Breast Carcinoma

Breast Carcinoma

Breast cancer originates in the tissues of the breast and most frequently diagnosed cancer in women. It is the second leading cause of cancer death among women.

The breast is composed mainly of fatty tissue and rich in blood vessels and lymphatic channels. The milk glands contained within it are connected to the nipple by a series of ducts. Male breasts are rudimentary in comparison to the females and therefore incidence of breast cancer in males is rare. Adenocarcinoma of the breast originates in the milk ducts and/or lobules (glandular tissue) of the breast.

 

Types of carcinoma in breast

The two main types of breast cancer:

  • Ductal carcinoma originates in the milk ducts. This form is predominant.
  • Lobular carcinoma starts in lobules that produce milk.

The cancer may originate in other parts of the breast rarely.

Both of the above types can stay in one place (in situ) or become invasive, or “infiltrating” carcinomas.

There are invasive breast carcinomas that are less deadly than infiltrating ductal carcinomas, including adenocystic, medullary, mucinous, papillary, and tubular carcinomas. Metaplastic and mixed carcinomas are more difficult to treat.

Other rare types include: Inflammatory breast cancer, triple-negative breast cancer, Phyllodes tumor (cystosarcoma phyllodes), and angiosarcoma.

If the carcinoma spreads to other tissues it is called invasive, otherwise it is non-invasive.

Epidemiology

There are approximately 1 million new cases of breast cancer in the world each year. Although, females are much more prone to this disease, 1 % of all breast cancers occur in males. In the United States, it has been estimated that in 2012 there will be 226,870 cases of invasive breast cancer diagnosed, while the number of new cases of localized carcinoma (in situ) is expected to be about 63,000. Some 39,150 women are expected to die from the disease. The incidence of breast cancer is more frequent among Caucasians in the United States. There are fewer cases in African American women, and an even lower rate in Hispanic/Latina women, American Indian/Alaska Natives, and Asian American/Pacific Islanders

The incidence of breast cancer increases with age. The average of diagnosis of breast cancer is 60. Studies show that the disease is more frequent in affluent women.

Risk factors

Some of the most important risk factors for breast cancer include the following:

First-degree female relatives with breast cancer: This includes sisters and mothers.

Mutations: Mutations in BRCA1 and BRCA2 (autosomal dominant genes located on the long arms of chromosomes 17 and 13 respectively) increase the chance of developing breast cancer in general as well as at a younger age. These mutations are inherited from close relatives. There are other genetic mutations associated with breast cancer under study.

Early menarche or late menopause: Women with early menarche or late menopause have increased risk of breast cancer.

Age: The age of women at first pregnancy also matters, with an increased risk in women who have their first pregnancy after age 30. Women who have never been pregnant as well women who never breast fed their children are at increased the risk of breast cancer.

Sex: Men have a much lower risk of developing breast cancer than women.

Previous history: Women with a history of breast, ovarian, uterine or bowel cancer have a higher chance of developing breast cancer.

Smoking, alcohol consumption and high fat containing diet: All these habits are correlated with breast cancer development. Obesity after menopause may also increase the risk.

Increased levels of female hormones: Hormone replacement therapy (HRT) after menopause can also be a risk factor for breast cancer if both estrogen and progesterone are used. Birth control pills containing female hormones may slightly increase risk of breast cancer.

Radiation to the chest increases the risk of breast cancer.

Chemicals like monocyclic, polycyclic, and heterocyclic amines: All these may increase the rate of breast cancer. Toxic chemicals like benzene, vinyl chloride, polyclinic aromatic hydrocarbons (PAHs) may cause breast cancer.

Smoking may increase the risk of breast cancer.

Symptoms

At the initial stages, the symptoms of the breast cancer may include the following:

  • The shape, appearance and feel of the breast changes.
  • A hard lump may be detected.
  • Redness and dimpling may also be observed.
  • Fluid containing blood and pus may come out.

Symptoms of advanced breast cancer may include:

  • Pain in nearby areas and bones
  • Sores on the skin
  • Unexpected loss of weight
  • Swelling of the arm closest to the affected breast

Diagnosis

Diagnosis at an early stage can prevent the progress and cure the disease. The following techniques are employed:

Clinical and self breast exams: Lumps can be diagnosed by a woman herself or during clinical exams by healthcare providers.

Mammography: Radiography that usesX-rays to detect cancer. This technique is not useful for women under 40 because they have dense breast tissue which makes abnormalities hard to see. Lobular carcinoma in situ (LCIS) usually remains undetectable on mammograms.

Genetic screening: Screening does not detect cancers, but may reveal a tendency to develop cancer. Commercial testing of mutations in BRCA1 and BRCA2 is available. Patients with a familial history of breast cancer, especially in first degree relatives, should consider being tested to see whether they have this risk factor for developing breast cancer.

Ultrasound imaging: This is mainly used to detect small cancers in dense breasts. It also helps to analyze whether the suspected region is a fluid-filled cyst or a solid tumor. A cyst is very rarely cancerous.

Magnetic resonance imaging (MRI): MRI can detect cancers not visible on mammograms. Recent developments in MRI imaging have helped to screen for in situ carcinomas.

Molecular breast imaging (MBI): It is a nuclear medicine technique that is under development.

Breast biopsy: A biopsy is done to remove cells or tissues of the breast lump for laboratory tests. Excisional biopsy removes the whole lump. Incisional biopsy takes a sample of the tumor. Needles can be used to obtain samples, including the core biopsy in which tissue is removed with the help of a wide needle and fine-needle aspiration in which tissue or fluid is removed with a thin needle.

Treatment

Surgery

Surgery is performed to remove the tumor together with the surrounding tissue in the breast. It can be of many different types.

Lumpectomy: This is surgery in which only the lump of cancerous breast tissue and a very small portion of the surrounding tissue is excised.

Quadrantectomy: With this surgery, one-fourth of the breast is excised, in the area of the tumor.

Mastectomy: A mastectomy means the entire breast is excised. A radical mastectomy involves removing more surrounding tissue.

Adjuvant breast cancer treatment, given along with surgery includes:

  • Hormone blocking therapy: Drugs such as tamoxifen can be used to block estrogen receptors in estrogen-receptor positive cancers. Alternatively, an aromatase inhibitor like anastrozole can inhibit the hormone estrogen.
  • Chemotherapy: A combination of cyclophosphamide and doxorubicin can be used as chemotherapeutic agents. Taxane can be added to the above combination of drugs. A combined treatment with cyclophosphamide, methotrexate and fluorouracil (CMF) is another form of chemotherapy.
  • Biological therapy with monoclonal antibodies: The HER2/neu gene over-expression is a cause of breast cancer. Trastuzumab (Herceptin), a monoclonal antibody against HER2 can be used to enhance survival rates. Antibodies may also be used to inhibit angiogenesis and signal transduction pathways inside cancer cells. The growth factor receptors erbB1 (epidermal growth factor receptor 1) and erbB2 (HER2/neu receptor) can be blocked by Lapatinib to stop the proliferation of breast cancer cells.
  • Radiotherapy: Radiotherapy is used to destroy tumor cells after surgery. Radiation decreases the chances that the disease may recur. It is mostly done after lumpectomy.

Treatment Based on stages:

Stage I and II – Surgical removal of the lump or the whole breast and affected lymph nodes is the standard treatment. Post-surgery a patient can be treated with radiation. Chemotheraputic agents and hormones can also be used for further treatment if necessary.

Stage III – Surgical excision of the breast is done. Post-surgical treatments may be done with chemotherapeutic agents, hormones and antibodies.

Stage IV — Surgical excision of the breast is followed with treatments with a combination of different treatments, which include radiotherapy, chemotherapy, biological and hormonal therapies.

Prognosis of Breast Cancer

Early breast cancer has a good (greater than 80%) 5 year survival. Important prognostic factors include: Stage (based on TNM staging), grade, histologic subtypes, estrogen/progesterone status and the age and health of the patient.

Ductal Carcinoma in Situ (DCIS) has an exceptionally good prognosis with a ten-year, disease-free survival of about 98%. If the cancer has metastasized (spread) to other organs at diagnosis, 5-year survival rates are significantly lower. “Early” breast cancer refers to Stage I, and some Stage II only. Both have a survival rate between 95-100 %.

The prognosis for a younger woman is poorer than a post-menopausal woman. Stage III and Stage IV tumors show a 5-year survival rate of 57% and 20% respectively. Prognosis is poor if recurrence occurs.

References

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  8. This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.