Preoperative Systemic Therapy vs Upfront Surgery in HER2 Positive Early Breast Cancer
Condition: Breast Cancer; HER2; Preoperative Systemic Treatment
MeSH terms: Breast Neoplasms
Study type: Observational

Summary: 
      Preoperative systemic treatment can make patients getting more opportunity for
      breast-conserving surgery, down-staging and new drugs developing. It is particularly common
      in human epidermal growth factor receptor 2 (HER2)-over expressing subtype for as high as
      40%~60% pCR rate of such a population. Even though, in NSABP B18/27 trials, it had been
      proved that PST could not improve either disease-free survival (DFS) or overall survival (OS)
      comparing with postoperatively systemic treatment in total population. We designed a
      real-world study to investigate the prognosis of anti-HER2 treatment combined with
      chemotherapy preoperatively versus postoperatively in HER2-positive early breast cancer
    

Detailed description: 
      Patients with a diagnosis of HER2 positive early invasive breast cancer (cT1-3N0-1M0), from
      January 2012 to December 2014 were identified and enrolled continuously. The conditions of
      HER2-positive expression of primary breast cancer were defined as follows: HER2 3+ by
      immunohistochemical (IHC) method or HER2 2+ by IHC with a further positive result by
      fluorescence in situ hybridization (FISH). According to the real upfront treatment, all
      eligible patients were classified as PST group and surgery group. All the patients accepted
      standard one-year trastuzumab as anti-HER2 treatment combined with chemotherapy. In the PST
      group, the effect was evaluated according to RECIST1.1 every two cycles, the patients with
      clinical complete response (cCR) or partial response (PR) would receive the whole course of
      chemotherapy, those with stable disease (SD) or progressive disease (PD) would receive
      surgery promptly. After surgery, all patients underwent irradiation and endocrine therapies
      if necessary. The pCR was defined as the absence of infiltrating residual invasive disease in
      the breast and axillary nodes. For those non-pCR patients after PST, intensive adjuvant
      chemotherapy was not routine treatment except patients with progressive disease.The primary
      endpoint was DFS defined as the time from enrollment to local, regional, or distant
      recurrences; the occurrence of contralateral breast cancer; or death without evidence of
      breast cancer. Patients suffered disease progress becoming inoperable before surgery were
      counted as local treatment failures. The second endpoint was OS defined as the time from
      study entry to death from any cause. All the endpoints were compared between PST group and
      upfront surgery group, also further analysis according to pathological response status
      stratified in PST group.
    

Intervention name(s): Preoperative systemic treatment
Intervention type(s): Procedure
Intervention description(s): neoadjuvant chemotherapy combined with trastuzumab as preoperative systemic treatment
Other intervention name(s): neoadjuvant treatment
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        HER2 positive early invasive breast cancer, using trastuzumab for one year both in
        neoadjuvant or adjuvant setting.
      
Keywords: breast cancer; HER2; preoperative systemic treatment