Clinical results and toxicity for short-course preoperative radiotherapy and total mesorectal excision in rectal cancer patients

A single arm phase 2 clinical trial of YIV-906 with neoadjuvant concurrent chemo-radiation therapy in patients with locally advanced rectal cancer

Background

Pre-operative chemoradiation for rectal cancer is often associated with severe gastrointestinal (GI) toxicity which can interrupt, delay, and/or lead to termination of treatment. In this study, we evaluated whether the addition of YIV-906, a novel herbal medicine proven to reduce GI toxicity associated with chemotherapy could also reduce GI side effects during standard pre-operative capecitabine and pelvic radiation therapy (RT) in the neoadjuvant setting for the treatment of locally advanced rectal cancer.

Methods

This single arm clinical study enrolled 24 patients between Dec 23, 2014-Sep 17, 2018 at Smilow Cancer Hospital, a comprehensive cancer center at Yale New Haven Hospital. All patients were age ≥18 years, Eastern Cooperative Oncology Group 0-1 and with histologically confirmed T3-T4 and N0-N2, M0 adenocarcinoma of the rectum. Median follow-up was 61.9 months. All patients received concurrent pelvic external beam RT (50.4 Gy in 28 fractions), YIV-906 (taken orally 800 mg twice daily on days 1-4 of RT each week), and oral capecitabine delivered in a neo-adjuvant fashion, followed by definitive surgery. Toxicity was assessed weekly during radiation and until acute symptoms resolved and then at 28 days, 4 months, 7 months and 10 months. Toxicities were graded in accordance with Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.

Results

At the time of surgery, 4 patients (16.7%) had a complete or near-complete response. At a median follow-up of 61.9 months, the mean overall survival (OS) of our patient cohort was 74.9 months [95% confidence interval (CI): 67.3-82.5]. The estimated 5-year OS was 82.0%. We observed 0% acute grade 4 toxicities, and only two cases of acute grade 3 diarrhea (8.3%).

Conclusions

The addition of YIV-906 to capecitabine based chemoradiation for locally advanced rectal cancer led to reduced rates of GI toxicity compared to historical controls, in particular grade 3 or greater diarrhea. These findings suggest YIV-906 should be evaluated in a randomized clinical trial to further assess potential reductions in the toxicity profile of chemoradiation for GI cancers.

Short-course preoperative radiotherapy increases pelvic fracture risk in rectal cancer

Introduction

Pelvic insufficiency fractures (PIFs) are adverse events associated with chemoradiotherapy (CRT) administered preoperatively in rectal cancer, with incidences of 0-33.6% reported in the literature. Data on PIFs after 5 × 5 Gy fractionated short-course radiotherapy (SCRT) using highly conformal radiotherapy techniques such as volumetric modulated arc therapy (VMAT) is limited.

Methods

The Turku University Hospital colorectal cancer database was searched for patients operated on for stage I-III rectal cancer during the years 2014-2018. The hospital's routine follow-up includes a 2-year computed tomography (CT) scan, which was systemically re-evaluated to detect PIFs. Only radiotherapy delivered using VMAT and image-guided approaches was included. Baseline demographics, tumor data, and dose-volume data were collected to identify risk factors for PIFs.

Results

Median time to CT scan was 24 months. Among the 164 patients analyzed, the 2-year PIF incidence was 22.2% for SCRT (n = 12/54, OR 9.1 (CI95% 1.9-42.9), p = 0.004), 9.1% for CRT (n = 4/44, OR 3.2 (CI95% 0.6-18.3), p = 0.13) and 3.0% (n = 2/66, reference) for those operated on without radiotherapy. The PIF incidence was not explained by differences in dose-volume data in either the SCRT or CRT groups. Fracture risk was higher in women, up to 50% after SCRT.

Conclusions

Every fifth patient treated with SCRT and rectal surgery presented with a PIF. Critical bony structures to be avoided during radiotherapy contouring could not be identified. Clinicians, especially those involved with the follow-up of rectal cancer, should be aware of this potentially debilitating and surprisingly common adverse event.

The optimal timing for the interval to surgery after short course preoperative radiotherapy (5 ×5 Gy) in rectal cancer - are we too eager for surgery?

BACKGROUND

The improved overall survival (OS) after short course preoperative radiotherapy (SCPRT) using 5 × 5 Gy reported in the early rectal cancer trials could not be replicated in subsequent phase III trials. This original survival advantage is attributed to poor quality of surgery and the large differential in local recurrence rates, with and without SCPRT. Immuno-modulation during and after SCPRT and its clinical implications have been poorly investigated. We propose an alternative explanation for this survival benefit in terms of immunological mechanisms induced by SCPRT and the timing of surgery, which may validate the concept of consolidation chemotherapy.

MATERIAL AND METHODS

We reviewed randomized controlled trials (RCTs) and studies of SCPRT from 1985 to 2019. We aimed to examine the precise timing of surgery in days following SCPRT and identify evidence for immune modulation, neo-antigens and memory cell induction by radiation.

RESULTS

Considerable variability is reported in randomised trials for median overall treatment time (OTT) from start of SCPRT to surgery (8-14 days). Only three early trials showed a benefit in terms of OS from SCPRT, although the level of benefit in preventing local recurrence was consistent across all trials. Different patterns of immune effects are observed within days after SCPRT depending on the OTT, but human leukocyte antigen (HLA)-1 expression was not upregulated.

CONCLUSIONS

SCPRT has a substantial immune-stimulatory potential. The importance of the timing of surgery after SCPRT may have been underestimated. An optimal interval for surgery after 5 × 5 Gy may lead to better outcomes, which is possibly exploited in total neoadjuvant therapy schedules using consolidation chemotherapy. Individual patient meta-analyses from appropriate SCPRT trials examining outcomes for each day and prospective trials are needed to clarify the validity of this hypothesis. The interaction of SCPRT with tumour adaptive immunology, in particular the kinetics and timing, should be examined further.

Overcoming radioresistance in WiDr cells with heavy ion irradiation and radiosensitization by 2-deoxyglucose with photon irradiation

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2-DG acts as a radiosensitizer to photons depending on the time of its application.

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There is no sensitization to ¹²C irradiation by 2-DG.

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¹²C combination therapy still has the higher dose effectiveness.

Background and purpose

Radiosensitizers and heavy ion irradiation could improve therapy for female patients with malignant tumors located in the pelvic region through dose reduction. Aim of the study was to investigate the radiosensitizing potential of 2-deoxy-d-glucose (2-DG) in combination with carbon ion-irradiation (¹²C) in representative cell lines of cancer in the female pelvic region.

Materials and methods

The human cervix carcinoma cell line CaSki and the colorectal carcinoma cell line WiDr were used. 2-DG was employed in two different settings, pretreatment and treatment simultaneous to irradiation. Clonogenic survival, α and β values for application of the linear quadratic model and relative biological effectiveness (RBE) were determined. ANOVA tests were used for statistical group comparison. Isobolograms were generated for curve comparisons.

Results

The comparison of monotherapy with ¹²C versus photons yielded RBE values of 2.4 for CaSki and 3.5 for WiDr along with a significant increase of α values in the ¹²C setting. 2-DG monotherapy reduced the colony formation of both cell lines. Radiosensitization was found in WiDr for the combination of photon irradiation with synchronous application of 2-DG. The same setup for ¹²C showed no radiosensitization, but rather an additive effect. In all settings with CaSki, the combination of irradiation and 2-DG exhibited additive properties.

Conclusion

The combination of 2-DG and photon therapy, as well as irradiation with carbon ions can overcome radioresistance of tumor cells such as WiDr.

Is there a need for neoadjuvant short-course radiotherapy in T3 rectal cancer with positive lymph node involvement? A single-center retrospective cohort study

Background

Neoadjuvant short-course radiotherapy is used to reduce local recurrences in stage III rectal cancer. Radiotherapy is not harmless, and meticulous total mesorectal excision surgery alone has been reported to result in low local recurrence rate in favorable stage III tumors. The aim was to evaluate the effect of short-course (5 × 5 Gy) radiotherapy on the local recurrence risk in patients with pT3N1-2 rectal cancer.

Materials and methods

This was a retrospective study with 151 consecutive pT3N1-2M0 rectal cancer patients operated on at Helsinki University Hospital, Helsinki, Finland, during January 2005 to June 2014. Short-course radiotherapy was given to 94 patients, and 57 patients were operated on without neoadjuvant radiotherapy. The main outcome measurement was the effect of radiotherapy on local recurrence. Also, the risk factors for local recurrence were analyzed.

Results

Local recurrence occurred in a total 17 of 151 (11.3%) patients, 8 of 57 (14.0%) in surgery only group compared with 9 of 94 (9.6%) in radiotherapy plus surgery group (p = 0.44). In univariate Cox regression analysis, the risk factors for local recurrence were tumor location under 6 cm from the anal verge (p = 0.01), involved lateral margin (p < 0.001), tumor perforation (p < 0.001), and mucinous histology (p = 0.006). In multivariate analysis, risk factors were tumor location under 6 cm from anal verge (p = 0.03) and involved lateral margin (p = 0.002).

Conclusion

Neoadjuvant short-course radiotherapy did not affect the local recurrence risk of pT3N1-2M0 rectal cancer. Further studies with larger patient number are needed to evaluate the role of short-course radiotherapy in different T3 subgroups (3a–c) as well as in N1 and N2 cancers in separate.

An update on the multimodality of localized rectal cancer

New strategies have reduced the local recurrence (LR) rate and extended the duration of overall survival (OS) in patients with localized rectal cancer (RC) in recent decades. The mainstay of curative treatment remains radical surgery; however, downsizing the tumor by neo-adjuvant chemo-radiotherapy and adjuvant cytotoxic therapy for systemic disease has shown significant additional benefit. The standardization of total mesorectal excision (TME), radiation treatment (RT) dose and fractionation, and optimal timing and sequencing of treatment modalities with the use of prolonged administration of fluoropyrimidine concurrent with RT have significantly decreased the rates of LR in locally advanced rectal cancer (LARC) patients. This review focuses on the optimization of multi-modality therapies in patients with localized RC.

Erectile and urinary function in men with rectal cancer treated by neoadjuvant chemoradiotherapy and neoadjuvant chemotherapy alone: a randomized trial report

OBJECTIVE

The aim was to evaluate erectile and urinary function of male patients with rectal cancer treated by neoadjuvant (NA) chemoradiotherapy (CRT) or NA chemotherapy only.

METHODS

In this prospective randomized trial (ClinicalTrials.gov NCT01211210; "FOWARC"), we included 102 men who received NA therapy for stage II-III rectal cancer between January 2011 and June 2013. Before surgery, patients received either NA mFOLFOX6 chemotherapy with radiation (RCS group, n = 54) or NA mFOLFOX6 chemotherapy alone (CS group, n = 48). Erectile and urinary dysfunctions were assessed with the five-item International Index of Erectile Function (IIEF-5) scale and the International Prostatic Symptom Score (IPSS), respectively. Questionnaires were completed at baseline and at 3, 6, and 12 months (t0-t3, respectively) after surgery.

RESULTS

At t3, mean IIEF-5 score was significant higher in the CS group (15.3 ± 5.5) than in the RCS group (12.6 ± 5.7; P < 0.05). And score difference was statistically higher in RCS group compared with CS group at t2 and t3, especially t3 (9.3 ± 5.5 vs. 6.1 ± 5.1, P < 0.01). Univariate analysis of the RCS group's IIEF-5 scores associated age, stoma, location, and tumor size to erectile dysfunction. However, mean IPSS scores did not differ between the two groups at any point.

CONCLUSIONS

Compared with the CS group, erectile and urinary functions were significantly affected by NA CRT. Age, stoma, tumor location, and tumor size were also correlated with erectile dysfunction in the RCS group.