Axillary Dissection Based on the Histological Result of the Sentinel Node, in Patients With Breast Carcinoma
Condition: Breast Carcinoma
MeSH terms: Carcinoma; Breast Neoplasms
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): quadrantectomy and axillary dissection; quadrantectomy + sentinel node biopsy
Intervention type(s): Procedure; Procedure
Intervention description(s): standard quadrantectomy and axillary dissection; standard quadrantectomy and selective axillary dissection only if sentinel node biopsy is positive
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment