Conservative surgery and radiation therapy for invasive lobular carcinoma of the breast

Background: There is debate as to whether infiltrating lobular carcinoma (ILC) can be effectively treated with breast conservative surgery (CS) and radiotherapy (RT) because of a perceived high risk of local recurrence. This retrospective study examined the outcome of patients with ILC treated by CS and RT. Methods: Between November 1979 and December 1994, 57 women with UICC Stage I or II ILC were treated by CS and RT at Westmead Hospital, New South Wales, Australia. The median age was 55 years (range 28-79). Twelve patients (21%) underwent a re-excision after initial CS. The final margins were clear for 43 patients (75.4%), positive (invasive or in situ) for nine patients (15.8%), and indeterminate for five patients (8.8%). All patients received whole-breast irradiation (45-50.4 Gy) usually supplemented by a boost (10-30 Gy). Fifty-three of 57 patients (93%) had their pathology reviewed at Westmead Hospital. Results: After a median follow up of 69 months (range 36- 162) three patients (5.3%) developed a local recurrence. One of 43 patients (2.3%) with known clear margins developed a local recurrence compared with two of 14 patients (14.3%) with positive or indeterminate margins (P = NS). The 5- and 10-year rates of freedom from local recurrence were 96 and 93%, respectively. The 5-year disease-free survival was 85% (node-negative, 92%; node-positive, 66%). Overall survival was 94% at 5 years. No patient developed a contralateral breast cancer. Conclusion: Patients with ILC can be effectively treated with CS and RT.