Early assessment with 18F-fluorodeoxyglucose positron emission tomography/computed tomography can help predict the outcome of neoadjuvant chemotherapy in triple negative breast cancer

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Abstract

Background

In patients with triple-negative breast cancer (TNBC), pathology complete response (pCR) to neoadjuvant chemotherapy (NAC) is associated with improved prognosis. This prospective study was designed and powered to investigate the ability of interim 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) to predict pathology outcomes to NAC early during treatment.

Patients and methods

Consecutive TNBC women underwent 18FDG-PET/CT at baseline and after two courses of NAC. Maximum standardised uptake value (SUVmax) in the primary tumour and lymph nodes at each examination and the evolution (ΔSUVmax) between the two scans were measured. NAC was continued irrespective of PET results. Correlations between PET parameters and pathology response, and between PET parameters and event-free survival (EFS), were examined.

Results

Fifty patients without distant metastases were enroled. At completion of NAC, surgery showed pCR in 19 patients, while 31 had residual tumour. Mean follow-up was 30.3 months. Thirteen patients, all with residual tumour, experienced relapse. Of all assessed clinical, biological and PET parameters, ΔSUVmax in the primary tumour was the most predictive of pathology results (p < 0.0001; Mann–Whitney-U test) and EFS (p = 0.02; log rank test). A threshold of 42% decrease in SUV was identified because it offered the best accuracy in predicting EFS. There were 32 metabolic responders (⩾42% decrease in SUVmax) and 18 non-responders. Within responders, the pCR rate was 59% and the 3-year EFS 77.5%. In non-responders, the pCR rate was 0% and the 3-year EFS 47.1%.

Conclusion

Interim 18FDG can early predict the inefficacy of NAC in TNBC patients. It shows promise as a potential contributory biomarker in these patients.

Introduction

Triple-negative breast cancer (TNBC) accounts for 10–20% of invasive breast cancers and is characterised by the lack of oestrogen receptor (ER) and progesterone receptor (PR), and absence of HER2 over-expression [1], [2]. Patients with TNBC have a relatively poor outcome with higher relapse rates than those with other breast tumour types [1], [2]. However, these aggressive tumours have more intrinsic responsiveness to neoadjuvant chemotherapy (NAC) than ER-positive tumours. Also, TNBC patients with pathological complete response (pCR) after NAC have a good prognosis [3], [4]. Therefore, obtaining pCR for TNBC patients is an important clinical objective.

Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18FDG) is gaining importance for the staging of patients with large or locally advanced breast cancer [5], [6]. On the other hand, an early change in 18FDG uptake of the primary breast tumour (ΔSUVmax) is a potential predictive biomarker of response to NAC [7], [8]. Some teams suggested that 18FDG PET can also be used to predict response in axillary lymph nodes [9], [10]. Triple-negative tumours show high 18FDG uptake [11], [12]. Therefore, the TNBC subtype is probably ‘a good candidate’ to investigate response assessment with PET. The present prospective study investigated the ability of PET parameters (maximum standardised uptake value (SUVmax) at baseline, after two cycles of NAC, and ΔSUVmax) at early predicting pathological response and event-free survival (EFS) during NAC in a large series of TNBC patients. We also compared prediction offered by PET to that offered by baseline clinical or biological factors [3], [13].

Section snippets

Patients

From November 2007 to September 2012, 55 consecutive patients with clinical stage II or III breast carcinoma and a triple negative phenotype underwent 18FDG-PET/CT examination before starting NAC (PET1). Five of these patients had distant metastases identified at PET/CT and received treatment tailored to metastatic disease. The other 50 patients form the basis of the present study. All of them underwent a second 18FDG-PET/CT examination after the second cycle of chemotherapy (PET2). After

Results

One hundred 18FDG-PET/CT scans were performed in 50 M0 consecutive patients. Patients and tumour characteristics at baseline are summarised in Table 1.

At completion of NAC, breast-conserving surgery was performed in 21 women and mastectomy in 29. All patients had axillary lymph nodes dissection. Histopathology revealed pCR (pathological responders) in 19 patients (38%) while 31 (62%) had residual disease (non-pCR).

Discussion

Pathologic complete response is a surrogate end-point when TNBC patients are treated by neoadjuvant chemotherapy [3], [4]. In this prospective study of 50 women, the 3-year EFS was 100% in patients with pCR versus 51% [34.9-74.7] in those with residual tumour at surgery. We chose to present EFS data with follow-up from start of NAC, rather than disease free survival with follow-up from the date of surgery [15]. Indeed, trials with NAC often use EFS because patients are not disease-free at

Conflict of interest statement

None declared.

Acknowledgement

No external found was received in this study.

References (30)

  • J. Schwarz-Dose et al.

    Monitoring primary systemic therapy of large and locally advanced breast cancer by using sequential positron emission tomography imaging with [18F]fluorodeoxyglucose

    J Clin Oncol

    (2009)
  • D. Groheux et al.

    Early monitoring of response to neoadjuvant chemotherapy in breast cancer with (18)F-FDG PET/CT: defining a clinical aim

    Eur J Nucl Med Mol Imaging

    (2011)
  • C. Rousseau et al.

    FDG PET evaluation of early axillary lymph node response to neoadjuvant chemotherapy in stage II and III breast cancer patients

    Eur J Nucl Med Mol Imaging

    (2011)
  • B.B. Koolen et al.

    Early assessment of axillary response with (18)F-FDG PET/CT during neoadjuvant chemotherapy in stage II–III breast cancer: implications for surgical management of the axilla

    Ann Surg Oncol

    (2013)
  • D. Groheux et al.

    Performance of FDG PET/CT in the clinical management of breast cancer

    Radiology

    (2012)
  • Cited by (0)

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