Breast cancer is the malignancy in the tissues of the breast. It is one of most common types of cancer affecting women. This type of cancer in men is very rare.
There are different types of breast cancer depending upon the site, type of the tissue or appearance of the disease (inflammatory breast cancer). Most commonly, cancer develops in the ducts (milk producing tissue) or lobules (milk supplying tissue) of the breast, such as lobular carcinoma in situ (LCIN) and ductal carcinoma in situ (DCIN).
Breast cancer can be invasive or non-invasive depending on whether they are confined to the tissue or spread elsewhere.
There is also a classification of breast cancer based on the hormone receptors, i.e. estrogen, progesterone and HER2 receptors present in the cancer cells. If the cancer cells have all three receptors present, it is called triple positive.
If they are devoid of receptors for estrogen and progesterone, they are called double negative. The cancer is called triple negative if the cells are devoid of all the three hormone receptors.
The symptoms of breast cancer include lump in the breast, bloody or clear discharge from nipples, peel like appearance, pain in nipples or unusual pain in the breasts, swelling in the armpit, inverted nipple, etc.
In advanced stages, underarm lymph nodes are affected, and other symptoms accompany like bone pain, shortness of breath, weight loss, appetite loss, headache, weakness, etc.
The causes of breast cancer are mostly known to be due to the genetic inheritance of BACR1 and BACR2 genes, hormonal alterations, lifestyle and dietary problems and certain carcinogens (X-Ray).
The factors that increase the risk of getting breast cancer include the previous history of this disease, presence of the disease in a first-degree relative (sister, mother, father or daughter), early menstruation, late pregnancy, older age, use of contraceptive pills, physical inactivity, obesity, alcohol consumption, etc.
The type of treatment in this disease is employed depending on the type of cancer. Surgery is the most popular one which is often combined with chemotherapy or radiotherapy. Hormonal therapy is also often applied, and gene therapy is gaining popularity as well.
The conventional treatment options have several drawbacks such as nausea, weight gain, depression, hair loss, increased risk of infections, blood clots in lungs and legs, bone loss, early menopause, skin rash, etc.
Natural remedies are increasingly in demand due to the risks associated with the conventional treatments options. There are many natural substances that are potentially anti-cancerous.
One such an extraordinary compound is the turmeric polyphenol, curcumin.
What is curcumin?
Curcumin, chemically known as diferuloylmethane is the compound obtained from the roots of the plant Curcuma longa or turmeric.
This compound is the most abundant constituent of turmeric and responsible for the colour of the spice. Its biological activity is also remarkable.
Curcumin can interact with various molecular pathways of a living cell that enables it with numerous properties of therapeutic significance. These properties include anti-inflammatory, antioxidant, anti-microbial, anticancer, immune-modulatory and other such properties.
Many research studies have proven the benefit of these properties in a number of diseases of mild to severe nature. Curcumin has found its medicinal application in arthritis, diabetes, cardiovascular disorders, neurodegenerative disorders, cancer and many other such diseases.
6 Proven Benefits of Curcumin in Breast Cancer
The benefits of curcumin in cancer are increasingly being unfolded with a large number of recent and ongoing research studies. The anti-cancer activity of curcumin is effective against almost all types of cancer, including the breast cancer.
1. Curcumin kills breast cancer cells
Breast cancer is caused due to the mutations in the DNA of one or other different types of cells composing the breast. This mutation may be inherited in the form of breast cancer susceptibility genes (BRCA1 & BRCA2) or may be induced by certain factors.
Just like other types of cancer, the survival of breast cancer cells is also ensured by the various cytokines, anti-apoptotic factors, and other survival pathways.
Curcumin has potential to kill the cancer cells by targeting various survival pathways and thus, inducing apoptosis (cell death) in the cells.
It has been found to induce apoptosis in the breast cancer cells by inhibiting the expression of Bcl-2 (an anti-apoptotic protein) and stimulating the expression of Bax (a pro-apoptotic protein). It results in a reduction of the tumour.
It regulates numerous other genes and in turn, their gene products for the induction of apoptosis in the breast cancer cells. It up-regulates the pro-apoptotic genes like CASP1, PCNA, MCL-1, etc. and down-regulates the anti-apoptotic genes like TNFb, CASP9, CAS, etc.
The down-regulation of the NF-kappa B gene by curcumin is involved in the anti-tumour activity as well.
In triple negative breast cancer (TNBC), curcumin modulates the expression of BCRA1 gene leading to DNA damage in the TNBC cells. Thus, it induces apoptosis in the triple-negative breast cancer.
The inhibition of HER2 pathway (involved in the development of TNBC) is also known to induce apoptosis in the TNBC.
What does it mean?
It means curcumin can be employed in the treatment of breast cancer due to its ability to kill the cancer cells. Curcumin targets several cell survival pathways and induces death in the cancer cells by decreasing the activity of the anti-apoptotic proteins and increasing the activity of the pro-apoptotic proteins.
2. Curcumin inhibits angiogenesis
Angiogenesis, i.e. the process of development of blood vessels is integral to the tumour progression in the breast cancer. It is mainly triggered by hypoxia (low oxygen levels) in the tumour to supply the nutrients to the cancer cells.
There are various factors that mediate angiogenesis in the breast cancer, such as, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), cytokines and some angioproteins.
Curcumin is known to exhibit anti-angiogenic effect, i.e. it can inhibit angiogenesis by acting on certain pro-angiogenic factors.
The inhibition of the NF-kappa B gene expression by a curcumin analog has been found to inhibit angiogenesis in breast cancer. Thus, curcumin indirectly inhibits the activity of the pro-angiogenic cytokines (gene products of the NFkappa B pathway).
What does it mean?
It means curcumin can inhibit the process of angiogenesis in the breast cancer. Curcumin can help in the treatment of breast cancer as the tumour progression is inhibited by its anti-angiogenic action.
3. Curcumin inhibits metastasis
Metastasis is the phenomena encountered at an advanced stage of the breast cancer, where cancer spreads to other parts of the body, such as brain, bones, lungs or liver through the bloodstream or lymphatic system.
The metastasis is mediated by angiogenesis, proteins like integrins, selectins, MMP (matrix metalloproteins), etc.
Curcumin has a potential against metastasis as well. It is known to prevent tumour invasion and metastasis in various types of cancer, including the breast cancer.
It has been found to decrease the expressions of the proteins (E-cadherin, β-catenin, fibronectin, etc.) that are involved in the migration of cancer to other parts of the body.
Curcumin can also increase the activity of miR181b (a micro-RNA involved in tumour suppression) and decreases the activity of the inflammatory cytokines, CXCL-1 and CXCL-2. These actions of curcumin have anti-metastatic implications.
The suppression of NFkappa B expression by curcumin also helps in its anti-metastatic activity and protects from the spread of cancer to other parts of the body.
What does it mean?
Curcumin administration can inhibit metastasis in the breast cancer and protect the body from the spread of cancer to other parts.
4. Curcumin overcomes drug resistance and aids in chemotherapy
Drug-resistance is often encountered in the breast cancer cells caused by many factors such as genetic alterations, pH abnormalities, expression of breast cancer resistance protein (BCRP), over-expression of HER2, etc.
Curcumin and its various derivatives and formulations have been studied and found to be effective against drug-resistance in the breast cancer. It suppresses the STAT3 pathway (involved in drug resistance in cancer) and produces reactive oxygen species to induce apoptosis and overcome the drug resistance.
The resistance to drugs induced by HER2 over-expression in the breast cancer cells is also overcome by induction of cell cycle arrest and apoptosis.
In the case of resistance to the drug Adriamycin, curcumin alters the micro RNA dysfunctions to control the resistance.
Curcumin not only reduces drug resistance but also assists the chemotherapeutic drugs to increase their effectiveness in the treatment of breast cancer.
Its anti-tumour ability help to enhance the activity of drugs used in the treatment of breast cancer, like doxorubicin, cyclophosphamide, paclitaxel, mitomycin, etc.
Combining curcumin with the drug paclitaxel has been found to increase the efficiency of the drug against breast cancer and inhibit multi-drug resistance.
What does it mean?
It means a combination of curcumin with the chemotherapeutic drugs can enhance their efficiency and inhibit the drug-resistance in the breast cancer cells induced by various factors.
5. Curcumin has chemopreventive activity
Prevention of the occurrence of a fatal disease like breast cancer is unparallel to their treatment. There are numerous chemopreventive compounds that are efficacious in suppressing the molecular pathways that lead to the development of cancer.
One of the natural substances with an extraordinary chemopreventive property is curcumin. Its abilities to inhibit angiogenesis & metastasis and to induce death in the cancer cells have cancer-preventive implications.
Curcumin can also inhibit the activation of carcinogenic (cancer causing) substances in the body.
In the case of breast cancer, curcumin has been found to be a very effective chemopreventive agent. It has shown anti-cancer effects in many breast cancer cell lines.
What does it mean?
It means the regular use of curcumin can prevent the occurrence of breast cancer by disrupting or delaying the molecular pathways involved in the cancer development.
6. Curcumin protects from the side effects of chemotherapeutic drugs
The vigorous treatment regimen of the chemotherapeutic drugs in breast cancer leads to several side-effects and affect the quality of the life of patients. These include nausea, anemia, hair loss, weight gain, neuropathy, reproductive dysfunction, heart problems and lung toxicity, etc.
Curcumin has been found to have protective effects against multiple chemotherapeutic drugs induced toxicities/ side effects.
Doxorubicin or Adriamycin is frequently employed for the treatment of breast cancer. It is known to cause toxicity to heart, kidneys, and lungs.
The antioxidant action of curcumin ameliorates the doxorubicin-induced toxicities by scavenging the free radicals generated in response to the drug’s treatment.
Curcumin’s antioxidant activity has been found to significantly protect against the doxorubicin-induced side-effects in the heart tissues, in turn protecting from heart failure and other heart problems.
Cisplatin is also a widely used chemotherapeutic drug against breast cancer. It causes severe nephrotoxicity, i.e. side-effects to the kidney by inducing injury and death in the kidney cells. It results in various types of kidney disorders and may even lead to kidney failure.
Administration of curcumin in a breast cancer model with cisplatin-induced kidney damage shows nephroprotective effects. It attenuates the kidney damage by its anti-inflammatory action.
Paclitaxel is another drug used in the breast cancer treatment that causes several toxicities, one of which is ototoxicity or damage to the inner ears. Pretreatment of curcumin has shown to protect the ears considerably against the paclitaxel-induced ear damage.
What does it mean?
It means curcumin treatment can protect the different organs and tissues of the body from the chemotherapy-induced side-effects. The properties of curcumin like those of antioxidant and anti-inflammatory prevent the damage caused by these drugs.
Dosage of Curcumin For Breast Cancer
There is no specific dose of curcumin developed for breast cancer. However a dose plan can be followed by the breast cancer patients to maximize the benefits. Turmeric/ Curcumin Dosage for Cancer: A Scientific Plan.
Many studies utilize curcumin in the amounts of 200 mg per day to 8 g per day.
Curcumin supplements are normalized 95% Curcumin with Bioperine. The combination of curcumin with piperine and natural fats boosts its bioavailability in the body. (Read How to improve the bioavailability of curcumin?)
Various curcumin formulations have been developed to overcome the bioavailability problems and used in the breast cancer treatment. These formulations include nanocrystals, liposomes, polymer-based nano-formulations, Meriva, Theracumin, etc.
There are diverse other curcumin supplements that have an improved absorption in the body. (Read 8 Popular curcumin supplement types)
Preferably, curcumin intake should be started with small doses. The dose can be enhanced gradually over weeks.
Moreover, curcumin should be consumed is after meals. Also, a gap of 3-4 hours must be maintained between curcumin intake and medicines.
Safety of turmeric in the diet is renowned. Curcumin has also been established to be safe even in high doses in most of the studies.
A few precautions are necessary to take while using curcumin. (Read Side-effects & Precautions of Curcumin)
Curcumin may cause allergies in sensitive individuals. Please conduct a patch test before applying curcumin topically.
Curcumin may cause acid reflux in the prone individuals. Therefore, it should be consumed after a meal.
Large dose of curcumin can cause gastric discomfort like diarrhea, bloating, nausea etc. Therefore, it is advisable to start curcumin with low doses, and its intake should be avoided in case any severe gastric side-effects are observed.
Curcumin interferes in drug metabolism. Therefore, 3-4 hours gap must be maintained between taking curcumin and any medication. An expert’s opinion is best to take in this matter.
Curcumin may increase the risk of bleeding owing to its blood thinning activity. Therefore, people with bleeding disorders or on blood thinning medication should refrain from curcumin. (Read Is turmeric a blood thinner?)
Curcumin intake should be discontinued at least two weeks ahead of a surgery and after that as well.
Gallstone Patients should take curcumin supplements if advised by health practitioner.(Read Is turmeric safe in gallstones?)
Curcumin supplements must be devoid of contamination. Curcumin supplements can have contaminants such as heavy metals, harmful chemicals, fillers or additives. These contaminants may be a potent disease (such as cancer, ulcers, etc.) causing agents.
Curcumin supplements are excellent when combined with bioavailability boosters. Curcumin is poorly available to the body. Therefore, it is best to integrate curcumin with the agents like Bioperine which increase its absorption in the body.
A medical expert must be consulted before using curcumin supplements, especially in cancer therapy.
Curcumin is a wonder natural substance for the breast cancer patients. It has a very wide scope in the treatment of breast cancer.
Curcumin kills the cancer cells, prevents the cancer proliferation and metastasis. It majorly attacks the integral survival pathways of the cancer cells to achieve the feat.
Moreover, curcumin also helps in overcoming drug-resistance in the breast cancer cells and acts synergistically with the chemotherapeutic drugs to improve the treatment.
It has protective action in the normal cells of the body against the side-effects of the chemotherapeutic drugs as well.
Additionally, regular consumption of curcumin can also protect the body from developing cancer owing to its chemopreventive property.
Altogether, curcumin is a miraculous and viable treatment option for breast cancer.