Optimal fractionation of preoperative radiotherapy and timing to surgery for rectal cancer (Stockholm III): a multicentre, randomised, non-blinded, phase 3, non-inferiority trial

Predictors of Definitive Treatment Interruptions of Long-Course Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

Introduction To identify predictors of definitive treatment interruptions (DTI) of the neoadjuvant long-course radiotherapy (LCRT) in locally advanced rectal cancer (LARC), and to determine their impact on clinical outcomes. Methods Patients with stage II-III LARC treated between 2009-2018 were retrospectively analyzed (n=101, median FU 49.5 months). Logistic regression models evaluated the impact of relevant clinical variables on grade 3 or greater (G3+) acute toxicity, definitive treatment interruption (DTI), pCR, and definitive ostomy (dOST) rates. The secondary outcomes were LRC, MFS, PFS, CSS, and OS. Results The incidences of grade 3 and 4 toxicities were 25.3%, and 1.1%, respectively. The most common G3+ toxicities were peri-anal dermatitis (14.7%) and diarrhea (7.4%), which were more frequent in females (p=0.040) and tumors close to the anal verge (p=0.019). In this study, 11 patients (10.9%) developed DTI, which was associated with these G3+ events (p<0.001). Resection occurred after 7.1 weeks (median, IQR:6.1-8.9). Downstaging occurred in 57.4% (17.8% pCR), 88% achieved negative margins and the dOST rate was 56.4%. The five-year LRC, MFS, PFS, CSS and OS were: 94.4%, 78.9%, 74.7%, 85.2% and 81.6%, respectively. DTI events did not impact any outcome. The factors associated with loco-regional failure were close/positive margins (p<0.001) and stage ypIII (p=0.002). Conclusions: Tumors close to the anal verge and female sex were associated with increased G3+ toxicity, which was predictive of DTI. The resultant partial/complete omission of the planned boost, however, dose did not increase the chance of LR. Further studies to clarify the benefit and optimal timing to deliver the boost are warranted, especially for positive margins.

Downstaging in Advanced Rectal Cancers: A Propensity-Matched Comparison Between Short-Course Radiotherapy Followed by Chemotherapy and Long-Course Chemoradiotherapy

BACKGROUND

Short-course radiotherapy followed by chemotherapy has not been widely evaluated as an alternative to traditional long-course chemoradiotherapy in locally advanced rectal cancer.

OBJECTIVE

This study compared the oncological and short-term outcomes between short-course radiotherapy + chemotherapy and long-course chemoradiotherapy in locally advanced rectal cancer.

DESIGN

This is a retrospective propensity-matched study.

SETTINGS

The study was conducted in a colorectal department at a tertiary care oncology center in India.

PATIENTS

There were 173 patients. Group A had 47 patients and group B had 126 patients. A 1:2.7 matching was done for age, sex, distance of tumor from the anal verge, sphincter preservation surgeries, MRI-based pretreatment T stage, and circumferential resection margin.

INTERVENTIONS

The interventions performed were short-course radiotherapy + chemotherapy (group A) and long-course chemoradiotherapy (group B) in locally advanced rectal cancer.

MAIN OUTCOME MEASURES

The primary measures were pathological circumferential resection margin positivity, downstaging, tumor regression grade, and postoperative complications.

RESULTS

Of the patients, 52% had a positive circumferential resection margin on MRI, 57% had low rectal tumors, and 20% had T4 tumors. Distribution of rectal surgeries was similar between the 2 groups. pT downstaging and tumor regression scores were significantly better in group B ( p = 0.028 and 0.026). Pathological circumferential resection margin, distal resection margin, and nodal yield were similar. On multivariate analysis, pretreatment N status was the only independent predictive factor for pathological circumferential resection margin status. Grade 3 to 4 Clavien-Dindo complications, anastomotic leak rates, and hospital stay were similar between the 2 groups.

LIMITATIONS

This was a retrospective study. Although propensity matching was performed, selection bias cannot be eliminated completely, as seen in the difference in the surgical approaches between the 2 groups.

CONCLUSIONS

In a cohort containing a significant portion of MRI circumferential resection margin-positive low rectal cancers, short-course radiotherapy + chemotherapy followed by delayed surgery resulted in lower T downstaging and lower tumor regression scores compared with long-course chemoradiotherapy, but pathological circumferential margin status, distal resection margin, nodal yield, and perioperative morbidity were similar between the 2 groups. This suggests that short-course radiotherapy + chemotherapy could be a viable alternative to long-course chemoradiotherapy in locally advanced rectal cancers. See Video Abstract at http://links.lww.com/DCR/B855 .

REDUCCIN DEL ESTADIO EN LOS CNCERES RECTALES AVANZADOS UNA COMPARACIN DE PROPENSIN EQUIPARADA ENTRE LA RADIACIN DE CICLO CORTO SEGUIDA DE QUIMIOTERAPIA Y LA QUIMIO RADIACIN DE CICLO LARGO

ANTECEDENTES:La radioterapia de ciclo corto seguida de quimioterapia no ha sido evaluada ampliamente como una alternativa a la tradicional quimio radioterapia de ciclo largo en el cáncer de recto localmente avanzado.OBJETIVO:Estudio que compara los resultados oncológicos y a corto plazo entre la radioterapia de ciclo corto + quimioterapia y la quimio radioterapia de ciclo largo en el cáncer de recto localmente avanzado.DISEÑO:Estudio comparado de propensión de manera retrospectiva.AJUSTE:Departamento colorrectal en un centro de atención oncológica de tipo terciario en la India.PACIENTES:Hubo 173 pacientes. El grupo A tenía 47 y el grupo B tenía 126 pacientes. Se realizó una comparación de 1: 2,7 para edad, sexo, distancia del tumor desde el margen anal, cirugías de preservación del esfínter, estadio T previo al tratamiento basada en resonancia magnética y margen de resección circunferencial (CRM).INTERVENCIONES:Radioterapia de ciclo corto + quimioterapia (grupo A) y quimio radioterapia de ciclo largo (grupo B) en cáncer de recto localmente avanzado (LARC).PRINCIPALES MEDIDAS DE RESULTADO:Positividad histopatológica de CRM, reducción del estadio tumoral, grado de regresión tumoral, complicaciones posoperatorias.RESULTADOS:El 52% de los pacientes han tenido un margen de resección circunferencial positivo en la resonancia magnética, 57% de tumores rectales bajos, 20% de tumores T4. La distribución de cirugías rectales fue similar entre los 2 grupos. Las puntuaciones de regresión tumoral y de reducción del estadio de pT fueron significativamente mejores en el grupo B ( p = 0.028 y 0.026 respectivamente). El margen de resección circunferencial patológico, el margen de resección distal y los ganglios arrojados fueron similares. En el análisis multivariado, el estadio N previo al tratamiento fue el único factor predictivo independiente para el estadio de pCRM. Las complicaciones Clavien-Dindo de grado 3-4, las tasas de fuga anastomótica y la estancia hospitalaria fueron similares entre los dos grupos.LIMITACIONES:Retrospectiva; aunque la propensión coincide, existe potencial sesgo de selección.CONCLUSIONES:En una cohorte que contenía una porción significativa de cánceres rectales bajos con margen de resección circunferencial positivo por resonancia magnética, la radioterapia de ciclo corto + quimioterapia seguida de cirugía tardía dio como resultado una mayor reducción del estadio T y de regresión tumoral en comparación con la quimio radioterapia de ciclo largo. Pero el estatus histopatológico del margen circunferencial, el margen de resección distal, el rendimiento ganglionar y la morbilidad perioperatoria fueron similares entre los dos grupos. Esto sugiere que la radioterapia de ciclo corto + quimioterapia podría ser una alternativa viable a la quimio radioterapia de ciclo largo en cánceres rectales localmente avanzados. Consulte Video Resumen en http://links.lww.com/DCR/B855 . (Traducción-Dr. Osvaldo Gauto ).

Protocol: The role of defunctioning stoma prior to neoadjuvant therapy for locally advanced colonic and rectal cancer-A systematic review

Defunctioning stomas (ileostomy and colostomy) may be used prior to commencement of neoadjuvant therapy in patients with locally advanced colon or rectal cancer, in order to prevent clinical large bowel obstruction caused by radiotherapy associated oedema or progression of disease in patients who are not obstructed. However, the exact rate of clinical obstruction in patients undergoing neoadjuvant therapy who do not receive a defunctioning stoma is not known. Furthermore, it is not clear which factors predispose patients to developing clinical large bowel obstruction. Given that defunctioning stomas are associated with post operative and intra-operative risks, it is not currently possible to tailor defunctioning stomas to patients who have the greatest risk of developing obstruction. This systematic review which is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement (PRISMA), aims to define the role of defunctioning stomas in prevention of obstruction patients with locally advanced colon or rectal cancer while undergoing neoadjuvant therapy. Two researchers will perform the literature search which will include all published and "in process" articles published in the English language between 2002-2022 in the following databases: EMBASE (OVID), MEDLINE (EBSCO), CINHAL complete, Web of Science, Cochrane Central Registry of Controlled Trials, Clinical Trials Registry. The full text of the selected articles will be independently screened by two researchers against the inclusion criteria. Data will be extracted from each article regarding: study design, participants, type of intervention and outcomes. The effect size will be expressed in incidence rates and when appropriate in relative risk with 95% confidence intervals. If possible, we will perform a meta-analysis. Heterogeneity will be assessed using I2 statistics. We will pool the data extracted from the randomised controlled trials to perform a meta-analysis using the Review Manager 5 software (RevMan 5). The Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system will be used to assess the certainty of the evidence.

The role of colonic motility in low anterior resection syndrome

Low anterior resection syndrome (LARS) describes the symptoms and experiences of bowel dysfunction experienced by patients after rectal cancer surgery. LARS is a complex and multifactorial syndrome exacerbated by factors such as low anastomotic height, defunctioning of the colon and neorectum, and radiotherapy. There has recently been growing awareness and understanding regarding the role of colonic motility as a contributing mechanism for LARS. It is well established that rectosigmoid motility serves an important role in coordinating rectal filling and maintaining continence. Resection of the rectosigmoid may therefore contribute to LARS through altered distal colonic and neorectal motility. This review evaluates the role of colonic motility within the broader pathophysiology of LARS and outlines future directions of research needed to enable targeted therapy for specific LARS phenotypes.

Prolonged neoadjuvant chemotherapy without radiation versus total neoadjuvant therapy for locally advanced rectal cancer: A propensity score matched study

Background

Although neoadjvuant chemoradiotherapy (CRT) improves the local control rate of locally advanced rectal cancer (LARC), it fails to significantly improve disease-free survival (DFS) and overall survival (OS). We explored the efficacy of prolonged neoadjuvant chemotherapy (pNCT) without radiation and compared this schema with total neoadjuvant therapy (TNT).

Material and methods

Patients diagnosed with LARC and received TNT (4 cycles of induction CapeOX/FOLFOX followed with CRT) or pNCT (6~8 cycles of CapeOX/FOLFOX) between June 2016 and October 2021 were retrospective analyzed. All patients underwent total mesorectal excision (TME). A 1:1 propensity score match was performed to adjust baseline potential confounders. The tumor response, toxicity, recurrence-free survival (RFS) and OS were observed.

Results

A total of 184 patients with 92 patients in each group were finally enrolled. The median follow-up time was 35 months. TNT showed better pathological complete response (pCR) rate (25.0% vs 16.3%) and objective regression rate (73.9% vs 59.8%) than pNCT. TNT and pNCT produce similar 3-year RFS and OS rates in patients with mid-to-upper rectal cancer. TNT was associated with improved tumor responsiveness in all patients and improved 3-year RFS rates in those with low rectal cancer.

Conclusion

pNCT is an option for patients with mid-to-upper rectal cancer, but radiation is still necessary for low rectal cancer. To determine optimal schema for neoadjuvant therapy and patient selection, additional randomized controlled studies are needed.

The Effect of Continuing Chemotherapy after Chemoradiotherapy during the Time to Surgery on Tumor Response and Survival for Local Advanced Rectal Cancer

Aim

The current standard treatment of locally advanced rectal carcinoma is total mesorectal excision and postoperative adjuvant chemotherapy after neoadjuvant concurrent chemoradiotherapy (NCRT). Many studies have shown that pathological complete response (pCR) is an important prognostic factor for patients receiving NCRT. Many studies have therefore been conducted to increase pCR rates by changing the perioperative treatment strategies. Prolonging the chemotherapy time may be a reasonable way to increase the effectiveness of NCRT, pCR, and survival rates. We investigated whether neoadjuvant consolidation chemotherapy had an effect on tumor response and survival.

Methods

The data of 163 patients diagnosed with locally advanced rectal carcinoma were evaluated. The data of 107 patients (Group 1) who were radiologically T3–T4 and/or N+ and received chemotherapy after NCRT until their operations were compared with the data of 56 patients (Group 2) who were operated after NCRT.

Results

Group 1 patients had tumor and node downstaging. Their pCR was found significantly higher than in Group 2 (p = 0.005). In Group 1 patients with T3, pCR was significantly higher than for those with T4. The elapsed time between NCRT and surgery was significantly longer in patients with pCR (respectively, p = 0.012 and p = 0.008).

Conclusion

Neoadjuvant consolidation chemotherapy after NCRT is a safe approach that can lead to higher pathological complete response rates. The time until surgery with neoadjuvant consolidation chemotherapy may provide the chance to follow the patient without surgery in addition to increasing pCR.

Three perspectives: the approach to neoadjuvant treatment of rectal cancer according to medical oncologists, radiation oncologists, and surgeons

Background: Two treatment options considered for radiotherapy are short-course radiotherapy and immediate surgery, or chemoradiation with 5-Fluorouracil based chemotherapy and delayed surgery. Aim of the study: Evaluate the real-life treatment approaches of medical, radiation, and surgical oncologists, to neoadjuvant treatment of rectal cancers. Material and methods: An online survey was established via Google Forms. The survey was taken voluntarily by medical oncologists, radiation oncologists, surgical oncologists, and general surgeons. Results: Of those who participated, 183 were medical oncologists, 36 were radiotherapists, and 36 were surgeons. Most of the study population preferred long-course radiation therapy and chemotherapy (85%). Meanwhile, two-thirds of the participants preferred chemotherapy prior to operating. The most frequent chemotherapy cycles for the pre-operative setting were ‘three’ and ‘four-or-more’ (27.8% and 25.1%, respectively). Medical oncologists had a significantly higher tendency to offer chemotherapy between radiation therapy and surgery compared to the other groups. Optimal time of surgery was different between groups, but there was no difference among groups between surgery and the ‘watch & wait’ strategy. Neoadjuvant chemotherapy regimens were significantly different between groups. Conclusions: We found that the new pre-operative chemotherapy regimen with short-course radiotherapy was slowly adopted into current practice. Also, medical oncologists tended to prefer pre-operative chemotherapy in comparison to the other groups.

The in-silico feasibility of dose escalated, hypofractionated radiotherapy for rectal cancer

Background and purpose

Short course radiotherapy (SCRT) has a low biological prescription dose. Rectal cancer has a dose response relationship and moderate α/β ratio (∼5). We hypothesise hypofractionated dose escalation has radiobiological advantages. We assessed in-silico dose escalation to the primary tumour using a simultaneous integrated boost (SIB) technique.

Materials and methods

Patients who had received 25 Gy/5# were enrolled. GTV was macroscopic tumour including lumen. CTVA was GTV + 10 mm. CTVB included elective nodes. PTV_Low was created from CTVF (CTVA + CTVB) + 7 mm. PTV_High (SIB) was GTV + 5 mm margin. OAR were as per RTOG guidelines. Each patient had 4 plans created at increasing dose levels (27.5 Gy, 30 Gy, 32.5 Gy and 35 Gy) to PTV_High. PTV_Low was 25 Gy/5#.5 test plans were created for each patient in Eclipse™ v15.5 and consisted of 2 VMAT full arcs (6 MV), Varian Truebeam (2.7). Planning objectives were set in the Photon optimiser (PO) and recalculated using Acuros v15.5. A priori feasibility was defined as 90% of plans achieving the planning objectives at 32.5 Gy dose level (EqD2 53.4 Gy).

Results

20 SCRT patients median age 70, F (n = 5), M (n = 15). Rectum level; low (n = 12), mid (n = 3) and upper (n = 5). 100 plans were analysed. Mean volume of PTV_High was 130 cm³ (SD 81.5) and PTV_Low 769.6 cm³ (SD 241.1). 100% plans complied with mandatory planning dose metrics for each structure at the 25 Gy/5# plan and each dose level.

Conclusion

Hypofractionated dose escalation to the primary tumour up to 35 Gy/5# is technically feasible in rectal cancer radiotherapy.

Assessment of Radiation-Induced Bladder and Bowel Cancer Risks after Conventionally and Hypo-Fractionated Radiotherapy for the Preoperative Management of Rectal Carcinoma

Preoperative management of rectal carcinoma can be performed by employing either conventionally or hypo-fractionated Radiotherapy (CFRT or HFRT, respectively), delivered by Intensity Modulated Radiotherapy (IMRT) or Volumetric Modulated Arc Therapy (VMAT) plans, employing 6 MV or 10 MV photon beams. This study aims to dosimetrically and radiobiologically compare all available approaches, with emphasis on the risk of radiation-induced second cancer to the bladder and bowel. Computed Tomography (CT) scans and relevant radiotherapy contours from 16 patients were anonymized and analyzed retrospectively. For each case, CFRT of 25 × 2 Gy and HFRT of 5 × 5 Gy were both considered. IMRT and VMAT plans using 6 MV and 10 MV photons were prepared. Plan optimization was performed, considering all clinically used plan quality indices and dose–volume constraints for the critical organs. Resulting dose distributions were analyzed and compared. Moreover, the Lifetime Attributable Risk (LAR) for developing radiation-induced bladder and bowel malignancies were assessed using a non-linear mechanistic model, assuming patient ages at treatment of 45, 50, 55 and 60 years. All 128 plans created were clinically acceptable. Risk of second bladder cancer reached 0.26% for HFRT (5 × 5 Gy) and 0.19% for CFRT (25 × 2 Gy) at the age of 45. Systematically higher risks were calculated for HFRT (5 × 5 Gy) as compared to CFRT (25 × 2 Gy), with 6 MV photons resulting in slightly increased LAR, as well. Similar or equal bowel cancer risks were calculated for all techniques and patient ages investigated (range 0.05–0.14%). This work contributes towards radiotherapy treatment protocol selection criteria for the preoperative irradiation of rectal carcinoma. However, more studies are needed to establish the associated radiation-induced risk of each RT protocol.

Total neoadjuvant therapy or standard chemoradiotherapy for locally advanced rectal cancer: A systematic review and meta-analysis

Background and Aim

The effectiveness of total neoadjuvant therapy (TNT) on patients with locally advanced rectal cancer (LARC) is controversy. This study aims to compare the prognostic value of TNT with standard neoadjuvant chemoradiotherapy (CRT) for LARC.

Methods

We searched databases (Embase [Ovid], Medline [Ovid], PubMed, Cochrane Library, and Web of Science) for articles published between January 1, 2000, and March 10, 2022. Studies on evaluating the effects of TNT and standard CRT on the prognosis of LARC were included. The primary outcomes were overall survival (OS) and disease-free survival (DFS).

Results

19 primary studies, involving 10 randomized controlled trials, 3 prospective studies and 6 retrospective studies, with data on 5,074 patients treated for LARC were included in the meta-analysis. Statistical analyses revealed that, compared with standard CRT, TNT significantly improved OS (hazard ratio [HR]=0.77, 95% confidence interval [CI]=0.65–0.90, I² = 30%, P = 0.17), DFS (HR = 0.85, 95% CI = 0.74–0.97, I² = 11%, P = 0.35), distant metastases-free survival (DMFS, HR = 0.76, 95% CI = 0.65–0.90, I² = 0%, P = 0.50), pathological complete response rate (pCR, OR = 1.89, 95% CI = 1.61–2.22, I² = 0%, P = 0.47), and R0 resection rate (OR = 1.33, 95% CI = 1.07–1.67, I² = 16%, P = 0.28), but local recurrence-free survival (LRFS, HR = 1.12, 95% CI = 0.90–1.39, I² = 4%, P = 0.37).

Conclusions

Comprehensive literature research shows that TNT showed excellent short-term efficacy in terms of pCR and R0 resection rate while also improved the long-term outcomes of OS, DFS and DMFS, might become a new standard of treatment in patients with LARC. Even so, more studies and longer follow-up were still warranted.

The implications from the interplay of neoadjuvant chemoradiotherapy and the immune microenvironment in rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) is recommended for the treatment of locally advanced rectal cancer. Even though the combination of nCRT and immune checkpoint inhibitors (ICIs) has received much attention, the specific combination modes and dose fractions in radiotherapy (RT) are still indistinct. This review focuses on the immunological mechanism involved in nCRT, the clinical efficacy, the immunological effect of different combined strategies, concurrent or sequential nCRT plus ICIs, long-course RT and short-course RT. This review discusses the impact of nCRT on tumor immunity and summarizes the availability of different dose fractions in RT and distinct combined strategies, aiming at providing clues for optimal neoadjuvant therapy options that maximize efficacy and minimize side effects.

Multimodal Treatment of Rectal Cancer

BACKGROUND

Colorectal cancer is one of the three most common types of cancer in Germany. Approximately 30% of these cancers are located in the rectum, corresponding to about 18 000 new cases per year.

METHODS

This review is based on publications retrieved by a selective search in the PubMed database, including current guidelines and recommendations.

RESULTS

Specialized imaging, particularly magnetic resonance imaging, is essential for treatment planning. In very early stages of this disease, tumors without risk factors can be excised locally. Otherwise, radical surgical resection with lymphadenectomy remains the standard treatment, and can be performed either minimally invasive or open. At present, neoadjuvant treatment plans are evolving in the direction of total neoadjuvant therapy. In addition, recent studies investigate whether the improved efficacy of neoadjuvant therapy might now enable patients with a complete clinical remission to be spared from surgical resection (organ-preserving watch-and-wait strategy).

CONCLUSION

The treatment of rectal cancer is a prime example of an interdisciplinary, multimodal approach. In the past, the focus was mainly on improving oncologic outcomes; at present, increasing attention is being devoted to the patients' quality of life as well and the functional aspects of the various modes of treatment.

Biologics in rectal cancer

INTRODUCTION

Despite the use of multimodality therapy, locally advanced rectal cancer (LARC) still presents high rates of disease recurrence. Fluoropyrimidine-based chemotherapy concurrently with radiation therapy (RT) remains the cornerstone of neoadjuvant therapy of LARC, and novel therapies are urgently needed in order to improve the clinical outcomes.

AREAS COVERED

We aim to summarize data from completed and ongoing clinical trials addressing the role of biological therapies, including monoclonal antibodies, immune checkpoint inhibitors (ICIs), antibody-drug conjugates, bispecific antibodies, and gene therapies in the systemic therapy of rectal cancer.

EXPERT OPINION

Deeper understanding of the molecular biology of colorectal cancer (CRC) has allowed meaningful advances in the systemic therapy of metastatic disease in the past few years. The larger applicability of biological therapy in CRC, including genome-guided targeted therapy, antiangiogenics, and immunotherapy, gives us optimism for the personalized management of rectal cancer. Microsatellite instability (MSI) tumors have demonstrated high sensitivity to ICIs, and preliminary findings in the neoadjuvant setting of rectal cancer are promising. To date, antiangiogenic and anti-EGFR therapies in LARC have not demonstrated the same benefit seen in metastatic disease. The outstanding results accomplished by biomarker-guided therapy in metastatic CRC will guide future developments of biological therapy in LARC.

Total Neoadjuvant Therapy for Rectal Cancer in the CAO/ARO/AIO-12 Randomized Phase 2 Trial: Early Surrogate Endpoints Revisited

Background: Early efficacy outcome measures in rectal cancer after total neoadjuvant treatment are increasingly investigated. We examined the prognostic role of pathological complete response (pCR), tumor regression grading (TRG) and neoadjuvant rectal (NAR) score for disease-free survival (DFS) in patients with rectal carcinoma treated within the CAO/ARO/AIO-12 randomized phase 2 trial. Methods: Distribution of pCR, TRG and NAR score was analyzed using the Pearson’s chi-squared test. Univariable analyses were performed using the log-rank test, stratified by treatment arm. Discrimination ability of non-pCR for DFS was assessed by analyzing the ROC curve as a function of time. Results: Of the 311 patients enrolled, 306 patients were evaluable (Arm A:156, Arm B:150). After a median follow-up of 43 months, the 3-year DFS was 73% in both groups (HR, 0.95, 95% CI, 0.63–1.45, p = 0.82). pCR tended to be higher in Arm B (17% vs. 25%, p = 0.086). In both treatment arms, pCR, TRG and NAR were significant prognostic factors for DFS, whereas survival in subgroups defined by pCR, TRG or NAR did not significantly differ between the treatment arms. The discrimination ability of non-pCR for DFS remained constant over time (C-Index 0.58) but was slightly better in Arm B (0.61 vs. 0.56). Conclusion: Although pCR, TRG and NAR were strong prognostic factors for DFS in the CAO/ARO/AIO-12 trial, their value in selecting one TNT approach over another could not be confirmed. Hence, the conclusion of a long-term survival benefit of one treatment arm based on early surrogate endpoints should be stated with caution.

GLOBOCAN 2020 Report on Global Cancer Burden: Challenges and Opportunities for Surgical Oncologists

Cancer is emerging as a major public health challenge globally. Recently, IARC (International Association of Research on Cancer) published global cancer burden using GLOBOCAN 2020 estimates for 36 cancers in 185 countries of the world. As per the estimates of the World Health Organization (WHO) in 2019, cancer is the first or second leading cause of death in 112 of 183 countries. The major takeaways of the GLOBOCAN 2020 report relevant to the surgical oncology community include the rising global burden of cancer, global disparity in cancer incidence and mortality in different geographic regions, and the impact of the human development index (HDI) on cancer incidence and projected global cancer burden by 2040. In this article, we discuss the implications of the GLOBOCAN report on future global cancer control strategies and the role of surgical oncologists in the fight against cancer.

Radiobiological analysis of preliminary results of a phase II study of pelvic hypofractionated and accelerated radiotherapy for high-risk prostate cancer patients

Purpose

Conventionally fractionated radiotherapy (CRT) is widely applied for the treatment of high-risk prostate cancer. Pelvic node irradiation improves control of the disease. Although the therapeutic guidelines support the use of hypofractionated and accelerated radiotherapy (HypoAR), this is addressed to prostate and seminal vesicles. At the same time, the safety and efficacy of HypoAR for pelvic node irradiation remain obscure.

Material and Methods

In a phase II study, we evaluated the feasibility of pelvic HypoAR in 22 high-risk prostate cancer patients. The RT scheme delivers 14 consecutive fractions of 3.67 Gy (total 51.38 Gy) to the prostate, 3.5 Gy (total 49 Gy) to the seminal vesicles, and 2.7 Gy (total 37.8 Gy) to the lymph nodes, using image-guided volumetric modulated arc therapy. A comparative radiobiological analysis of dose-volume histogram is performed (HypoAR vs. hypothetical equivalent CRT regimens, without and with time correction).

Results

Our clinical experience shows impressively low early and short-term late toxicities, without any grade III events, within a median follow-up of 30 months. Only one biochemical relapse was recorded 30 months after irradiation. In radiobiological analysis, considering an α/β-value of 4 Gy and a λ-value of 0.2 Gy/day for late effects, all comparisons predicted significantly lower toxicity for the HypoAR regimen (p < 0.05). For early toxicities (α/β = 10 Gy), a λ-value lower than 0.4 Gy/day favors the HypoAR regimen, which is along with the clinical results.

Conclusion

Radiobiological analysis favors HypoAR as a safe and effective regimen for high-risk prostate cancer patients, which is confirmed in the current phase II clinical study.

Total neoadjuvant therapy for the treatment of locally advanced rectal cancer: a systematic minireview

Colorectal carcinoma is the second leading cause of cancer-related deaths, and indeed, rectal cancer accounting for approximately one third of newly diagnosed patients. Gold standard in the treatment of rectal cancer is a multimodality approach, aiming at a good control of the local disease. Distant recurrences are the major cause of mortality. Currently, Locally Advanced Rectal Cancer (LARC) patients undergo a combined treatment of chemotherapy and radiotherapy, followed by surgery. Eventually, more chemotherapy, namely adjuvant chemotherapy (aCT), may be necessary. Total Neoadjuvant Therapy (TNT) is an emerging approach aimed to reduce distant metastases and improve local control. Several ongoing studies are analyzing whether this new approach could improve oncological outcomes. Published results were encouraging, but the heterogeneity of protocols in use, makes the comparison and interpretation of data rather complex. One of the major concerns regarding TNT administration is related to its effect on larger and more advanced cancers that might not undergo similar down-staging as smaller, early-stage tumors. This minireview, based on a systematic literature search of randomized clinical trials and meta-analysis, summarizes current knowledge on TNT. The aim was to confirm or refute whether or not current practice of TNT is based on relevant evidence, to establish the quality of that evidence, and to address any uncertainty or variation in practice that may be occurring. A tentative grouping of general study characteristics, clinical features and treatments characteristics has been undertaken to evaluate if the reported studies are sufficiently homogeneous in terms of subjects involved, interventions, and outcomes to provide a meaningful idea of which patients are more likely to gain from this treatment.

Consensus Quality Measures and Dose Constraints for Rectal Cancer From the Veterans Affairs Radiation Oncology Quality Surveillance Program and American Society for Radiation Oncology (ASTRO) Expert Panel

PURPOSE

Ensuring high quality, evidence-based radiation therapy for patients with cancer is of the upmost importance. To address this need, the Veterans Affairs (VA) Radiation Oncology Program partnered with the American Society for Radiation Oncology and established the VA Radiation Oncology Quality Surveillance program. As part of this ongoing effort to provide the highest quality of care for patients with rectal cancer, a blue-ribbon panel comprised of rectal cancer experts was formed to develop clinical quality measures.

METHODS AND MATERIALS

The Rectal Cancer Blue Ribbon panel developed quality, surveillance, and aspirational measures for (a) initial consultation and workup, (b) simulation, treatment planning, and treatment, and (c) follow-up. Twenty-two rectal cancer specific measures were developed (19 quality, 1 aspirational, and 2 surveillance). In addition, dose-volume histogram constraints for conventional and hypofractionated radiation therapy were created.

CONCLUSIONS

The quality measures and dose-volume histogram for rectal cancer serves as a guideline to assess the quality of care for patients with rectal cancer receiving radiation therapy. These quality measures will be used for quality surveillance for veterans receiving care both inside and outside the VA system to improve the quality of care for these patients.

ATR-mediated CD47 and PD-L1 up-regulation restricts radiotherapy-induced immune priming and abscopal responses in colorectal cancer

Radiotherapy (RT) of colorectal cancer (CRC) can prime adaptive immunity against tumor-associated antigen (TAA)-expressing CRC cells systemically. However, abscopal tumor remissions are extremely rare, and the postirradiation immune escape mechanisms in CRC remain elusive. Here, we found that irradiated CRC cells used ATR-mediated DNA repair signaling pathway to up-regulate both CD47 and PD-L1, which through engagement of SIRPα and PD-1, respectively, prevented phagocytosis by antigen-presenting cells and thereby limited TAA cross-presentation and innate immune activation. This postirradiation CD47 and PD-L1 up-regulation was observed across various human solid tumor cells. Concordantly, rectal cancer patients with poor responses to neoadjuvant RT exhibited significantly elevated postirradiation CD47 levels. The combination of RT, anti-SIRPα, and anti-PD-1 reversed adaptive immune resistance and drove efficient TAA cross-presentation, resulting in robust TAA-specific CD8 T cell priming, functional activation of T effectors, and increased T cell clonality and clonal diversity. We observed significantly higher complete response rates to RT/anti-SIRPα/anti-PD-1 in both irradiated and abscopal tumors and prolonged survival in three distinct murine CRC models, including a cecal orthotopic model. The efficacy of triple combination therapy was STING dependent as knockout animals lost most benefit of adding anti-SIRPα and anti-PD-1 to RT. Despite activation across the myeloid stroma, the enhanced dendritic cell function accounts for most improvements in CD8 T cell priming. These data suggest ATR-mediated CD47 and PD-L1 up-regulation as a key mechanism restraining radiation-induced immune priming. RT combined with SIRPα and PD-1 blockade promotes robust antitumor immune priming, leading to systemic tumor regressions.

Quality-of-Life Outcomes and Toxic Effects Among Patients With Cancers of the Uterus Treated With Stereotactic Pelvic Adjuvant Radiation Therapy: The SPARTACUS Phase 1/2 Nonrandomized Controlled Trial

IMPORTANCE

Adjuvant radiation plays an important role in reducing locoregional recurrence in patients with uterine cancer. Although hypofractionated radiotherapy may benefit health care systems and the global community while decreasing treatment burden for patients traveling for daily radiotherapy, it has not been studied prospectively nor in randomized trials for treatment of uterine cancers, and the associated toxic effects and patient quality of life are unknown.

OBJECTIVE

To evaluate acute genitourinary and bowel toxic effects and patient-reported outcomes following stereotactic hypofractionated adjuvant radiation to the pelvis for treatment of uterine cancer.

DESIGN, SETTING, AND PARTICIPANTS

The Stereotactic Pelvic Adjuvant Radiation Therapy in Cancers of the Uterus (SPARTACUS) phase 1/2 nonrandomized controlled trial of patients accrued between May 2019 and August 2021 was conducted as a multicenter trial at 2 cancer centers in Ontario, Canada. In total, 61 patients with uterine cancer stages I through III after surgery entered the study.

INTERVENTIONS

Stereotactic adjuvant pelvic radiation to a dose of 30 Gy in 5 fractions administered every other day or once weekly.

MAIN OUTCOMES AND MEASURES

Assessments of toxic effects and patient-reported quality of life (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and endometrial EN24) were collected at baseline, fractions 3 and 5, and at 6 weeks and 3 months of follow-up. Descriptive analysis was conducted, calculating means, SDs, medians, IQRs, and ranges for continuous variables and proportions for categorical variables. Univariate generalized linear mixed models were generated for repeated measurements on the quality-of-life scales.

RESULTS

A total of 61 patients were enrolled (median age, 66 years; range, 51-88 years). Tumor histologic results included 39 endometrioid adenocarcinoma, 15 serous or clear cell, 3 carcinosarcoma, and 4 dedifferentiated. Sixteen patients received sequential chemotherapy, and 9 received additional vault brachytherapy. Median follow-up was 9 months (IQR, 3-15 months). Of 61 patients, worst acute gastrointestinal tract toxic effects of grade 1 were observed in 33 patients (54%) and of grade 2 in 8 patients (13%). For genitourinary worst toxic effects, grade 1 was observed in 25 patients (41%) and grade 2 in 2 patients (3%). One patient (1.6%) had an acute grade 3 gastrointestinal tract toxic effect of diarrhea at fraction 5 that resolved at follow-up. Only patient-reported diarrhea scores were both clinically (scores ≥10) and statistically significantly worse at fraction 5 (mean [SD] score, 35.76 [26.34]) compared with baseline (mean [SD] score, 6.56 [13.36]; P < .001), but this symptom improved at follow-up.

CONCLUSIONS AND RELEVANCE

Results of this phase 1/2 nonrandomized controlled trial suggest that stereotactic hypofractionated radiation was well tolerated at short-term follow-up for treatment of uterine cancer. Longer follow-up and future randomized studies are needed to further evaluate this treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04866394.

Quality of life and late toxicity after short-course radiotherapy followed by chemotherapy or chemoradiotherapy for locally advanced rectal cancer - The RAPIDO trial

BACKGROUND AND PURPOSE

The RAPIDO trial demonstrated a decrease in disease-related treatment failure (DrTF) and an increase in pathological complete responses (pCR) in locally advanced rectal cancer (LARC) patients receiving total neoadjuvant treatment (TNT) compared to conventional chemoradiotherapy. This study examines health-related quality of life (HRQL), bowel function, and late toxicity in patients in the trial.

MATERIALS AND METHODS

Patients were randomized between short-course radiotherapy followed by pre-operative chemotherapy (EXP), or chemoradiotherapy and optional post-operative chemotherapy (STD). The STD group was divided into patients who did (STD+) and did not (STD-) receive post-operative chemotherapy. Three years after surgery patients received HRQL (EORTC QLQ-C30, QLQ-CR29 and QLQ-CIPN20) and LARS questionnaires. Patients who experienced a DrTF event before the toxicity assessments (6, 12, 24, or 36 months) were excluded from analyses.

RESULTS

Of 574 eligible patients, 495 questionnaires were returned (86%) and 453 analyzed (79% completed within time limits). No significant differences were observed between the groups regarding QLQ-C30, QLQ-CR29 or LARS scores. Sensory-related symptoms occurred significantly more often in the EXP group compared to all STD patients, but not compared to STD+ patients. Any toxicity of any grade and grade ≥ 3 toxicity was comparable between the EXP and STD groups at all time-points. Neurotoxicity grade 1-2 occurred significantly more often in the EXP and STD+ group at all time-points compared to the STD- group.

CONCLUSION

The results demonstrate that TNT for LARC, yielding improved DrTF and pCRs, does not compromise HRQL, bowel functional or results in more grade ≥3 toxicity compared to standard chemoradiotherapy at three years after surgery in DrTF-free patients.

Impact of Age on Multimodality Treatment and Survival in Locally Advanced Rectal Cancer Patients

Background: Optimal treatment for locally advanced rectal cancer is neoadjuvant (chemo)radiation followed by radical surgery. This is challenging in the aging population because of frequently concomitant comorbidity. We analyzed whether age below and above 70 years is associated with differences in treatment strategy and outcome in this population-based study. Methods: Data between 2008 and 2016 were extracted from the Netherlands Cancer Registry with follow-up until 2021. Differences in therapy, referral and outcome were analyzed using χ2 tests, multivariable logistic regression and relative survival analysis. Results: In total, 6524 locally advanced rectal cancer patients were included. A greater proportion of patients <70 years underwent resection compared to older patients (89% vs. 71%). Patients ≥70 years were more likely treated with neoadjuvant radiotherapy (OR 3.4, 95% CI 2.61−4.52), than with chemoradiation (OR 0.3, 95% CI 0.23−0.37) and less often referred to higher volume hospitals for resection (OR 0.7, 95% CI 0.51−0.87). Five-year relative survival after resection following neoadjuvant therapy was comparable and higher for both patients <70 years and ≥70 years (82% and 77%) than after resection only. Resection only was associated with worse survival in the elderly compared to younger patients (56% vs. 75%). Conclusion: Elderly patients with locally advanced rectal cancer received less intensive treatment and were less often referred to higher volume hospitals for surgery. Relative survival was good and comparable after optimal treatment in both age groups. Effort is necessary to improve guideline adherence, and multimodal strategies should be tailored to age, comorbidity and performance status.

Tegafur-Uracil/Leucovorin Plus Oxaliplatin (TEGAFOX) as Consolidation Regimen after Short-Course Radiotherapy Is Effective for Locally Advanced Rectal Cancer

This study aimed to explore the safety and efficacy of neoadjuvant SCRT and tegafur−uracil/leucovorin plus oxaliplatin (TEGAFOX) for LARC in comparison to those of the modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX-6) regimen. We retrospectively evaluated 15 and 22 patients with LARC who underwent SCRT, followed by consolidation chemotherapy with TEGAFOX and mFOLFOX-6 before surgery, respectively, between January 2015 and December 2019. The primary endpoint was the tumor response rate. The secondary endpoints were compliance, toxicity, complications, overall survival (OS), and disease-free survival (DFS). The dose reduction rate was lower in the TEGAFOX group (0 vs. 9.1% (n = 2)). No grade III-IV toxicities occurred in the TEGAFOX group. Two and four patients in the TEGAFOX and mFOLFOX-6 groups, respectively, achieved clinical complete responses. The pathologic complete response rate was lower in the TEGAFOX group (7.7% vs. 17.6%). Overall, 11 (73.3%) and 17 (81.0%) patients had a neoadjuvant rectal (NAR) score of <16 in the TEGAFOX and mFOLFOX-6 groups, respectively. All patients in this study received sphincter-preservation surgery. One patient in each group developed Clavien−Dindo grade III complications. There were no significant between-group differences in the 3-year OS (81.8% vs. 84.8%, p = 0.884) and 3-year DFS (72% vs. 71.6%, p = 0.824) rates. TEGAFOX, as consolidation chemotherapy after SCRT, achieves good tumor downstaging and patient compliance in LARC. The toxicity, complications, and surgical outcomes are similar to those of mFOLFOX-6. Thus, TEGAFOX can be considered a chemotherapy option for rectal cancer treatment.

Neoadjuvant Short-Course Radiotherapy Followed by Consolidation Chemotherapy before Surgery for Treating Locally Advanced Rectal Cancer: A Systematic Review and Meta-Analysis

Neoadjuvant short course radiotherapy (SCRT) followed by consolidation chemotherapy (CCT) is an alternative treatment for locally advanced rectal cancer (LARC). We performed this systematic review and meta-analysis to explore the tumor response and oncological outcomes of this new approach compared to conventional chemoradiotherapy (CRT). An online search of the PubMed, Embase, and Cochrane Library databases was performed. This review included 7507 patients from 14 different cohorts. The pCR rate was higher with SCRT + CCT than that with CRT (RR: 1.60; 95% CI: 1.35−1.91; p < 0.01). SCRT + CCT provided a higher ypN0 response (RR: 1.06; 95% CI: 1.01−1.12; p = 0.02). There were no differences in R0 resection and positive CRM rates; however, more sphincter-preservation surgeries were performed in the SCRT + CCT arm (RR: 1.06; 95% CI: 1.01−1.11; p = 0.02). There was no difference in the OS and DFS between the SCRT + CCT and the CRT arms (OS: HR: 0.85, p = 0.07; DFS: HR: 0.88, p = 0.08). The compliance and toxicity were comparable between the SCRT and CRT groups. In the subgroup analysis, patients who underwent four or more cycles of CCT had better pCR and DFS events. Therefore, SCRT followed by consolidation chemotherapy might be an effective alternative treatment for LARC.

The Multimodal Management of Locally Advanced Rectal Cancer: Making Sense of the New Data

In the past 40 years, the treatment of locally advanced rectal cancer has evolved with the addition of radiotherapy or chemoradiotherapy and providing (neo)adjuvant systemic chemotherapy to major surgery. However, recent trends have focused on improving our ability to risk-stratify patients and tailoring treatment to achieve the best oncologic outcome while limiting the impact on long-term quality of life. Therefore, there has been increasing interest in pursuing a watch-and-wait approach to achieve organ preservation. Several retro- and prospective studies suggest safety of the watch-and-wait approach, though it is still considered controversial due to limited clinical evidence, concerns about tumor regrowth, and subsequent distant progression. To further reduce treatment, MRI risk stratification, together with patient characteristics and patient preferences, can guide personalized treatment and reserve radiation and chemotherapy for a select patient population. Ultimately, improved options for reassessment during neoadjuvant treatment may allow for more adaptive therapy options based on treatment response. This article provides an overview of some major developments in the multimodal treatment of locally advanced rectal cancer. It reviews some relevant, controversial issues of the watch-and-wait approach and opportunities to personally tailor and reduce treatment. It also reviews the overall neoadjuvant treatment, including total neoadjuvant therapy trials, and how to best optimize for a potential complete response. Finally, it provides an algorithm as an example of how such a personalized, tailored, adaptive, and reduced treatment could look like in the future.

The Long and the Short of it: the Role of Short-course Radiotherapy in the Neoadjuvant Management of Rectal Cancer

Total mesorectal excision is the cornerstone of treatment for rectal cancer. Multiple randomised trials have shown a reduction in local recurrence rates with the addition of preoperative radiotherapy, either as a 1-week hypofractionated short-course (SCRT) or a conventionally fractionated long-course (LCRT) schedule with concurrent chemotherapy. There is also increasing interest in the addition of neoadjuvant chemotherapy to radiotherapy with the aim of improving disease-free survival. The relative use of SCRT and LCRT varies considerably across the world. This is reflected in, and is probably driven in part by, disparity between international guideline recommendations. In addition, different approaches to treatment may exist both between and within countries, with variation related to patient, disease and treatment centre and financial factors. In this review, we will specifically focus on the use of SCRT for the treatment of rectal cancer. We will discuss the literature base and current guidelines, highlighting the challenges and controversies in clinical application of this evidence. We will also discuss potential future applications of SCRT, including its role in optimisation and intensification of treatment for rectal cancer.

Predicting outcomes for locally advanced rectal cancer treated with neoadjuvant chemoradiation with CT-based radiomics

A feasibility study was performed to determine if CT-based radiomics could play an augmentative role in predicting neoadjuvant rectal score (NAR), locoregional failure free survival (LRFFS), distant metastasis free survival (DMFS), disease free survival (DFS) and overall survival (OS) in locally advanced rectal cancer (LARC). The NAR score, which takes into account the pathological tumour and nodal stage as well as clinical tumour stage, is a validated surrogate endpoint used for early determination of treatment response whereby a low NAR score (< 8) has been correlated with better outcomes and high NAR score (> 16) has been correlated with poorer outcomes. CT images of 191 patients with LARC were used in this study. Primary tumour (GTV) and mesorectum (CTV) were contoured separately and radiomics features were extracted from both segments. Two NAR models (NAR > 16 and NAR < 8) models were constructed using Least Absolute Shrinkage and Selection Operator (LASSO) and the survival models were constructed using regularized Cox regressions. Area under curve (AUC) and time-dependent AUC were used to quantify the performance of the LASSO and Cox regression respectively, using ten folds cross validations. The NAR > 16 and NAR < 8 models have an average AUCs of 0.68 ± 0.13 and 0.59 ± 0.14 respectively. There are statistically significant differences between the clinical and combined model for LRFFS (from 0.68 ± 0.04 to 0.72 ± 0.04), DMFS (from 0.68 ± 0.05 to 0.70 ± 0.05) and OS (from 0.64 ± 0.06 to 0.66 ± 0.06). CTV radiomics features were also found to be more important than GTV features in the NAR prediction model. The most important clinical features are age and CEA for NAR > 16 and NAR < 8 models respectively, while the most significant clinical features are age, surgical margin and NAR score across all the four survival models.

Neoadjuvant Therapy for Primary Resectable Retroperitoneal Sarcomas-Looking Forward

Simple Summary

This review summarizes the current evidence around neoadjuvant radiotherapy and systemic therapy for retroperitoneal sarcoma (RPS). While surgery is the cornerstone of treatment for these tumors, data from prospective studies, retrospective studies, early phase trials, and—most recently—our first phase III randomized trial for RPS suggest there are clinical scenarios in which neoadjuvant therapy may provide benefit. This review evaluates the STRASS results in the setting of other recent studies, identifies active trials of interest, and suggests future directions of study in this field. The intersection of STRASS and STRASS2 is considered and a summary of current acceptable approaches to neoadjuvant therapy for RPS is provided.

Abstract

The cornerstone of therapy for primary retroperitoneal sarcomas (RPS) is complete surgical resection, best achieved by resecting the tumor en bloc with adherent structures even if not overtly infiltrated. Until recently, trials designed to elucidate the role of neoadjuvant radiation or chemotherapy for RPS have been unable to achieve sufficient enrollment. The completion of the STRASS trial, which explored neoadjuvant radiotherapy for primary resectable RPS, is a major milestone in RPS research, but has prompted further questions about histology-driven treatment paradigms for RPS. Though it was ultimately a negative trial with respect to its primary endpoint of abdominal recurrence-free survival, STRASS produced a signal that suggested improved abdominal recurrence-free survival with neoadjuvant radiotherapy (RT) for patients with liposarcoma (LPS). No effect was seen for leiomyosarcoma (LMS) or high-grade dedifferentiated (DD) LPS, consistent with recent literature suggesting LMS and high-grade DD-LPS have a predominant pattern of distant rather than local failure. These results, along with those from other recent studies conducted at the bench and the bedside, emphasize the importance of a histology-specific approach to RPS research. Recent evidence for patterns of distant failure in LMS and high-grade DD-LPS has prompted the initiation of STRASS2, a study of neoadjuvant chemotherapy for these histologies. As this study unfolds, evidence may emerge for novel systemic therapy options in specific sarcoma histotypes given the explosion in targeted and immunotherapeutic applications over the last decade. This article reviews current and recent evidence around neoadjuvant radiation and chemotherapy as well as avenues for future study to optimize these treatment approaches.

SEOM-GEMCAD-TTD clinical guidelines for localized rectal cancer (2021)

The management of localized rectal cancer requires a multidisciplinary approach to optimize outcomes, reduce morbidity and prevent under or overtreatments. While early stages may obtain benefit of local resections without any additional therapies, locally advanced rectal cancer becomes a challenge defining the better sequential strategy of surgery, radiotherapy and chemotherapy. The latest results of international phase III studies have positioned the total neoadjuvant therapy as a potential new standard of care in high risk rectal cancers, however, the best schedule is still not well defined.

[Place of radiotherapy in the treatment of rectal cancer in the elderly]

Rectal cancer is a common disease of the elderly. Current treatment recommendations are established for young subjects in good general health condition, without taking into account the frailty, comorbidities and polymedications inherent in patients over 75 years old. For locally advanced lower and middle rectal cancers (T3, T4 or N+), these are based on variations of regimens including neoadjuvant chemoradiotherapy, surgery of the rectum with total removal of the mesorectum, and a possibility of adjuvant chemotherapy. This restrictive treatment presents a problem of compliance and is not without adverse effects. Treatment by short exclusive radiotherapy or chemoradiotherapy with close monitoring according to the Watch and Wait strategy can be proposed to fragile patients not eligible for surgery, even if there is a non-negligible risk of recurrence.

Benchmarking Outcomes for Definitive Treatment of Young-Onset, Locally Advanced Rectal Cancer

PURPOSE

There has been an increase in the incidence of rectal cancer diagnosed in young adults (age < 50 years). We evaluated outcomes among young adults treated with pre-operative long course chemoradiation (CRT) and total mesorectal excision (TME).

METHODS

The medical records of 219 patients, age 18-49, with non-metastatic, cT3-4, or cN1-2 rectal adenocarcinoma treated from 2000 to 2017 were reviewed for demographic and treatment characteristics, as well as pathologic and oncologic outcomes. The Kaplan-Meier test, log-rank test, and Cox regression analysis were used to evaluate survival outcomes.

RESULTS

The median age at diagnosis was 44 years. CRT followed by TME and post-operative chemotherapy was the most frequent treatment sequence (n = 196), with FOLFOX (n = 115) as the predominant adjuvant chemotherapy. There was no difference in sex, stage, MSS/pMMR, or pCR by age (< 45 years [n = 111] vs. ≥ 45 years [n = 108]). The 5-year rates of DFS were 77.2% for all patients, 69.8% for age < 45 years and 84.7% for age ≥ 45 years (P = .01). The 5-year rates of OS were 89.6% for all patients, 85.1% for patients with age < 45 years and 94.3% for patients with age ≥ 45 years (P = .03). Age ≥ 45 years was associated with a lower risk of disease recurrence or death on multivariable Cox regression analysis (HR = 0.55, 95% CI 0.31-0.97, P = .04).

CONCLUSION

Among young adults, patients with age < 45 years had lower rates of DFS and OS, compared to those with age ≥ 45 years. These outcomes could serve as a benchmark by which to evaluate newer treatment approaches.

Neoadjuvant Therapy for Rectal Cancer

The treatment of locally advanced rectal cancer is challenging and requires a multidisciplinary approach. Neoadjuvant treatment has improved local control by the combination of radiotherapy, surgery, and chemotherapy. However, neoadjuvant treatment has not yet been shown to improve overall survival and is associated with toxicities and late sequelae that impair the quality of life of patients. Currently, different types of neoadjuvant strategies have raised the question about which one is the optimal strategy for rectal cancer treatment. In this article, we explore the different neoadjuvant treatment regimens currently available, their associated benefits and toxicities, and novel approaches in this area.

New Frontiers in Management of Early and Advanced Rectal Cancer

It is important to understand advances in treatment options for rectal cancer. We attempt to highlight advances in rectal cancer treatment in the form of a systematic review. Early-stage rectal cancer focuses on minimally invasive endoluminal surgery, with importance placed on patient selection as the driving factor for improved outcomes. To achieve a complete pathologic response, various neoadjuvant chemoradiation regimens have been employed. Short-course radiation therapy, total neoadjuvant chemotherapy, and others provide unique advantages with select patient populations best suited for each. With a clinical complete response, a "watch and wait" non-operative surveillance has been introduced with preliminary equivalency to radical resection. Various modalities for total mesorectal excision, such as robotic or transanal, have advantages and can be utilized in select patient populations. Tumors demonstrating solid organ or peritoneal spread, traditionally defined as unresectable lesions conveying a terminal diagnosis, have recently undergone advances in hepatic and pulmonary metastasectomy. Hepatic and pulmonary metastasectomy has demonstrated clear advantages in 5-year survival over standard chemotherapy. With the peritoneal spread of colorectal cancer, HIPEC with cytoreductive therapy has emerged as the preferred treatment. Understanding the various therapeutic interventions will pave the way for improved patient outcomes.

Total Neoadjuvant Therapy With Short-Course Radiation: US Experience of a Neoadjuvant Rectal Cancer Therapy

BACKGROUND

Short-course radiation followed by chemotherapy as total neoadjuvant therapy has been investigated primarily in Europe and Australia with increasing global acceptance. There are limited data on this regimen's use in the United States, however, potentially delaying implementation.

OBJECTIVE

This study aimed to compare clinical performance and oncologic outcomes of 2 rectal cancer neoadjuvant treatment modalities: short-course total neoadjuvant therapy versus standard chemoradiation.

DESIGN

This is a retrospective cohort study.

SETTING

This study was performed at a National Cancer Institute-designated cancer center.

PATIENTS

A total of 413 patients had locally advanced rectal cancers diagnosed from June 2009 to May 2018 and received either short-course total neoadjuvant therapy or standard chemoradiation.

INTERVENTIONS

There were 187 patients treated with short-course total neoadjuvant therapy (5 × 5 Gy radiation followed by consolidation oxaliplatin-based chemotherapy) compared with 226 chemoradiation recipients (approximately 50.4 Gy radiation in 28 fractions with concurrent fluorouracil equivalent).

MAIN OUTCOME MEASURES

Primary end points were tumor downstaging, measured by complete response and "low" neoadjuvant rectal score rates, and progression-free survival. Secondary analyses included treatment characteristics and completion, sphincter preservation, and recurrence rates.

RESULTS

Short-course total neoadjuvant therapy was associated with higher rates of complete response (26.2% vs 17.3%; p = 0.03) and "low" neoadjuvant rectal scores (40.1% vs 25.7%; p < 0.01) despite a higher burden of node-positive disease (78.6% vs 68.9%; p = 0.03). Short-course recipients also completed trimodal treatment more frequently (88.4% vs 50.4%; p < 0.01) and had fewer months with temporary stomas (4.8 vs 7.0; p < 0.01). Both regimens achieved comparable local control (local recurrence: 2.7% short-course total neoadjuvant therapy vs 2.2% chemoradiation, p = 0.76) and 2-year progression-free survival (88.2% short-course total neoadjuvant therapy (95% CI, 82.9-93.5) vs 85.6% chemoradiation (95% CI, 80.5-90.7)).

LIMITATIONS

Retrospective design, unbalanced disease severity, and variable dosing of neoadjuvant consolidation chemotherapy were limitations of this study.

CONCLUSIONS

Short-course total neoadjuvant therapy was associated with improved downstaging and similar progression-free survival compared with chemoradiation. These results were achieved with shortened radiation courses, improved treatment completion, and less time with diverting ostomies. Short-course total neoadjuvant therapy is an optimal regimen for locally advanced rectal cancer. See Video Abstract at http://links.lww.com/DCR/B724.TERAPIA NEOADYUVANTE TOTAL CON RADIACIÓN DE CORTA DURACIÓN: EXPERIENCIA ESTADOUNIDENSE DE UNA TERAPIA NEOADYUVANTE CONTRA EL CÁNCER DE RECTO.

ANTECEDENTES

La radiación de corta duración seguida de quimioterapia como terapia neoadyuvante total se ha investigado principalmente en Europa y Australia con una aceptación mundial cada vez mayor. Sin embargo, datos limitados sobre el uso de este régimen en los Estados Unidos, han potencialmente retrasando su implementación.

OBJETIVO

Comparar el desempeño clínico y los resultados oncológicos de dos modalidades de tratamiento neoadyuvante del cáncer de recto: terapia neoadyuvante total de corta duración versus quimioradiación. estándar.

DISEO

Cohorte retrospectivo.

AJUSTE

Centro oncológico designado por el NCI.

PACIENTES

Un total de 413 cánceres rectales localmente avanzados diagnosticados entre junio de 2009 y mayo de 2018 que recibieron cualquiera de los regímenes neoadyuvantes.

INTERVENCIONES

Hubo 187 pacientes tratados con terapia neoadyuvante total de ciclo corto (radiación 5 × 5 Gy seguida de quimioterapia de consolidación basada en oxaliplatino) en comparación con 226 pacientes de quimiorradiación (aproximadamente 50,4 Gy de radiación en 28 fracciones con equivalente de fluorouracilo concurrente).

PRINCIPALES MEDIDAS DE RESULTADO

Los criterios primarios de valoración fueron la disminución del estadio del tumor, medido por la respuesta completa y las tasas de puntuación rectal neoadyuvante "baja", y la supervivencia libre de progresión. Los análisis secundarios incluyeron las características del tratamiento y las tasas de finalización, conservación del esfínter y recurrencia.

RESULTADOS

La terapia neoadyuvante total de corta duración, se asoció con tasas más altas de respuesta completa (26,2% versus 17,3%, p = 0,03) y puntuaciones rectales neoadyuvantes "bajas" (40,1% versus 25,7%, p < 0,01) a pesar de una mayor carga de enfermedad con ganglios positivos (78,6% versus 68,9%, p = 0,03). Los pacientes de ciclo corto también completaron el tratamiento trimodal con mayor frecuencia (88,4% versus 50,4%, p < 0,01) y tuvieron menos meses con estomas temporales (4,8 versus 7,0, p < 0,01). Ambos regímenes lograron un control local comparable (recidiva local: 2,7% de SC-TNT versus 2,2% de TRC, p = 0,76) y supervivencia libre de progresión a 2 años (88,2% de SC-TNT [IC: 82,9 - 93,5] versus 85,6% CRT [CI: 80,5 - 90,7]).

LIMITACIONES

Diseño retrospectivo, gravedad de la enfermedad desequilibrada y dosificación variable de quimioterapia neoadyuvante de consolidación.

CONCLUSIONES

La terapia neoadyuvante total de ciclo corto se asoció con una mejora en la reducción del estadio y una supervivencia libre de progresión similar en comparación con la quimioradiación. Estos resultados se lograron con ciclos de radiación más cortos, tratamientos mejor finalizados y menos tiempo en ostomías de derivación. La terapia neoadyuvante total de corta duración es un régimen óptimo para el cáncer de recto localmente avanzado. Consulte Video Resumen en http://links.lww.com/DCR/B724. (Traducción- Dr. Fidel Ruiz Healy).

Perioperative Complications After Proctectomy for Rectal Cancer: Does Neoadjuvant Regimen Matter?

OBJECTIVE

Investigate the association between neoadjuvant treatment strategy and perioperative complications in patients undergoing proctectomy for nonmetastatic rectal cancer.

SUMMARY OF BACKGROUND DATA

Neoadjuvant SC-TNT is an alternative to neoadjuvant CRT for rectal cancer. Some have argued that short-course radiation and extended radiation-to-surgery intervals increase operative difficulty and complication risk. However, the association between SC-TNT and surgical complications has not been previously investigated.

METHODS

This single-center retrospective cohort study included patients undergoing total mesorectal excision for nonmetastatic rectal cancer after SC-TNT or CRT between 2010 and 2018. Univariate analysis of severe POM and multiple secondary outcomes, including overall POM, intraoperative complications, and resection margins, was performed. Logistic regression of severe POM was also performed.

RESULTS

Of 415 included patients, 156 (38%) received SC-TNT and 259 (62%) received CRT. The cohorts were largely similar, though patients with higher tumors (69.9% vs 47.5%, P < 0.0001) or node-positive disease (76.9% vs 62.6%, P = 0.004) were more likely to receive SC-TNT. We found no difference in incidence of severe POM (9.6% SC-TNT vs 12.0% CRT, P = 0.46) or overall POM (39.7% SC-TNT vs 37.5% CRT, P = 0.64) between cohorts. Neoadjuvant regimen was also not associated with a difference in severe POM (odds ratio 0.42, 95% confidence interval 0.04-4.70, P = 0.48) in multivariate analysis. There was no significant association between neoadjuvant regimen and any secondary outcome.

CONCLUSION

In rectal cancer patients treated with SC-TNT and proctectomy, we found no significant association with POM compared to patients undergoing CRT. SC-TNT does not significantly increase the risk of POM compared to CRT.

Cost-effectiveness of Total Neoadjuvant Therapy With Short-Course Radiotherapy for Resectable Locally Advanced Rectal Cancer

IMPORTANCE

Short-course radiotherapy and total neoadjuvant therapy (SCRT-TNT) followed by total mesorectal excision (TME) has emerged as a new treatment paradigm for patients with locally advanced rectal adenocarcinoma. However, the economic implication of this treatment strategy has not been compared with that of conventional long-course chemoradiotherapy (LCCRT) followed by TME with adjuvant chemotherapy.

OBJECTIVE

To perform a cost-effectiveness analysis of SCRT-TNT vs LCCRT in conjunction with TME for patients with locally advanced rectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

A decision analytical model with a 5-year time horizon was constructed for patients with biopsy-proven, newly diagnosed, primary locally advanced rectal adenocarcinoma treated with SCRT-TNT or LCCRT. Markov modeling was used to model disease progression and patient survival after treatment in 3-month cycles. Data on probabilities and utilities were extracted from the literature. Costs were evaluated from the Medicare payer's perspective in 2020 US dollars. Sensitivity analyses were performed for key variables. Data were collected from October 3, 2020, to January 20, 2021, and analyzed from November 15, 2020, to April 25, 2021.

EXPOSURES

Two treatment strategies, SCRT-TNT vs LCCRT with adjuvant chemotherapy, were compared.

MAIN OUTCOMES AND MEASURES

Cost-effectiveness was evaluated using the incremental cost-effectiveness ratio and net monetary benefits. Effectiveness was defined as quality-adjusted life-years (QALYs). Both costs and QALYs were discounted at 3% annually. Willingness-to-pay threshold was set at $50 000/QALY.

RESULTS

During the 5-year horizon, the total cost was $41 355 and QALYs were 2.21 for SCRT-TNT; for LCCRT, the total cost was $54 827 and QALYs were 2.12, resulting in a negative incremental cost-effectiveness ratio (-$141 256.77). The net monetary benefit was $69 300 for SCRT-TNT and $51 060 for LCCRT. Sensitivity analyses using willingness to pay at $100 000/QALY and $150 000/QALY demonstrated the same conclusion.

CONCLUSIONS AND RELEVANCE

These findings suggest that SCRT-TNT followed by TME incurs lower cost and improved QALYs compared with conventional LCCRT followed by TME and adjuvant chemotherapy. These data offer further rationale to support SCRT-TNT as a novel cost-saving treatment paradigm in the management of locally advanced rectal cancer.

Postoperative hypofractionated-accelerated radiotherapy (HypoAR) for locally advanced rectal cancer

BACKGROUND

despite the advances in preoperative hypofractionated-accelerated radiotherapy for patients with locally advanced rectal cancer, postoperative radiotherapy delivered with standard fractionation (46-50 Gy in 5 weeks) remains a standard adjuvant schedule. The role of hypofractionated-accelerated radiotherapy in a postoperative setting remains largely unexplored.

METHODS

eighty-eight patients with rectal cancer infiltrating the rectal wall and/or having metastasis to the perirectal lymph nodes were treated with surgery followed by adjuvant chemotherapy and, subsequently, with hypofractionated-accelerated radiotherapy. Ten fractions of 3.4 Gy were delivered to the pelvis for 10 consecutive fractions, within 12 days. The follow-up of patients alive at the time of analysis ranges from 12-120 months (median 48).

RESULTS

mild abdominal discomfort and diarrhoea were frequent, but medical medication was demanded in 14/88 (15.9%) of patients. The incidence of late toxicities was low; 4/88 (3.5%) patients complained for intermittent intestinal urgency. Locoregional recurrence occurred in 8/88 patients (9%). The 5-year locoregional relapse-free survival was achieved in 89.7% of patients, and this dropped to 84% in node-positive patients (P = 0.45). The 5-year disease-specific overall survival was 72.4%. Nodal involvement showed a trend to negatively affect prognosis (5-year overall survival 68.2 vs. 79.6%; P = 0.23).

CONCLUSION

postoperative hypofractionated-accelerated radiotherapy has minimal early and late toxicity. The locoregional control and disease-specific survival rates are similar to the expected from conventional postoperative chemoradiotherapy. The 2.5-fold decrease of radiotherapy treatment time, reduction of waiting lists and the lower overall cost of radiotherapy are additional benefits associated with hypofractionated-accelerated radiotherapy.

Preoperative short-course radiotherapy followed by consolidation chemotherapy for treatment with locally advanced rectal cancer: a meta-analysis

Background

The addition of consolidation chemotherapy to preoperative short-course radiotherapy during the prolonged interval between the completion of radiation and surgery in locally advanced rectal cancer (LARC) could enhance pathologic response and might act on potential micrometastasis. We performed this meta-analysis to evaluate whether short-course radiotherapy followed by consolidation chemotherapy (SCRT/CCT) could be a neoadjuvant treatment option compared with conventional long-course chemoradiotherapy (LCCRT).

Methods

We searched the PubMed, EMBASE, MEDLINE, and Cochrane Library databases. The primary endpoints were pathological outcomes, and the secondary endpoints included survival rate, sphincter preservation rate, R0 resection rate and toxicity. RevMan 5.3 was used to calculate pooled risk ratio (RRs) and 95% confidence intervals (CIs).

Results

A total of seven eligible studies and 1865 participants were included in this meta-analysis. Compared with the LCCRT, SCRT/CCT increased pathologic complete response (pCR) rate [RR = 1.74, 95% CI (1.41, 2.15), P < 0.01] and led to a lower proportion of patients with adjuvant pathologic tumor stage 3–4 (ypT3-4) disease [RR = 0.88, 95% CI (0.80, 0.97), P = 0.01] or lymph node positive (ypN +) disease [RR = 0.83, 95% CI (0.71, 0.98), P = 0.02]. In addition, the disease-free survival (DFS) was better in SCRT/CCT group [RR = 1.10, 95% CI (1.02, 1.18), P = 0.01], while overall survival rate and toxicity and surgical procedures were similar between two groups.

Conclusion

Based on better pathological outcomes and DFS in SCRT/CCT group, we recommended preoperative short-course radiotherapy followed by consolidation chemotherapy as the optional neoadjuvant treatment for LARC.

Locally Advanced Rectal Cancer: What We Learned in the Last Two Decades and the Future Perspectives

The advancement in surgical techniques, optimization of systemic chemoradiotherapy, and development of refined diagnostic and imaging modalities have brought a phenomenal shift in the treatment of the locally advanced rectal cancer. Although each therapeutic option has shown substantial progress in their field, it is finding their ideal amalgamation which has baffled the clinician and researchers alike. In the effort to identifying the perfect salutary treatment plan, we have even shifted our attention from the trimodal approach to non-operative "watchful waiting" to more recent individualized care. In this article, we acknowledge the scientific progress in the management of locally advanced rectal cancer and compare the opportunities as well as the obstacles while implementing them clinically. We also explore the current challenges and controversies surrounding the multidisciplinary approach and highlight the new trends and recent advances with an ultimate goal to improve the patients' quality of life.

OUP accepted manuscript

Purpose

Methods

Results

Conclusion

Could Five Be the New Twenty-Five? Long-term Oncologic Outcomes from a Phase II, Prospective, 5-Fraction Pre-operative Radiation Therapy Trial in Patients with Localized Soft Tissue Sarcoma

Purpose

Management of adult soft tissue sarcomas entails a multidisciplinary approach with surgery and radiation therapy with or without chemotherapy. The use of preoperative irradiation has been well established, and although conventional fractionation involves daily treatments over the course of 5 weeks, higher doses per fraction may be beneficial due to the radiobiologic profile of sarcoma. In this study we report long-term oncologic outcomes from a single-institution, phase II study evaluating a 5-fraction hypofractionated course of preoperative radiation.

Methods and materials

Preoperative hypofractionated radiation therapy was administered to 35 Gy in 5 fractions every other day followed by resection 4 to 6 weeks later. If given, chemotherapy consisted of a doxorubicin-ifosfamide-based regimen delivered neoadjuvantly. The primary endpoint was local control. Additional survival and pathologic outcomes, including overall and distant metastasis-free survival, tumor, and treatment-related pathology, as well as acute and late toxicity were examined.

Results

Thirty-two patients were enrolled in this prospective, single-arm phase II trial. At a median follow-up of 36.4 months (range, 3-56), no patient developed a local recurrence, and the 3-year overall and distant metastasis-free survival was 82.2% and 69%, respectively. Major acute postoperative wound complications occurred in 25% of patients. Grade 2 and 3 fibrosis occurred in 21.7% and 13% of patients, respectively. The 2-year median and mean Musculoskeletal Tumor Society score for all patients was 28 and 27.4, respectively.

Conclusions

A condensed course of preoperative hypofractionated radiation therapy leads to excellent rates of local control and survival with acceptable toxicity profiles. Potential studies ideally with phase II or III randomized trials would help corroborate these findings and other preoperative hypofractionated results in soft tissue sarcomas.

Tumor Microenvironment Modifications Recorded With IVIM Perfusion Analysis and DCE-MRI After Neoadjuvant Radiotherapy: A Preclinical Study

PURPOSE

Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. Some clinical studies demonstrated that both timing of surgery and RT schedule influence tumor dissemination, and subsequently patient overall survival. Previously, we developed a pre-clinical model demonstrating the impact of NeoRT schedule and timing of surgery on metastatic spreading. We report on the impact of NeoRT on tumor microenvironment by MRI.

METHODS

According to our NeoRT model, MDA-MB 231 cells were implanted in the flank of SCID mice. Tumors were locally irradiated (PXI X-Rad SmART) with 2x5Gy and then surgically removed at different time points after RT. Diffusion-weighted (DW) and Dynamic contrast enhancement (DCE) MRI images were acquired before RT and every 2 days between RT and surgery. IntraVoxel Incoherent Motion (IVIM) analysis was used to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor) and subsequently tumor vessels perfusion. For DCE-MRI, we performed semi-quantitative analyses.

RESULTS

With this experimental model, a significant and transient increase of the perfusion factor F [50% of the basal value (n=16, p<0.005)] was observed on day 6 after irradiation as well as a significant increase of the WashinSlope with DCE-MRI at day 6 (n=13, p<0.05). Using immunohistochemistry, a significant increase of perfused vessels was highlighted, corresponding to the increase of perfusion in MRI at this same time point. Moreover, Tumor surgical resection during this peak of vascularization results in an increase of metastasis burden (n=10, p<0.05).

CONCLUSION

Significant differences in perfusion-related parameters (F and WashinSlope) were observed on day 6 in a neoadjuvant radiotherapy model using SCID mice. These modifications are correlated with an increase of perfused vessels in histological analysis and also with an increase of metastasis spreading after the surgical procedure. This experimental observation could potentially result in a way to personalize treatment, by modulating the time of surgery guided on MRI functional data, especially tumor perfusion.

Debating Pros and Cons of Total Neoadjuvant Therapy in Rectal Cancer

Simple Summary

Rectal cancers represent one third of all colorectal tumours. Patients diagnosed with localised colon cancer undergo surgery upfront, likely followed by adjuvant chemotherapy. Those diagnosed with localised rectal cancer, however, frequently benefit from neoadjuvant treatments with either radiotherapy or chemoradiotherapy before undergoing surgery. On the other hand, the benefit of adjuvant chemotherapy in this setting is more controversial. The main challenges in treating patients affected by rectal cancer encompass: decreasing the risks of local relapse and distant metastases, preserving the sphincter and minimising treatment-associated functional sequelae, and improving overall survival. Some of these fuelled the concept of total neoadjuvant therapy, namely giving all available treatments including radiotherapy and systemic chemotherapy before surgery. Here, we critically review the pros and cons of such a treatment strategy, but also discuss the biological rational to support neoadjuvant treatment intensification.

Abstract

Recently, two large, randomised phase III clinical trials of total neoadjuvant therapy (TNT) in locally advanced rectal cancer were published (RAPIDO and PRODIGE 23). These two trials compared short-course radiotherapy (SCRT) followed by chemotherapy with standard chemoradiotherapy (CRT) and chemotherapy followed by CRT with standard CRT, respectively. They showed improvement in some of the outcomes such as distant recurrence and pathological complete response (pCR). No improvement, however, was observed in local disease control or the de-escalation of surgical procedures. Although it seems lawful to integrate TNT within the treatment algorithm of localised stage II and III rectal cancer, many questions remain unanswered, including which are the optimal criteria to identify patients who are most likely to benefit from this intensive treatment. Instead of providing a sterile summary of trial results, we put these in perspective in a pros and cons manner. Moreover, we discuss some biological aspects of rectal cancer, which may provide some insights into the current decision-making process, and represent the basis for the future development of alternative, more effective treatment strategies.

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).

[Complete response after neoadjuvant therapy of rectal cancer: implications for surgery]

For (locally advanced) rectal cancer, a multimodal therapy concept comprising neoadjuvant radiotherapy/chemoradiotherapy, radical surgical resection with partial/complete mesorectal excision and subsequent adjuvant chemotherapy represents the current international standard of care. Further developments in neoadjuvant therapy concepts, such as the principle of total neoadjuvant therapy, lead to an increasing number of patients who show a complete clinical response in restaging after neoadjuvant therapy without clinically detectable residual tumor. In view of the risk associated with radical surgical resection in terms of perioperative morbidity and a potentially non-continence-preserving procedure, the question of the oncological justifiability of an organ-preserving procedure in the case of a complete clinical response under neoadjuvant therapy is increasingly being raised. The therapeutic principle of watch and wait, defined by refraining from immediate radical surgical resection and inclusion in a close-meshed, structured follow-up program, currently appears to be oncologically justifiable based on the current study situation; however, for the initial evaluation of the extent of the clinical response and for the structuring of the close-meshed follow-up program, further optimization and standardization based on broadly designed studies appear necessary in order to be able to provide this concept to a clearly defined patient collective as an oncologically equivalent therapy principle also outside specialized centers.