The impact of delivery daytime and seasonality of radiotherapy for head and neck cancer on toxicity burden

Impact of chrono-radiotherapy on the prognosis and treatment-related toxicity in patients with locally advanced nasopharyngeal carcinoma: A multicenter propensity-matched study

The timing of radiotherapy (RT) delivery has been reported to affect both cancer survival and treatment toxicity. However, the association among the timing of RT delivery, survival, and toxicity in locally advanced nasopharyngeal carcinoma (LA-NPC) has not been investigated. We retrospectively reviewed patients diagnosed with LA-NPC who received definitive RT at multiple institutions. The median RT delivery daytime was categorized as morning (DAY) and night (NIGHT). Seasonal variations were classified into the darker half of the year (WINTER) and brighter half (SUMMER) according to the sunshine duration. Cohorts were balanced according to baseline characteristics using propensity score matching (PSM). Survival and toxicity outcomes were evaluated using Cox regression models. A total of 355 patients were included, with 194/161 in DAY/NIGHT and 187/168 in WINTER/SUMMER groups. RT delivered during the daytime prolonged the 5-year overall survival (OS) (90.6% vs. 80.0%, p = 0.009). However, the significance of the trend was lost after PSM (p = 0.068). After PSM analysis, the DAY cohort derived a greater benefit in 5-year progression-free survival (PFS) (85.6% vs. 73.4%, p = 0.021) and distant metastasis-free survival (DMFS) (89.2% vs. 80.8%, p = 0.051) in comparison with the NIGHT subgroup. Moreover, multivariate analysis showed that daytime RT was an independent prognostic factor for OS, PFS, and DMFS. Furthermore, daytime RT delivery was associated with an increase in the incidence of leukopenia and radiation dermatitis. RT delivery in SUMMER influenced only the OS significantly (before PSM: p = 0.051; after PSM: p = 0.034). There was no association between toxicity and the timing of RT delivery by season. In LA-NPC, the daytime of radical RT served as an independent prognostic factor. Furthermore, RT administered in the morning resulted in more severe toxic side effects than that at night, which needs to be confirmed in a future study.

A signature based on circadian rhythm-associated genes for the evaluation of prognosis and the tumour microenvironment in HNSCC

The morbidity and mortality rates of head and neck squamous cell carcinoma (HNSCC) remain high worldwide. Therefore, there is an urgent need to identify a new prognostic biomarker to guide the personalized treatment of HNSCC patients. Increasing evidence suggests that circadian rhythm genes play an important role in the development and progression of cancer. We aimed to explore the value of circadian rhythm genes in predicting prognosis and guiding the treatment of HNSCC. We first obtained a list of circadian rhythm genes from previous research. The sequencing data were retrieved from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Finally, univariate Cox proportional hazard analysis, least absolute shrinkage and selection operator (LASSO) regression, and multivariate Cox proportional hazard analysis were performed to develop a prognostic signature (Circadian Rhythm-Related Gene Prognostic Index, CRRGPI) consisting of nine circadian rhythm genes. The signature exhibited good performance in predicting overall survival. Patients with low CRRGPI scores had lower metabolic activities and an active antitumour immunity ability. Additionally, a clinical cohort was used to further evaluate the ability of the CRRGPI to predict the efficacy of immune checkpoint inhibitors. In conclusion, the novel circadian rhythm-related gene signature can provide a precise prognostic evaluation with the potential capacity to guide individualized treatment regimens for HNSCC patients.

Season of radiotherapy and outcomes of head & neck cancer patients in the MACH-NC & MARCH meta-analyses

BACKGROUND

A single institution retrospective study suggested that head and neck squamous cell cancer (HNSCC) patients receiving radiotherapy (RT) during "dark" season (fall/winter) may have better outcomes than those treated during "light" season (spring/summer), possibly secondary to seasonal variations in cell cycle progression. We investigated the impact of season of RT in two large, multi-institutional, prospective datasets of randomized trials.

METHODS

Individual patient data from the MACH-NC and MARCH meta-analyses were analyzed. Dark season was defined as mid-radiotherapy date during fall or winter and light the reverse, using equinoxes to separate the two periods. Primary endpoint was progression-free survival (PFS) and secondary endpoint was locoregional failure (LRF). The effect of season was estimated with a Cox model stratified by trial and adjusted on sex, tumor site, stage, and treatment. Planned sensitivity analyses were performed on patients treated around solstices, who received "complete radiotherapy", patients treated with concomitant radio-chemotherapy and on trials performed in Northern countries.

RESULTS

11320 patients from 33 trials of MARCH and 6276 patients from 29 trials of MACH-NC were included. RT during dark season had no benefit on PFS in the MARCH (hazard ratio[HR]: 1.01 [95%CI 0.97;1.05],p=0.72) or MACH-NC dataset (HR:1.00 [95%CI 0.94;1.06],p=1.0. No difference in LRF was observed in the MARCH (HR:1.00 [95%CI 0.94;1.06,p=0.95) or MACH-NC dataset (HR:0.99 [95%CI 0.91; 1.07],p=0.77). Sensitivity analyses showed similar results.

CONCLUSION

Season of RT had no impact on PFS or LRF in two large databases of HNSCC.

Circadian rhythm-based cancer therapy in randomised clinical trials

INTRODUCTION

Since the 2017 Nobel Prize awarded to J. Hall, M. Rosbash and M.W. Young for their discoveries of molecular mechanisms behind the biological clock, circadian rhythm-based therapy, also known as chronotherapy, is receiving more attention in oncology and the number of anatomical sites of interest in this field is increasing. This observation is in line with the clinical evidence provided by trials on head and neck, lung, colorectal and cervical cancers, as well as the presently ongoing chronotherapy trials for breast and brain cancers.

AREAS COVERED

The aim of this review was to collate all randomized trials conducted on chronotherapy for various tumor sites and to appraise the evidence for chrono-oncology to advance personalized therapy. Relevant literature was collected from Pubmed/Medline databases and from clinicatrials.gov.

EXPERT OPINION

Current randomized clinical trials offer a certain level of evidence for the potential of chronotherapy to personalize oncologic treatment. However, comparison of trial results is hindered by the differences in timing of radiation/chemotherapy, the absence of harmonized recommendations for treatment outcome evaluation and not ultimately, the general lack of considering gender as a matched variable in trials, which was found to be a powerful factor influencing response to treatment.

Chronotherapy in dentistry: A scoping review

The circadian clock modulates almost all vital aspects of our physiology and metabolism, including processes relevant to dentistry, such as healing, inflammation and nociception. Chronotherapy is an emerging field aiming to improve therapeutic efficacy and decrease adverse effects on health outcomes. This scoping review aimed to systematically map the evidence underpinning chronotherapy in dentistry and to identify gaps in knowledge. We conducted a systematic scoping search using four databases (Medline, Scopus, CINAHL and Embase). We identified 3908 target articles screened by two blinded reviewers, and only original animal and human studies investigating the chronotherapeutic use of drugs or interventions in dentistry were included. Of the 24 studies included, 19 were human studies and five were animal studies. Chrono-radiotherapy and chrono-chemotherapy reduced treatment side effects and improved therapeutic response, leading to higher survival rates in cancer patients. Animal studies reported that tooth movement and periodontal tissue response to orthodontic forces follow a diurnal rhythm that might influence bone metabolism. Profound and prolonged local anesthesia could be achieved when injected in the evening. Although the overall quality of the included studies was low, chronotherapy applications in dentistry seem to have favourable outcomes, especially in head and neck cancer treatments.

Can chronoradiotherapy offer benefits to cervical cancer patients? A scoping review

The objective of this scoping review was to synthesize the available evidence and evaluate the effectiveness of chronoradiotherapy interventions in cervical cancer patients. This scoping review was performed by searching in the PubMed, Cochrane Library, Embase, Web of Science, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), China National Knowledge Infrastructure (CNKI), Wanfang, Wenpu, and Chinese Biomedical Literature (CBM) databases. Databases were searched for studies published in English or Chinese from inception to 21 May 2021, and reference lists of relevant reports were scanned. Two investigators independently screened eligible studies in accordance with predetermined eligibility criteria and extracted data. The included studies were summarized and analyzed. Five studies including a total of 422 patients with cervical cancer were included in the scoping review; four studies were Chinese, and one was Indian. Main themes identified included the efficiency of chronoradiotherapy and relevant toxic and side effects, including diarrhea toxicity, hematologic toxicity, myelosuppression, gastrointestinal mucositis, and skin reactions. Administration of radiotherapy at different times of the day resulted in similar efficacy. However, the toxic side effects of morning radiotherapy (MR) and evening radiotherapy (ER) differed, with radiotherapy in the evening leading to more severe hematologic toxicity and myelosuppression. There were conflicting conclusions about gastrointestinal reactions with chronoradiotherapy, and further studies are needed. Radiation responses may be associated with circadian genes, through the influence of cell cycles and apoptosis.

Clock in radiation oncology clinics: cost-free modality to alleviate treatment-related toxicity

A large number of studies have reported that tumor cells are often out of sync with the surrounding healthy tissue. Exploiting this misalignment may be a way to obtain a substantial gain in the therapeutic window. Specifically, based on reports to date, we will assess whether radiotherapy outcomes differ depending on the administration time. Collectively, 24 studies met the inclusion criteria, out of which 12 at least reported that radiation therapy is less toxic when administered at a particular time, probably because there is less collateral damage to healthy cells. However, discrepancies exist across studies and urge further investigation. Mechanistic studies elucidating the relationship between radiotherapy, circadian rhythms, and cell cycle, combined with either our “digital” or “biological” chronodata, would help oncologists successfully chronotype individual patients and strategize treatment plans accordingly.

Developments on tumour site-specific chrono-oncology towards personalised treatment

Research into chronotherapy has seen notable developments over the past decades, with a clear focus on the identification of circadian clock genes as potential treatment targets. Moreover, new factors are investigated, such as gender and the role of cancer stem cells in influencing the outcome of chronomodulated treatments. These factors could add to the arsenal of parameters that assist with patient stratification and treatment personalisation. Literature analysis showed that certain anatomical sites received more attention and the associated studies reported clinically significant results, even though some findings are contradictory. The aim of this work was to review the existing studies on chrono-oncology using a tumour site-specific approach and to highlight the status of research in various cancers. Inconsistencies in data reporting, the nature of the studies and the highly heterogeneous patient characteristics, highlight the need for well-designed randomised controlled trials to elucidate the real potential of chronotherapy in oncology.

The Time for Chronotherapy in Radiation Oncology

Five decades ago, Franz Halberg conceived the idea of ​​a circadian-based therapy for cancer, given the differential tolerance to treatment derived from the intrinsic host rhythms. Nowadays, different experimental models have demonstrated that both the toxicity and efficacy of several anticancer drugs vary by more than 50% as a function of dosing time. Accordingly, it has been shown that chemotherapeutic regimens optimally timed with the circadian cycle have jointly improved patient outcomes both at the preclinical and clinical levels. Along with chemotherapy, radiation therapy is widely used for cancer treatment, but its effectiveness relies mainly on its ability to damage DNA. Notably, the DNA damage response including DNA repair, DNA damage checkpoints, and apoptosis is gated by the circadian clock. Thus, the therapeutic potential of circadian-based radiotherapy against cancer is mainly dependent upon the control that the molecular clock exerts on DNA repair enzymes across the cell cycle. Unfortunately, the time of treatment administration is not usually considered in clinical practice as it varies along the daytime working hours. Currently, only a few studies have evaluated whether the timing of radiotherapy affects the treatment outcome. Several of these studies show that it is possible to reduce the toxicity of the treatment if it is applied at a specific time range, although with some inconsistencies. In this Perspective, we review the main advances in the field of chronoradiotherapy, the possible causes of the inconsistencies observed in the studies so far and provide some recommendations for future trials.