Axillary Dissection Based on the Histological Result of the Sentinel Node, in Patients With Breast Carcinoma
Axillary Dissection Based on the Histological Result of the Sentinel Node, in Patients With Breast Carcinoma
The purpose of this study is to evaluate the disease free and overall survival of patients
 with breast carcinomas of small size, i.e., not greater than 2.0 cm and with clinically non
 palpable axillary lymph nodes, undergoing either conservative surgery and axillary
 dissection, or a similar treatment for the primary tumor and rapid analysis of the sentinel
 lymph node, the result of which determines axillary node dissection or its avoidance is
 based.
The axillary lymph nodes represent the most frequent site of metastasis from breast
 carcinoma. In previous studies, it has been shown that the process of metastasis to the
 axillary nodes proceeds in an orderly and progressive fashion from the I to the II and to the
 III level and that a "saltatory" event of metastasis represents a rare event described in
 only 2% to 6% of cases.

 The risk of metastasis is directly correlated with the size of the primary tumor. When
 smaller than 1 cm in diameter, the risk of metastasis is about 10%; when larger than 5 cm in
 diameter, the risk increases to more than 70%.

 The involvement of axillary lymph nodes by metastases constitutes today the most important
 prognostic factor in breast cancer. Massive invasion is most certainly associated with a poor
 outcome and therefore, the information that the lymph node status can provide, is
 indispensible for administration of appropriate therapies in the postoperative period.
 Nevertheless, in those cases where the lymph nodes are found to be free of metastases,
 axillary dissection is a useless treatment that can prove harmful if one considers all the
 possible short and long term complications.

 Presently, there are no diagnostic modalities that are able to provide an accurate lymph node
 staging preoperatively. This information can only be gained by histologic examination of all
 lymph nodes after complete axillary dissection.

 Standard treatment for operable breast cancer today always involves the dissection of the
 axillary lymph nodes, regardless of the surgical procedure used for resection of the primary
 tumor, i.e. conservative or demolitive. This not only results in a large expenditure of
 resources (longer surgical procedures under general anesthesia), but most notably, in an
 increased risk of complications (lymphedema and functional limitations of the involved
 extremity) for the patient, secondary to a more aggressive intervention on the axilla.

 A method utilizing preoperative lymphoscintigraphy and intraoperative use of a gamma-ray
 probe in order to evaluate the possibility of metastasis in the first axillary lymph node,
 i.e. the "sentinel node", has recently been put into practice at our institute. This method,
 which in its first part consists in the subcutaneous or peritumoral administration of a
 radiolabeled (99Tc) human albumin colloid (see methods section), has allowed isolation and
 excision of the sentinel lymph node with the use of the gamma-ray probe in 98.8% of cases.

 In the case that this procedure should prove highly predictable of patient outcome, numerous
 axillary lymphadenectomies could be avoided and with such, numerous complications associated
 with such aggressive intervention.

 A first phase study has evaluated 238 patients with breast carcinoma that would be candidates
 for complete axillary dissection. Patients with intraductal carcinoma, those candidates for
 primary chemotherapy, those diagnosed during pregnancy or lactation, and those with tumors
 less than 1 cm in size (because of inclusion in the randomized trial (053) evaluating the
 role of radiotherapy on the axilla in patients undergoing conservative surgery without
 axillary node dissection) were excluded from the study. The results of this first phase have
 shown a concordance in the histologic findings between the sentinel lymph node and all
 remaining axillary lymph nodes, subdivided into three levels, in 96.7% of cases. Furthermore,
 concordance was 100% in 18 patients with breast carcinoma of a size equal or less than 1.0
 cm.
Inclusion Criteria:

 -  Age between 40 and 75 years.

 -  Clinical, mammographic or ultrasonographic diagnosis of a unicentric carcinoma with an
 ultrasonographic diameter of equal or less than 2.0 cm.

 -  Although not a factor of exclusion, a breast scintigraphy using MDP-99m is recommended
 for accurate determination of possible multifocality or multicentricity of the tumor,
 as well as for the determination of possible bone metastasis.

 -  Axillary lymph nodes that cannot be palpated or that are not clinically suspicious for
 metastasis.

 -  No previously executed therapy (including biopsy) at any outside institution.

 -  Those patients with nonpalpable lesions will be subjected to preoperative radioactive
 occult lesion localization (ROLL) or stereotactic biopsy.

 -  Adequate patient information and signature of the informed consent.

 Exclusion Criteria:

 -  Lesions diagnosed as non-infiltrating (in-situ) ductal or lobular carcinoma.

 -  Paget's disease.

 -  Documented multicentricity and/or abundant multifocality of the neoplasm.

 -  Clinically metastatic lymph nodes.

 -  Patients previously biopsied at other institutions.

 -  Carcinomas detected during pregnancy or lactation.

 -  Histotypes diverse from breast carcinoma lesions.

 -  History of previous malignancy (excluding basocellular carcinoma, in-situ cervical
 carcinoma and/or contralateral breast carcinoma without recurrence for at least 15
 years of follow-up).