Breast cancer. Diagnosis methods 🔍
October is Breast Cancer Awareness month, so we decided to share with you a sequence of articles about this topic. Breast cancer is the most frequent cancer and the most common cause of death among women. It is a global public health problem with consequences also on a socio economic level. If numbers increase in the same manner as in the present, it is estimated that by 2050 there will be 3.2 new million cases per year.
Last week we talked about breast cancer risk factors.
Now we will talk about the many techniques, old and innovative, that can diagnose breast cancer.
Most of these methods can be used both for screening and diagnosing breast cancer. Cancer screening is a preventive method to identify risk factors and cancer in an early-stage, while cancer diagnosing is establishing the presence/absence of the cancer in order to apply the suitable treatment.
Diagnosing breast cancer in early stages is very important as it increases the chance of survival.
There are many ways of diagnosing/screening breast cancer and can be classified in multiple groups:
Clinical Breast Examination (CBE) and Breast Self Examination (BSE): although these are not methods that can medically diagnose breast cancer, by performing it monthly women can detect possible abnormalities, which could be linked to breast cancer, at an early stage. Check our article about BSE to find out more.
Breast biopsies: a tissue of breast is removed and analyzed in order to detect cancerous cells
Imaging techniques: mammography, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), positron-emission tomography (PET) and single-photon computed tomography (SPECT); these methods can be used for diagnosis and monitoring patients in different stages
Biochemical markers: are currently less used as a diagnostic tool as research is still needed to evaluate their efficacy, but it’s a promising future diagnosis method
Microwave breast imaging methods (MI): use different techniques to assess differences between healthy tissue and cancerous one based on electromagnetic radiation or electric frequency (Hz); it is still being tested but it is showing promising results
Imaging techniques, along with breast examination (by oneself or a physician) help monitor patients
Studies show that monitoring healthy subjects increases the chances of detecting small tumors that could lead to breast cancer development
These methods have some limitations as some of them are expensive, can lack sensitivity (the ability of the test to correctly identify the patients with a disease), are time consuming and not suitable for young women
The sensitivity issues can be improved by using radio-contrast substances; these agents are injected into the patient’s blood flow and improve the images recorded by imaging equipments
It is recommended for women starting from the age of 40 to undergo an annual mammography
It is known as the “gold standard” technique as it is characterized by high sensitivity* (approx. 68%) and specificity* (approx. 75%), it is not expensive and tolerated by patients
The sensitivity can vary, as it is influenced by age, ethnicity, medical history and the experience of the radiologist
Studies show that using mammography can reduce the mortality of breast cancer up to 19%
It is used to see the breast mass, image bone (used for determining the density of the bone), soft tissue and the blood vessels at the same time
Procedure time: few seconds
It has high rates of false-negative or false-positive result in patients under 40 (as their breasts are more dense) or in premenopausal women
There are some limitation of mammography as well: ionizing radiation (in high doses it can induce tissue damage and cancer), uncomfortable examination and the inaccuracy that can happen sometimes (in case of dense tissue), therefore it can induce false alarms, anxiety and pain
A new type of mammography, the CE digital mammography, that uses contrast substances has higher sensitivity, performance and accuracy than a regular mammography or ultrasound
The ultrasound is one of the common used techniques in diagnosing and monitoring patients
Advantages: it is very sensitive* (83%), does not have ionizing radiation and is cost-effective
It is recommended as an extra tool besides mammography for patients with high risk of developing breast cancer, pregnant women or women that can not undergo a mammography examination
It can asses lumps but it is not suitable for bone analysis
Procedure time: up to 20 minutes
The lack of ionizing radiation makes it suitable for the detection of tumors in young women and pregnant and breastfeeding women
3. MRI (magnetic resonance imaging)
MRI is one of the most reliable and suitable diagnostic tools for breast cancer
It has numerous uses: therapy, monitoring, assessment of cancer spreading to other organs and study of tumor recurrence
It is especially indicated to young women that have high risk of developing breast cancer
It provides more details than a mammography or ultrasound, can detect small tumors (even foci of cancer, which are cell tumors that can be seen only microscopically) and it is not affected by breast density
Sensitivity* is around 95%
Procedure time: up to 60 minutes
It still has some limitations, as it can provide a false-positive result as well, it is expensive and time consuming, needs experienced radiologists
4. PET (positron-emission tomography) and SPECT (single-photon computed tomography)
PET and SPECT can be used for diagnosing breast cancer as well
Studies show that these techniques can detect bone metastasis (the tumor originated from another organ has spread to bones) in breast cancer patients
Procedure time: up to 4 hours
Types of biochemical markers: proteins, enzymes, hormones, DNA,
They can provide information on the tumor growth stage
They are involved in breast cancer development, therefore these markers can be used to target molecular process that lead to cancer development
The protein biomarkers are the most suitable for detecting breast cancer
Limitations: expensive, trained people needed, not suitable for early detection because the low concentration of cancer markers present in the patient
Microwave Breast imaging Methods (MI)
There are several methods that can detect breast cancer by noticing differences between healthy and cancerous tissue
These methods can be grouped in passive or active techniques
Passive technique of MI uses electromagnetic radiation to measure the temperature differences between healthy and cancerous tissue
Active technique of MI measures the difference of electric frequency (Hz) in healthy and cancerous tissue
Clinical trials show that these methods can detect tumors of 1 cm in size, making them suitable for early breast cancer detection
Limitation: this method is not fully developed as it has been tested more on phantoms (scientific device that has similarities to human tissue) than on patients
*Sensitivity and specificity vary by the type of breast cancer present and by the breast composition.
There are currently many techniques that can detect breast cancer, but all of them have limitations in usage, costs, safety and sensitivity. Researchers are working on developing safer and more efficient techniques, and biomarkers and microwave imaging methods seem promising. In the meantime, remember it is better to prevent than to treat. Therefore, do a monthly Breast Self Examination (sign up to our newsletter and you will get a monthly reminder to do it), consult with your doctors about your risk factors and suitable screening methods.
Be smart. Be (c)LIT. Fly with us!🌺🐝