Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Practice-changing clinical trials in radiation oncology for gastrointestinal malignancies in 2021-2023

Gastrointestinal cancers are one of the most frequent cancers and a leading cause of cancer deaths worldwide. We provide an overview of the most important practice-changing trials that were either published or presented at the international scientific meetings in 2021-2023. Highlights included reports on three phase III trials (CONCORDE/PRODIGE 26, ARTDECO, and a study by Xu et al.) that evaluated dose escalation in the definitive setting for locally advanced oesophageal cancers, as well as two phase III trials that evaluated the role of chemotherapy (neo-AEGIS) and targeted therapy (NRG/RTOG 1010) in the neoadjuvant setting for adenocarcinoma oesophageal cancers or gastroesophageal junction cancer. CheckMate 577 evaluated nivolumab in patients who had residual pathological disease after neoadjuvant chemoradiation followed by complete resection. The use of radiation therapy for borderline and locally advanced pancreatic cancer is also discussed (SMART and CONKO-007 trials). Stereotactic body radiation therapy followed by sorafenib was compared to sorafenib alone in patients with hepatocellular carcinoma in the NRG/RTOG 1112 study. New options in the management of rectal cancer are emerging such as total neoadjuvant treatment (PRODIGE 23, RAPIDO, PROSPECT), organ preservation (OPRA, OPERA), and the role of immunotherapy in patients with DNA mismatch-repair deficient/microsatellite instability. Finally, preliminary results of the ACT 4 trial that evaluated de-escalation in anal cancer are presented.

Clinical applications of high dose rate endorectal brachytherapy for patients with rectal cancer

With the establishment of total mesorectal excision for the treatment of rectal cancer, local recurrence rates have significantly decreased. The addition of preoperative external beam irradiation further reduces this risk to less than 6%. As the local treatment becomes successful and more widely used, the associated treatment-related toxicity is becoming clinically important. If 4 to 6% of the patients are to benefit from neo-adjuvant therapy before total mesorectal excision, the acute and the long-term toxicity burden must be reasonable. With the introduction of better-quality imaging for tumour visualization and treatment planning, a new-targeted radiation treatment was introduced with high dose rate endorectal brachytherapy. The treatment concept was tested in phase I and II studies first in the preoperative setting, then as a boost after external beam radiation therapy as a dose escalation study to achieve higher tumour local control in a radical treatment setting with no surgery. High dose rate endorectal brachytherapy is safe and effective in achieving high tumour regression rate and was well tolerated. It is presently explored in a phase III dose escalation study in the non-operative management of patients with operable rectal cancer.

[Stereotactic radiotherapy of non-tumoral brain pathologies: Arteriovenous malformations and trigeminal neuralgias]

Stereotactic radiotherapy and radiosurgery allow delivery of high irradiation doses in a limited volume. These techniques are specially adapted to brain and nervous pathologies. Indication are not only cancers and tumors but also non tumor tissues such as arteriovenous malformations. In some case purpose of stereotactic radiotherapy is solely functional, for example for trigeminal neuralgia. We detail the questions that raise treatment of these non-tumor pathologies. These pathologies imply a multidisciplinary approach that associate radiation oncologists, neuro-radiologist and neurosurgeons.

[Anal cancer: Focus on current treatment and future perspective]

Anal cancer is considered a rare tumor, accounting for 6 % of digestive cancers and about 2000 new cases per year in France. It is mostly diagnosed at a localized stage. For many years, the standard of care for patients with localized disease is an association with radiotherapy and chemotherapy including Mitomycin C and 5-Fluorouracil. There weren't any major changes in the therapeutic management of these tumors despite several phase III studies. However, there is an improvement in patient prognostic. This can be explained by imaging progress, using magnetic resonance imaging and positron emission tomography-computed tomography, permitting better staging and evaluation of disease. Moreover, irradiation modalities changed because of the development of Intensity Modulated Radiotherapy. Actual research focuses on a more personalized strategy according to tumoral stages. Patients with early-stage tumors are potentially over-treated with a risk of chronic digestive toxicities. Several studies are interested in irradiation de-escalation for these patients. On the other hand, treatment results for patients with advanced tumoral stages are disappointing. It seems relevant to propose a therapeutic intensification for these patients, such as dose escalation, association with new therapies like immunotherapy or induction chemotherapy using taxans given promising results at the metastatic stage.

[Organ preservation for rectal cancer: What are the arguments in favor of radiotherapy?]

Standard care for rectal cancers relies on both tumor (location relative to the sphincter, T and N stage, sphincter involvement) and patients characteristics. Radical surgery (total mesorectal excision) following short-course radiotherapy (RT) or standard chemo-radiotherapy, associated with induction or consolidation chemotherapy (total neoadjuvant treatment), remains the cornerstone of locally advanced rectal cancer (T3cd, T4 and/or N+) treatment. Nevertheless, for early stages, this radical resection could be avoided in favor of conservative approaches combining RT (external, contact, brachytherapy) with or without chemotherapy (concurrent, induction or consolidative), or even be limited, for good responders, to a local excision with view of organ-preservation strategies. This conservative approach could also be offered selectively to patients with complete clinical response after the induction sequence, irrespective of initial tumor characteristics. The Watch and Wait strategy relies on clinical, endoscopic and radiological evaluations, as well as sustained surveillance. Ongoing studies aim to improve response rates, either with chemotherapy intensification, or RT boost dose escalation with brachytherapy or contact-therapy.

Radiotherapy for cancers of the oesophagus, cardia and stomach

We present the updated recommendations of the French society for radiation oncology on radiotherapy of oesophageal cancer. Oesophageal cancer still remains a malignant tumour with a poor prognosis. Surgery remains the standard treatment for localized cancers, regardless of histology. For locally advanced stages, surgery remains a standard for adenocarcinomas after neoadjuvant treatment with chemotherapy or chemoradiotherapy. However, it is a therapeutic option after initial chemoradiotherapy for stage III squamous cell carcinomas, given the increased morbidity and mortality with a multimodal treatment, which results in an equivalent overall survival with or without surgery. Preoperative or exclusive chemoradiotherapy should be delivered according to validated regimens with an effective total dose (50Gy), if surgery is not planned or if the tumour is deemed resectable before chemoradiotherapy. Intensity-modulated radiotherapy significantly reduces irradiation of the lungs and heart and may reduce the morbidity of this treatment, especially in combination with surgery. In case of exclusive chemoradiotherapy, dose escalation beyond 50Gy is not currently recommended. Some technical considerations still remain questionable, such as the place of prophylactic lymph node irradiation, adaptive radiotherapy, evaluation of response during and after chemoradiotherapy and the value of proton therapy.

Radiotherapy of anal canal cancer

We present the update of the recommendations of the French society for radiation oncology on external radiotherapy and brachytherapy of anal canal carcinoma. The following guidelines are presented: indications, treatment procedure, as well as dose and dose-constraints objectives, immediate postoperative management, post-treatment evaluation, and long-term follow-up.

Rectal cancer radiotherapy

We present the updated recommendations of the French society of oncological radiotherapy for rectal cancer radiotherapy. The standard treatment for locally advanced rectal cancer consists in chemoradiotherapy followed by radical surgery with total mesorectal resection and adjuvant chemotherapy according to nodal status. Although this strategy efficiently reduced local recurrences rates below 5% in expert centres, functional sequelae could not be avoided resulting in 20 to 30% morbidity rates. The early introduction of neoadjuvant chemotherapy has proven beneficial in recent trials, in terms of recurrence free and metastasis free survivals. Complete pathological responses were obtained in 15% of tumours treated by chemoradiation, even reaching up to 30% of tumours when neoadjuvant chemotherapy is associated to chemoradiotherapy. These good results question the relevance of systematic radical surgery in good responders. Personalized therapeutic strategies are now possible by improved imaging modalities with circumferential margin assessed by magnetic resonance imaging, by intensity modulated radiotherapy and by refining surgical techniques, and contribute to morbidity reduction. Keeping the same objectives, ongoing trials are now evaluating therapeutic de-escalation strategies, in particular rectal preservation for good responders after neoadjuvant treatment, or radiotherapy omission in selected cases (Greccar 12, Opera, Norad).

Radiation therapy of pancreatic cancers

We present the update of the recommendations of the French society of oncological radiotherapy on radiotherapy of pancreatic tumors. Currently, the use of radiation therapy for patients with pancreatic cancer is subject to discussion. In the adjuvant setting, the standard treatment is six months of chemotherapy with 5-fluorouracile, irinotecan and oxaliplatin. Chemoradiation may improve the survival of patients with incompletely resected tumours (R1). This remains to be confirmed by a prospective trial. Neoadjuvant chemoradiation is a promising treatment especially for patients with borderline resectable tumours. For patients with locally advanced tumours, there is no standard. An induction chemotherapy followed by chemoradiation for non progressive patients reduces the rate of local relapse. Whereas in the first trials of chemoradiation large fields were used, the treated volumes have been reduced to improve tolerance. Tumour movements induced by breathing should be taken in account. Intensity modulated radiation therapy allows a reduction of doses to the organs at risk. Whereas widely used, this technique has poor evidence-based recommendation. Stereotactic body radiation therapy is also being studied, as a neoadjuvant or exclusive treatment.

[Role of stereotactic radiotherapy in the treatment of oligometastatic colorectal cancer]

Stereotactic radiotherapy is used for patients with oligometastases from colorectal cancer. It results in good local tumour control, especially for hepatic and pulmonary metastases, subject to a sufficiently high biologically effective dose, and is well-tolerated. It can be associated with other local treatments such as surgery or radiofrequency as part of combined treatments, in order to increase patient survival.

Intersphincteric resection for low rectal cancer: the risk is functional rather than oncological. A 25-year experience from Bordeaux

AIM

There are few data evaluating the long-term outcomes of intersphincteric resection (ISR), especially the impact of inclusion of more juxtapositioned and intra-anal tumours on oncological and functional outcomes. We compared the oncological and functional results of patients treated by total mesorectal excision and ISR for low rectal cancer over a 25-year period.

METHOD

This is a retrospective study from a single institution evaluating results of ISR over three periods: 1990-1998, 1999-2006 and 2007-2014. Patients treated by partial or total ISR, with or without neoadjuvant chemoradiotherapy, for low rectal cancer (≤ 6 cm from the anal verge) were included. We compared postoperative morbidity, quality of surgery and oncological and functional outcomes in the time periods studied.

RESULTS

Of 813 patients operated on for low rectal cancer, 303 had ISR. Tumour stage did not differ; however, the distance of the tumour from the anorectal junction decreased from 1 to 0 cm (P < 0.001) and the distal resection margin shortened from 25 to 10 mm (P < 0.001) from 1990 to 2014. The postoperative morbidity and quality of surgery did not change significantly over time. The 5-year local recurrence (4.3% vs 5.9% vs 3.5%; P = 0.741) and disease-free survival (72% vs 71% vs 75%; P = 0.918) did not differ between the three time periods. Functional results improved during the last period; however, overall 42% of patients experienced major bowel dysfunction.

CONCLUSION

Pushing the envelope of sphincter-saving resection in ultra-low rectal cancer reaching or invading the anal sphincter did not compromise oncological and functional outcomes. The main limitation of the ISR procedure appears to be functional rather than oncological, suggesting that bowel rehabilitation programmes should be developed.

Delayed coloanal anastomosis: an alternative option for restorative rectal cancer surgery after high-dose pelvic radiotherapy for prostate cancer

AIM

Restorative total mesorectal excision (TME) for rectal cancer after high-dose pelvic radiotherapy for prostate cancer has been reported to provide an unacceptable rate of pelvic sepsis. In a previous publication we proposed that delayed coloanal anastomosis (DCAA) should be performed in this situation. The present study aimed to assess the feasibility and outcomes of this strategy.

METHOD

Between 2000 and 2018, 1094 men were operated on for rectal cancer in our institution. All men with T2/T3 mid and low rectal cancer with preoperative radiotherapy and restorative TME were considered for this study (n = 416). Patients with external-beam high-dose radiotherapy (EBHRT) for prostate cancer (70-78 Gy) were identified and compared with patients with conventional long-course chemoradiotherapy (CRT) followed by TME. We compared our already published historical cohort (2000-2012), including arm A (CRT + TME; n = 236) and arm B (EBHRT + TME; n = 12), with our early cohort (2013-2018), including arm C (CRT + TME; n = 158) and arm D (EBHRT + TME-DCAA; n = 10). The end-points were morbidity, pelvic sepsis, reoperation rate and quality of the specimen.

RESULTS

Overall morbidity was not significantly different between groups. Pelvic sepsis decreased from 50% (arm B) to 10% (arm D) with the use of DCAA (P = 0.074), and was similar between arms A, C and D. Quality of the specimen was not significantly different between the four groups.

CONCLUSION

Our results suggest that TME with DCAA in patients with previous EBHRT is feasible, with the same postoperative pelvic sepsis rate as conventional CRT.

[Chemoradiation for oesophageal cancer: A critical review of the literature]

Locally advanced oesophageal cancer treatment requires a multidisciplinary approach with the combination of chemotherapy and radiotherapy for preoperative and definitive strategy. Preoperative chemoradiation improves the locoregional control and overall survival after surgery for locally advanced oesophageal cancer. Definitive chemoradiation can also be proposed for non-resectable tumours or medically inoperable patients. Besides, definitive chemoradiation is considered as an alternative option to surgery for locally advanced squamous cell carcinomas. Chemotherapy regimen associated to radiotherapy consists of a combination of platinum derived drugs (cisplatinum or oxaliplatin) and 5-fluorouracil or a weekly scheme combination of carboplatin and paclitaxel according to CROSS protocol in a neoadjuvant strategy. Radiation doses vary from 41.4Gy to 45Gy for a preoperative strategy or 50 to 50.4Gy for a definitive treatment. The high risk of lymphatic spread due to anatomical features could justify the use of an elective nodal irradiation when the estimated risk of microscopic involvement is higher than 15% to 20%. An appropriate delineation of the gross tumour volume requires an exhaustive and up-to-date evaluation of the disease. Intensity-modulated radiation therapy represents a promising approach to spare organs-at-risk. This critical review of the literature underlines the roles of radiotherapy for locally advanced oesophageal cancers and describes doses, volumes of treatment, technical aspects and dose constraints to organs-at-risk.

Multidisciplinary meetings specific to hepatocellular carcinoma: How to proceed?

The French "cancer plan" has created a framework for good practice in the course of care for cancer patients. Decisions must be made in a multidisciplinary team meeting (MDM) and an individualized care plan (ICP) is to be established for each patient. Hepatocellular carcinoma (HCC) is a common cancer with complex treatments that warrant a dedicated meeting. Cancer coordination centers (3C) ensure the organization and the functioning of MDMs. Multidisciplinary, standardized and systematic assessment of HCC patients allows for personalized management and orients them toward treatment that is either curative (transplantation, surgical resection, ablathermy) or palliative (chemoembolization, radiotherapy, systemic treatment, supportive care). MDMs bring together all the professionals treating the disease, and who are tasked with producing an enforceable document effective that justifies decisions and is often an essential step towardinclusion of patients in a clinical trial. It must be carried out according to a systematic schema in an approach applied from initial diagnosis to treatment outset and throughout the treatment. Numerous advances in HCC treatments have rendered their management complex, with the possibility of liver transplantation, twhose access is regulated by the Biomedicine Agency requiring the submission of MDM reports. MDMs must meet specific quality criteria to ensure effective management based on general guidelines and yet specifically tailored to each patient.

[Anal canal cancer: In the era of intensity-modulated radiotherapy, outstanding issues]

Intensity-modulated radiotherapy makes possible to optimize the irradiation and spare normal tissues. The toxicity remains important with concomitant chemotherapy often associated. The improvement of MRI and PET-CT define more precisely the target volumes, which need a higher dose, but necessitates to respect the rules of contouring. The treatment is uniform whatever the stage but should be individualized based on clinical stage and tumor response. New paradigms concern biology, staging, volumes and doses, fractionation and combined treatments.