Primary systemic treatment and concomitant low dose radiotherapy for breast cancer: Final results of a prospective phase II study

Clinical Studies on Ultrafractionated Chemoradiation: A Systematic Review

Aim

The efficacy of low-dose fractionated radiotherapy (LDFRT) and chemotherapy (CHT) combination has large preclinical but little clinical evidence. Therefore, the aim of this review was to collect and analyze the clinical results of LDRT plus concurrent CHT in patients with advanced cancers.

Methods

A systematic literature search was conducted on PubMed using the PRISMA methodology. Only studies based on the combination of LDFRT (< 1 Gy/fraction) and CHT were included. Endpoints of the analysis were tumor response, toxicity, and overall survival, with particular focus on any differences between LDFRT-CHT and CHT alone.

Results

Twelve studies (307 patients) fulfilled the selection criteria and were included in this review. Two studies were retrospective, one was a prospective pilot trial, six were phase II studies, two were phase I trials, and one was a phase I/II open label study. No randomized controlled trials were found. Seven out of eight studies comparing clinical response showed higher rates after LDFRT-CHT compared to CHT alone. Three out of four studies comparing survival reported improved results after combined treatment. Three studies compared toxicity of CHT and LDFRT plus CHT, and all of them reported similar adverse events rates. In most cases, toxicity was manageable with only three likely LDFRT-unrelated fatal events (1%), all recorded in the same series on LDFRT plus temozolomide in glioblastoma multiforme patients.

Conclusion

None of the analyzed studies provided level I evidence on the clinical impact of LDFRT plus CHT. However, it should be noted that, apart from two small series of breast cancers, all studies reported improved therapeutic outcomes and similar tolerability compared to CHT alone.

Systematic Review Registration

www.crd.york.ac.uk/prospero/, identifier CRD42020206639.

Chemopotentiating effects of low-dose fractionated radiation on cisplatin and paclitaxel in cervix cancer cell lines and normal fibroblasts from patients with cervix cancer

The aim of the present study was to compare the effects (assessed by clonogenic survival and γH2AX foci assays) of low-dose fractionated radiation LDFR (4 × 0.125 Gy, 4 × 0.25 Gy and 4 × 0.5 Gy) versus single radiation doses (0.5 Gy, 1 Gy and 2 Gy) on cisplatin and paclitaxel in HRS-negative cervix cancer cell lines SiHa and CaSki to see if the effects of LDFR can emerge in cells that not present low-dose hyper-radiosensitivity (HRS) phenomenon. Additionally, we report the effects in normal fibroblasts (HRS-negative and HRS-positive) from two patients with cervix cancer to see if the chemopotentiating effects of LDFR also apply to normal cells. LDFR (4 × 0.125 Gy, 4 × 0.25 Gy and 4 × 0.5 Gy) as well as single doses (0.5 Gy, 1 Gy and 2 Gy) enhanced cytotoxicity of cisplatin and paclitaxel in all the cell lines. Cisplatin-potentiating effects were maximum with LDFR 4 × 0.5 Gy, and were two-fold greater than those with a single dose of 2 Gy in SiHa, CaSki and HFIB2 cells. Paclitaxel-enhancing effects were also maximum with LDFR 4 × 0.5 Gy, however only in HRS-positive HFIB2 fibroblasts were significantly greater than those with a single dose of 2 Gy. The results demonstrate that LDFR may enhance the effects of cisplatin and paclitaxel in SiHa and CaSki cells, although they lack HRS phenomenon, and show that the magnitude of the potentiating effects of LDFR depends on cytostatic type and the size of low doses. In normal fibroblasts the chemopotentiating effects of LDFR seem to depend on HRS status. In conclusion, the unique enhancing effects of LDFR on cisplatin in cervical cancer cell lines, even when HRS negative, suggest that all patients with cervical cancer may benefit from the addition of LDFR to adjuvant cisplatin-based chemotherapy.

A systematic review of neo-adjuvant radiotherapy in the treatment of breast cancer

Introduction

The use of neo-adjuvant radiotherapy (NRT) has been proven effective at improving cancer related outcome measures, including overall-survival (OS) in the management of solid cancers. However, its utilisation in breast cancer has not been explored to the extent of neo-adjuvant chemotherapy (NAC). The evidence for the application of NRT in breast cancer is evaluated.

Methods

PubMed, Embase and the Cochrane Library databases were searched systematically in August 2020 for studies that addressed the role of NRT in the treatment of breast cancer. Studies were deemed eligible if they reported on objective outcome measurements of OS, disease free-survival (DFS) or pathological complete response (pCR) and attained a satisfactory quality assessment.

Findings

A total of 23 studies reported upon 3,766 patients who had received NRT of which 3,233 also received NAC concurrently (neo-adjuvant chemo-radiotherapy (NCRT)). The pCR values ranged from 14% to 42%, 5-year DFS 61.4% to 81% and 5-year OS 71.6% to 84.2%. Complications were confined to radiation dermatitis with no cases of implant loss reported during breast reconstruction. The application of NRCT alone showed no significant difference in OS or DFS compared to NCRT followed by surgery.

Interpretation

Numbers of patients receiving exclusively NRT is small. However, NCRT is oncologically safe with a low side-effect profile including preceding breast reconstruction. Potential benefits include precise cancer volume targeting, chemosensitisation, elimination of delays in adjuvant therapies and alternatives to chemotherapy in oestrogen receptor positive patients. These factors warrant further exploration within randomised controlled-trials.

Low-dose fractionated radiation with induction docetaxel and cisplatin followed by concurrent cisplatin and radiation therapy in locally advanced nasopharyngeal cancer: A randomized phase II-III trial

OBJECTIVE/BACKGROUND

To evaluate the efficacy and outcome of adding low-dose fractionated radiotherapy (LDFRT) to induction chemotherapy plus concurrent chemoradiation in locally advanced nasopharyngeal carcinoma (LANPC).

METHODS

A single-institute, phase II-III, prospectively controlled randomized clinical trial was performed at King Faisal Specialist Hospital and Research Centre. Patients aged 18-70 years with WHO type II and III, stage III-IVB nasopharyngeal carcinoma, Eastern Cooperative Oncology Group performance score of 0-2, with adequate hematological, renal, and hepatic function were eligible. In total, 108 patients were enrolled in this trial. All patients received two cycles of induction docetaxel and cisplatin (75 mg/m² each) chemotherapy on Days 1 and 22, followed by concurrent chemoradiation therapy. Radiation therapy consisted of 70 Gy in 33 fractions, with concurrent cisplatin 25 mg/m² for 4 days on Days 43 and 64. Patients were randomly assigned to either adding LDFRT (0.5 Gy twice daily 6 hours apart for 2 days) to induction chemotherapy in the experimental arm (54 patients) or induction chemotherapy alone in the control arm (54 patients).

RESULTS

There was no significant difference in the post-induction response rates (RRs) or in toxicity between the two treatment arms. The 3-year overall survival (OS), locoregional control (LRC), and distant metastases-free survival (DMFS) rates for experimental arm and control arm were 94% versus 93% (p = .8), 84.8% versus 87.5% (p = .58), and 84.1% versus 91.6% (p = .25), respectively.

CONCLUSION

The results showed no benefit from adding LDFRT to induction chemotherapy in terms of RR, OS, LRC, and DMFS.

Effect of particle size on the biodistribution, toxicity, and efficacy of drug-loaded polymeric nanoparticles in chemoradiotherapy

Nanoparticle (NP) chemotherapeutics can improve the therapeutic index of chemoradiotherapy (CRT). However, the effect of NP physical properties, such particle size, on CRT is unknown. To address this, we examined the effects of NP size on biodistribution, efficacy and toxicity in CRT. PEG-PLGA NPs (50, 100, 150 nm mean diameters) encapsulating wotrmannin (wtmn) or KU50019 were formulated. These NP formulations were potent radiosensitizers in vitro in HT29, SW480, and lovo rectal cancer lines. In vivo, the smallest particles avoided hepatic and splenic accumulation while more homogeneously penetrating tumor xenografts than larger particles. However, smaller particles were no more effective in vivo. Instead, there was a trend toward enhanced efficacy with medium sized NPs. The smallest KU60019 particles caused more small bowel toxicity than larger particles. Our results showed that particle size significantly affects nanotherapeutics' biodistrubtion and toxicity but does not support the conclusion that smaller particles are better for this clinical application.

The predictive value of 18F-FDG PET-CT for assessing the clinical outcomes in locally advanced NSCLC patients after a new induction treatment: low-dose fractionated radiotherapy with concurrent chemotherapy

Background

Patients with locally advanced non-small-cell lung cancer (LA-NSCLC) have poor prognosis despite several multimodal approaches. Recently, low-dose fractionated radiotherapy concurrent to the induction chemotherapy (IC-LDRT) has been proposed to further improve the effects of chemotherapy and prognosis. Until now, the predictive value of metabolic response after IC-LDRT has not yet been investigated. Aim: to evaluate whether the early metabolic response, assessed by ¹⁸F-fluoro-deoxyglucose positron emission-computed tomography (¹⁸F-FDG PET-CT), could predict the prognosis in LA-NSCLC patients treated with a multimodal approach, including IC-LDRT.

Methods

Forty-four consecutive patients (35males, mean age: 66 ± 7.8 years) with stage IIIA/IIIB NSCLC were retrospectively evaluated. Forty-four patients underwent IC-LDRT (2 cycles of chemotherapy, 40 cGy twice daily), 26/44 neo-adjuvant chemo-radiotherapy (CCRT: 50.4Gy), and 20/44 surgery. ¹⁸F-FDG PET-CT was performed before (baseline), after IC-LDRT (early) and after CCRT (final), applying PET response criteria in solid tumours (PERCIST). Patients with complete/partial metabolic response were classified as responders; patients with stable/progressive disease as non-responders. Progression free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meyer analysis; the relationship between clinical factors and survivals were assessed using uni-multivariate regression analysis.

Results

Forty-four out of 44, 42/44 and 23/42 patients underwent baseline, early and final PET-CT, respectively. SUL_peak of primary tumour and lymph-node significantly (p = 0.004, p = 0.0002, respectively) decreased after IC-LDRT with a further reduction after CCRT (p = 0.0006, p = 0.02, respectively). At early PET-CT, 20/42 (47.6%) patients were classified as responders, 22/42 (52.3%) as non-responders. At final PET-CT, 19/23 patients were classified as responders (12 responders and 7 non-responders at early PET-CT), and 4/23 as non-responders (all non-responders at early PET-CT). Early responders had better PFS and OS than early non-responders (p ≤ 0.01). Early metabolic response was predictive factor for loco-regional, distant and global PFS (p = 0.02, p = 0.01, p = 0.005, respectively); surgery for loco-regional and global PFS (p = 0.03, p = 0.009, respectively).

Conclusions

In LA-NSCLC patients, ¹⁸F-FDG metabolic response assessed after only two cycles of IC-LDRT predicts the prognosis. The early evaluation of metabolic changes could allow to personalize therapy. This multimodality approach, including both low-dose radiotherapy that increases the effects of induction chemotherapy, and surgery that removes the disease, improved clinical outcomes. Further prospective investigation of this new induction approach is warranted.

Comparison of two radiation techniques for the breast boost in patients undergoing neoadjuvant treatment for breast cancer

OBJECTIVE

After breast conservative surgery (BCS) and whole-breast radiotherapy (WBRT), the use of boost irradiation is recommended especially in patients at high risk. However, the standard technique and the definition of the boost volume have not been well defined.

METHODS

We retrospectively compared an anticipated pre-operative photon boost on the tumour, administered with low-dose fractionated radiotherapy, and neoadjuvant chemotherapy with two different sequential boost techniques, administered after BCS and standard adjuvant WBRT: (1) a standard photon beam (2) and an electron beam technique on the tumour bed of the same patients. The plans were analyzed for the dosimetric coverage of the CT-delineated irradiated volume. The minimal dose received by 95% of the target volume (D95), the minimal dose received by 90% of the target volume (D90) and geographic misses were evaluated.

RESULTS

15 patients were evaluated. The sequential photon and electron boost techniques resulted in inferior target volume coverage compared with the anticipated boost technique, with a median D95 of 96.3% (range 94.7-99.6%) and 0.8% (range 0-30%) and a median D90 of 99.1% (range 90.2-100%) and 54.7% (range 0-84.8%), respectively. We observed a geographic miss in 26.6% of sequential electron plans. The results of the anticipated boost technique were better: 99.4% (range 96.5-100%) and 97.1% (range 86.2-99%) for median D90 and median D95, respectively, and no geographic miss was observed. We observed a dose reduction to the heart, with left-sided breast irradiation, using the anticipated pre-operative boost technique, when analyzed for all dose-volume parameters. When compared with the sequential electron plans, the pre-operative photon technique showed a higher median ipsilateral lung Dmax.

CONCLUSION

Our data show that an anticipated pre-operative photon boost results in a better coverage with respect to the standard sequential boost while also saving the organs at risk and consequently fewer side effects.

ADVANCES IN KNOWLEDGE

This is the first dosimetric study that evaluated the association between an anticipated boost and neoadjuvant chemotherapy treatment.

Chemically enhanced radiotherapy: visions for the future

Radiotherapy (RT) is an important part of cancer management, with more than a third of all cancer cures being attributable to RT. Despite the advances in RT over the past century, the overall outcomes in a majority of malignancies are still unsatisfactory. There has been a constant endeavor to enhance the outcome of RT, and this has been in the form of altered fractionation, oxymimetic radiosensitizers, the use of concurrent chemotherapy, anti-angiogenic therapy and anti-growth factor receptor targeted therapies. This article presents a vision for the future, with emphasis upon emerging prospects which could enhance RT outcomes. Positive speculations regarding the use of immunological aspects, the use of nanoscale technology and the adoption of metronomic concurrent chemotherapy have been presented. Also, the potential with the use of low dose hyperradiosensitivity in enhancing chemotherapy outcomes too has been discussed. In this era of evidence based clinical practise, there exists a strong obsession towards the 'present' with 'contempt towards the future'. Accepting the shortcomings of the existing modalities, there must be a strong zeal towards discovering better methodologies to enhance radiotherapeutic outcomes for the sake of a better future.