Is there evidence that a breast biopsy (biopsy of breast tissue) can disseminate malignancy, causing cancer to spread?

From the Guidelines

There is no substantial evidence that breast biopsies cause cancer to spread, and patients should feel confident proceeding with recommended breast biopsies when clinically indicated. Breast biopsies are a standard and necessary diagnostic procedure to determine if a suspicious breast lesion is cancerous. While theoretical concerns have been raised about the potential for needle track seeding (where cancer cells might be displaced along the needle path) or mechanical disruption of tumor cells, multiple large-scale studies, including those from the National Comprehensive Cancer Network (NCCN) 1, have not demonstrated any significant increase in cancer recurrence, metastasis, or mortality in patients who undergo breast biopsies.

The benefits of accurate diagnosis through biopsy far outweigh any theoretical risks. Modern biopsy techniques, such as core needle biopsy, are designed to minimize tissue disruption, and pathologists carefully examine biopsy specimens for signs of cancer spread 1. The American College of Radiology Appropriateness Criteria also support the use of biopsy in the evaluation of palpable breast masses, particularly when imaging findings are suspicious for malignancy 1. Delaying diagnosis through biopsy could actually lead to worse outcomes by postponing necessary treatment.

Key points to consider include:

• The sensitivity of core needle biopsy is high, ranging from 97% to 99% when directed by ultrasound or stereotaxis 1.
• Breast biopsy is recommended if diagnostic imaging findings or clinical findings are suspicious (BI-RADS 4) or highly suggestive of malignancy (BI-RADS 5) 1.
• Image-guided core biopsy is preferred over fine-needle aspiration biopsy (FNAB) due to its superior sensitivity, specificity, and ability to provide correct histological grading of palpable masses 1.
• The American College of Radiology Appropriateness Criteria support the use of diagnostic mammography, targeted-breast ultrasound, and biopsy in the evaluation of palpable breast masses, depending on patient age and degree of radiologic suspicion 1.

From the Research

Breast Biopsy and Cancer Spread

• There is no direct evidence from the provided studies that a breast biopsy concerning for malignancy causes the cancer to spread as a result of the biopsy 2, 3, 4, 5, 6.
• The studies primarily focus on comparing the diagnostic accuracy and effectiveness of different biopsy methods, such as fine-needle aspiration (FNA) and core needle biopsy (CNB), in detecting breast cancer 2, 3, 4, 5.
• Some studies suggest that CNB may be superior to FNA in certain cases, particularly for patients with BI-RADS 5 lesions or nonpalpable tumors 2, 3.
• However, none of the studies explicitly address the question of whether a breast biopsy can cause cancer to spread 2, 3, 4, 5, 6.
• One study notes that surgical biopsy remains a valuable method of last resort for breast cancer diagnosis, but strategies to limit benign breast surgery are needed to reduce unnecessary procedures 6.

Biopsy Methods and Diagnostic Accuracy

• The studies compare the sensitivity and specificity of FNA and CNB in diagnosing breast cancer, with some finding that CNB may have higher sensitivity and specificity 2, 3, 5.
• One study found that combining FNA and CNB may improve diagnostic accuracy in certain cases 4.
• Another study notes that FNA performed by pathologists may be more sensitive than FNA performed by nonpathologists 5.

Clinical Implications

• The studies suggest that clinicians should carefully consider the choice of biopsy method and diagnostic approach for patients with suspected breast cancer 2, 3, 4, 5, 6.
• Further research is needed to fully understand the relationship between breast biopsy and cancer spread, as well as to optimize diagnostic and treatment strategies for breast cancer patients 2, 3, 4, 5, 6.