Is ultrasound-guided vacuum-assisted excision reliable for removing small breast cancers?

Michaela Björnström, University of Helsinki and Helsinki University Hospital, Finland, and colleagues revealed that none of the small invasive breast cancer was completely removed with VAE under ultrasound guidance, therefore, they suggested that it is not a reliable method for the removal of small breast cancers. However, they also revealed that after the excision of visible lesions, there are still small foci of cancer and ductal carcinoma in situ (DCIS) left, implying that a larger amount of tissue than visible on ultrasound needs to be removed for complete lesion excision.

Cancer detection comes earlier when tumours are smaller with advancements in imaging technology such as screening mammography. Currently, it is challenging to determine which of these small tumours will become malignant, VAE under local anaesthesia is a method that safely removes tumours.

Previous studies have suggested that this method is successful in the removal of nonmalignant lesions. However, the research team point out a lack of data on whether VAE is reliable for removing small breast cancers. Therefore, Björnström and colleagues aimed to evaluate if it is possible to completely remove small breast cancer tumours with vacuum-assisted excision (VAE) under ultrasound guidance.

For this purpose, the researchers selected women ≥ 50 years old with a biopsy-proven invasive cancer ≤ 10 mm based on referrals and enrolled in the prospective study. To remove the tumour, the patients underwent VAE within six weeks after the biopsy. Following the excision of the tumour and shaving of biopsy cavities margins, a radioactive seed was inserted into the biopsy cavity.

Surgical excision was done of the VAE excision cavity and surrounding tissue. Preliminary VAE results were assessed after ten patients. For the study to progress at least 80 % of the breast cancer tumours had to be completely removed by VAE.

The study led to the following findings:

• The tumour median size in mammography was 8.5 mm and in ultrasound 6.5 mm.
• The shape of the lesion was round in three (30 %), oval in two (20 %) and irregular in five (50 %) patients.
• None of the tumours were completely removed in the first VAE specimen, meaning that there was invasive cancer or ductal carcinoma in situ (DCIS) in the “shaved margins” and/or the surgical specimen.
• In 50 % of the cases, the surgical specimen was free of invasive cancer and DCIS.

The study authors wrote, "Their study size was small, they could not proceed with the study since none of the 10 first tumours treated with VAE could be successfully removed."

They added, "Most of the lesions in the study were located in the breast's fatty part. Breast tumours are heavier than surrounding fat tissue, making it harder for the vacuum to suck out the tumour."

"Slowly growing tumours can consist of tight fibrotic tissue and therefore may be more difficult to remove by vacuum-assisted excision," they concluded.

Reference:

Björnström, M., Niinikoski, L., Arlan, K., Meretoja, T. J., Ståhls, A., & Hukkinen, K. (2023). Vacuum-assisted excision of small breast cancers under ultrasound guidance. European Journal of Radiology, 167, 111049. https://doi.org/10.1016/j.ejrad.2023.111049