Does intraductal breast cancer spread in a segmental distribution? An analysis of residual tumour burden following segmental mastectomy using tumour bed biopsies

Introduction: Breast-conserving surgery for early breast cancer is now rout inely used as an alternative to mastectomy. Despite post-operative radiothe rapy, early local recurrence of tumour remains a concern. It has been repor ted that invasive and in-situ ductal carcinoma spread locally through the d uctal tree in a segmental distribution, however, there is no consensus as t o the best surgical method to maximize tumour clearance whilst leaving a go od cosmetic result. Aim: We aimed to measure the effectiveness of segmental mastectomy (excisio n of tumour plus associated segmental ductal tissue) in the clearance of di fferent tumour types. Bed biopsy of the excision cavity was employed to ass ess the rate of incomplete excision or the multifocality of certain breast cancers. Methods: One hundred and one patients with breast cancers underwent segment al mastectomy and cavity bed biopsies. Specimens were assessed for tumour t ype and completeness of excision. An excision of the cancer was considered incomplete if the margins were involved or if any of the bed biopsies showe d residual or multifocal tumour. Results: A total of 24 patients had incomplete tumour excision. Invasive du ctal carcinoma was more likely to be completely excised by segmental mastec tomy than invasive lobular carcinoma (P<0.05). incomplete excision was asso ciated with multifocality and the presence of extensive DCIS. The report of clear pathological margins was significantly more likely to be accurate, a s measured by negative bed biopsies, in invasive ductal carcinoma when comp ared to invasive lobular carcinoma (P<0.05). Conclusion: These results support the concept that ductal carcinomas spread locally in a segmental fashion. patients with invasive ductal carcinomas a re more likely to benefit from breast conserving surgery that is tailored t o include the associated ductal tissue, in a segmental fashioned excision. (C) 2001 Harcourt Publishers Ltd.