Recent research findings on skin cancer developing after breast cancer treatment are gaining attention. Did you know that patients who have undergone breast cancer treatment may develop new cancers decades later? In this post, we will explore how radiation therapy can lead to new cancers, using the case of a 70-year-old female patient.

The Course of Breast Cancer Treatment

Twenty-five years ago, a woman in her 70s was diagnosed with left breast cancer. She overcame the cancer through a mastectomy, chemotherapy, and adjuvant radiation therapy. However, three years after treatment, she returned to the hospital with a lump on her left breast. Fortunately, the biopsy results were not malignant, but the lump began to grow over time.

Discovery and Diagnosis of Skin Cancer

A recent physical examination confirmed that her mass had increased in size and was accompanied by inflammation. The research team suspected a recurrence of breast cancer and performed a biopsy. However, the cells identified in the detailed tissue examination looked entirely different from the original breast cancer cells. Consequently, it was revealed that a new skin cancer had developed due to radiation therapy.

The Risk of Radiation-Induced Sarcoma

This patient was diagnosed with a high-grade malignant skin cancer called 'dedifferentiated liposarcoma'. This cancer, which appeared 25 years after radiation therapy, is known as radiation-induced sarcoma. The incidence rate of radiation-induced sarcoma is low, at 0.03% to 0.2%, but it requires caution due to its poor prognosis. Notably, since various cancer patients, not just breast cancer patients, receive radiation therapy, such complications can occur.

The Importance of Detailed Examination and Early Detection

If new lumps or skin abnormalities appear after radiation therapy, it is crucial to undergo a detailed tissue examination. Imaging tests alone cannot distinguish between recurrent cancer and radiation-induced sarcoma, making accurate diagnosis through immunohistochemistry essential. In particular, you should visit a hospital immediately if the following symptoms appear:

• An unexplained lump on the left breast area
• A hard mass
• Abnormal skin signs

The number of breast cancer survivors in Korea now exceeds approximately 300,000, with 25,000 to 28,000 new patients diagnosed annually. Of these, about 60% to 70% receive radiation therapy. Therefore, patients who have undergone radiation therapy need continuous attention regarding chronic complications.

Prognosis and Treatment Methods

Radiation-induced sarcoma tends to spread to surrounding tissues, and its high rate of metastasis and recurrence leads to a poor prognosis. Because it typically does not respond well to standard chemotherapy, surgical resection is often necessary. If surgery is not possible, radiation therapy or supportive care may be administered to alleviate symptoms.

It is important to recognize the risk of radiation-induced sarcoma developing after breast cancer treatment and to make efforts for early detection. Even after cancer treatment, it is vital to continuously monitor your body's condition and consult a specialist if any abnormal signs appear.