[Eight Cases of Breast Cancer That Relapsed More Than Ten Years after Initial Treatment].

Recurrence is more common for breast cancer than other solid tumors. In the last 5 years, we experienced 8 cases that relapsed more than 10 years after initial treatment. All cases were hormone-sensitive and HER2-negative. The Ki-67 percentage score was less than 15% in 7 cases. The age range at recurrence was 56-93 years(mean, 74.6 years), and the time to recurrence was 10-14 years and 20 or more years in 6 and 2 cases(mean, 14.6 years), respectively. The triggers for diagnosis were subjective symptoms, follow-up, and examination for other diseases in 3, 3, and 2 cases, respectively. The recurrence sites included the axilla, pleura/lung, liver/lung, skin, and chest wall in 3, 2, 1, 1, and 1 case, respectively. Treatment included an aromatase inhibitor(AI)and AI plus CDK4/6 inhibitor in 5 and 3 cases, respectively. The post-recurrence treatment period was 6-31 months(mean, 21.6 months), with 4 cases of PR, 3 cases of SD, and 1 case of death from other disease. There were 3 cases of axillary recurrence and 1 case each of neuropathic pain, upper limb edema, and local pain; all were alleviated by the treatment. In 2 cases, the pleural effusion decreased without chest tube drainage. Hormone receptor- positive late-relapse cases are generally highly therapeutically sensitive with favorable prognosis. In many cases, AI alone was selected considering patient age, side effects, treatment costs, and other factors.