Purpose: To assess the frequency and prognosis of skin recurrences after breast-conserving therapy (BCT) compared with other breast recurrences.
Materials and methods: From 1968 to 1986, 1,624 patients with unilateral stage I or II breast cancer treated with BCT at the Joint Center for Radiation Therapy (Boston, MA) underwent gross tumor excision and received a dose of > or = 60 Gy to the tumor bed. Skin recurrences (SR) were defined as breast recurrences without associated parenchymal disease. An invasive breast recurrence with any parenchymal disease noted clinically or radiographically was scored as an other breast recurrence (OBR). Median follow-up for survivors was 137 months.
Results: SR represented 8% (18 of 229) of all breast recurrences and occurred in 1.1% of all patients. The outcome after local recurrence was different for patients with SR and invasive OBR. Patients with SR more frequently had uncontrolled local failure (50%; 9 of 18) than did patients with OBR (14%; 26 of 188) (P = .0007). Forty-four percent (8 of 18) of patients with SR had distant metastasis simultaneously or within 2 months of the recurrence compared with 5% (9 of 188) of invasive OBR patients (P < .0001). For patients without distant metastasis at the time of recurrence, the 5-year actuarial rate of development of distant metastasis was 60% for SR patients compared with 39% for invasive OBR patients (P = .07), and the corresponding 5-year actuarial survival rates beyond the time of local failure were 51% and 79%, respectively (P = .06).
Conclusion: In contrast to other types of invasive breast recurrence after breast-conserving therapy, skin recurrences are rare and are associated with a significantly higher rate of distant metastasis and uncontrolled local disease as well as a lower rate of survival.