What are the other Names for this Condition? (Also known as/Synonyms)

• Carcinoma of Breast with Apocrine Differentiation
• Mammary Carcinoma with Apocrine Differentiation

What is Breast Carcinoma with Apocrine Differentiation? (Definition/Background Information)

• Breast cancer is the most common type of cancer diagnosed in women. It is a type of cancer in which certain cells in the breast become abnormal, grow uncontrollably, and form a malignant mass (tumor). There are various types of breast cancers
• Breast Carcinoma with Apocrine Differentiation is a rare subtype of invasive breast carcinoma that presents apocrine differentiation when the tumor cells are observed under the microscope by a pathologist. This form of cancer is observed frequently in adults
• The cause of development of Breast Carcinoma with Apocrine Differentiation is not well-established. Several genetic abnormalities have been identified. The condition can cause a painless mass in the breast, nipple discharge, and other signs and symptoms. The carcinoma may be diagnosed via breast biopsy
• The treatment of Breast Carcinoma with Apocrine Differentiation usually involves a complete removal of the tumor. Depending on the stage of the malignancy, radiotherapy and/or chemotherapy may be administered by the healthcare providers treating the condition
• The prognosis depends on many factors, but particularly on the stage of the tumor. Since there is a risk for recurrence and metastasis, close clinical monitoring is necessary with periodic follow-ups. An early diagnosis and adequate treatment can significantly improve the outcomes

Who gets Breast Carcinoma with Apocrine Differentiation? (Age and Sex Distribution)

• Breast Carcinoma with Apocrine Differentiation is rare and represents 1% of all breast cancers. It is usually observed in women
• When compared to those diagnosed with classical invasive ductal carcinoma of breast, Breast Carcinoma with Apocrine Differentiation is usually noted in older patients
• All racial and ethnic groups are affected, and no specific predilection is seen

What are the Risk Factors for Breast Carcinoma with Apocrine Differentiation? (Predisposing Factors)

The risk factors for Breast Carcinoma with Apocrine Differentiation are not well established since the condition is rare. Some reports indicate that the malignancy may be associated with Cowden syndrome, a genetic disorder.

In general, the risk factors for developing breast cancer may include:

• Women have a much greater chance of developing breast cancer than men
• Age: The risk increases for women over the age of 55 years
• Personal history: Having cancer in one breast, puts a woman at risk for having cancer in the other breast as well
• Family history: Women with a mother, sister, or daughter diagnosed with breast cancer have a higher risk for developing the condition
• Inherited gene mutations: Mutations in certain genes (BRCA1 or BRCA2) can lead to a much higher risk
• Radiation therapy: Receiving radiation therapy to the chest or breast area can also increase the risk. It is noted that the risk for developing breast cancer later in life is the greatest for radiation therapy administered during puberty
• Obesity: Being overweight or obese elevates the risk after menopause
• Alcohol use: Consuming alcohol more than one drink per day; the more the alcohol consumed, the greater is the risk
• Menstrual cycle: Women who got their period before the age of 12 years, and those who reached menopause after age 55 have an increased risk
• Postmenopausal hormone therapy: Women taking hormone replacement therapy medications containing both estrogen and progesterone for menopause have a higher risk of developing breast cancer
• Reproductive history: Having the first child after the age of 35, or never having children
• Physical inactivity: A lack of physical exercise (leading a sedentary life) can increase the risk
• Breastfeeding: Not breastfeeding one's child can increase the risk for developing the condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Breast Carcinoma with Apocrine Differentiation? (Etiology)

The exact cause of development of Breast Carcinoma with Apocrine Differentiation is currently not well understood. The malignancy is known to occur sporadically.

• In many cases, mutations on AKT, PIK3CA, PTEN, and TP53 genes are noted
• Less commonly, mutations involving the BRAF, KRAS, and NRAS genes have also been observed
• When associated with Cowden syndrome, germline mutations on the PTEN gene are reported

What are the Signs and Symptoms of Breast Carcinoma with Apocrine Differentiation?

The signs and symptoms of Breast Carcinoma with Apocrine Differentiation are similar to those of invasive breast carcinomas and may include:

• A growing painless lump or firm mass
• Discharge from the nipple
• Thickening or swelling of part of the breast; change in the size or shape of the breast
• Inversion of the nipple (pulling-in of nipple into the breast) 
• Changes to the skin covering the breast or nipple area, including dimpling, irritation, redness, scaling, peeling, or puckering 
• The condition can be unilateral (involving only one breast) or bilateral (affecting both breasts)

How is Breast Carcinoma with Apocrine Differentiation Diagnosed?

Breast Carcinoma with Apocrine Differentiation may be diagnosed in the following manner:

• Complete physical examination with comprehensive medical and family history evaluation
• Breast exam to check for any lumps or unusual signs in the breasts
• Blood tests including complete blood count (CBC) test
• Mammogram: A mammogram uses X-rays to provide images of the breast
• Galactography: A mammography using a contrast solution, mostly used to analyze the reason behind a nipple discharge
• Breast ultrasound scan: Using high-frequency sound waves to produce images of the breast
• Computerized tomography (CT) or magnetic resonance imaging (MRI) scan of the breast
• Positron emission tomography (PET) scan to help determine, if the cancer has spread to other organ systems
• Breast biopsy:
  • A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform additional studies, which may include immunohistochemical stains and molecular studies to assist in the diagnosis

Biopsies are the only methods used to determine whether an abnormality is benign or cancerous. These are performed by inserting a needle into a breast mass and removing cells or tissues, for further examination. There are different types of biopsies:

• Fine needle aspiration biopsy (FNAB) of breast mass: In this method, a very thin needle is used to remove a small amount of tissue
• Core needle biopsy of breast mass: A wider needle is used to withdraw a small cylinder of tissue from an abnormal area of the breast
• Open tissue biopsy of breast mass: A surgical procedure used less often than needle biopsies, it is used to remove a part or all of a breast lump for analysis

The differential diagnosis to exclude conditions with similar presentations include:

• Granular cell tumor of breast
• Micropapillary carcinoma of breast
• Mucinous carcinoma of breast
• Oncocytic carcinoma of breast
• Pleomorphic lobular carcinoma of breast

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Breast Carcinoma with Apocrine Differentiation?

The complications of Breast Carcinoma with Apocrine Differentiation may include:

• Emotional distress due to the presence of breast cancer
• Recurrences following surgery may be observed; incompletely excised tumors may recur
• Metastasis of the tumor to local and regional sites
• Treatment side effects

How is Breast Carcinoma with Apocrine Differentiation Treated?

Treatment options available for individuals with Breast Carcinoma with Apocrine Differentiation are dependent upon the following:

• Type of cancer
• The staging of the cancer: If a breast cancer is diagnosed, staging helps determine whether it has spread, and what treatment options are best-suited for the patient
• Whether the cancer cells are sensitive to certain particular hormones, and
• One’s personal preferences

Surgery: Surgery is generally the most common form of treatment involving the removal of the tumor. Various types of surgery to remove the malignant tumor include:

• Lumpectomy: Breast-sparing surgery (least invasive breast cancer surgery) in which the tumor, as well as a small portion of the surrounding tissue is removed
• Mastectomy: Surgery to remove all of the breast tissue; it may be simple (removal of the breast, nipple, areola, sentinel lymph nodes) or radical mastectomy (removal of the breast, nipple, areola, all axillary lymph nodes, and underlying muscle of the chest wall)
• Sentinel node biopsy: Procedure done to examine the “sentinel lymph node,” or lymph node(s) closest to the tumor, as this is the most likely location, where cancer cells may have spread to. This lymph node is removed and tested for cancerous cells
• Axillary node dissection: This procedure is performed to remove some axillary lymph nodes in the underarm area, to allow dissection and examination. This helps in establishing whether the cancer has spread to more than one lymph node

Other treatment options may include chemotherapy and radiation therapy.

• Radiotherapy can be used as primary therapy in situations where the tumor cannot be removed completely, or when the tumor reappears after surgery
• Radiotherapy can also be used as additional therapy after surgery, if there is a possibility of tumor recurrence after surgery, or if there are inadequate margins (possibility of tumor left behind) following surgery. In some cases, due to location of tumor, a complete surgical removal of the tumor is difficult
• The role of chemotherapy in treating Breast Carcinoma with Apocrine Differentiation is not well-established; only limited information is available

How can Breast Carcinoma with Apocrine Differentiation be Prevented?

Currently, no specific preventive measures are available for Breast Carcinoma with Apocrine Differentiation. In general, it is important to be aware of the following:

• Learning to do regular ‘breast self-exams’ in order to help identify any unusual lumps or signs in the breast
• Maintain a healthy body weight and exercise regularly
• Implement and follow a well-balanced diet; a high intake of fiber via fresh fruits and vegetables helps in a healthy lifestyle
• Avoid or completely stop smoking
• If taking alcohol, only drink in moderation; limit to one or (maximum) two drinks a day
• Limit combination hormone therapy used to treat symptoms of menopause. It is advised that individuals be aware of the potential benefits and risks of such hormonal medications
• Cancer screenings can help detect any breast cancer during the early stages

What is the Prognosis of Breast Carcinoma with Apocrine Differentiation? (Outcomes/Resolutions)

• Breast Carcinoma with Apocrine Differentiation is a rare form of breast cancer. The prognosis of the condition generally depends upon the stage of the tumor
• However, according to medical literature, it has a worse prognosis compared to classical invasive carcinoma of breast
• The prognosis of breast cancer, in general, depends upon a set of several factors that include: 
  • The grade of the breast tumor such as grade1, grade2, and grade 3. Grade1 indicates a well-defined tumor, whereas grade 3 indicates a poorly-defined tumor
  • The size of the breast tumor: Individuals with small-sized tumors fare better than those with large-sized tumors
  • Stage of breast cancer: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • Cell growth rate
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • Individuals with bulky disease of the breast cancer have a poorer prognosis
  • Involvement of the lymph node, which can adversely affect the prognosis
  • Involvement of vital organs may complicate the condition
  • The surgical resectability of the tumor (meaning if the tumor can be removed completely)
  • Whether the tumor is occurring for the first time or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur 
  • Response to treatment of breast cancer: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment
  • Progression of the condition makes the outcome worse
• An early diagnosis and prompt treatment of the tumor generally yields better outcomes than a late diagnosis and delayed treatment

Additional and Relevant Useful Information for Breast Carcinoma with Apocrine Differentiation:

The following DoveMed website links are useful resources for additional information:

https://www.dovemed.com/healthy-living/womens-health/

https://www.dovemed.com/diseases-conditions/cancer/