Breast cancer: ideal diagnostic tools for early detection

A diagnosis of cancer is devastating news for the patient and his or her family. Cancer not only takes a toll on the patient’s body but also on the mental health and finances of the family. The incidence of cancer is often associated with the family medical history, lifestyle choices, or something else in the environment—factors that you cannot control completely.

Of all types of cancer, the incidence of invasive breast cancer has been increasing by about 0.5% per year since the mid-2000s.¹ In 2020, breast cancer was the most commonly diagnosed cancer in females with 2.3 million new cases (11.7%), and constituted 6.9% of all cancer deaths.² The American Cancer Society has estimated that there will be 287,850 new cases of invasive breast cancer diagnosed in women in the United States of America (USA) in 2022, accounting for a staggering 30% of all estimated new cancer cases in women.¹

Moreover, despite the availability of highly effective treatment with a 90% 5-year survival rate, breast cancer is associated with significant mortality in women. It is estimated that 43,250 women will die from breast cancer in the USA alone in 2022.¹ This is a huge proclamation. So, what steps must be taken to stop this from happening? Can the earlier diagnosis of breast cancer help in reducing the mortality associated with it? If so, how can we ensure that cancer is detected at an early stage? Tools for early detection of breast cancer in women are a necessity to save the lives of women.

In the following blog, we shall evaluate the efficacy of diagnostic tools in the early detection of breast cancer and try to find treatment for the same.

To begin with, what are the latest diagnostic methods to detect breast cancer?

e latest diagnostic methods for early breast cancer detection include digital breast tomosynthesis (DBT), abbreviated breast MRI (AB-MRI), nuclear medicine tests (radionuclide imaging), contrast-enhanced mammography (CEM), elastography, optical imaging tests, and electrical impedance tomography (EIT).³ These technologies, along with routine breast imaging procedures like mammograms, ultrasounds, and breast MRI, could considerably reduce breast cancer mortality through prompt and accurate patient screening.

But how reliable are these diagnostic techniques at detecting cancer, though? We’ll try to answer this question by analyzing the findings of different case studies in the following section.

DBT more reliable than mammography in detecting early-stage breast cancer!

In a comparative study, the sensitivity, specificity, predictive values, and accuracy of full-field digital mammography (FFDM) and DBT were compared in 90 female patients from the breast clinic. They belonged to the age group of 32 to 70 years and were followed-up for up to 18 months as required.

It was found in the study that DBT is more sensitive, specific, and precise than FFDM, with higher predictive values when it comes to diagnosing patients with breast cancer. It detects and describes breast lesions better than FFDM, especially in younger females with dense breasts, reducing the number of negative biopsies. DBT is thus a better option for screening breast cancer patients. The study results are summarized in Figure 1.⁴

Figure 1: Diagnostic efficacy of FFDM and DBT

In another case study conducted on women aged 40 to 75 years with extremely dense breasts between December 2016 and November 2017, 1444 women completed the breast cancer examination using AB-MRI and DBT. They were even followed up for an additional year, or until cancer was diagnosed.

It was found that AB-MRI had sensitivity and invasive cancer detection rates of 95.7% and 11.8%, respectively, when compared to DBT, which had values of 39.1% and 4.8%. So, AB-MRI eliminated the need for additional imaging. As a result, it is a more accurate diagnostic tool for screening breast cancer in women with dense breasts.⁵

AB-MRI is the only diagnostic technique suitable for women with dense breasts. Is it true?

In order to find the best diagnostic tool suitable for women with dense breast parenchyma, the accuracy of CEM, DBT, and breast ultrasound were evaluated as complementary techniques to mammography in 37 patients with dense breasts diagnosed with 63 breast lesions.

It was found that other than AB-MRI, breast ultrasound, DBT, and CEM have higher sensitivity, specificity, and accuracy than mammography in detecting cancer in dense breast parenchyma. Hence, they could be better diagnostic tools than mammography. The study findings are shown in Figure 2.⁶

Figure 2: Diagnostic efficacy of mammography, CEM, DBT, and breast ultrasound for breast cancer detection

What does these studies imply?

It is clear from the foregoing discussion that in terms of identifying breast cancer, breast ultrasonography, DBT, CEM, and AB-MRI are far more accurate than regular mammography. In fact, CEM helped the researchers identify architectural deformation, non-enhancing lesions, and even micro-calcifications in thick breast parenchyma, proving its higher sensitivity and specificity in comparison with other techniques.

And how about its treatment advancements?

Even though the majority of women with breast cancer have responded well to treatments like surgery, radiation, chemotherapy, hormone therapy, and targeted therapy, further research is still required to identify effective therapies for patients with advanced or metastatic cancers.

As a matter of fact, the FDA recently approved Palbociclib (Ibrance) in combination with letrozole for the treatment of postmenopausal women with advanced or metastatic HR+ or HER2-breast cancer. As shown in Figure 3, 99.23% of patients in the phase 3 clinical trial (ClinicalTrials.gov Identifier: NCT02600923) did not experience any significant adverse effects during treatment.⁷ Another drug, Sacituzumab Govitecan, is currently being tested in a phase 3 clinical trial for treating patients with refractory or relapsed metastatic triple-negative breast cancer.⁸

In the following blog, we shall evaluate the efficacy of diagnostic tools in the early detection of breast cancer and try to find treatment for the same.

Figure 3: Percentage of adverse effects in treated patients

Conclusion

Though CEM has been proven to be the best diagnostic tool as it is less expensive and takes less time than an MRI, it does involve the injection of contrast media, which may cause adverse reactions in some patients. So, it should only be used when other tests fail to produce conclusive results. Moreover, further research is still going on to improve the diagnostic precision of all diagnostic techniques while lowering the risks of radiation exposure and over diagnosis. Ultrasonography, on the other hand, is a risk-free diagnostic method that does not involve any radiation or contrast media chemicals. So, it could be used for routine patient screening. In suspected patients, however, ultrasonography and mammography can be followed by DBT. As diagnostic tools advance, breast cancer will be diagnosed earlier in the future, resulting in better treatment outcomes.

References

American cancer Cancer facts & figures 2022. Cancer.org. Accessed on 5 August, 2022. https://www.cancer.org/cancer/breast-cancer/about/how-common-is-breast- cancer.html#:~:text=have%20increased%20by-,0.5%25,-per%20year. https://www.cancer.org/cancer/breast-cancer/about/how-common-is-breast- cancer.html#:~:text=have%20increased%20by-,0.5%25,-per%20year.
Sung H, Ferlay J, Siegel RL, et Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2021;71(3):209-49. doi. 10.3322/caac.21660.
American cancer society. Newer and experimental breast imaging tests. Cancer.org. Updated on 14 January, 2022. Accessed on 5 August, 2022. https://www.cancer.org/cancer/breast- cancer/screening-tests-and-early-detection/experimental-breast-imaging.html
Naeim RM, Marouf RA, Nasr MA, El-Rahman A, Marwa E. Comparing the diagnostic efficacy of digital breast tomosynthesis with full-field digital mammography using BI-RADS EJRNM. 2021;52(1):1-3. doi. 10.1186/s43055-021-00421-4.
Comstock CE, Gatsonis C, Newstead GM, et al. Comparison of abbreviated breast MRI vs digital breast tomosynthesis for breast cancer detection among women with dense breasts undergoing JAMA. 2020;323(8):746-756. doi:10.1001/jama.2020.0572.
Azzam H, Kamal RM, Hanafy MM, Youssef A, Hashem LM. Comparative study between contrast-enhanced mammography, tomosynthesis, and breast ultrasound as complementary techniques to mammography in dense breast EJRNM. 2020;51(1):1-9. doi.10.1186/s43055-020-00268-1.
gov. Palbociclib plus letrozole for postmenopausal women with HR(+) HER2(-) advanced breast cancer for whom letrozole is deemed appropriate. clinicaltrials.gov. Updated on 20 January, 2022. Accessed on 5 August, 2022.

gov. Trial of sacituzumab govitecan in participants with refractory/relapsed metastatic triple-negative breast cancer (TNBC) (ASCENT). clinicaltrials.gov. Updated on 15 June, 2022. Accessed on 25 August, 2022.

Author: Geetika Garg

Reviewer: Priyanka