[Occurrence of squamous cell lung carcinoma in the irradiated field after radiotherapy for breast cancer].

ABSTRACT

Radiotherapy for breast cancer reduces the incidence of disease recurrence and breast cancer mortality.However, it has also been associated with an increased risk of developing secondary cancers in exposed sites.Recently, we observed a 64-year-old woman who developed squamous cell lung carcinoma in the field irradiated with a total dose of 55 Gy after conservative breast surgery for left breast cancer 16 years previously.The patient underwent left upper lobectomy combined with chest wall resection.She had no recurrence of the breast cancer for 16 years.The secondary lung cancer tumor was of a different histological type than the primary breast cancer, and it appeared in the irradiated field.In conclusion, we regarded her lung cancer as a radiation-induced cancer, although it is difficult to clearly define radiation-induced cancer.In addition, the patient 's lung cancer may not only be a result of the late effect of irradiation, but might also be due to her smoking habit.