Expert UK consensus on the definition of high risk of recurrence in HER2-negative early breast cancer: A modified Delphi panel

BACKGROUND

There is currently no standardised definition for patients at high risk of recurrence of human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (eBC; stages 1-3) after surgery. This modified Delphi panel aimed to establish expert UK consensus on this definition, separately considering hormone receptor (HR)-positive and triple-negative (TN) patients.

METHODS

Over three consecutive rounds, results were collected from 29, 24 and 22 UK senior breast cancer oncologists and surgeons, respectively. The first round aimed to determine key risk factors in each patient subgroup; subsequent rounds aimed to establish appropriate risk thresholds. Consensus was pre-defined as ≥70% of respondents.

RESULTS

Expert consensus was achieved on need to assess age, tumour size, tumour grade, number of positive lymph nodes, inflammatory breast cancer and risk prediction tools in all HER2-negative patients. There was additional agreement on use of tumour profiling tests and biomarkers in HR-positive patients, and pathologic complete response (pCR) status in TN patients. Thresholds for high recurrence risk were subsequently agreed. In HR-positive patients, these included age <35 years, tumour size >5 cm (as independent risk factors); tumour grade 3 (independently and combined with other high-risk factors); number of positive nodes ≥4 (independently) and ≥1 (combined). For TN patients, the following thresholds reached consensus, both independently and in combination with other factors: tumour size >2 cm, tumour grade 3, number of positive nodes ≥1.

CONCLUSIONS

The results may be a valuable reference point to guide recurrence risk assessment and decision-making after surgery in the HER2-negative eBC population.

Results of the c-TRAK TN trial: a clinical trial utilising ctDNA mutation tracking to detect molecular residual disease and trigger intervention in patients with moderate- and high-risk early-stage triple-negative breast cancer

BACKGROUND

Post-treatment detection of circulating tumour DNA (ctDNA) in early-stage triple-negative breast cancer (TNBC) patients predicts high risk of relapse. c-TRAK TN assessed the utility of prospective ctDNA surveillance in TNBC and the activity of pembrolizumab in patients with ctDNA detected [ctDNA positive (ctDNA+)].

PATIENTS AND METHODS

c-TRAK TN, a multicentre phase II trial, with integrated prospective ctDNA surveillance by digital PCR, enrolled patients with early-stage TNBC and residual disease following neoadjuvant chemotherapy, or stage II/III with adjuvant chemotherapy. ctDNA surveillance comprised three-monthly blood sampling to 12 months (18 months if samples were missed due to coronavirus disease), and ctDNA+ patients were randomised 2 : 1 to intervention : observation. ctDNA results were blinded unless patients were allocated to intervention, when staging scans were done and those free of recurrence were offered pembrolizumab. A protocol amendment (16 September 2020) closed the observation group; all subsequent ctDNA+ patients were allocated to intervention. Co-primary endpoints were (i) ctDNA detection rate and (ii) sustained ctDNA clearance rate on pembrolizumab (NCT03145961).

RESULTS

Two hundred and eight patients registered between 30 January 2018 and 06 December 2019, 185 had tumour sequenced, 171 (92.4%) had trackable mutations, and 161 entered ctDNA surveillance. Rate of ctDNA detection by 12 months was 27.3% (44/161, 95% confidence interval 20.6% to 34.9%). Seven patients relapsed without prior ctDNA detection. Forty-five patients entered the therapeutic component (intervention n = 31; observation n = 14; one observation patient was re-allocated to intervention following protocol amendment). Of patients allocated to intervention, 72% (23/32) had metastases on staging at the time of ctDNA+, and 4 patients declined pembrolizumab. Of the five patients who commenced pembrolizumab, none achieved sustained ctDNA clearance.

CONCLUSIONS

c-TRAK TN is the first prospective study to assess whether ctDNA assays have clinical utility in guiding therapy in TNBC. Patients had a high rate of metastatic disease on ctDNA detection. Findings have implications for future trial design, emphasising the importance of commencing ctDNA testing early, with more sensitive and/or frequent ctDNA testing regimes.

Bevacizumab with peri-operative epirubicin, cisplatin and capecitabine (ECX) in localised gastro-oesophageal adenocarcinoma: a safety report

BACKGROUND

Peri-operative chemotherapy and surgery is a standard treatment of localised oesophagogastric adenocarcinoma; however, the outcomes remain poor.

PATIENTS AND METHODS

ST03 is a multicentre, randomised, phase II/III study comparing peri-operative ECX with or without bevacizumab (ECX-B). The primary outcome measure of phase II (n = 200) was safety, specifically gastrointestinal (GI) perforation rates and cardiotoxicity.

RESULTS

Two hundred patients were randomised between October 2007 and April 2010. Ninety-one/101 (90%) ECX and 86/99 (87%) ECX-B patients completed pre-operative chemotherapy; 7 ECX and 9 ECX-B patients stopped due to toxicity. Gastrointestinal perforations (3 ECX, 1 ECX-B), cardiac events (1 ECX, 4 ECX-B) and venous thromboembolic events (VTEs, 8 ECX, 7 ECX-B) were uncommon. Arterial thromboembolic events (ATEs, myocardial infarction (MI) or cerebrovascular accident) were more frequent with ECX-B (5 versus 1 with ECX). Delayed wound healing, anastomotic leaks and GI bleeding rates were similar. More asymptomatic left ventricular ejection fraction (LVEF) falls (≥15% and/or to <50%) occurred with ECX-B (21.2% versus 11.1% with ECX). Clinically significant falls (≥10% to below lower limit of normal, LLN) occurred in (15.3%) and (8.9%) respectively, with no associated cardiac failure (median 22 months follow-up).

CONCLUSIONS

Addition of bevacizumab to peri-operative ECX chemotherapy is feasible with acceptable toxicity and no negative impact on surgical outcomes.

Meta-analysis of the REAL-2 and ML17032 trials: evaluating capecitabine-based combination chemotherapy and infused 5-fluorouracil-based combination chemotherapy for the treatment of advanced oesophago-gastric cancer

BACKGROUND

The REAL-2 and ML17032 trials demonstrated that the oral fluoropyrimidine, capecitabine, is noninferior to 5-fluorouracil (5-FU) for overall survival (OS) and progression-free survival (PFS), respectively, in advanced oesophago-gastric cancer.

METHODS

Individual patient data were collected on all patients randomised within the trials (n = 1318). Kaplan-Meier survival curves were generated and the log-rank test was used to compare OS and PFS between patients receiving 5-FU combinations and capecitabine combinations. Stepwise multivariate Cox regression analysis was used to calculate corrected hazard ratios (HRs) and 95% confidence intervals (CIs) for OS and PFS. Logistic regression was used for objective response rate. Forest plots with tests of heterogeneity were generated.

RESULTS

OS was superior in the 654 patients treated with capecitabine combinations compared with the 664 patients treated with 5-FU combinations; HR 0.87 (95% CI 0.77-0.98, P = 0.02). Poor performance status, age <60 and metastatic disease were independent predictors of poor survival. There was no significant difference in PFS between treatment groups on multivariate analysis. Assessable patients treated with capecitabine combinations were significantly more likely to have an objective response to treatment than those treated with 5-FU combinations; odds ratio 1.38 (95% CI 1.10-1.73, P = 0.006).

CONCLUSION

OS is superior in patients treated with capecitabine combinations compared with 5-FU combinations in advanced oesophago-gastric cancer.