Cancers canalaires in situ du sein avec micro-invasion

Recent advances in the surgical care of breast cancer patients

A tremendous improvement in every aspect of breast cancer management has occurred in the last two decades. Surgeons, once solely interested in the extipartion of the primary tumor, are now faced with the need to incorporate a great deal of information, and to manage increasingly complex tasks.

As a comprehensive assessment of all aspects of breast cancer care is beyond the scope of the present paper, the current review will point out some of these innovations, evidence some controversies, and stress the need for the surgeon to specialize in the various aspects of treatment and to be integrated into the multisciplinary breast unit team.

Sentinel node procedure is warranted in ductal carcinoma in situ with high risk of occult invasive carcinoma and microinvasive carcinoma treated by mastectomy

Axillary lymph node dissection in patients with ductal carcinoma in situ (DCIS) of the breast is not warranted because DCIS has no metastatic potential. However, the risk of microinvasive carcinoma (MIC) exists in large DCIS treated by mastectomy. The aim of this series is to evaluate the incidence of lymph node metastases in DCIS and DCIS-MIC. We analyzed retrospectively patients treated in six French cancer centers for pure DCIS or DCIS-MIC. Surgical procedures were lumpectomy or mastectomy associated with an axillary sentinel node (SN) procedure. We included 161 patients suffering from pure DCIS (116/161, 72%) or DCIS-MIC (45/161, 28%). Mean age was 56 years (32-78). We observed underestimation between core biopsy and histological result in 43/142 cases (30%). These data show an association between lesion size, solid subtype, high-grade DCIS, and underestimation. Forty-eight breast conservative procedures were performed and 113 mastectomies (70%). SN procedure was performed using blue dye, technetium, or both. In our series, we selected patients with a high risk of occult invasive carcinoma: high grade (55%), mean size (27 mm), and mastectomy (112). Six SN were found positive (3.7%). In the five patients treated with complete axillary dissection, the SN was the only positive node. SN in DCIS is an interesting procedure but not necessary for all patients. We need to focus on the subgroup with or a high risk of occult MIC: extensive calcifications or palpable mass, DCIS diagnosed by core biopsy and underestimation, multifocality, high grade, large tumor size, MIC, and mastectomy.

Cancer canalaire in situ du sein avec micro-invasion. Place du ganglion sentinelle

OBJECTIVES

To investigate the role of sentinel lymph node biopsy for microinvasive ductal carcinoma in situ of the breast.

PATIENTS AND METHODS

From January 2001 to January 2006, lymphatic mapping was performed using radiocolloid and/or blue dye technique. Full axillary lymph node dissection was accomplished systematically in 10 instances at the beginning of the study, and furthermore when the sentinel node was involved (macrometastatic or micrometastatic disease).

RESULTS

Identification rate was 98% (40/41), the unsuccessful procedure occurred after incisional biopsy for diagnosis. The number of sentinel nodes removed was 2 in average (1-5). Sentinel node involvement was found in 10% of cases (4/40): 1 sentinel node macrometastasis pN1, 2 sentinel node micrometastases determined by hematoxylin and eosin staining pN1 (mi), 1 sentinel node micrometastasis detected only by immunohistochemical staining pN0 (mi).

DISCUSSION AND CONCLUSION

Sentinel lymph node sampling should not be currently applied for management of every ductal carcinoma in situ of the breast but a selective utilization is proposed in documented high risk subset of patients according to clinical, mammographic, and histologic features obtained by percutaneous biopsies. Ductal carcinoma in situ (DCIS) with proved or suspected microinvasion could be scheduled for sentinel node procedure a fortiori in cases undergoing mastectomy because of extensive DCIS before the occurrence of disturbances of lymphatic drainage induced by surgical breast dissection.

Sentinel lymph node metastasis from mammary ductal carcinoma in situ with microinvasion

Axillary lymph node dissection (ALND) in patients with ductal carcinoma in situ with microinvasion (DCISM) of the breast was controversial, because of the relevant morbidity incurred by the procedure and the low incidence of axillary involvement. The introduction of the sentinel lymph node (SLN) biopsy as a minimally invasive procedure for axillary staging has prompted new interest in this issue. However, as DCISM is a rare type of cancer, data on the incidence of SLN metastasis are scarce. The aim of the present paper was therefore to assess the prevalence of SLN metastasis in a multi-institutional series of DCISM patients, in order to ascertain whether SLN biopsy might be justified as a standard procedure in the presence of microinvasive cancer. Between 1999 and 2004, 43 patients with a diagnosis of DCISM underwent SLN biopsy. Microinvasion was defined as one or more foci of invasion beyond the basal membrane, none exceeding 1mm. SLNs were examined following haematoxylin-eosin and immunohistochemical staining. SLN metastases were found in four out of 43 cases (9.3%). In one patient, SLN contained only micrometastasis. All four patients with positive SLN underwent complete ALND and in all these cases further metastatic axillary nodes were found. In conclusion, given the relevant incidence of nodal metastases and the low morbidity of the procedure, we believe that SLN biopsy should be considered in all patients with a diagnosis of DCISM. In cases of SLN involvement, even if micrometastatic, our policy is to perform a complete ALND.