Cysteine Cathepsins in Breast Cancer: Promising Targets for Fluorescence-Guided Surgery.

The majority of breast cancer patients is treated with breast-conserving surgery (BCS) combined with adjuvant radiation therapy. Up to 40% of patients has a tumor-positive resection margin after BCS, which necessitates re-resection or additional boost radiation. Cathepsin-targeted near-infrared fluorescence imaging during BCS could be used to detect residual cancer in the surgical cavity and guide additional resection, thereby preventing tumor-positive resection margins and associated mutilating treatments. The cysteine cathepsins are a family of proteases that play a major role in normal cellular physiology and neoplastic transformation. In breast cancer, the increased enzymatic activity and aberrant localization of many of the cysteine cathepsins drive tumor progression, proliferation, invasion, and metastasis. The upregulation of cysteine cathepsins in breast cancer cells indicates their potential as a target for intraoperative fluorescence imaging. This review provides a summary of the current knowledge on the role and expression of the most important cysteine cathepsins in breast cancer to better understand their potential as a target for fluorescence-guided surgery (FGS). In addition, it gives an overview of the cathepsin-targeted fluorescent probes that have been investigated preclinically and in breast cancer patients. The current review underscores that cysteine cathepsins are highly suitable molecular targets for FGS because of favorable expression and activity patterns in virtually all breast cancer subtypes. This is confirmed by cathepsin-targeted fluorescent probes that have been shown to facilitate in vivo breast cancer visualization and tumor resection in mouse models and breast cancer patients. These findings indicate that cathepsin-targeted FGS has potential to improve treatment outcomes in breast cancer patients.

Compliance and tolerability of short-course radiotherapy followed by preoperative chemotherapy and surgery for high-risk rectal cancer - Results of the international randomized RAPIDO-trial.

BACKGROUND: Preoperative chemoradiotherapy (CRT) followed by total mesorectal excision is widely accepted as the standard of care for high-risk rectal cancer. Adjuvant chemotherapy is advised in several international guidelines, although the survival benefit remains unclear and compliance is poor. The current multidisciplinary approach has led to major improvements in local control, yet the occurrence of distant metastases has not decreased accordingly. The combination of short-course radiotherapy (SCRT) and chemotherapy in the waiting period before surgery might have several benefits, including higher compliance, downstaging and better effect of systemic therapy. METHODS: This is an investigator-initiated, international multicentre randomized phase III trial. High-risk rectal cancer patients were randomized to SCRT followed by chemotherapy (6 cycles CAPOX or alternatively 9 cycles FOLFOX4) and subsequent surgery, or long-course radiotherapy (25-28 × 2-1.8 Gy) with concomitant capecitabine followed by surgery and optional postoperative chemotherapy (8 cycles CAPOX or 12 cycles FOLFOX4) according to local institutions' policy. The primary endpoint is time to disease-related treatment failure. Here, we report the compliance, toxicity and postoperative complications in both study groups. FINDINGS: Between June 2011 and June 2016, 920 patients were enrolled. Of these, 901 were evaluable (460 in the experimental arm and 441 in the standard arm). All patients in the experimental arm received 5 × 5 Gy radiotherapy, and 84% of all patients received at least 75% of the prescribed chemotherapy. In the standard arm, the compliance for CRT was 93% and 58% for postoperative chemotherapy. Toxicity ≥grade 3 occurred in 48% of patients in the experimental arm, compared to 25% of patients in the standard arm during preoperative treatment and 35% of patients during postoperative chemotherapy. No statistically significant differences in surgical procedures or postoperative complications were observed. INTERPRETATION: High compliance (84%) of preoperative systemic treatment could be achieved with the experimental approach. Although considerable toxicity was observed during preoperative therapy, this did not lead to differences in surgical procedures or postoperative complications. Longer follow-up time is needed to assess the primary endpoint and related outcomes.