written by  Dr. Sanjana V.B Bhms,dbrm,cdn
Reviewed by SIAHMSR

Founder & medical director of siahmsr wellness.in

all rights reserved with siahmsr digital healthcare[siahmsr wellness]

Overview

    Breast cancer is one of the most common cancers in women and it primarily develops from breast tissue, the milk duct cells and manifested as a lump in the breast, a change in breast shape, dimpling or fluid coming from the nipple, inverted nipple, or a red or scaly patch of skin.

Breast cancer typically evolves silently, and often it is discovered on routine screening mammography test in the Western world. This test is not routinely done in developing countries in other parts of the world in healthy people. Without screening, breast cancer is often detected as a palpable breast mass in these places.  

Once breast cancer is suspected by mammography test, it is followed with further testing with ultrasound or MRI. The treatment for breast cancer includes surgery, radiation, chemotherapy, and immunotherapy or in combination depending on the stage and type of cancer. The development in these treatment modalities have helped to achieve better survival in cancer affected women.

Epidemiology

   Breast cancer is the second most common cause of cancer deaths among women globally. The cancer types vary among women and invasive breast cancer remains the most common cancer worldwide, accounting for approximately 11.7% of new cases in 2020.

In 2022, there were 2.3 million women diagnosed with breast cancer and 670 000 deaths globally. Breast cancer occurs in almost all the geographical regions of the world in women at any age. The risk begins after puberty as a girl enters into reproductive period. However, the cancer risk increases more with advancing age.

Risk factors for breast cancer

 The risk for breast cancer is associated with increasing age, obesity, harmful use of alcohol, family history of breast cancer, history of radiation exposure, reproductive history (such as age that menstrual periods began and age at first pregnancy- after 30 years), tobacco use and postmenopausal hormone therapy.

 However, it has been found that approximately half of breast cancers develop in women who have no identifiable risk factor or familial predisposition.

·       Age

The incidence rate of breast cancer increases with age, from 1.5 cases per 100,000 in women aged 20 to 24 to a peak of 421.3 cases per 100,000 in women aged 75 to 79; 95% of new cases occur in women aged 40 years or older.

·       Genes or family history

The risk for breast cancer is high in women having some inherited gene mutations. The most dominant being mutations in the genes BRCA1, BRCA2 and PALB-2. Genetic factors cause 5% to 10% of all breast cancer cases.

Gene mutations may account for the occurrence of 25% of breast cancer cases in women younger than 30 years. BRCA1 and BRCA2 are the most important genes responsible for increased breast cancer susceptibility.

·       Hormonal therapy for a prolonged period of time with oestrogen.

Therefore, risk reduction strategies play significant role in reducing the incidence of breast cancer in women.

What is carcinoma in situ or localized cancer & invasive breast cancer?

Breast cancer cells begin to grow mostly inside the milk ducts and/or the milk-producing lobules of the breast. The earliest form of localized cancer is called carcinoma in situ which can be detected in early stages if proper screening tests are done. It is not a life-threatening condition if appropriate management is taken.

But cancer cells can spread into nearby breast tissue and the process is called cancer invasion. This invasion creates tumours or swellings manifested as lumps or thickening. Invasive cancers can spread to nearby lymph nodes or other organs and the spread is called metastasis. So invasive cancer can be life-threatening and fatal if appropriate treatment is not taken.

The following are the most common histologic types of invasive breast cancers.

·       Ductal adenocarcinoma: This type of breast cancer comprises 50% to 75% of all invasive breast cancers. Clinically, these tumors are often felt as a breast mass secondary to a significant fibrotic reaction

·       Ductal adenocarcinoma: This histologic type comprises 50% to 75% of all invasive breast cancers. Clinically, these tumors are often felt as a breast mass secondary to a significant fibrotic reaction. Microscopically, the lesion arises in the terminal duct-lobular unit with abnormal epithelial cells with varying degrees of atypia. These cells invade the basement membrane.

·       Lobular carcinoma: Invasive lobular cancer makes up 10% to 15% of breast cancer &typically remain clinically occult. That means they fail to be detected on mammography or physical examination until the disease advances or worsen.

·       Mucinous carcinoma:  which make up 2% to 5% of breast cancers, and occur mostly in older women.

·       Tubular carcinoma: 1% to 2% of breast cancers are among this subtype.

·       Medullary carcinoma: These cancers are aggressive types and are poorly differentiated and seen more commonly in BRCA mutant and younger patients.

                   SIAHMSR                                                           

Signs &symptoms of breast cancer

Breast cancer can have combinations of symptoms, especially when it is more advanced. Symptoms of breast cancer can include:

A breast lump or thickening, often without pain

Change in size, shape or appearance of the breast

Dimpling, redness, pitting or other changes in the skin

Change in nipple appearance or the skin surrounding the nipple (areola)

Abnormal or bloody fluid from the nipple.

People with an abnormal breast lump should seek medical care, even if the lumps are not painful. Most breast lumps are not cancers.

Breast cancers may spread to other areas of the body and  the most common first detectable site of spread is to the lymph nodes under the arm although it is possible to have cancer-bearing lymph nodes that cannot be felt on examination.

The cancerous cells may spread to other organs including the lungs, liver, brain and bones. This metastasis [spread] may cause symptoms in those areas also.

Tests for diagnosing breast cancer

In Western countries, breast cancer is diagnosed by screening rather than due to symptoms.

Breast cancer is diagnosed through physical examination, breast imaging, and tissue biopsy.

A few breast cancer cases do not manifest any symptoms in the beginning.  Therefore, screening with mammography is important in early cancer detection.

Once a suspicious lesion is identified, tissue biopsy with stereotactic core needle biopsy is performed with imaging guidance. Core needle biopsy is superior to fine needle aspiration In patients with clinically positive regional lymph nodes, an ultrasound-guided core needle biopsy is performed.

Treatment of breast cancer

Treatment for breast cancer depends on the subtype of cancer and its stage.

Staging is based on how much it has spread outside of the breast to lymph nodes (stages II or III) or to other parts of the body (stage IV].

The treatment include :

·       surgery to remove the breast tumour.

·       radiation therapy to reduce recurrence risk in the breast and surrounding tissues.

·       medications to kill cancer cells and prevent spread, including hormonal therapies, chemotherapy or targeted biological therapies.

Treatments for breast cancer are more effective when it is started early and the full course of treatment is completed.

 There are various types of surgeries depending on the nature and stages of cancer. Lump or the whole breast may be removed. Surgery may also remove lymph nodes to assess the cancer’s ability to spread.

Radiation therapy treats residual cancer cells left behind in the breast tissue and/or lymph nodes and minimizes the chances of cancer recurring on the chest wall.

Advanced cancers can cause ulcers on breast. it may not be painful always. Non- healing ulcers of breast should be tested with core biopsy.

Medicines are chosen based on the biological properties of the cancer as determined by special tests (tumour marker determination]

Radiotherapy also has crucial role in treating breast cancer. With early-stage breast cancers, radiation can prevent a woman having to undergo a mastectomy.

In late stages of cancers, radiotherapy may help to reduce cancer recurrence risk even when a mastectomy has been performed.

The effectiveness of breast cancer therapies depends on the full course of treatment. Partial treatment is less likely to lead to a positive outcome.

Prevention of breast cancer occurrence in women

The WHO Global Breast Cancer Initiative (GBCI) is working with a vision to reduce global breast cancer mortality by 2.5% per year, thereby averting 2.5 million breast cancer deaths globally between 2020 and 2040.

To reduce the risk of development of invasive breast cancers the following initiatives may help.

·       Public health education to improve awareness among women of the signs and symptoms of breast cancer.

·       Women should understand the importance of early detection and treatment of breast cancer  and more women could approach medical doctors when breast lumps are suspected.

·       Screening

Breast cancer screening means testing otherwise-healthy women for diagnosing breast tumors early, even before lumps can be felt on the breast during physical examinations. At this stage of cancer treatments are more successful. The most common screening test for breast cancer is mammography. This is low-dose X-ray imaging of the breast. Mammography can detect around 90% of breast tumors in the least dense breasts (called fatty breasts), but only 60% in the most dense breasts . Women with particularly dense breasts can be  further screened by ultrasound, magnetic resonance imaging (MRI).

Regular screening mammography reduces breast cancer deaths by at least 20%. Most of the medical guidelines recommend annual screening mammograms for women aged 50–70.

Screening also reduces breast cancer mortality in women aged 40–49, and some guidelines recommend annual screening in this age group also.

   However, mammography has some disadvantages also. Overall, screening mammograms miss about 1 in 8 breast cancers. Further, they can also give false-positive results about cancer and it may be causing extra anxiety and making patients undergo unnecessary additional exams, such as biopsies. However, this drawback is negligible. Mammograms have advantages more than disadvantages in cancer diagnosis.

 Written by Dr.Sanjana v.b . BHMS DBRM,CDN [ copyright]

Reference

1.    https://www.who.int/news-room/fact-sheets/detail/breast-cancer

2.    https://www.nature.com/articles/s41572-019-0111-2

3.    https://en.wikipedia.org/wiki/Breast_cancer

4.    https://www.cancer.org/cancer/types/breast-cancer/screening-tests-and-early-detection/mammograms/limitations-of-mammograms.html

5.    https://www.ncbi.nlm.nih.gov/books/NBK482286/

6.    https://www.cancer.org/cancer/types/breast-cancer/about/types-of-breast-cancer.html