Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030.

BACKGROUND: We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy. PATIENTS AND METHODS: We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence. RESULTS: Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12. CONCLUSIONS: Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.

Body composition and survival in the early clinical trials setting.

PURPOSE: Delineate the relationships between body composition parameters, 90-day mortality and overall survival, and correlate them with known prognostic factors in an early clinical trials clinic. PATIENTS AND METHODS: We studied 306 consecutive patients with various tumours; body composition was analysed by computerised tomography images. Survival was measured from the first clinic visit, at 90-day period and until death/last follow-up visit. RESULTS: Median patient age was 56 years; 159 patients were men. Ninety-day mortality rate was 12%. Median overall survival was 9 months. In multivariate analyses, high MD Anderson Cancer Center (MDACC) score (p < 0.0001) [lactate dehydrogenase (LDH) > normal, albumin < normal, Eastern Cooperative Oncology Group (ECOG) performance status > 1, metastatic sites > 2, gastrointestinal (GI) tumours], low skeletal muscle index (SMI) (p = 0.0406) and male gender (p = 0.0077) were independent predictors of poor survival. If Royal Marsden Hospital (RMH) score (LDH > normal, albumin 2) was used in lieu of MDACC score, it was also significant (p = 0.0003). Including SMI and gender in the MDACC or RMH score improved the accuracy of the original model (p = 0.006 and p = 0.0037, respectively). CONCLUSION: Patients with low SMI have shorter survival. Gender and SMI strengthens the accuracy of MDACC or RMH scores as prognostic tools. Prospective validation of these findings is warranted.