In 2014, I went for a routine mammogram and screening ultrasound. I know that being sent for both tests for a routine checkup is not the norm in Ontario or Canada, but my doctor is an unusual one. The ultrasound picked up a cancerous tumour that the mammogram had missed. Not only did my first mammogram miss it, but after the ultrasound, I was also sent to a breast cancer clinic for the latest “3D” mammography (Tomosynthesis). The tumour was only visible on ultrasound, not mammography. Ultrasound may very well have saved my life because it detected an early stage tumour.
Mammography has a 97% accuracy rate for women with fatty breasts but for dense breasts, close to 50% of cancers are missed. That is why Dense Breasts Canada (DBC) is advocating for access to ultrasound for women with dense breasts. Of course, first women need to be told if they have dense breasts. That’s a whole other blog topic. For now, this blog is focusing on our controversial goals regarding ultrasound.
Why are DBC’s goals controversial?
It is not protocoled to use ultrasound as a screening tool for women with dense breasts. One of the major reasons for this is that ultrasound is a sensitive test and carries the risk of false positives and possibly unnecessary biopsies. False positives are abnormalities that turn out not to be cancerous. They can result from cysts and fibroadenomas (benign tumours). There is no question that a false positive can create anxiety for a woman. However, much of the anxiety can be alleviated with education, especially if it is done at the time of screening. Patients can be informed that it’s not uncommon to be recalled. It is a fact that all types of screening tools (Pap tests, PSA tests, colonoscopy, etc) may detect findings that may require additional testing or biopsy. It is better to be safe than sorry.
According to a survey conducted by the Canadian Breast Cancer Foundation, the vast majority of women said they would rather be worried for a while and wait for the necessary diagnostic tests to be done than face an increased risk of mortality because they weren’t offered the opportunity to be screened. How would you feel? Is it worth putting women through the worry of a false positive or even a needle biopsy if it can save a life?
Our answer is a resounding “YES!” Instead of focusing on false negatives and biopsies, we must shift the focus on the fact that we have excellent technology that can discover cancer in dense breasts at an earlier stage. It’s a proven fact screening ultrasound finds more cancers in dense breasts missed by mammography. Denying women with dense breasts a chance to detect a growing tumour because of the risk of a false positive is to deny women their basic right to know what is happening in their bodies and in some cases deny them a chance for early diagnosis.