Local relapse in primary breast cancer patients with unexcised positive surgical margins after lumpectomy, radiotherapy and chemoendocrine therapy

Background: Inadequate surgical excision with residual involvement of resec tion margins by tumour after breast conservation results in increased local recurrence rates. To reduce this risk positive margins are, therefore, usu ally excised. Systemic treatment with tamoxifen or chemotherapy reduces loc al recurrence, along with radiotherapy. However, no studies to date have ex amined the correlation between chemoendocrine treatment, together with radi otherapy, and local relapse in patients with unexcised involved resection m argins, having had breast conservation treatment. Patients and methods: The histopathology reports were reviewed of 184 patie nts who were treated from June 1991 to August 1995 within our randomised st udy of neoadjuvant versus adjuvant chemoendocrine therapy with mitozantrone and methotrexate (2M) +/- mitomycin-C (3M) and tamoxifen, used concurrentl y with radiation following conservation surgical treatment. Histological re section margin was considered positive if ductal carcinoma in situ (DCIS) o r invasive carcinoma was present microscopically less than 1mm from the exc ision margin. Results: Although 38% of patients had unexcised microscopically involved ma rgins, local relapse rate as first site of relapse was only 1.9% after a me dian follow up of 57 months. There was no difference in distant relapse (P = 0.2) and survival (P = 0.5) between the positive and negative margins gro ups. Conclusions: The presence of positive unexcised margins does not have a sig nificant effect on outcome in patients who are treated with chemoendocrine therapy together with radiotherapy. Further clinical trials are required.