Image of a breast cancer cell, photographed by a scanning electron microscope. 鈥擶IKIMEDIA COMMONS/NATIONAL CANCER INSTITUTE

A medical oncologist debunked claims that a biopsy, a medical procedure used to accurately diagnose cancer, can cause the disease to spread or become more aggressive.

鈥淚t’s a very wrong notion,鈥 Dr. Marvin Jonne L. Mendoza, medical oncologist at St. Luke鈥檚 Medical Center, said during a breast cancer awareness forum organized by AstraZeneca on Wednesday.

鈥淭he conduct of the biopsy is really very important…it enables us to know if the cancer is malignant or not,鈥 Mr. Mendoza added.

After a cancer screening, such as a mammogram for breast cancer, a biopsy is usually performed to collect and examine a sample of tissue from a suspicious lump or lesion to confirm whether it is cancerous or benign.

Mr. Mendoza said the procedure is also necessary for oncologists as it allows them to determine the cancer鈥檚 pathology, or how the disease affects the patient鈥檚 body.

According to the American Cancer Society鈥檚 report, cancer spread after a biopsy, also called tumor seeding, is technically possible, but it occurs only in extremely rare cases and is far outweighed by the benefits of the procedure.

Tumor seeding may occur when the needle used during a biopsy touches the tumor and accidentally dislodges some cancer cells, which could then spread to nearby areas, the report said.

In a separate study that it cited, 42 patients were reported to experience tumor seeding after a prostate biopsy via a needle, most following transperineal procedures (through the skin between the scrotum and anus) and nine after transrectal procedures (through the rectum), with the overall incidence estimated at less than 1%.

However, it concluded that this complication is rare, and its actual incidence is currently difficult to quantify. It added that the benefits of the biopsy still outweigh any potential risks from seeding.

Mr. Mendoza urged people, especially women, to undergo early screening for breast cancer鈥攖he most common cancer in the country鈥攁nd to have a biopsy if needed to ensure proper and timely treatment. 鈥 Edg Adrian A. Eva