that start in the breast ducts. Ductal carcinomas also can be divided into numerous subtypes. The two major subtypes are ductal carcinoma in situ and invasive ductal carcinoma.
Ductal carcinoma in situ (also known as DCIS or intraductal carcinoma) refers to cancer cells confined to the cells lining a breast duct. DCIS may be further subdivided by how the cancer cells grow in and along the ducts. Some tumors may be solid while others have holes or projections. DCIS may be multifocal, which means it can be found along the breast duct in more than one area of the breast. Depending on the number of ducts that contain DCIS, it can be referred to as either localized or diffuse.
Some DCIS cells may have small calcium deposits called microcalcifications. DCIS is frequently discovered by the appearance of these microcalcifications on screening mammograms. This type of cancer is typically noninvasive and is considered the earliest stage of breast cancer. Some experts view this type of cancer as a precancerous condition.
The other major subtype of ductal carcinoma is invasive ductal carcinoma (IDC), also called infiltrating ductal carcinoma. IDC occurs when carcinoma in a duct breaks through the duct wall and invades other breast tissue. This form of ductal carcinoma is by far the most common of all invasive types of cancer, accounting for about 80 percent of all cases, according to the American Cancer Society.
Risk factors and causes of ductal carcinoma
The cause of most breast cancers (including ductal carcinoma) is unknown, although some tend to occur in families. Breast cancer is a common type of cancer among women in the United States, Canada and Europe. However, in Africa and Asia, the prevalence of breast cancer is much lower. Being female is the single greatest risk factor for developing ductal carcinoma because of the large number of ducts in the female breast. Additional risk factors include:
- Age. Breast cancer occurs more often in women over 50 and is less common in women before menopause.
- Family history. Having a mother or sister with either breast or ovarian cancer increases a woman’s risk of breast cancer.
- Genetic predisposition. Research continues to reveal numerous genetic mutations associated with many types of breast cancer. The best known are the BRCA1 or BRCA2 breast cancer genes. A woman with BRCA1 or BRCA2 genes has an 80 percent chance of developing breast cancer in her lifetime, according to the American Cancer Society.
- Ashkenazi Jewish heritage. This segment of the population has a significant prevalence of breast cancer.
- Previous history of breast cancer or benign breast tumors. This includes being diagnosed with breast cancer, and having biopsies for tumors that turn out to be benign (noncancerous).
- Race. Breast cancer is more common in white women than in women of other races.
- Radiation to the chest area. Women with Hodgkin’s lymphoma who are treated with radiation to the chest before age 30 have an increased risk of developing breast cancer.
- Hormone use. Until recently, hormone replacement therapy (HRT) was commonly prescribed to women to reduce the symptoms associated with menopause. Recent studies have shown strong evidence that HRT or or other extended exposure to estrogen or progesterone can increase a woman’s risk of breast cancer.
- Breast density. Women with breasts that are less fatty (e.g., older women) have an increased risk of breast cancer.
- Reproductive history. Women who give birth before the age of 30 have a lower risk of developing breast cancer in their lifetime, compared to women who have children later in life or who never have children at all.
- Menstrual history. Women who started their menstrual periods early (before age 12) or went through menopause late (after age 55) have an increased risk of breast cancer.
- Having taken diethylstilbestrol (DES). A synthetic estrogen widely prescribed from the early 1940s through the early 1970s for pregnant women, DES is believed to slightly increase a woman’s risk of breast cancer.
- Being obese after menopause. In postmenopausal women, estrogen is primarily produced by fat tissue. As a result, postmenopausal women who are significantly overweight have more estrogen, which increases their risk of breast cancer.
- Sedentary lifestyle. Women who are physically inactive have a higher rate of breast cancer, possibly due to a sedentary lifestyle leading to a person becoming overweight or obese (an independent risk factor for breast cancer in postmenopausal women).
- Use of alcohol. Several studies have found that increased consumption of alcohol raises the risk of breast cancer.
- Smoking. Smoking significantly increases the risk of developing breast cancer, particularly for those with a family history of the disease.
Signs and symptoms of ductal carcinoma
Early stage ductal carcinomas may not be noticeable during breast self-examinations, clinical breast examinations performed by a physician or other healthcare provider, or even in mammograms. Many cases of ductal carcinoma are diagnosed before they present any symptoms. Routine screening mammograms indicate microcalcifications or other signs that require further investigation. However, as malignant cells grow, over a period of months and sometimes several years, noticeable signs or symptoms may develop.
The cancermay start with cells that have not yet formed a lump. As the cancer progresses, the tumor grows and a lump may be felt (palpated) by the individual or a physician. In addition, the lymph nodes may become enlarged, indicating a possible spread (metastasis) of the cancer.
When symptoms do occur, they may include:
- A lump or thickening in the breast
- Rash on the skin of the breast, areola or nipple that appears scaly, red or swollen
- Ridges, pitting or dimpling of the breast
- Fluid from nipples (discharge)
- A lump in the underarm area
- Nipple tenderness
- A change in the size or shape of the breast
- A nipple turned inward (into the breast)
In the majority of breast cancer diagnoses, there is no pain associated with the development of breast cancer. However, some individuals have reported pain around the lump in the breast.
Diagnosis methods for ductal carcinoma
Regular physical examinations and maintaining an accurate medical history are important for maintaining good health, especially when screening for cancer. When ductal carcinoma is identified in its earliest stages, survival rates dramatically increase and therapies are often much more tolerable.
Most cases of ductal carcinoma are diagnosed after a screening mammogram. Mammograms provide x-ray images of breast tissue that may identify abnormalities before they can be felt by the patient or a physician. Mammograms can identify tumors and tiny calcium deposits called microcalcifications, which are characteristic of ductal carcinoma.
In its earliest stages, ductal carcinoma in situ (DCIS) appears only on the mammogram as tiny specks or calcifications. These specks are the buildup of degenerated material left from dead cancer cells, which often become calcified. In contrast, invasive ductal carcinoma normally forms a hard lump and can be felt as well as detected by a mammogram. Although mammograms often offer the best way to detect ductal carcinoma at its earliest stages, they may produce false negatives or occur at too broad an interval to detect a fast spreading cancer. False positives also may occur.
The National Cancer Institute (NCI) recommends that all women age 40 or older receive mammograms every one to two years. Women who are at greater risk for breast cancer may be advised to have mammograms performed more frequently. Women younger than 40 who are at an elevated risk for breast cancer should discuss their risk factors and screening needs with their physician.
In addition to mammograms, clinical breast examinations and breast self-examinations (BSE) are two more ways to screen for breast cancer. The clinical breast examination, which takes about 10 minutes, is performed by a physician or other healthcare provider who palpates the breasts with the pads of the fingers. Using this method, the entire breast area will be checked for signs of cancer, including under the arms, around the collarbone area and the nearby lymph nodes. Many women perform a BSE every month to check for possible changes in their breasts. BSEs are intended to supplement but not replace clinical breast examinations or mammograms.
If mammogram results are inconclusive, a physician may send the patient for a breast ultrasound or magnetic resonance imaging (MRI) scan. When a clinical breast examination, mammogram or ultrasound shows an area of possible concern, a breast biopsy is typically performed. A biopsy involves the removal of cells or tissues for analysis under a microscope by a pathologist. The pathologist can determine whether or not the cells are cancerous and specifics about the type of tumor, which may provide information for treatment planning.
Ductal lavage is another technique that may be used for some women at high risk for breast cancer. With this procedure, the physician inserts a tiny catheter into the lining of a duct within the breast. Through the catheter, a sample of cells can be removed and examined for changes that take place before tumors can be detected by a mammogram. Ductal lavage may be more useful to identify women at risk rather than diagnose the disease. Some studies of women already diagnosed with breast cancer have produced ductal lavages that showed no abnormalities.
Other tests may be performed to determine if cancer has spread to other areas. These may include chest x-rays to examine the lungs and CT scans or PET scans.
Treatment options for ductal carcinoma
There are many treatments available for patients diagnosed with ductal carcinoma. Treatments are most likely to be curative or at least effective in improving the situation when cancer is diagnosed in its early stages.
Ductal carcinoma is staged according to information obtained from the biopsy and other tests. Staging the cancer identifies whether the cancer has spread and, if so, how far and to what areas of the body. After the cancer is staged, a treatment plan will be designed for the patient. Treatment plans are designed based on information about the tumor, such as its stage, location, size and hormone-receptor status, which indicates if it will respond to certain types of therapy. The patient’s age, general health, menstrual status and personal preferences are also factors in treatment planning.
Other factors normally taken into consideration include whether or not the ductal carcinoma has just been diagnosed or if it is a recurrence. After patients are diagnosed with cancer, their treatment plan will be designed by a cancer care team. This group of health care professionals may include:
- Radiation oncologist
- Plastic surgeon
- Oncology nurse
- Social worker
There are risks and benefits associated with all cancer treatment types. A brief overview of treatment options for ductal carcinoma includes:
- Breast cancer surgery. There are several types of breast cancer surgery and the type performed may depend on the size of tumor involved, as well as its location within the breast. A common option for some patients is a lumpectomy (also called a segmental mastectomy), which attempts to remove the tumor and surrounding margins of normal tissue while conserving as much of the patient’s breast as possible. Following lumpectomy, most women also receive radiation therapy to destroy any remaining cancer cells within the breast. A mastectomy may be performed to remove part or all of a breast. Breast reconstruction may also be an option for some patients following a mastectomy.
- Lymph node removal. In addition to breast cancer surgery, many surgeons also perform an axillary lymph node dissection on patients with invasive ductal carcinoma to determine whether or not the cancer has spread. This procedure removes some or all of the axillary (underarm) lymph nodes for inspection by a pathologist for evidence of cancer. A sentinel lymph node biopsy, an alternative to the axillary lymph node dissection, is another procedure that requires removal of only one or a few lymph nodes to determine if the cancer has spread.
- Radiation therapy. Most often involves the use of high-energy x-rays concentrated on the tumor site or the area from which a tumor was removed. The radiation kills cells in the area, which may include noncancerous as well as cancerous cells. Radiation therapy may also be used to shrink a tumor prior to surgical removal. For ductal carcinoma, many patients have lumpectomy followed by radiation therapy. Radiation is also used to treat symptoms such as bone pain and organ blockage, which may occur when cancer spreads.
- Chemotherapy. Chemotherapy drugs are used to treat cancer by destroying cancer cells, preferably before they reproduce and spread throughout the body, although chemotherapy can be used even if a limited number of cells have spread. Chemotherapy is used to treat metastatic cancer as well. These powerful medications may also damage noncancerous cells. Chemotherapy may also be used in addition to other cancer treatments.
- Hormone therapy. This type of therapy is most commonly prescribed for women with breast cancer that has metastasized (spread to other areas of the body). However, it may also be recommended for women with certain early stage breast cancers to prevent a recurrence. Hormone therapy keeps cancer cells from gaining access to the hormones that help the cancer grow. Hormone therapy drugs such as tamoxifen and aromatase inhibitors are commonly used in addition to other types of cancer treatment. Some women take tamoxifen for up to five years to prevent recurrence of breast cancer. Another type of hormone therapy is surgical removal of the ovaries (bilateral oophorectomy), which removes hormones produced by the ovaries and causes instant menopause.
- Biological therapy. The treatment is designed to bolster the body’s natural defense system, the immune system, against cancer. Biological therapy is very different from chemotherapy, but it is often used in combination with chemotherapy, since biological therapy does not kill all types of cancer cells and it can help reduce the side effects of chemotherapy.
According to the National Cancer Institute (NCI), recommended treatment options for DCIS patients include the following:
- Breast-conserving surgery and radiation therapy, with or without the drug tamoxifen
- Breast-conserving surgery without radiation therapy
- Mastectomy with or without tamoxifen
Prevention methods for ductal carcinoma
There are no known ways to prevent any type of breast cancer, including ductal carcinoma. However, there are tangible ways to reduce the impact of the disease by finding it early. Women are urged to have a breast examination performed by a physician or other healthcare provider every three years until they reach the age of 40. After age 40, women are urged to also schedule a mammogram every year or every other year. This is particularly important because ductal carcinoma in situ (DCIS) is detected only with a mammogram. In addition, all women are advised to conduct periodic breast self-examinations.
Other preventive measures include:
- Limiting alcohol consumption
- Maintaining a healthy weight
- Consulting a physician regarding taking estrogen or other hormones
- Incorporating physical activity into daily life
- Eating foods high in fiber and low in fat
- Eating plenty of fruits and vegetables
- Avoiding exposure to pesticides
- Avoiding unnecessary antibiotics
- Not using tobacco products of any kind
Staging of breast cancer
Physicians use a staging method to classify all forms of breast cancer, including ductal carcinoma. This information helps them identify the best treatment options for a patient. The stages are:
- Stage 0. When the cancer is contained to the area where it began. Ductal carcinoma in situ (DCIS) is considered Stage 0.
- Stage I. When the cancer has spread beyond a breast duct, but not outside the breast. The tumor size at this stage is equal to or less than 1 inch in diameter (2 centimeters).
- Stage II. Tumors can range from less than 1 inch across (2 centimeters) to more than 2 inches across (5 centimeters). They may or may not have spread to the axillary (underarm) lymph nodes.
- Stage III. All types of stage III tumors are considered a locally advanced form of breast cancer. In these cases, the cancer has spread to the axillary lymph nodes, tissues near the breast (such as the skin or chest wall) or to lymph nodes inside the chest wall. Tumors can range from smaller than 2 inches in diameter (5 centimeters) to larger than 2 inches.
- Stage IV. Metastatic cancer is considered stage IV, which is cancer that has spread from the site of origin to other organs of the body. Frequent metastases sites for breast cancer are the bones, lungs, liver or brain.
Questions for your doctor on ductal carcinoma
Preparing questions in advance can help patients have more meaningful discussions with healthcare providersregarding their condition. Patients may wish to ask their doctor the following questions related to ductal carcinoma:
- How frequently should I perform a breast self-exam?
- How often should I have a mammogram?
- How will you diagnose ductal carcinoma?
- How should I prepare for my diagnostic test?
- What type of ductal carcinoma do you suspect – in situ or invasive?
- When and from whom will I receive my test results?
- What is the stage of my ductal carcinoma?
- What are my treatment options? What are their risks or side effects?
- Do you have information about whether lumpectomy or mastectomy is a better treatment for me?
- Will treatment affect my ability to have children?
- Are my daughters at greater risk for ductal carcinoma?
- Will I have to take tamoxifen or any other medications after treatment? For how long?