The evolution of treatment methodologies over the decades in breast cancer care
Breast cancer is the most common form of cancer among women across the world, including India. In fact, breast cancer accounts for one-third of all the cancers that affect women in the country. According to an ICMR study, the current age-standardised rate of breast cancer is approximately 25.8 per one lakh women and is expected to rise to 35 per one lakh women by 2026. It is the most common invasive cancer in women and the second leading cause of cancer-related deaths after lung cancer. Breast cancer forms in the lobules or ducts of the breast. It can also occur in the fatty tissue or the fibrous connective tissue within the breast. The cancer can spread outside the breast through blood and lymph vessels. Breast cancer can be categorised as ‘invasive’, ‘non-invasive’, or ‘in-situ’. While invasive breast cancer spreads from the breast ducts or glands to other parts of the body, non-invasive breast cancer does not spread from the original tissue.
Factors such as rise in sedentary lifestyles, smoking, obesity, consumption of alcohol and genetics, have contributed to the increasing incidence of breast cancer. Sadly, the prevalence of taboos, myths and low awareness surrounding the disease and its treatment leads to late presentation and affects the success rate of treatment. Breast cancer is among the most well-known researched cancers in the medical ecosystem and technological advancements in screening, diagnosis and subsequent treatment have helped improve patient outcomes drastically. The evolution in breast cancer treatment over the last two decades has been phenomenal with the possibility of picking up cancers as small as 3-5 mm in the breast through various imaging techniques and detecting distant metastases with scans like PET-CT. Advancements in imaging technology allow acquisition of clinically important and real-time actionable information on the disease.
Evolution of treatment methodologies over the decades
1. Mastectomy, which was first performed around 1882, is the surgical removal of the entire breast. At the time, mastectomies were highly invasive, requiring the removal of the breast, lymph nodes, and underlying muscle. The radical procedure caused long-term pain and disability in patients. However, mastectomy has evolved over time and currently the procedure is less radical and in suitable cases, there are even ways to preserve the skin (skin-sparing mastectomy) and also the nipple (nipple-sparing mastectomy) in combination with reconstructive surgeries, to shape a new breast with tissues taken from other parts if the body or with silicone.
Benefits: Helps local control of breast cancer in those who have the extensive local disease. It is also used as a risk-reducing method in patients who have a gene abnormality that increases their risk of breast cancer.
2. Lumpectomy, also known as breast-conserving surgery, was developed during the 1970s and was a less invasive surgical option as compared to mastectomies. By 1985, research revealed that a lumpectomy followed by radiation treatment gave women a chance of survival equal to the more invasive mastectomy. This procedure is currently used to remove the cancerous tumour and a small margin of healthy tissue around the tumour and offers the same benefits that it did earlier.
Benefits: Allows women to retain their breasts, with huge psychological benefits.
3. Sentinel lymph node biopsy was a procedure that was developed in 1991 to identify, remove, and examine the first draining nodes in the armpit (sentinel lymph nodes) for detecting cancerous cells. In selected patients, this procedure helps to avoid a more extensive surgery in the armpit. Saving nodes that don’t have cancer is not only oncologically safe but also prevents the development of potentially serious side effects of removing all the glands that function to aid in lymph drainage.
Benefits: Sentinel lymph node biopsy is the standard of care and can help minimise the damage to the lymphatic drainage of the arm by preserving the nodes and lymphatics in the armpit.
4. Axillary lymph node dissection, first advocated as part of the treatment of invasive breast cancer in the 18th century, involves the removal of multiple lymph nodes from under the arm. The actual number of lymph nodes removed varies from person to person. An axillary lymph node dissection is needed only for those women with early-stage breast cancer with small amounts of cancer in the sentinel lymph nodes.
Benefits: This helps remove cancer cells from the armpit and the number of involved nodes is a marker of aggressiveness of the tumour guide.
5. Radiation therapy developed in the 20th century to shrink cancerous tumours of all kinds involves the use of high-energy x-rays or other particles to destroy cancer cells. For breast cancer, radiotherapy is used to reduce the risk of the cancer developing again in the conserved breast or in the chest wall after mastectomy. There are several different types of radiation therapy-- external-beam radiation therapy (given from a machine outside the body), intra-operative radiation therapy (given using a probe in the operating room) and brachytherapy (given by placing radioactive sources into the tumour). Recently, researchers have developed ultra-high-dose rate radiation therapy beam to treat cancer while reducing the side-effects.
Benefits: Reduce the risk of local recurrence. It can also be used to shrink and kill metastatic cancer cells that have spread from the breast to bones or brain.
6. Therapies using the medication can be categorised into - chemotherapy, hormonal therapy, targeted therapy and immunotherapy. While chemotherapy became an option after World War II, hormonal therapy came into being in the 1960s and targeted therapy was discovered in the 1970s. Immunotherapy was developed in 1986, with the expansion of immunotherapy drugs occurring in the early and mid-1990s. These can also help destroy cancer cells. The common ways to administer systemic therapies include an intravenous (IV) tube placed into a vein using a needle, an injection into a muscle or under the skin, or in a pill or capsule that is swallowed (orally). It is used to shrink cancerous tumours before surgery, prevent recurrences after surgery, and treat cancer that is metastasized, or has spread to other parts of the body. Highly specialised gene tests can be performed on the tumour tissue to profile it and to assess the need for chemotherapy in a more definitive fashion, thus preventing over or under-treatment in a huge number of patients.
Benefits: Such therapies are used to reduce risk of cancer spread, treat cancer that has spread and reduce risk of the disease recurring.
The bottom line
Breast cancer treatment is in a continual state of great evolution. There are huge advances in all fields starting from preventive measures to early detection and effective targeted treatments. This approach of individualisation of care, tailored specifically to each woman, has led to phenomenally high rates of cure. The most important message though is that the success of treatments depends on the stage at presentation. The bottom line is that early detection is always the key!