Dr Shilpa Lad, specialised radiologist in breast imaging and interventions, NM Medical Center, Mumbai, India, shares details of the various evolving technologies for diagnosis and management of breast cancer in India, in an interview with Atandra Ray
What are the new technologies developed lately for diagnosis and management of breast cancer? And what are the success rates for the same?
Breast cancer is now the most common cancer amongst urban Indian women. As per Population Based Cancer Registry (PBCR), breast cancer accounts for 25-32 per cent of all female cancers in urban Indian cities. This implies that breast cancer comprises one fourth of all female cancer cases are breast cancer.
The cause for concern is that for every two women newly diagnosed with breast cancer, one woman is dying of it in India. Since more patients in India present at later stages, they do not survive long, irrespective of the treatment they may get, hence the mortality is fairly high.
Lack of awareness of breast cancer and screening for disease are significant contributory factors for the relatively late stage of the disease presentation in India.
Screening mammography (which means mammogram, a specialised X-ray performed in asymptomatic women with the intension of early detection of breast cancer) is the most powerful breast cancer detection tool. Mammograms don’t prevent breast cancer but they can save lives by finding breast cancers as early as possible. According to a report by WHO, mammograms have been shown to reduce breast cancer mortality by around 20 per cent in women by early detection.
Modern day digital breast tomosynthesis, also called 3D digital mammography, has a 25 per cent to 50 per cent better detection rate as compared to conventional 2D analogue mammography and involves negligent radiation even less than a standard chest X-ray. In future, it is expected that 3D digital mammography will become more and more common. Most oncologists agree that breast screening mammography should start at the age of 40 and earlier in patients with high risks like genetic predisposition (BRCA 1 and BRCA 2 genetic mutation) and those with strong family history.
Breast health awareness implies that women should be aware of the common presenting symptoms of breast cancer such as painless palpable lump in the breast or underarm, nipple inversion, spontaneous bloody or clear nipple discharge, change in size of breast or skin dimpling. Typically, there is no pain associated with breast cancer. Therefore, women often do not realise the above mentioned symptoms until it is too late.
If a woman experiences any of the above symptoms, she should immediately consult her physician and undergo a diagnostic mammogram. If the mammogram is abnormal the radiologist will recommend a breast ultrasound for further characterisation of the mammographic abnormality followed by imaging guided breast biopsy for accurate pathology diagnosis of breast cancer or in simple words confirming the diagnosis of breast cancer.
Pathology diagnosis or tissue diagnosis plays a crucial role in diagnosis and management of breast cancer. There are several types of imaging guided breast biopsy techniques such as Fine Needle Aspiration Biopsy (FNAB), Trucut or Core Needle Biopsy (CNB) and Vacuum Assisted Biopsy (VAB). The selection of the biopsy technique depends on the availability of resources and the characteristics of the breast lesion.
Give us more insights on techniques such as FNAB, CNB and VAB.
FNAB, also called fine needle aspiration cytology (FNAC), is a technique by which a few cells are aspirated from the concerning breast lump under imaging guidance, typically ultrasound guidance. FNAB is the most widely available and cheapest biopsy technique for confirmation of breast cancer. However, FNAB has a number of limitations. This technique is cytologists dependent and is often associated with false negatives (i.e. cancer is present but not detected in the aspirated sample) in about 27 per cent of unsatisfactory samples. In such a situation, the patient often assumes that there is no cancer in the biopsy and therefore does not receive any further treatment, only to return later with an advanced stage of breast cancer. Moreover, this type of biopsy is unable to provide information on the cancer subtype and receptors or tumour markers such as oestrogen receptors, progesterone receptors and hereceptin receptors which are crucial for further management of breast cancer.
CNB involves obtaining cores of tissue from the breast mass under ultrasound guidance. The sensitivity of this type of biopsy for accurate diagnosis is 96 per cent to 98 per cent. Moreover, information about cancer subtype and receptors or tumour markers is available from this type of biopsy. This type of biopsy technique is now widely available and is relatively cost-effective.
VAB involves bigger needle with vacuum assistance for optimal sampling for non palpable breast lesions such as micro-calcifications as well as for complex solid cystic masses with a high accuracy rate of almost 100 per cent. This technique also has applications for non-surgical removal of benign lesions such as small fibroadenomas.
In which stages of breast cancer can these techniques be used and how effective are they?
Image-guided biopsy techniques are typically performed for diagnosis of indeterminate or suspicious breast lumps. The biggest advantage of image-guided percutaneous biopsy is that the patient has to undergo a single surgical procedure for treatment of breast cancer following confirmation of breast cancer. Before the advent of image-guided breast biopsy, patients would have have to undergo two surgical procedures. The first surgical procedure for excision biopsy for diagnosis of the breast lump and the second surgical procedure for complete clearance of the breast cancer. Therefore, image-guided percutaneous biopsy is superior to open surgical biopsy for several reasons, including increased accuracy, decreased cost as well as decreased surgical morbidity and cosmetic deformity.
Can exposure to radiation emitted through diagnostic imaging techniques such as mammography, X-ray etc., cause cancers?
There is a significant myth and misconception associated with the radiation involved in diagnostic imaging. Medical radiation is based on the ALARA concept, which means As Low As Reasonably Achievable. For most women, there is very little risk from routine X-ray imaging such as mammography, chest X-ray or dental X-ray. The average glandular dose from a mammogram is about three millisieverts (mSv) or milliigray (mGy) which is equivalent to the ionising radiation that one receives from natural resources such as sunlight in a given year.
Children and teens who receive high doses of radiation to treat lymphoma or other cancers are more likely to develop additional cancers later in life. As far as diagnostic medical radiation is concerned, there are no clinical trials that have assessed cancer from medical radiation in healthy adults. Most of what we know about the risks of ionising radiation comes from long term studies of people who survived the 1945 atomic bomb blasts at Hiroshima and Nagasaki. Needless to say, the atomic blast is not the perfect model for exposure to medical radiation because the bomb released extremely high doses of radiation all at once, while medical imaging involves minuscule doses of radiation, that too spread over time.
And last but not the least is the risk benefit ratio (RBR). The risk of developing locally advanced breast cancer or stage 3 breast cancer which causes significant morbidity and mortality is a real threat rather than the postulated theory of radiation-induced cancers. Which means the benefit of a screening or diagnostic mammogram aiding in timely diagnosis of breast cancer and thus leading to effective treatment far out weighs the potential risk from radiation.
What are the major factors/ causes for growing incidence breast cancer. What are the measures that can be taken to bring down the incidence of the disease?
Epidemiological studies worldwide have established risk associations with breast cancer. They are as follows:
Age: Age is by far the greatest risk factor for breast cancer. The incidence of breast cancer increases with age with approximately 50 per cent of breast cancers occurring in women aged 50-64 years.
Family history: The risk of breast cancer is increased two to three fold in women with more than two first degree relatives typically on the maternal side diagnosed with breast cancer before the age of 50 years.
Menses: Early menarche (<12 years) and late menopause (>55 years) is associated with an increased risk of breast cancer.
Pregnancy and lactation: For women who have their first child before the age of 25 years, have about half the risk of breast cancer as compared to women who have their first child after the age of 30 years. In addition, breast feeding is also believed to have a protective effect against breast cancer.
Obesity: Obesity is associated with an increased risk of breast cancer in post menopausal women. The increased risk may be due to conversion of adrenal androgens to oestrogen in adipose tissue.
Alcohol consumption: The consumption of approximately 15 g or more of alcohol (equivalent to two to three glasses of wine) each day increases the risk of breast cancer by about 50 per cent.
Oral contraceptives: The relative risk of breast cancer is marginally increased in women who have used oral contraceptives within 10 years but there is no risk in those who had used oral contraceptives more than 10 years previously.
Hormone Replacement Therapy (HRT): HRT is linked to an increased incidence of breast cancer, raising breast cancer risk proportionate to an individual’s pre-existing risk.
Genetics: Breast cancer genes BRCA1 and BRCA2 denote high risk but account for only a small proportion of cancers. Li-Fraumeni Syndrome and Cowden’s Syndrome are also associated with increased risk of breast cancer.
To summarise, age, family history, menses and genetic predisposition are factors that are beyond our control. However, lifestyle changes such as minimising the intake of alcohol, healthy eating habits and increased activity to control obesity, avoiding prolonged use of oral contraceptives and hormone replacement therapy and planning first pregnancy at an early age followed by breast feeding are some of the factors that we can incorporate in our life to minimise the risk of breast cancer.
Is there anything that you would like to highlight?
These are exciting times with the state-of-the-art technologies being available for diagnosis and management of breast cancer patients in India. The earlier we start applying these technologies in clinical practice the better will be the outcomes in the long run. The fact remains that we cannot prevent breast cancer. However, we can certainly detect breast cancer early for favourable outcomes and increased survival. One cannot underestimate the value of timely and accurate diagnosis for women with breast cancer. Early diagnosis is the only way to complete cure. At the end of the day, if you save a woman, you save the entire family!”
(Atandra Ray is an intern with Express Healthcare)