Breast cancer starts when cells in the breast begin to grow out of control. These cells usually form a tumor that can often be seen on an x-ray or felt as a lump. The tumor is malignant (cancer) if the cells can grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the body. Breast cancer occurs almost entirely in women, but men can get breast cancer, too.
Breast cancer can spread when the cancer cells get into the blood or lymph system and are carried to other parts of the body.
Changes or mutations in DNA can cause normal breast cells to convert into cancer. Certain DNA changes are passed on from parents (inherited) and can greatly increase your risk for breast cancer. Other lifestyle-related risk factors, such as what you eat and how much you exercise, can increase your chance of developing breast cancer, but it’s not yet known exactly how some of these risk factors cause normal cells to become cancer. Hormones seem to play a role in many cases of breast cancer, but just how this happens is not fully understood.
Breast cancer is the most frequently encountered cancer in females worldwide and in India. In 2020, there were 2.3 million women diagnosed with breast cancer and 685 000 deaths globally. As of the end of 2020, there were 7.8 million women alive who were diagnosed with breast cancer in the past 5 years, making it the world’s most prevalent cancer. Women from less developed countries have more number of cases when compared to more developed regions. Although the incidence of breast cancer has increased globally over the last several decades, the greatest increase has been in Asian countries. In Asia, breast cancer incidence peaks among women in their forties, whereas in the United States and Europe, it peaks among women in their sixties. Breast Cancer is the most common cancer, combined, in cities and rural areas of India as well. As per the Globocan 2020 data, in India, breast cancer accounted for 13.5% (178361) of all cancer cases and 10.6% (90408) of all deaths. In India, premenopausal patients constitute about 50% of all patients. When it comes to the 5-year overall survival, it is reported to be 95% for stage I patients, 92% for stage II, 70% for stage III and only 21% for stage IV patients. The survival rate of patients with breast cancer is poor in India as compared to Western countries due to earlier age at onset, late stage of disease at presentation, delayed initiation of definitive management and inadequate/fragmented treatment.
The most common symptom of breast cancer is a new lump or mass. A painless, hard mass that has irregular edges is more likely to be cancer, but breast cancers can be tender, soft, or rounded. They can even be painful. For this reason, it is important to have any new breast mass, lump, or breast change checked by a health care professional experienced in diagnosing breast diseases.
Although any of these symptoms can be caused by things other than breast cancer, if you have them, they should be reported to a health care professional so that the cause can be found.
Mammography sensitivity has been reported to vary from 64% to 90% and specificity from 82% to 93%. However there is a lack of adequate mammography machines and trained manpower. Digital mammography uses computer-aided detection software but remains costly. It is due to these reasons that mass-scale routine mammography screening is not a favored option for a transitioning country like India.
Ultrasonography has an overall sensitivity of 53% to 67% and specificity of 89% to 99% and might be particularly helpful in younger women (aged 40 to 49 years). Though breast self-examination is not accepted as an early detection method for BC, this technique, if used diligently and skillfully, can serve as a useful adjunct to making the woman aware of her normal breast.
Management of BC is multidisciplinary and has come a long way. In the past, the widely used treatment option was mastectomy followed by adjuvant chemotherapy for locally advanced BC, triple-negative breast cancer and HER2neu expressing tumours (human epidermal growth factor receptor 2). At present, it includes a loco-regional approach (targeting only the tumour with the help of surgery and radiation therapy) and a systemic therapy approach that targets the entire body.
The systemic therapy includes endocrine therapy for hormone receptor-positive disease, chemotherapy, anti-HER2 therapy for HER2 positive disease, bone stabilizing agents, polymerase inhibitors for BRCA (breast cancer gene) mutation carriers and, recently, immunotherapy. However, the majority of patients still undergo primary surgical procedures. Gene expression profiling in hormone receptor-positive disease is also a promising option but has financial implications.
Breast-conserving surgery (lumpectomy or partial mastectomy) can often be used for early-stage breast cancers. But for some women, it can result in breasts of different sizes and/or shapes. For larger tumors, it might not even be possible, and a mastectomy might be needed instead. Some doctors are addressing this problem by combining cancer surgery and plastic surgery techniques, known as oncoplastic surgery. This typically involves reshaping the breast at the time of the initial surgery, such as doing a partial breast reconstruction after breast-conserving surgery or a full reconstruction after mastectomy. Oncoplastic surgery may mean operating on the other breast as well to make the breasts more alike.
Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. It affects cells only in the part of the body that is treated with the radiation. Breast cancer radiation therapy may be used to destroy any remaining mutated cells that remain in the breast or armpit area after surgery.
Targeted therapies are a group of drugs that specifically target gene changes in cancer cells that help the cells grow or spread i.e. PARP inhibitors. These drugs are most likely to be helpful against cancers caused by BRCA gene mutations, and have shown some promise in treating some types of breast cancers.
Early Detection is the key to fight against Breast Cancer
Dr. Ajay Sharma
Sr. Consultant – Medical Oncology, RGCIRC, Delhi