A 44-year-old mother felt a lump while breastfeeding. Doctors warned it could be pregnancy-related breast cancer.

A 44-year-old mother named Wang from Xitun, Taichung, unexpectedly felt a lump in her right breast when her daughter was 8 months old and was still breastfeeding. She originally thought it was a blocked breast duct, which is common during breastfeeding. Unexpectedly, the lump continued to grow in size. She was diagnosed with triple-negative breast cancer by the Zhongrong Women's Medicine Department. She urgently removed the entire right breast and performed a right axillary sentinel lymph node dissection. Fortunately, no remaining invasive cancer cells could be found after the operation.

Ms. Wang is an elderly mother. She found a lump in her right breast that continued to grow in size while breastfeeding last year (2025). She received treatment from Liu Zhigu, a physician at the Department of Women's Medicine, Taichung General Hospital, and was referred to breast oncology surgery for further biopsy. She was diagnosed with triple-negative breast cancer. At that time, the tumor had reached 5 cm and contained multiple lesions.

"One case may occur in every 3,000 pregnancies," said Dr. Cai Yizhen, a breast oncology surgeon at Zhongrong. Pregnancy-Associated Breast Cancer (PABC) refers to breast cancer diagnosed during pregnancy and within one year after delivery. According to international statistics, the incidence rate is 1 in 3,000. Women's lactation period is affected by hormones and lactation. The breasts are prone to swelling, hardening, or lumps, which are often misjudged as "milk filling" or changes in breastfeeding.

The medical team arranged for Ms. Wang to receive immunotherapy combined with chemotherapy for about half a year. After the tumor shrank, she underwent a right total mastectomy and right axillary sentinel lymph node dissection. The hospital emphasized that after the surgery, the tissue was sent for pathological examination and no remaining invasive cancer cells could be found, achieving what is medically called "pathological complete remission."

Total mastectomy for malignant tumors, including traditional total mastectomy and traditional nipple-sparing excision, is covered by health insurance. If you choose minimally invasive total excision surgery such as endoscopic surgery or Da Vinci robotic arm, you will need to pay for part of the surgery and equipment at your own expense.

According to the National Health Service, breast cancer is most common in women between the ages of 45 and 69. As women marry later and have children later, it is more likely to occur. Zhongrong calls on mothers not to "treat breast changes as milk congestion."

Dr. Liu Zhigu said that Mrs. Wang is currently undergoing post-operative immunotherapy. Breast cancer is the most common cancer among Taiwanese women. If the lump persists for a period of time, or even continues to grow in size, or there are changes in the appearance of the breast, sunken skin, abnormal nipple discharge, or unknown lumps under the armpits, you should seek medical examination as soon as possible.