Objectives: Assess the importance of systematic surgical exploration of the tumor focus in case of complete clinical response to neoadjuvant chemotherapy for operable breast cancer.
Patients and methods: Between 1985 and 1997, first intention chemotherapy (4 to 6 cures) was given to 433 breast cancer patients with resectable tumors measuring > or = 3 cm but who required mammectomy. Complete clinical response was observed in 112 patients (26%); 31 of them had normal mammography and ultrasound examinations (7%). Local treatment in this favorable context varied: 82 patients underwent surgery (71 conservative procedures, 11 radical procedures) and 30 patients received radiation therapy alone.
Results: Complete histological response was obtained in 22 cases accounting for 6% of the entire series, 27% of the complete clinical responses, and 45% of the complete clinical and imaging responses. The incidence of local recurrence at a mean 107 month follow-up was compared between patients given complementary surgical or radiation therapy after complete clinical response. Recurrence was observed in 10 of the 82 operated patients versus 8 of the 30 nonoperated patients (12% versus 27%, NS).
Conclusion: Complete clinical response after neoadjuvant chemotherapy does not rule out the need for surgical resection of the tumor focus because the risk of neoplastic reliquats remains high (3 out of 4 cases) and because the surgical specimen provides important histological information for prognosis (in vivo chemosensitivity test). lumpectomy also contributes to reducing the risk of local recurrence.