Prognostic value of pathologic complete response after neoadjuvant therapy in locally advanced rectal cancer: long-term analysis of 566 ypCR patients

Current evidence regarding the role of adjuvant chemotherapy in rectal cancer patients with pathologic complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

PURPOSE

The aim of this meta-analysis was to investigate the role of adjuvant chemotherapy (AC) in rectal cancer patients with pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) and curative resection.

METHODS

This study was completed in accordance to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The electronic scholar databases (Medline, Web of Science, Scopus) were screened for eligible articles. The level of evidence (LoE) was assessed using the GRADE methodology.

RESULTS

Overall, 23 non-randomized studies and 17,406 patients were included in the present meta-analysis. Pooled comparisons confirmed that AC improved overall survival (HR: 0.68, p=0.0003), but not disease-free (p=0.22) and recurrence-free survival (p=0.39). However, the LoE for all outcomes was characterized as "very low," due to the absence of RCTs.

CONCLUSIONS

Considering the study limitations and the lack of randomized studies, further high-quality RCTs are required to confirm the findings of our study.

Oncological Outcomes of Pathological T1 Lower Rectal Cancer Patients With or Without Preoperative Chemoradiotherapy

BACKGROUND/AIM

It remains unclear whether rectal cancers down-staged by preoperative chemoradiotherapy (CRT) have similar prognoses to those of the same stage without preoperative CRT. We compared prognoses of pT1 rectal cancer patients stratified by preoperative CRT.

PATIENTS AND METHODS

We retrieved data of patients with pathological T1 rectal cancer between 2003 and 2020. Patients were divided into the "ypT1 group" who received preoperative CRT following surgery and the "pT1 group" who underwent surgery alone. Factors associated with relapse-free survival (RFS) were investigated.

RESULTS

Among 86 patients, ypT1 and pT1 groups comprised 18 and 68 patients, respectively. There was no significant difference in RFS between the groups (p=0.19). Tumor location within 5 cm from the anal verge was associated with recurrence (hazard ratio: 0.13, p=0.034).

CONCLUSION

The prognosis of patients with ypT1 rectal cancer was similar to that of patients with pT1. Low tumor location was a poor prognostic factor.

Association Between Pathological Complete Response and Tumor Location in Patients with Rectal Cancer After Neoadjuvant Chemoradiotherapy, a Prospective Cohort Study

Background: Colorectal cancers are the third common malignancies after lung and breast neoplasms. Some contributing factors for pathological complete response (pCR) to neoadjuvant therapy of rectal cancer have been defined. Despite various studies in this era, there are few studies on the location of tumors. Objectives: Regarding the high prevalence of colorectal cancer in Iran and the importance of neoadjuvant chemoradiation for survival and morbidity, this study was carried out to determine the association between pathologic complete response and tumor location in patients with rectal cancer after neoadjuvant chemoradiotherapy. Methods: In this prospective cohort, 100 cases with rectal adenocarcinoma from 2017 to 2019 were enrolled. Distance between anal verge and tumor was measured by clinical examination, colonoscopy, endo-sonography, and MRI. Tumors were defined as distal (less than 5 cm from the anal verge) and none distal (more than 5 cm from the anal verge). Another subdivision was inferior (0 - 4.99 cm), middle (5 - 9.99 cm), and superior (10 - 15 cm). The pathological response was compared across the groups. Results: In this study, the pCR was seen in 30%. In univariate analysis body mass index (BMI), grade, N-stage, and distance from anal verge were related to pCR. In cases with BMI over 25 kg/m2 and in tumors with low to medium grade N0/N1, and distance less than 5 cm from the anal verge (low lying tumors) the pCR to neoadjuvant treatment was higher. In multivariate analysis tumor grade, N stage, and distance from anal verge were still related to pCR. Conclusions: According to the obtained results in this study, there may be some association between rectal tumor location and pathologic complete response.

Effect of Adding Bevacizumab to Chemotherapy on Pathologic Response to Preoperative Systemic Therapy for Resectable Colorectal Liver Metastases: A Systematic Review and Meta-analysis

BACKGROUND

Liver-limited metastatic colorectal cancer is a potentially curable disease. Pathologic response (pR) to preoperative chemotherapy (CT) for colorectal liver metastases (CLM) is a surrogate endpoint for overall survival (OS). We conducted the first meta-analysis of observational studies to estimate the overall effect of bevacizumab on pR in preoperative systemic therapy for CLM.

METHODS

We systematically searched PubMed, Cochrane Library, CINAHL, Web of Science, Embase, and LILACS for studies published between January 2004 and August 2019 that compared the pR of CT plus bevacizumab to CT alone as preoperative therapy for CLM. The primary endpoint was pathologic complete response (pCR). Secondary endpoints were pathologic major (pMaR) and minor (pMiR) response. Overall effects were expressed by odds ratios (ORs) and 95% confidence intervals (CIs) using a random-effects model.

RESULTS

Of the 1,452 studies yielded by the search, 9 were eligible, totaling 1,202 patients (516 CT plus bevacizumab and 686 CT alone). The addition of bevacizumab to CT increased the pCR rate without reaching statistical significance (OR: 1.24, 95% CI 0.81 to 1.92, P = .32). However, pMaR was significantly higher (OR: 2.45, 95% CI 1.85 to 3.25, P < .001), and pMiR was significantly lower (OR: 0.41, 95% CI 0.31 to 0.54, P < .001), in the bevacizumab group. The analyses showed a low level of heterogeneity (I² = 0% to 6%). Publication bias was not found.

CONCLUSIONS

This meta-analysis demonstrates that bevacizumab plus preoperative CT is associated with higher rates of pR in CLM. Antiangiogenics might improve the OS of CLM patients and should be evaluated in randomized clinical trials.

MICROABSTRACT

The benefit of perioperative chemotherapy for colorectal liver metastases (CLM) is uncertain, but pathologic response (pR) to preoperative chemotherapy is a strong prognostic factor. Our meta-analysis of observational studies compared the pR of bevacizumab plus chemotherapy to chemotherapy alone as preoperative systemic therapy in the management of CLM. The addition of bevacizumab was associated with significantly higher rates of pR.

Predictive Factors for Pathologic Complete Response Following Neoadjuvant Chemoradiotherapy for Rectal Cancer

Background:

An accurate assessment of potential pathologic complete response(pCR) following neoadjuvant chemoradiotherapy(NCRT) is important for the appropriate treatment of rectal cancer. However, the factors that predict the response to neoadjuvant chemoradiotherapy have not been well defined. Therefore, this study analyzed the predictive factors on the development of pCR after neoadjuvant chemoradiation for rectal cancer.

Methods:

From January 2008 to January 2018, a total of 432 consecutive patients from a single institution patients who underwent a long-course neoadjuvant chemoradiotherapy were reviewed in this study. The clinicopathological features were analyzed to identify predictive factors for pathologic complete response in rectal cancer after neoadjuvant chemoradiation.

Results:

The rate of pathologic complete response in rectal cancer after neoadjuvant chemoradiation was 20.8%, patients were divided into the pCR and non-pCR groups. The two groups were well balanced in terms of age, gender, body mass index, ASA score, tumor stage, tumor differentiation, tumor location, surgical procedure, chemotherapy regimen and radiation dose. The multivariate analysis revealed that a pretreatment carcinoembryonic antigen (CEA) level of ≤5 ng/mL and an interval of ≥8 weeks between the completion of chemoradiation and surgical resection were independent risk factors of an increased rate of pCR.

Conclusions:

Pretreatment carcinoembryonic antigen (CEA) level of ≤5 ng/mL and an interval of ≥8 weeks between the completion of chemoradiation and surgical resection are predictive factors for pathologic complete response in rectal cancer after neoadjuvant chemoradiation. Using these predictive factors, we can predict the prognosis of patients and develop adaptive treatment strategies. A wait-and-see policy might be possible in highly selective cases.

Could the conservative approach be considered safe in the treatment of locally advanced rectal cancer in case of a clinical near-complete or complete response? A retrospective analysis

BACKGROUND

Conservative approach has emerged as an option for the management of rectal cancer (RC) patients with a near or complete clinical response after neoadjuvant chemoradiotherapy (nCRT). The aim of this study is to assess the impact of the conservative approach by comparing patients' survival outcomes and quality of life with those who had surgical resection.

METHODS

A single-institution and retrospective study including RC patients who reached a near complete or complete clinical response after nCRT from January 2010 to September 2019. Conservative approaches included local excision or watch and wait strategy; surgery approaches included anterior resection or abdominal-perineal resection.Local regrowth (LR), overall survival, disease free survival, metastasis free survival and colostomy free survival were evaluated through Kaplan-Meier curves and compared trough log-rank tests. Quality of life was measured by the following validated questionnaires: EORTC QLC30, EORTC QLQ - CR29 and Fecal Incontinence Quality of Life scale.

RESULTS

Overall 157 patients were analyzed: 105 (66,9%) underwent radical surgery and 52 (33,1%) had a conservative approach. With a median follow-up of 51 months, 2 patients in the surgical group had a local recurrence and 8 in the conservative group had a LR, respectively. Distance metastasis occurred in 7 and 1 patients of surgical and conservative group, respectively. No differences were detected in terms of survival outcomes except for colostomy free survival (p: 0,01). The conservative group showed better intestinal (p < 0.01) and sexual (p: 0,04) function and emotional status (p: 0,02).

CONCLUSIONS

Conservative approach seems to be safe in terms of survival outcomes with a significant advantage on quality of life in RC patients who achieved clinical complete response after nCRT.

Short-course radiotherapy with consolidation chemotherapy versus conventionally fractionated long-course chemoradiotherapy for locally advanced rectal cancer: randomized clinical trial

BACKGROUND

The trial hypothesis was that, in a resource-constrained situation, short-course radiotherapy would improve treatment compliance compared with conventional chemoradiotherapy for locally advanced rectal cancer, without compromising oncological outcomes.

METHODS

In this open-label RCT, patients with cT3, cT4 or node-positive non-metastatic rectal cancer were allocated randomly to 5 × 5 Gy radiotherapy and two cycles of XELOX (arm A) or chemoradiotherapy with concurrent capecitabine (arm B), followed by total mesorectal excision in both arms. All patients received a further six cycles of adjuvant chemotherapy with the XELOX regimen. The primary endpoint was treatment compliance, defined as the ability to complete planned treatment, including neoadjuvant radiochemotherapy, surgery, and adjuvant chemotherapy to a dose of six cycles.

RESULTS

Of 162 allocated patients, 140 were eligible for analysis: 69 in arm A and 71 in arm B. Compliance with planned treatment (primary endpoint) was greater in arm A (63 versus 41 per cent; P = 0.005). The incidence of acute toxicities of neoadjuvant therapy was similar (haematological: 28 versus 32 per cent, P = 0.533; gastrointestinal: 14 versus 21 per cent, P = 0.305; grade III-IV: 2 versus 4 per cent, P = 1.000). Delays in radiotherapy were less common in arm A (9 versus 45 per cent; P < 0.001), and overall times for completion of neoadjuvant treatment were shorter (P < 0.001). The rates of R0 resection (87 versus 90 per cent; P = 0.554), sphincter preservation (32 versus 35 per cent; P = 0.708), pathological complete response (12 versus 10 per cent; P = 0.740), and overall tumour downstaging (75 versus 75 per cent; P = 0.920) were similar. Downstaging of the primary tumour (ypT) was more common in arm A (P = 0.044). There was no difference in postoperative complications between trial arms (P = 0.838).

CONCLUSION

Reduced treatment delays and a higher rate of compliance were observed with treatment for short-course radiotherapy with consolidation chemotherapy, with no difference in early oncological surgical outcomes. In time- and resource-constrained rectal cancer units in developing countries, short-course radiotherapy should be the standard of care.

Treatment Intensification for Locally Advanced Rectal Cancer: Impact on Pathological Complete Response and Outcomes

AIM

Pathological complete response (pCR) and clinical outcomes [overall survival (OS), disease-free survival (DFS), locoregional control (LC)] were evaluated in a single-institution experience of different schedules of neoadjuvant chemoradiotherapy (CRT) for patients with locally advanced rectal cancer (LARC).

PATIENTS AND METHODS

Data for 322 patients with LARC were retrospectively analyzed. pCR was evaluated according to Mandard tumor regression grade (TRG). The Kaplan-Meier method was used to estimate OS, DFS and LC.

RESULTS

Three hundred and three (94.1%) patients underwent surgery. pCR was observed in 81 patients (26.7%), with TRG1-2 rate of 41.8%. The 5- and 10-year OS, DFS and LC rates were 82.5%±2.5% and 65.5%±3.8%, 81.2%±2.4% and 79.3%±2.9%, 93.1%±1.7% and 90.5%±2.1%, respectively.

CONCLUSION

Neoadjuvant CRT in LARC patients resulted in favorable long-term oncological outcomes, with a high pCR rate and acceptable toxicity.

Prognostic factors in patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy and radical resection of rectal cancer

BACKGROUND

There are only a few studies on the prognosis of patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy (NCRT) and radical resection of rectal cancer. The aim of the study was to identify prognostic factors with regard to oncological outcome in ypT0 patients after NCRT and radical resection.

METHODS

All ypT0 patients with rectal cancer after NCRT and radical resection between January 2010 and June 2019 were included. Cox univariate and multivariate regression analyses were used to determine the prognostic factors of these patients.

RESULTS

Seventy-six patients with ypT0 rectal cancer were included. In nine patients (11.8%), lymph node metastasis was identified. Age, gender, elevated carcinoembryonic antigen (CEA) and ypN+ were risk factors associated with a worse 5-year disease-free survival (DFS) rate in univariate analysis (P = 0.08, 0.14, 0.007 and 0.003, respectively). In multivariate analysis, ypN+ and elevated CEA before NCRT were independent risk factors for worse 5-year DFS (P = 0.005 and 0.021, respectively). Elevated CEA before NCRT, post-operative chemotherapy and ypN+ were risk factors associated with worse overall survival in univariate analysis (P = 0.14, 0.002 and 0.17, respectively). However, in multivariate analysis, none of these three factors were independent risk factors for worse overall survival (P = 0.20, 0.34 and 0.06, respectively).

CONCLUSION

ypN+ and elevated CEA before NCRT were found to be independent risk factors for an unfavourable DFS in ypT0 patients with complete response of the tumour after neoadjuvant chemoradiotherapy for rectal cancer.

Preliminary results of simultaneous integrated boost intensity-modulated radiation therapy based neoadjuvant chemoradiotherapy on locally advanced rectal cancer with clinically suspected positive lateral pelvic lymph nodes

Background

Lateral pelvic lymph node (LPLN) is approximately 11–14% and always associated with poorer prognosis. This study investigated the efficacy and safety of simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) based on neoadjuvant chemoradiotherapy (NCRT) on locally advanced rectal cancer (LARC) patients with clinically suspected positive LPLNs.

Methods

We retrospectively screened distal LARC patients with NCRT in our center from May 2016 and June 2019. The diagnostic criteria of positive LPLN were nodes of over 7 mm in short axis and irregular border or mixed-signal intensity. All patients with clinically suspected positive LPLN received 56–60 Gy SIB-IMRT in the LPLN area. Concurrent chemotherapy regimens were capecitabine as monotherapy treatment or in combination with oxaliplatin. The toxicities, local-regional recurrence (LRR), and disease-free survival (DFS) were investigated.

Results

Fifty-two eligible patients with clinically suspected positive LPLN were screened and analyzed. The median distance from the distal tumor to the anal verge was 4 cm (range, 0–8 cm), while magnetic resonance imaging (MRI) analysis revealed the median short diameter of the pelvic LPLN to be 8 mm (range, 7–20 mm). There were 28 (53.8%) mesorectal fascia (MRF) positive and 22 (42.3%) extramural venous invasion (EMVI) positive patients. A radiotherapy dose of 41.8 Gy was administered to the pelvic area, while the LPLN received a median SIB dose of 60.0 Gy (range, 56–60 Gy) across 22 fractions. Synchronous capecitabine with or without oxaliplatin was administered during radiotherapy. In summary, 15 (28.8%) patients displayed grade 2–3 radiation-related toxicity, 8 (15.4%) patients underwent additional LPLN dissection, and positive nodes (26 nodes in total) were not observed. One patient suffered a LLR in the presacral region. The median follow-up duration was 21.2 months (range, 4.7–45.0 months), while the duration of 1- and 2-year DFS were 89.9% and 74.6%, respectively. Patients did not display LPLN recurrence.

Conclusions

The safety and efficacy of SIB-IMRT on clinically suspected positive LPLN of LARC patients were deemed acceptable. Patients did not exhibit in-field LPLN recurrence after NCRT combined with single total mesorectal excision (TME).

Risk Stratification Using Neoadjuvant Rectal Score in the Era of Neoadjuvant Chemoradiotherapy: Validation With Long-term Outcome Data

BACKGROUND

Despite the widespread use of neoadjuvant chemoradiotherapy, there is no prognostic surrogate marker established in locally advanced rectal cancer.

OBJECTIVE

This study evaluated the role of neoadjuvant rectal score as a prognostic factor to stratify individual-level risks of survival and tumor recurrence.

DESIGN

This is a retrospective study.

SETTINGS

This study was conducted at the Seoul National University Hospital.

PATIENTS

A total of 397 patients who underwent chemoradiotherapy plus total mesorectal excision were analyzed.

INTERVENTIONS

There was no intervention.

MAIN OUTCOME MEASURES

Harrell C statistic and receiver operating characteristic analysis, as well as Cox regression analysis, were used to assess the prognostic strength.

RESULTS

The low (<8), intermediate (8-16), and high (>16) neoadjuvant rectal score groups included 91 (23%), 208 (52%), and 98 patients (25%). A high neoadjuvant rectal score was independently associated with inferior overall survival and disease-free survival (p = 0.011 and 0.008). Regarding the prognostic models adjusted for neoadjuvant rectal score (I) and ypT/N stage (II), the c-index was higher in model I (0.799 and 0.787, p = 0.009 for overall survival; 0.752 and 0.743, p = 0.093 for disease-free survival). The predictive ability of the neoadjuvant rectal score was superior to tumor regression grade, ypT, and ypN in the receiver operating characteristic analyses (p < 0.05 for all). Adjuvant chemotherapy was associated with better overall and disease-free survival (p = 0.003 and 0.052) in the high neoadjuvant rectal score group.

LIMITATIONS

Potential selection bias attributed to the retrospective study design was a limitation.

CONCLUSIONS

We verified the applicability of the neoadjuvant rectal score to stratify the relapse risk at the individual level for patients with stage II/III rectal cancer undergoing neoadjuvant chemoradiotherapy. Additional studies are needed to validate the usability of neoadjuvant rectal score levels as a determinant of adjuvant strategy. See Video Abstract at http://links.lww.com/DCR/B354. ESTRATIFICACIÓN DE RIESGO UTILIZANDO LA PUNTUACIÓN RECTAL NEOADYUVANTE EN LA ERA DE LA QUIMIORRADIOTERAPIA NEOADYUVANTE: VALIDACIÓN CON DATOS DE RESULTADOS A LARGO PLAZO: A pesar del uso generalizado de la quimiorradioterapia neoadyuvante, no existe un marcador subrogado pronóstico establecido en el cáncer de recto localmente avanzado.Este estudio evaluó el papel de la puntuación rectal neoadyuvante como factor pronóstico para estratificar los riesgos a nivel individual de supervivencia y recurrencia tumoral.Este es un estudio retrospectivo.Este estudio se realizó en el Hospital de la Universidad Nacional de Seúl.Se analizaron un total de 397 pacientes que se sometieron a quimiorradioterapia más escisión mesorrectal total.No hubo intervención.El análisis estadístico C de Harrell y las características operativas del receptor, así como el análisis de regresión de Cox, se utilizaron para evaluar la fuerza pronóstica.Los grupos de puntaje rectal neoadyuvante bajo (<8), intermedio (8-16) y alto (> 16) incluyeron 91 (23%), 208 (52%) y 98 (25%) pacientes, respectivamente. Una puntuación rectal neoadyuvante alta se asoció independientemente con una supervivencia general y una supervivencia libre de enfermedad inferiores (p = 0.011 y 0.008, respectivamente). Con respecto a los modelos pronósticos ajustados por la puntuación rectal neoadyuvante (I) y el estadio ypT/N (II), el índice c fue mayor en el modelo I (0.799 y 0.787, p = 0.009 para la supervivencia general; 0.752 y 0.743, p = 0.093 para supervivencia libre de enfermedad). La capacidad predictiva de la puntuación rectal neoadyuvante fue superior al grado de regresión tumoral, ypT y ypN en los análisis de características operativas del receptor (p <0.05 para todos). La quimioterapia adyuvante se asoció con una mejor supervivencia global y libre de enfermedad (p = 0.003 y 0.052, respectivamente) en el grupo de puntaje rectal neoadyuvante alto.El sesgo de selección potencial debido al diseño retrospectivo del estudio fue la limitación.Verificamos la aplicabilidad de la puntuación rectal neoadyuvante para estratificar el riesgo de recurrencia a nivel individual para pacientes con cáncer rectal en estadio II/III sometidos a quimiorradioterapia neoadyuvante. Se necesitan más estudios para validar la usabilidad de los niveles de puntuación rectal neoadyuvante como determinante de la estrategia adyuvante. Consulte Video Resumen en http://links.lww.com/DCR/B354.

Timing to achieve the highest rate of pCR after preoperative radiochemotherapy in rectal cancer: a pooled analysis of 3085 patients from 7 randomized trials

PURPOSE

Optimal timing of surgery after neoadjuvant chemoradiotherapy (Nad-CRT) is still controversial in locally advanced rectal cancer (LARC). The primary goal of this study was to determine the best surgical interval (SI) to achieve the highest rate of pathological complete response (pCR) and secondly to evaluate the effect on survival outcomes according to the SI.

PATIENTS AND METHODS

Patients data were extracted from the international randomized trials: Accord12/0405, EORTC22921, FFCD9203, CAO/ARO/AIO-94, CAO-ARO-AIO-04, INTERACT and TROG01.04. Inclusion criteria were: age≥ 18, cT3-T4 and cN0-2, no clinical evidence of distant metastasis at diagnosis, Nad-CRT followed by surgery. Pearson's Chi-squared test with Yates' continuity correction for categorical variables, the Mann-Whitney test for continuous variables, Mann-Kendall test, Kaplan-Meier curves with log-rank test, univariate and multivariate logistic regression model was used for data analysis.

RESULTS

3085 patients met the inclusion criteria. Overall, the pCR rate was 14% at a median SI of 6 weeks (range 1-31). The cumulative pCR rate increased significantly when SI lengthened, with 95% of pCR events within 10 weeks from Nad-CRT. At univariate and multivariate logistic regression analysis, lengthening of SI (p< 0.01), radiotherapy dose (p< 0.01), and the addition of oxaliplatin to Nad-CRT (p< 0.01) had a favorable impact on pCR. Furthermore, lengthening of SI was not impact on local recurrences, distance metastases, and overall survival.

CONCLUSION

This pooled analysis suggests that the best time to achieve pCR in LARC is at 10 weeks, considering that the lengthening of SI is not detrimental concerning survival outcomes.

1.5 T MR-linac planning study to compare two different strategies of rectal boost irradiation

PURPOSE

To compare treatment plans of two different rectal boost strategies: up-front versus adaptive boost at the 1.5 T MR-Linac.

METHODS

Patients with locally advanced rectal cancer (LARC) underwent standard neoadjuvant radiochemotherapy with 50.4 Gy in 28 fractions. T2-weighted MRI prior and after the treatment session were acquired to contour gross tumor volumes (GTVs) and organs at risk (OARs). The datasets were used to simulate four different boost strategies (all with 15 Gy/5 fractions in addition to 50.4 Gy): up-front boost (5 daily fractions in the first week of treatment) and an adaptive boost (one boost fraction per week). Both strategies were planned using standard and reduced PTV margins. Intra-fraction motion was assessed by pre- and post-treatment MRI-based contours.

RESULTS

Five patients were included and a total of 44 MRI sets were evaluated. The median PTV volumes of the adaptive boost were significantly smaller than for the up-front boost (81.4 cm3 vs 44.4 cm3 for PTV with standard margins; 31.2 cm3 vs 15 cm3 for PTV with reduced margins; p = 0.031). With reduced margins the rectum was significantly better spared with an adaptive boost rather than with an up-front boost: V60Gy and V65Gy were 41.2% and 24.8% compared with 59% and 29.9%, respectively (p = 0.031). Median GTV intra-fractional motion was 2 mm (range 0-8 mm).

CONCLUSIONS

The data suggest that the adaptive boost strategy exploiting tumor-shrinkage and reduced margin might result in better sparing of rectum and anal canal. Individual margin assessment, motion management and real-time adaptive radiotherapy appear attractive applications of the 1.5 T MR-Linac for further testing of individualized and safe dose escalation in patients with rectal cancer.

Neoadjuvant treatment (FOLFOX4 plus hypofractionated tomotherapy) for patients with locally advanced rectal cancer: a multicenter phase II trial

AIMS

This study aims to evaluate the safety and efficacy of a new neoadjuvant regimen (FOLFOX4 plus hypofractionated tomotherapy) in patients with locally advanced rectal cancer.

METHODS

Patients with stage II-III rectal cancer were treated with the pre-operative chemoradiotherapy regimen comprising FOLFOX4 (two cycles), TomoTherapy (25 Gy in five consecutive fractions, one fraction per day in 5 days on the clinical target volume at the isodose of 95% of the total dose), FOLFOX4 (two cycles), followed by surgery with total mesorectal excision and adjuvant chemotherapy with FOLFOX4 (eight cycles). The primary endpoint was pathological complete response (pCR).

RESULTS

Fifty-two patients were enrolled and 50 patients were evaluable. A total of 46 (92%) patients completed chemoradiotherapy according to the study protocol and 49 patients underwent surgery. Overall, 12 patients achieved a pCR (24.5%, 95% CI 12.5-36.5). The most common grade 3 or more adverse events were neutropenia and alteration of the alvus. Adverse reactions due to radiotherapy, mainly grade 1-2 dermatitis, tenesmus, urinary dysfunction and pain, were tolerable and fully reversible. The most important surgical complications included infection, anastomotic leakage and fistula, all resolved with conservative treatment.

CONCLUSION

FOLFOX and hypofractionated TomoTherapy is effective and safe in patients with locally advanced rectal cancer. Long-term efficacy needs to be further evaluated.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02000050 (registration date: 26 November 2013) https://clinicaltrials.gov/ct2/show/NCT02000050.

Prognostic Value of Tumor Regression Grade on MR in Rectal Cancer: A Large-Scale, Single-Center Experience

Objective

To determine the prognostic value of MRI-based tumor regression grading (mrTRG) in rectal cancer compared with pathological tumor regression grading (pTRG), and to assess the effect of diffusion-weighted imaging (DWI) on interobserver agreement for evaluating mrTRG.

Materials and Methods

Between 2007 and 2016, we retrospectively enrolled 321 patients (male:female = 208:113; mean age, 60.2 years) with rectal cancer who underwent both pre-chemoradiotherapy (CRT) and post-CRT MRI. Two radiologists independently determined mrTRG using a 5-point grading system with and without DWI in a one-month interval. Two pathologists graded pTRG using a 5-point grading system in consensus. Kaplan-Meier estimation and Cox-proportional hazard models were used for survival analysis. Cohen's kappa analysis was used to determine interobserver agreement.

Results

According to mrTRG on MRI with DWI, there were 6 mrTRG 1, 48 mrTRG 2, 109 mrTRG 3, 152 mrTRG 4, and 6 mrTRG 5. By pTRG, there were 7 pTRG 1, 59 pTRG 2, 180 pTRG 3, 73 pTRG 4, and 2 pTRG 5. A 5-year overall survival (OS) was significantly different according to the 5-point grading mrTRG (p = 0.024) and pTRG (p = 0.038). The 5-year disease-free survival (DFS) was significantly different among the five mrTRG groups (p = 0.039), but not among the five pTRG groups (p = 0.072). OS and DFS were significantly different according to post-CRT MR variables: extramural venous invasion after CRT (hazard ratio = 2.259 for OS, hazard ratio = 5.011 for DFS) and extramesorectal lymph node (hazard ratio = 2.610 for DFS). For mrTRG, k value between the two radiologists was 0.309 (fair agreement) without DWI and slightly improved to 0.376 with DWI.

Conclusion

mrTRG may predict OS and DFS comparably or even better compared to pTRG. The addition of DWI on T2-weighted MRI may improve interobserver agreement on mrTRG.

Ten-year survival after pathologic complete response in rectal adenocarcinoma

BACKGROUND

Multimodal treatment is the standard of care for rectal adenocarcinoma, with a subset of patients achieving a pathologic complete response (pCR). While pCR is associated with improved overall survival (OS), long-term data on patients with pCR is limited.

METHODS

This is a single institution retrospective cohort study of all patients with clinical stages II/III rectal adenocarcinoma who underwent neoadjuvant chemoradiation therapy and operative resection (January 1, 2004-December 31, 2017). PCR was defined as no tumor identified in the rectum or associated lymph nodes by final pathology.

RESULTS

Of 370 patients in this cohort, 50 had a pCR (13.5%). For pCR patients, 5-year disease-free survival (DFS) was 92%, 5-year OS was 95%. Twenty-six patients had surgery > 10 years before the study end date, of which 20 had an OS > 10 years (77%) with median OS 12.1 years and 95% alive to date (19/20). Of the 50 pCR patients, there was a single recurrence in the lung at 44.3 months after proctectomy which was surgically resected.

CONCLUSION

For patients with rectal adenocarcinoma that undergo neoadjuvant chemoradiation and surgical resection, pCR is associated with excellent long-term DFS and OS. Many patients live greater than 10 years with no evidence of disease recurrence.

Multiparametric MRI as a Biomarker of Response to Neoadjuvant Therapy for Localized Prostate Cancer-A Pilot Study

RATIONALE AND OBJECTIVES

To explore a role for multiparametric MRI (mpMRI) as a biomarker of response to neoadjuvant androgen deprivation therapy (ADT) for prostate cancer (PCa).

MATERIALS AND METHODS

This prospective study was approved by the institutional review board and was HIPAA compliant. Eight patients with localized PCa had a baseline mpMRI, repeated after 6-months of ADT, followed by prostatectomy. mpMRI indices were extracted from tumor and normal regions of interest (TROI/NROI). Residual cancer burden (RCB) was measured on mpMRI and on the prostatectomy specimen. Paired t-tests compared TROI/NROI mpMRI indices and pre/post-treatment TROI mpMRI indices. Spearman's rank tested for correlations between MRI/pathology-based RCB, and between pathological RCB and mpMRI indices.

RESULTS

At baseline, TROI apparent diffusion coefficient (ADC) was lower and dynamic contrast enhanced (DCE) metrics were higher, compared to NROI (ADC: 806 ± 137 × 10^-6 vs. 1277 ± 213 × 10^-6 mm²/sec, p = 0.0005; K^trans: 0.346 ± 0.16 vs. 0.144 ± 0.06 min^-1, p = 0.002; AUC₉₀: 0.213 ± 0.08 vs. 0.11 ± 0.03, p = 0.002). Post-treatment, there was no change in TROI ADC, but a decrease in TROI K^trans (0.346 ± 0.16 to 0.188 ± 0.08 min^-1; p = 0.02) and AUC₉₀ (0.213 ± 0.08 to 0.13 ± 0.06; p = 0.02). Tumor volume decreased with ADT. There was no difference between mpMRI-based and pathology-based RCB, which positively correlated (⍴ = 0.74-0.81, p < 0.05). Pathology-based RCB positively correlated with post-treatment DCE metrics (⍴ = 0.76-0.70, p < 0.05) and negatively with ADC (⍴ = -0.79, p = 0.03).

CONCLUSION

Given the heterogeneity of PCa, an individualized approach to ADT may maximize potential benefit. This pilot study suggests that mpMRI may serve as a biomarker of ADT response and as a surrogate for RCB at prostatectomy.

Fusobacterium nucleatum persistence and risk of recurrence after preoperative treatment in locally advanced rectal cancer

BACKGROUND

Accumulating evidence has identified Fusobacterium as an important pathogenic gut bacterium associated with colorectal cancer. Nevertheless, only limited data exist about the role of this bacterium in locally advanced rectal cancer (LARC). In this study, we quantified Fusobacterium nucleatum in untreated and post-neoadjuvant chemoradiotherapy (nCRT) samples from LARC patients and investigated its association with therapy response and survival.

PATIENTS AND METHODS

A total of 254 samples from 143 patients with rectal adenocarcinomas were analyzed for the presence and abundance of F. nucleatum using RNA in situ hybridization and digital image analysis. Assay accuracy was determined using infected cell lines and tumor samples with available quantitative PCR data. We studied the impact of F. nucleatum load on pathologic complete response and relapse-free survival. Treatment-induced changes were evaluated in paired pre- and post-nCRT samples (n = 71). Finally, tumor microenvironment changes during nCRT were assessed in paired samples (n = 45) by immune contexture analysis.

RESULTS

F. nucleatum tissue levels by RNA in situ hybridization strongly correlated with quantitative PCR (r = 0.804, P < 0.001). F. nucleatum abundance was higher in untreated [median, 7.4; 95% confidence interval (3.7-16.2)] compared with treated [median, 1.6; 95% confidence interval (1.3-2.4)] tumors (P <0.001) with 58% (73/126) and 26% (22/85) positive tumors, respectively (P < 0.001). Baseline F. nucleatum levels were not associated with pathologic complete response. F. nucleatum positivity after nCRT, but not baseline status, significantly increased risk of relapse [hazard ratio = 7.5, 95% confidence interval (3.0-19.0); P < 0.001]. Tumors that turned F. nucleatum-negative after nCRT had a strong increase in CD8+ T cells post-nCRT (P < 0.001), while those that persisted F. nucleatum-positive after nCRT lacked CD8+ T cells induction in post-nCRT samples compared with baseline (P = 0.69).

CONCLUSION

F. nucleatum persistence post-nCRT is associated with high relapse rates in LARC, potentially linked to suppression of immune cytotoxicity.

Phase II Trial of Neoadjuvant Bevacizumab with Modified FOLFOX7 in Patients with Stage II and III Rectal Cancer

LESSONS LEARNED

Neoadjuvant bevacizumab with modified FOLFOX7 without radiation failed to meet the goal of pathological complete response rate; however, the low number of recurrence and disease-free survival in this population, with predominantly stage III, is encouraging and worth further exploration. The racial distribution of the patient population, as well as a wait time of more than 4 weeks after last chemotherapy, may have contributed to the findings.

BACKGROUND

Combination chemotherapy in lieu of radiation in rectal adenocarcinoma is under exploration in multiple trials. We evaluated the efficacy of neoadjuvant FOLFOX + bevacizumab in patients (pts) with clinical stage II and III disease.

METHODS

Pts received six cycles of bevacizumab (5 mg/kg) and modified FOLFOX7 (oxaliplatin 85 mg/m² , leucovorin 20 mg/m² , and fluorouracil [5-FU] 2,400 mg/m² ). Surgical resection was performed 6-8 weeks after completion of treatment and upon confirmation of nonmetastatic disease. We employed a Simon two-stage design and required three pathological complete responses (pCR) in the first 18 pts, with a prespecified pCR rate of 25% before moving to the next stage.

RESULTS

Seventeen pts enrolled; 65% at stage III. Median age was 57 (35-79), 65% were male, 47% were Hispanic, 35% were white, and 18% were Asian. All pts but one completed six cycles of therapy. One pCR was observed (6%), and 11 of 17 (65%) pts had pathological downstaging. One patient experienced systemic recurrence and remains on treatment. Probability of disease-free survival (DFS) at 5 years is 0.94 (SE, 0.06).

CONCLUSION

The study failed to meet the required three pCRs in the first 18 pts. The DFS in this population is encouraging and supports the hypothesis that select pts with rectal cancer may be spared from radiation.

External Validation of Early Regression Index (ERITCP) as Predictor of Pathologic Complete Response in Rectal Cancer Using Magnetic Resonance-Guided Radiation Therapy

PURPOSE

Tumor control probability (TCP)-based early regression index (ERI_TCP) is a radiobiological parameter that showed promising results in predicting pathologic complete response (pCR) on T2-weighted 1.5 T magnetic resonance (MR) images of patients with locally advanced rectal cancer. This study aims to validate the ERI_TCP in the context of low-tesla MR-guided radiation therapy, using images acquired with different magnetic field strength (0.35 T) and image contrast (T2/T1). Furthermore, the optimal timing for pCR prediction was estimated, calculating the ERI index at different biologically effective dose (BED) levels.

METHODS AND MATERIALS

Fifty-two patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy were enrolled in this multi-institutional retrospective study. For each patient, a 0.35 T T2/T1-weighted MR image was acquired during simulation and on each treatment day. Gross tumor volume was contoured according to International Commission on Radiation Units Report 83 guidelines. According to the original definition, ERI_TCP was calculated considering the residual tumor volume at BED = 25 Gy. ERI was also calculated in correspondence with several BED levels: 13, 21, 32, 40, 46, 54, 59, and 67. The predictive performance of the different ERI indices were evaluated in terms of receiver operating characteristic curve. The robustness of ERI_TCP with respect to the interobserver variability was also evaluated considering 2 operators and calculating the intraclass correlation index.

RESULTS

Fourteen patients showed pCR. ERI_TCP correctly 47 of 52 cases (accuracy = 90%), showing good results in terms of sensitivity (86%), specificity (92%), negative predictive value (95%), and positive predictive value (80%). The analysis at different BED levels shows that the best predictive performance is obtained when this parameter is calculated at BED = 25 Gy (area under the curve = 0.93). ERI_TCP results are robust with respect to interobserver variability (intraclass correlation index = 0.99).

CONCLUSIONS

This study confirmed the validity and the robustness of ERI_TCP as a pCR predictor in the context of low-tesla MR-guided radiation therapy and indicate 25 Gy as the best BED level to perform predictions.

Association between adjuvant chemotherapy and survival in patients with rectal cancer and pathological complete response after neoadjuvant chemoradiotherapy and resection

Background

For patients with locally advanced rectal cancer (LARC), it is unclear whether neoadjuvant chemoradiotherapy-induced pathologic complete response (pCR) individuals would further benefit from adjuvant chemotherapy (ACT).

Methods

The pCR individuals who received different ACT cycles were paired by propensity score matching. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were calculated by Kaplan–Meier and log-rank test.

Results

In total, 1041 pCR individuals were identified from 5567 LARC cases. Specifically, 303 pCR cases had no ACT treatment, and 738 pCR patients received fluoropyrimidine-based ACT (median, 4 cycles) treatment. After 1:3 propensity score matching, 297 cases without ACT treatment were matched to 712 cases who received ACT treatment. Kaplan–Meier analysis showed that pCR individuals treated with or without ACT had the similar 3-year outcome (OS, DFS, LRFS and DMFS) (all P > 0.05). Moreover, the pCR patients received different ACT cycle(s) (0 vs. 1–4 cycles, 0 vs. ≥5 cycles) had comparable 3-year OS, DFS, LRFS and DMFS (all P > 0.05). In stratified analysis, ACT treatment did not improve 3-year survival (OS, DFS, LRFS and DMFS) for the baseline high-risk (cT3–4/cN1–2) subgroup patients (all P > 0.05).

Conclusion

ACT, which did not improve survival, is unnecessary to neoadjuvant treatment-induced pCR LARC patients.

Trial registration

2019ZSLYEC-136 (24-6-2019).

Limited Role for Routine Restaging After Neoadjuvant Therapy in Locally Advanced Rectal Cancer

BACKGROUND

Although many patients with locally advanced rectal cancer undergo restaging imaging after neoadjuvant chemoradiotherapy and before surgery, the benefit of this practice is unclear. The purpose of this study was to examine the impact of reimaging on outcomes.

MATERIALS AND METHODS

We performed a retrospective analysis of consecutive patients with stage 2 and 3 rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy between May 2005 and April 2018. Patient and disease characteristics, imaging, treatment, and oncologic outcomes were compared between those who underwent restaging and those who went directly to surgery. Predictors of outcomes and cost effectiveness of restaging were determined.

RESULTS

Of 224 patients, 146 underwent restaging. Six restaged patients had findings leading to a change in management. There was no difference in freedom from recurrence (P = 0.807) and overall survival (P = 0.684) based on restaging. Pretreatment carcinoembryonic antigen level >3 ng/mL (P = 0.010), clinical T stage 4 (P = 0.016), and pathologic T4 (P = 0.047) and N2 (P = 0.002) disease increased the risk of death, whereas adjuvant chemotherapy decreased the risk of death (P < 0.001) on multivariate analysis. Disease recurrence was lower with pelvic exenteration (P = 0.005) and in females (P = 0.039) and higher with pathologic N2 (P = 0.003) and N3 (P = 0.002) disease. The average cost of reimaging is $40,309 per change in management; however, $45 is saved per patient when downstream surgical costs are considered.

CONCLUSIONS

Imaging restaging after neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer rarely changes treatment and does not improve survival. In a subset of patients at higher risk for worse outcome, reimaging may be beneficial.

Immunogenetic markers in IL17F predict the risk of metastases spread and overall survival in rectal cancer patients treated with neoadjuvant chemoradiotherapy

BACKGROUND AND PURPOSE

The role of the immune system in tumor response to chemo-radiotherapy (CRT) is an emerging issue. This work aimed at identifying predictive and prognostic immunogenetic variants in LARC patients after preoperative (po)-CRT and surgery.

MATERIALS AND METHODS

A set of 192 polymorphisms in 34 candidate genes involved in the regulation of the immune response signalling network, was selected and analyzed in 370 LARC patients treated with po-CRT and surgery, split into a Test Set (n = 233) and a Validation Set (n = 137). Immunogenetic markers were selected based on a concordant significant effect on 2-year relapse-free survival (2-yrRFS) (bootstrapped P < 0.05) in both patients Sets. The effect of the selected immunogenetic variants on 5-year metastases-free (5yrMFS), 5-year disease-free (5yrDFS), and 10-year overall (10yrOS) survival was tested in the entire Set of 370 patients.

RESULTS

Two immunogenetic IL17F (IL17F-rs641701 and IL17F-rs9463772) markers predictive of 2yrRFS, 5yrDFS, 5yrMFS, and 10yrOS were identified. The combination of tumor regression grade (TRG) and patients genotype for IL17F-rs641701 and IL17F-rs9463772 allowed the identification of subgroups of patients with differential prognosis in term of both 5yrDFS (HR 11.29, P-value <0.001, and HR 5.86, P-value = 0.001, respectively) and 10yrOS (HR 7.07, P-value = 0.005, and HR 6.05, P-value = 0.002, respectively).

CONCLUSION

IL17F-rs641701 and IL17F-rs9463772 were highlighted as promising immunogenetic markers significantly associated with the prognosis of LARC patients. After a prospective validation of the herein reported findings, the combination of TRG and patients genotype should be considered to provide additional stratification criteria for the selection of a personalized multimodality treatment.

[Preoperative intensity-modulated radiotherapy of rectal cancers: Relevance and modalities]

Preoperative radiotherapy boosted by chemotherapy is a recommended treatment in locally advanced rectal cancers. This treatment is delivered by three dimensional conformal irradiation, which is usually well tolerated but can induce potential toxicity such as rectitis, cystitis and hematologic adverse effects. Intensity-modulated radiotherapy, widely available nowadays, allows optimization of volume covering and sparing of organs at risk such as bladder and bone marrow. This review presents relevant clinical situations and requirements for a beneficial and safe preoperative irradiation of rectal cancers by intensity-modulated technique. This technique is compared to three-dimensional conformal radiotherapy.

Increased Rate of Complete Pathologic Response After Neoadjuvant FOLFIRINOX for BRCA Mutation Carriers with Borderline Resectable Pancreatic Cancer

BACKGROUND

Neoadjuvant FOLFIRINOX is a standard-of-care treatment for BRPC patients. Patients with gBRCAm who have demonstrated improved response to platinum-based chemotherapy may have impaired homologous repair deficiency. This study aimed to describe the pathologic complete response rate and long-term survival for patients with germline BRCA1 or BRCA2 mutation (gBRCAm) and borderline resectable pancreatic cancer (BRPC) treated with neoadjuvant FOLFIRINOX.

METHODS

A dual-center retrospective analysis was performed. Patients who had BRPC treated with neoadjuvant FOLFIRINOX followed by curative resection were identified from clinical databases. Pathologic complete response was defined as no viable tumor cells present in the specimen. Common founder Jewish germline BRCA1 or BRCA2 mutation was determined for available patients.

RESULTS

The 61 BRPC patients in this study underwent resection after neoadjuvant FOLFIRINOX. Analysis of BRCA mutation was performed for 39 patients, and 9 patients were found to be BRCA2 germline mutation carriers. The pathologic complete response rate was 44.4% for the gBRCAm patients and 10% for the BRCA non-carriers (p = 0.009). The median disease-free survival was not reached for the gBRCAm patients and was 7 months for the BRCA non-carriers (p = 0.03). The median overall survival was not reached for the gBRCAm patients and was 32 months for the BRCA non-carriers (p = 0.2). After a mean follow-up period of 33.7 months, all eight patients with pathologic complete response were disease-free.

CONCLUSIONS

The study showed that gBRCAm patients with BRPC have an increased chance for pathologic complete response and prolonged survival after neoadjuvant FOLFIRINOX. The results support the benefit of exposing gBRCAm patients to platinum-based chemotherapy early in the course of the disease. Neoadjuvant FOLFIRINOX should be considered for BRCA carriers who have resectable pancreatic cancer.

Carcinoembryonic Antigen Improves the Performance of Magnetic Resonance Imaging in the Prediction of Pathologic Response after Neoadjuvant Chemoradiation for Patients with Rectal Cancer

PURPOSE

The purpose of this study was to investigate the role of carcinoembryonic antigen (CEA) levels in improving the performance of magnetic resonance imaging (MRI) for the prediction of pathologic response after the neoadjuvant chemoradiation (NCRT) for patients with rectal cancer.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 524 rectal cancer patients who underwent NCRT and total mesorectal excision between January 2009 and December 2014. The performances of MRI with or without CEA parameters (initial CEA and CEA dynamics) for prediction of pathologic tumor response grade (pTRG) were compared by receiver-operating characteristic analysis with DeLong's method. Cox regression was used to identify the independent factors associated to pTRG and disease-free survival (DFS) after NCRT.

RESULTS

The median follow-up was 64.0 months (range, 3.0 to 113.0 months). On multivariate analysis, poor tumor regression grade on MRI (mrTRG; p < 0.001), initial CEA (p < 0.001) and the mesorectal fascia involvement on MRI before NCRT (mrMFI; p=0.054) showed association with poor pTRG. The mrTRG plus CEA parameters showed significantly improved performances in the prediction of pTRG than mrTRG alone. All of mrTRG, mrMFI, and initial CEA were also identified as independent factors associated with DFS. The initial CEA further discriminated DFS in the subgroups with good mrTRG or that without mrMFI.

CONCLUSION

The CEA parameters significantly improved the performance of MRI in the prediction of pTRG after NCRT for patients with rectal cancer. The DFS was further discriminated by initial CEA level in the groups with favorable MRI parameters.

Short-Term Clinical and Oncological Outcome of Prolonging Operation Interval After Neoadjuvant Chemoradiotherapy for Locally Advanced Middle and Low Rectal Cancer

Purpose

The purpose of this study is to evaluate the short-term clinical and oncological outcome of prolonging operation interval to 11 weeks after the end of radiotherapy for locally advanced middle and low rectal cancer.

Methods

A total of 123 patients with stage II/III (cT3/T4 or N+) low and middle rectal cancer who had undergone operation after neoadjuvant chemoradiotherapy were selected. According to the interval time between the last radiotherapy and operation, they were assigned to a short-interval group (SG, <11 weeks, n=66) and long-interval group (LG, ≥11 weeks, n=57). The relations among interval time and short-term clinical outcome and oncological outcome were analyzed.

Results

The analysis found that basic information, clinical characteristics, and preoperative treatment between the two groups had no significant difference. There were no differences in operation time, estimated intraoperative blood loss and postoperative complications. The rate of sphincter preservation in the low and middle rectum was 66.7% in the short-interval group and 59.7% in the long-interval group (P=0.42). The incidence of anastomotic leak in the long-interval group was higher than that in the short-interval group (P=0.08). There was no significant difference in the recovery time of intestinal function and median duration of hospitalization between the two groups. The pathological complete remission rate was 17.07%. Multivariate analysis showed interval time had no influence on pathological complete remission. There was no significant difference in 3-year overall survival and 3-year disease-free survival between the two groups. The risk of recurrence and metastasis in patients with positive lymph nodes was higher than those with negative lymph nodes (P<0.05), HR=4.812 (95% CI 2.4–9.648).

Conclusion

Prolonging the interval time of operation to 11 weeks after neoadjuvant chemoradiotherapy for middle and low rectal cancer does not improve the pathologic complete remission, morbidity, and mortality. There was no significant effect on oncologic outcome after prolonging the operation interval. Therefore, it is safe to prolong the interval of operation to 11 weeks.

Prognosis and risk factors for the development of pulmonary metastases after preoperative chemoradiotherapy and radical resection in patients with locally advanced rectal cancer

Background

Although preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) is currently considered effective for treating locally advanced rectal cancer (LARC), a proportion of patients develop postoperative pulmonary metastases. The current study aimed to assess the prognostic characteristics and risk factors for the development of rectal cancer pulmonary metastases after CRT and radical resection.

Methods

We retrospectively analyzed data collected on 544 consecutive patients who were diagnosed with LARC and underwent preoperative CRT followed by tumor radical resection between December 2003 and June 2014. Overall survival (OS), disease-free survival (DFS), and pulmonary metastasis rates were calculated and compared among the subgroups, and risk factors for pulmonary metastases were identified by Cox models.

Results

A total of 61 (11.2%) patients developed pulmonary metastases postoperatively, 45 of whom (73.8%) developed the condition in the first 24 months. The 1-, 2-, and 3-year pulmonary metastasis rates were 6.7%, 10.4%, and 11.7%, respectively. Compared with the disease-free group, the pulmonary metastases group had a significantly lower proportion of downstaging and pathological complete regression (pCR) rate and a significantly higher proportion of low rectum tumor. In multivariate analysis, a distance of the tumor ≤5 cm from the anal verge [hazard ratio (HR), 1.394; 95% confidence interval (CI), 1.211-3.736; P=0.003] was identified as an independent negative predictor of the 3-year pulmonary metastasis rate, and N0 stage (HR, 0.490; 95% CI, 0.261-0.919; P=0.026) and TNM downstaging (HR, 0.514; 95% CI, 0.265-0.997; P=0.049) were identified as independent positive predictors of the 3-year pulmonary metastasis rate.

Conclusions

Pulmonary metastases warranted a more intensive follow-up in patients with low rectal cancer, lymph node metastases and poor response after preoperative CRT and radical tumor resection.

Does A Longer Waiting Period After Neoadjuvant Radio-chemotherapy Improve the Oncological Prognosis of Rectal Cancer?: Three Years' Follow-up Results of the Greccar-6 Randomized Multicenter Trial

OBJECTIVE

The aim of this study was to report the 3-year survival results of the GRECCAR-6 trial.

SUMMARY BACKGROUND DATA

Current data on the effect of an extended interval between radiochemotherapy (RCT) and resection for rectal cancer on the rate of complete pathological response (pCR = ypT0N0) is controversial. Furthermore, its effect on oncological outcomes is unknown.

METHODS

The GRECCAR-6 trial was a phase III, multicenter, randomized, open-label, parallel-group, controlled trial. Patients with cT3/T4 or TxN+ tumors of the mid or lower rectum who had received RCT (45-50 Gy with 5-fluorouracil or capecitabine) were included and randomized into a 7- or 11-week waiting period. Primary endpoint was the pCR rate. Secondary endpoints were 3-year overall (OS), disease-free survival (DFS), and recurrence rates.

RESULTS

A total of 265 patients from 24 participating centers were enrolled. A total of 253 patients underwent a mesorectal excision. Overall pCR rate was 17% (43/253). Mean follow-up from surgical resection was 32 ± 8 months. Twenty-four deaths occurred with an 89% OS at 3 years. DFS was 68.7% at 3 years (75 recurrences). Three-year local and distant recurrences were 7.9% and 23.8%, respectively. The randomization group had no impact on the 3-year OS (P = 0.8868) or DFS (P = 0.9409). Distant (P = 0.7432) and local (P = 0.3944) recurrences were also not influenced by the waiting period. DFS was independently influenced by 3 factors: circumferential radial margin (CRM) ≤1 mm [hazard ratio (HR) = 2.03; 95% confidence interval (CI), 1.17-3.51], ypT3-T4 (HR = 2.69; 95% CI, 1.19-6.08) and positive lymph nodes (HR = 3.62; 95% CI, 1.89-6.91).

CONCLUSION

Extending the waiting period by 4 weeks following RCT has no influence on the oncological outcomes of T3/T4 rectal cancers.

Genomic variation as a marker of response to neoadjuvant therapy in locally advanced rectal cancer

There is variation in the responsiveness of locally advanced rectal cancer to neoadjuvant chemoradiation, from complete response to total resistance. This study compared genetic variation in rectal cancer patients who had a complete response to chemoradiation versus poor response, using tumor tissue samples sequenced with genomics analysis software. Rectal cancer patients treated with chemoradiation and proctectomy June 2006-March 2017 were grouped based on response to chemoradiation: those with no residual tumor after surgery (CR, complete responders, AJCC-CPR tumor grade 0, n = 8), and those with poor response (PR, AJCC-CPR tumor grade two or three on surgical resection, n = 8). We identified 195 variants in 83 genes in tissue specimens implicated in colorectal cancer biopathways. PR patients showed mutations in four genes not mutated in complete responders: KDM6A, ABL1, DAXX-ZBTB22, and KRAS. Ten genes were mutated only in the CR group, including ARID1A, PMS2, JAK1, CREBBP, MTOR, RB1, PRKAR1A, FBXW7, ATM C11orf65, and KMT2D, with specific discriminating variants noted in DMNT3A, KDM6A, MTOR, APC, and TP53. Although conclusions may be limited by small sample size in this pilot study, we identified multiple genetic variations in tumor DNA from rectal cancer patients who are poor responders to neoadjuvant chemoradiation, compared to complete responders.

Surgical treatment following neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Colorectal cancer is a major public health problem worldwide, and locally advanced rectal cancer (LARC) is known for its poor prognosis. A multimodal treatment approach is the only method to achieve satisfactory local recurrence and survival rates in LARC. Determining which therapeutic modality for LARC has the most satisfactory influence on quality of life and disease outcome is still controversial. LARC treatment is subject to continuous advancement due to the development of new and better diagnostic tools, radiotherapy techniques, and chemotherapeutic agents. Herein, we review various therapeutic modalities for LARC from several aspects. In addition to radiotherapy techniques such as neoadjuvant chemoradiotherapy (NCRT), we discuss the progress of chemotherapy, appropriate time interval between NCRT and surgery, relationship between tumor location and NCRT efficacy/safety, wait-and-watch policy, and predictors of treatment response following NCRT. Because of the controversies and unanswered questions regarding NCRT treatments for LARC, additional investigations are required to determine which therapeutic approach is the most feasible for LARC patients.

Impact of clinical complete response on treatment outcomes in patients with locally advanced HPV-negative oropharyngeal squamous cell carcinoma

OBJECTIVE

To evaluate treatment outcomes after definitive chemoradiotherapy (CRT) for human papilloma virus (HPV)-negative oropharyngeal squamous cell carcinoma (OPSCC).

MATERIALS AND METHODS

We analyzed data concerning HPV-negative OPSCC patients treated with curative intent. All patients received concomitant high-dose cisplatin-based chemotherapy. Two different RT techniques were used: (1) sequential boost IMRT (S-IMRT) to a total dose of 70 Gy (2 Gy/fraction); (2) simultaneously integrated boost (SIB-IMRT) to a total dose of 67.5 Gy (2.25 Gy/fraction). Survival outcomes were estimated.

RESULTS

In total, 69 HPV-negative OPSCC patients were included (n = 40 S-IMRT; n = 29 SIB-IMRT). The median follow-up time was 40 months. The 3-year overall survival, disease-free survival, distant metastasis-free survival and locoregional-free survival were 67.1%, 63.3%, 64.5% and 66.0%, respectively. Alcohol abuse and advanced stage disease at presentation were the main risk factors for worse survival outcomes. Complete clinical response (cCR) at 3 months after CRT improved overall survival (86.3% versus 42.5%, p < 0.01). The cCR events were greater but not statistically significant in SIB-IMRT group compared to S-IMRT patients (69% versus 47.5%, p = 0.09).

CONCLUSIONS

The positive impact of cCR at 3 months on survival needs to be confirmed in randomized clinical trials, as well as its close correlation with SIB-IMRT technique. A proper stratification of HPV-negative OPSCC patients should be paramount to tailor treatment strategy in the near future.

Magnetic Resonance Guided Radiotherapy for Rectal Cancer: Expanding Opportunities for Non-Operative Management

Colorectal cancer is the third most common cancer in men and the second most common in women worldwide, and the incidence is increasing among younger patients. 30% of these malignancies arise in the rectum. Patients with rectal cancer have historically been managed with preoperative radiation, followed by radical surgery, and adjuvant chemotherapy, with permanent colostomies in up to 20% of patients. Beginning in the early 2000s, non-operative management (NOM) of rectal cancer emerged as a viable alternative to radical surgery in select patients. Efforts have been ongoing to optimize neoadjuvant therapy for rectal cancer, thereby increasing the number of patients potentially eligible to forgo radical surgery. Magnetic resonance guided radiotherapy (MRgRT) has recently emerged as a treatment modality capable of intensifying preoperative radiation therapy for rectal cancer patients. This technology may also predict which patients will achieve a complete response to preoperative therapy, thereby allowing for more appropriate selection of patients for NOM. The present work seeks to illustrate the potential role MRgRT could play in personalizing rectal cancer treatment thus expanding the role of NOM in rectal cancer.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

Global variation in the long-term outcomes of ypT0 rectal cancers

BACKGROUND

Colorectal cancer mortality presents world-wide variation. In rectal cancers presenting a complete/nearly-complete tumor response (ypT0/ypTis) following neoadjuvant treatment, the features correlated to nodal metastases and relapses still need to be defined.

METHODS

An international cohort study enrolling ypT0/ypTis rectal cancers surgically treated from 2012 to 2017 was conducted. A propensity matching was used to balance nodal-positive and nodal-negative patients and statistical analyses were performed to investigate survivals, using a bootstrap model for internal validation. The features correlated with nodal metastasis were studied. Countries with participating centers were ranked using the World Bank (WBI), Human Development (HDI) and Global Gender Gap (GGG) indexes to compare survivals.

RESULTS

680 ypT0/ypTis from 52 European, Australian, Indian and American Institutions were analyzed. Mean follow-up was of 30.4 months. 96.5% were treated with total mesorectal excision, 7.2% were nodal-positive and 8.8% relapsed. Distal cancers (HR 0.71 95%CI: 0.56-0.91) and nodal metastasis and nodal metastasis (HR 3.85 95%CI:1.12-13.19) correlated with worse DFS, whereas a younger age was of borderline significance (HR 0.95 95%CI:0.91-0.99). The bootstrap analysis validated the model on 5000 repetitions. A short-course radiotherapy (OR 0.18 95%CI:0.09-0.37) correlated with the occurrence of nodal metastasis. Those countries classified in the low/medium-WBI, medium-HDI and lower-GGG ranks documented worse DFS curves (respectively p < 0.0001, p < 0.0001 and p 0.0002). However, the clinical stages were similar and patients from medium-HDI countries received more adjuvant chemotherapy than the others (p < 0.0001).

CONCLUSION

Sub-groups at risk for relapses and nodal metastasis were identified. A global variation exists also when benchmarking a rectal cancer complete regression.

Predictive factors of disease-free survival after complete pathological response to neoadjuvant radiotherapy for rectal adenocarcinoma: retrospective case series

Background

Many data suggest that patients with low rectal adenocarcinoma who achieved ypT0N0 status have improved survival and disease-free survival (DFS) compared to all other stages however only few data are available regarding the specific prognosis factors of this subgroup. This study aimed to evaluate predictive factors for disease free survival after complete pathological response (CPR) in cases of low rectal adenocarcinoma.

Materials and methods

From January 2005 to December 2013, all patients with low rectal adenocarcinoma who underwent neoadjuvant chemoradiotherapy followed by total mesorectal excision and achieved CPR were included at 7 Moroccan and 1 Algerian centres. Predictive factors for disease-free survival were analysed by uni and multivariate analysis.

Results

Eigthy-four (12.1%) patients achieved a CPR (ypT0N0). Multivariate analysis revealed that both poorly differentiated tumors (OR, 9.23; 95 CI 1.35–62.82; P = 0.023) and the occurrence of perineal sepsis (OR, 13.51; 95 CI 1.96–93.12; P = 0.008) were independently associated with impaired DFS.

Conclusions

Patients with low rectal cancer who exhibited a CPR after neoadjuvant therapy have good prognoses; however, the occurrence of perineal sepsis and/or poor initial differentiation may be associated with impaired DFS in these patients.

Trial registration: The study was retrospectively registered the 28th July 2018 in ClinicalTrials.gov register with the reference NCT03601689.

Efficacy and Feasibility of Adding Induction Chemotherapy to Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: A Phase II Clinical Trial

PURPOSE

Currently, neoadjuvant chemoradiation (CRT) followed by total mesorectal resection is considered the standard of care for treating locally advanced rectal cancer. This study aimed to investigate the efficacy and feasibility of adding induction chemotherapy to neoadjuvant CRT in locally advanced rectal cancer.

METHODS

This phase-II clinical trial included 54 patients with newly diagnosed, locally advanced (clinical T3-4 and/or N1-2, M0) rectal cancer. All patients were treated with 3 cycles of preoperative chemotherapy using the XELOX (capecitabine + oxaliplatin) regimen before and after a concurrent standard long course of CRT (45-50.4 Gy) followed by standard radical surgery. Pathologic complete response (PCR) rate and toxicity were the primary and secondary endpoints, respectively.

RESULTS

The study participants included 37 males and 17 females, with a median age of 59 years (range, 20-80 years). Twenty-nine patients (54%) had clinical stage-II disease, and 25 patients (46%) had clinical stage-III disease. Larger tumor size (P = 0.006) and distal rectal location (P = 0.009) showed lower PCR compared to smaller tumor size and upper rectal location. Pathologic examinations showed significant tumor regression (6.1 ± 2.7 cm vs. 1.9 ± 1.8 cm, P < 0.001) with 10 PCRs (18.5%) compared to before the intervention. The surgical margin was free of cancer in 52 patients (96.3%). Treatment-related toxicities were easily tolerated, and all patients completed their planned treatment without interruption. Grade III and IV toxicities were infrequent.

CONCLUSION

The addition of induction chemotherapy to neoadjuvant CRT is an effective and well-tolerated treatment approach in patients with rectal cancer.

Association Between Adjuvant Chemotherapy and Overall Survival in Patients With Rectal Cancer and Pathological Complete Response After Neoadjuvant Chemotherapy and Resection

Importance

Although American guidelines recommend use of adjuvant chemotherapy in patients with locally advanced rectal cancer, individuals who achieve a pathological complete response (pCR) following neoadjuvant chemoradiotherapy are less likely to receive adjuvant treatment than incomplete responders. The association and resection of adjuvant chemotherapy with survival in patients with pCR is unclear.

Objective

To determine whether patients with locally advanced rectal cancer who achieve pCR after neoadjuvant chemoradiation therapy and resection benefit from the administration of adjuvant chemotherapy.

Design, Setting, and Participants

This retrospective propensity score-matched cohort study identified patients with locally advanced rectal cancer from the National Cancer Database from 2006 through 2012. We selected patients with nonmetastatic invasive rectal cancer who achieved pCR after neoadjuvant chemoradiation therapy and resection.

Exposures

We matched patients who received adjuvant chemotherapy to patients who did not receive adjuvant treatment in a 1:1 ratio. We separately matched subgroups of patients with node-positive disease before treatment and node-negative disease before treatment to investigate for effect modification by pretreatment nodal status.

Main Outcome and Measures

We compared overall survival between groups using Kaplan-Meier survival methods and Cox proportional hazards models.

Results

We identified 2455 patients (mean age, 59.5 years; 59.8% men) with rectal cancer with pCR after neoadjuvant chemoradiation therapy and resection. We matched 667 patients with pCR who received adjuvant chemotherapy and at least 8 weeks of follow-up after surgery to patients with pCR who did not receive adjuvant treatment. Over a median follow-up of 3.1 years (interquartile range, 1.94-4.40 years), patients treated with adjuvant chemotherapy demonstrated better overall survival than those who did not receive adjuvant treatment (hazard ratio, 0.44; 95% CI, 0.28-0.70). When stratified by pretreatment nodal status, only those patients with pretreatment node-positive disease exhibited improved overall survival with administration of adjuvant chemotherapy (hazard ratio, 0.24; 95% CI, 0.10-0.58).

Conclusions and Relevance

The administration of adjuvant chemotherapy in patients with rectal cancer with pCR is associated with improved overall survival, particularly in patients with pretreatment node-positive disease. Although this study suggests a beneficial effect of adjuvant treatment on survival in patients with pCR, these results are limited by the presence of potential unmeasured confounding in this nonrandomized study.

MR-guided radiotherapy in rectal cancer: First clinical experience of an innovative technology

•This study represents one of the first reports of online MRgRT.•Integrated Low-field MR provides better anatomical visualization than CBCT or MVCT.•Better visualization of the target can help to reduce the margins from CTV to PTV.•MRgRT appears a feasible option in rectal cancer treatment offering potential benefits.•MRgRT represents a promising technology for rectal cancer management.

Novel phase I trial design to evaluate the addition of cediranib or selumetinib to preoperative chemoradiotherapy for locally advanced rectal cancer: the DREAMtherapy trial

BACKGROUND

The DREAMtherapy (Dual REctal Angiogenesis MEK inhibition radiotherapy) trial is a novel intertwined design whereby two tyrosine kinase inhibitors (cediranib and selumetinib) were independently evaluated with rectal chemoradiotherapy (CRT) in an efficient manner to limit the extended follow-up period often required for radiotherapy studies.

PATIENTS AND METHODS

Cediranib or selumetinib was commenced 10 days before and then continued with RT (45 Gy/25#/5 wks) and capecitabine (825 mg/m2 twice a day (BID)). When three patients in the cediranib 15-mg once daily (OD) cohort were in the surveillance period, recruitment to the selumetinib cohort commenced. This alternating schedule was followed throughout. Three cediranib (15, 20 and 30 mg OD) and two selumetinib cohorts (50 and 75 mg BID) were planned. Circulating and imaging biomarkers of inflammation/angiogenesis were evaluated.

RESULTS

In case of cediranib, dose-limiting diarrhoea, fatigue and skin reactions were seen in the 30-mg OD cohort, and therefore, 20 mg OD was defined as the maximum tolerated dose. Forty-one percent patients achieved a clinical or pathological complete response (7/17), and 53% (9/17) had an excellent clinical or pathological response (ECPR). Significantly lower level of pre-treatment plasma tumour necrosis factor alpha (TNFα) was found in patients who had an ECPR. In case of selumetinib, the 50-mg BID cohort was poorly tolerated (fatigue and diarrhoea); a reduced dose cohort of 75-mg OD was opened which was also poorly tolerated, and further recruitment was abandoned. Of the 12 patients treated, two attained an ECPR (17%).

CONCLUSIONS

This novel intertwined trial design is an effective way to independently investigate multiple agents with radiotherapy. The combination of cediranib with CRT was well tolerated with encouraging efficacy. TNFα emerged as a potential predictive biomarker of response and warrants further evaluation.

Endoscopy and magnetic resonance imaging-based prediction of ypT stage in patients with rectal cancer who received chemoradiotherapy: Results from a prospective study of 110 patients

Accurate tumor response determination remains inconclusive after preoperative chemoradiation therapy (CRT) for rectal cancer. This study aimed to investigate whether clinical assessment, such as endoscopy and magnetic resonance imaging (MRI), can accurately predict ypT stage and select candidates for pelvic organ-preserving surgery in rectal cancer after preoperative CRT. A total of 110 patients who underwent preoperative CRT followed by curative resection for rectal cancer were prospectively enrolled. Magnetic resonance tumor regression grade (mrTRG) using T2-MRI, endoscopic evaluation, and combination modality (combination of endoscopy and mrTRG) were used to analyze tumor response after preoperative CRT. Endoscopic findings were categorized as 3 grades and the mrTRG was assessed into 5 grades. Twenty-nine patients (26.4%) had achieved pathologic complete response. When predicting ypT0, endoscopy showed significantly higher area under the curve (AUC 0.818) than did mrTRG (AUC 0.568) and combination modality (AUC 0.768) in differentiating good response from poor response (P < .001). Both endoscopy and combination modality showed significantly higher diagnostic performance in sensitivity (79.31%), positive predictive value (PPV 67.65%), negative predictive value (NPV 92.11%), and accuracy (84.55%) than those of MR tumor response (sensitivity 37.93%, PPV 36.67%, NPV 77.50%, and accuracy 66.36%) for the prediction of ypT0 (P < .001). Combination modality showed significantly higher diagnostic performance in sensitivity (56.92%), NPV (56.92%), and accuracy (67.27%) compared with those of mrTRG. Neither endoscopy, nor mrTRG, nor the combination modality had adequate diagnostic performances to be clinically acceptable in selecting candidates for nonoperative treatment strategies. However, endoscopy may be incorporated in clinical restaging strategy in planning the extent of surgical resection in patients with rectal cancer.

Adjuvant chemotherapy in rectal cancer patients who achieved a pathological complete response after preoperative chemoradiotherapy: a systematic review and meta-analysis

This study evaluated the prognostic impact of ACT in patients who achieved a pathological complete response (pCR). Articles published from January 1990 to September 2018 were searched in EMBASE, PubMed, Ovid, Web of Science, and Cochrane Library. Hazard ratios (HRs) and 95% confidence intervals (CIs) of overall survival (OS) were extracted. Thirteen observational studies were included. There were four National Cancer Database studies with overlapping study periods, thus individual pooled analyses of four different datasets were conducted (n = 3,182, 3,330, 3,575, and 4,739 for pooled analysis sets including Dossa et al., Polanco et al., Xu et al., and Shahab et al., respectively). Although a trend toward improved OS with ACT was observed, statistical significance was not proven (P = 0.09, P = 0.03, P = 0.12, and P = 0.10, respectively). When we performed a stratified analysis comparing the results from single institution and multicenter studies, there was no significant prognostic benefit of ACT. Publication bias was not observed. Routine use of ACT in patients with a pCR could not be warranted from the present meta-analysis. Further study of individual patient data from randomized trials is needed to clarify the role of ACT.

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios as predictive and prognostic markers in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation

Background

A standard therapy for locally advanced rectal cancer (LARC) includes fluoropyrimidine (FP)-based neoadjuvant chemoradiation (nCRT). Previous studies have inconsistently demonstrated that baseline neutrophil- and platelet-to-lymphocyte ratios (NLR and PLR) are predictive of response to nCRT or prognostic of outcomes in LARC.

Methods

We reviewed patients with LARC undergoing nCRT followed by surgery from 2005 to 2013 across 8 Canadian cancer centres. Outcome measures of interest were pathological complete response (pCR), disease-free survival (DFS) and overall survival (OS). Logistic regression and Cox proportional hazard models were used to assess for associations between baseline hematologic variables and outcomes.

Results

Of 1527 identified patients, 1237 (81%) were included in the DFS/OS analysis. Median age was 62 (range 23–88), 69% were male, and 80% had performance status (PS) 0–1. Twenty-six percent had elevated NLR (≥ 4), and 66% had elevated PLR (≥ 150). Ninety-seven percent of patients received FP-based nCRT, with 96% receiving ≥44 Gy. 81% completed neoadjuvant chemotherapy and 95% completed neoadjuvant radiotherapy, with a pCR rate of 18%. After a median follow-up time of 71 months, 8% developed local recurrence, 22% developed distant recurrence and 24% died. 5-year DFS and OS were 69% (95% CI 66–72%) and 79% (95% CI 77–82%), respectively. In multivariate analyses, elevated baseline NLR and PLR were neither prognostic for DFS and OS nor predictive of pCR.

Conclusions

NLR and PLR were not found to be independently prognostic for DFS or OS and did not predict for pCR in patients with LARC undergoing nCRT followed by surgery.

Is It Possible a Conservative Approach After Radiochemotherapy in Locally Advanced Rectal Cancer (LARC)? A Systematic Review of the Literature and Meta-analysis

BACKGROUND

Locally advanced rectal cancer is usually treated with a preoperative approach with radiochemotherapy followed by surgery. Patients obtaining a pathologic complete response have a very favorable long-term prognosis. This study was intended to assess whether major surgery can reduce tumor recurrences and prolong survival of patients with a complete response after radiochemotherapy.

METHODS

Computerized literature search was performed to identify relevant articles. Comparative studies reporting the outcomes of non-operative and operative management in patients after neoadjuvant treatment were reviewed. Data synthesis was performed using Review Manager 5.0 software.

RESULTS

Twelve non-randomized comparative studies with a total of 1812 patients were suitable for analysis. There was no significant difference in overall survival at 3 and 5 years (odds ratio [OR] 1.31; 95% CI 0.64-2.69; p = 0.46 and 1.48; 95% CI 1.00-2.20; p = 0.50) and in disease-free survival at 3 and 5 years (odds ratio [OR] 1.20; 95% CI 0.68-2.14; p = 0.53 and 1.22; 95% CI 0.86-1.74; p = 0.26, respectively) between locally advanced rectal cancer patients treated with and without operative approach.

CONCLUSIONS

Major surgery does not seem to improve prognosis in patients obtaining a complete response after radiochemotherapy. Clinical trials, using clear criteria to identify complete response patients, are needed to recommend non-operative approach.

Adjuvant chemotherapy for rectal cancer with complete pathological response (pCR) may not be necessary: a pooled analysis of 5491 patients

Background

It is recommended postoperative adjuvant chemotherapy for all rectal cancers undergoing neo-chemoradiotherapy regardless of the final yield pathology. However, the role of adjuvant chemotherapy in pathological complete response (pCR) remains controversial. We aimed to identify the necessarily of adjuvant chemotherapy in pCR.

Methods

Consecutive patients with pCR in Fudan University Shanghai Cancer Center (FUSCC) were enrolled. Meanwhile, a pooled analysis of individual patient with pCR was performed from PubMed and Embase databases for validation.

Results

A total of 171 patients form FUSCC were identified to achieve pCR with up to almost 10 years follow-up. Among them, those receiving adjuvant chemotherapy had no survival benefits compared to those without adjuvant chemotherapy (log-rank test = 0.17, P = 0.676). The 5y-DFS rates for patients in chemo group and no-chemo group was 87.5 and 88.8%, respectively, showing no significant difference (p = 0.854). No matter chemotherapy regimens, T stage, EMVI and CRM status varied, the results remained consistent. Meantime, the COX model did not demonstrate adjuvant chemotherapy as the independent risk factor for OS and DFS. Additionally, among 18 systemic recurrences in all, the rate of relapse surged rapidly on the 12 months and rose up to peak in the 36th months. In order to validate these results, nine controlled trials involving 5491 patients with pCR were included in this pooled-analysis. For both 5-year overall survival and disease-free survival, the pooling data did not produce a statistically significant effect in cases of adjuvant chemotherapy performed (RR = 0.79 and RR = 0.95, respectively, all p > 0.05).

Conclusion

This study suggested that rectal cancer patients with pCR did not benefit from adjuvant chemotherapy and we recommended that achievement of pCR require more prolonged close follow care in case of distant metastasis.

Circulating Biomarkers for Response Prediction of Rectal Cancer to Neoadjuvant Chemoradiotherapy

Rectal cancer response to neoadjuvant Chemoradiotherapy (pCRT) is highly variable. In fact, it has been estimated that only about 21 % of patients show pathologic Complete Response (pCR) after therapy, while in most of the patients a partial or incomplete tumour regression is observed. Consequently, patients with a priori chemoradioresistant tumour should not receive the treatment, which is associated with substantial adverse effects and does not guarantee any clinical benefit. For Locally Advanced Rectal Cancer Patients (LARC), a standardized neoadjuvant treatment protocol is applied, the identification and the usefulness of prognostic or predictive biomarkers can improve the antitumoural treatment strategy, modifying the sequence, dose, and combination of radiotherapy, chemotherapy and surgical resection. For these reasons, a growing number of studies are actually focussed on the discovery and investigation of new predictive biomarkers of response to pCRT. In this review, we have selected the most recent literature (2012-2017) regarding the employment of blood-based biomarkers potentially predicting pCR in LARC patients and we have critically discussed them to highlight their real clinical benefit and the current limitations of the proposed methodological approaches.

Preoperative Volumetric Modulated Arc Therapy With Simultaneous Integrated Boost for Locally Advanced Distal Rectal Cancer

The aim of this study was to evaluate the safety and clinical efficacy of a combined preoperative regimen consisting of volumetric modulated arc therapy–simultaneous integrated boost and capecitabine chemotherapy for distal rectal cancer. A total of 26 patients with locally advanced distal rectal cancer were enrolled from March 2015 to May 2016. The radiation dose fractionation was 58.75 Gy/25 fractions (2.35 Gy/fraction) for rectal tumor and pelvic lymph node metastasis and 50 Gy/25 fractions for pelvic lymph node stations, accompanied with simultaneous capecitabine chemotherapy. Completion of the simultaneous chemotherapy was ensued by 1 week of rest and then another cycle of induction chemotherapy with capecitabine. A radical rectal cancer surgery was performed 6 to 8 weeks after the simultaneous chemoradiotherapy. The primary end points were the complete pathological response rate and the postoperative sphincter preservation rate. All 26 patients completed the neoadjuvant chemoradiotherapy, among which 25 received surgical treatment. The postoperative complete pathological response rate was as high as 32% (8/25), while the sphincter preservation rate was 60% (15/25), the overall tumor/node (T/N) downstaging rate was 92% (23/25), and the R0 resection rate was 100%. During the chemoradiation, the most common adverse events were grade 1 and 2; grade 3 radiodermatitis occurred in 2 cases but no occurrence of acute adverse events occurred that were grade 4 and above. After the surgery, there was one case of ureteral injury and one case of intestinal obstruction, but no perioperative deaths occurred. In conclusion, the chemoradiation regimen of preoperative volumetric modulated arc therapy-simultaneous integrated boost (VMAT-SIB_58.75Gy) and a single cycle of induction chemotherapy with capecitabine for patients with distal rectal cancer is safe and feasible with a satisfactory complete pathological response rate, sphincter preservation rate, and R0 resection rate.

Tumor Heterogeneity as a Predictor of Response to Neoadjuvant Chemotherapy in Locally Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) is the standard of care for locally advanced adenocarcinoma of the rectum, but it is currently unknown which patients have disease that will respond. This study tested the correlation between response to nCRT and intratumoral heterogeneity using next-generation sequencing assays.

PATIENTS AND METHODS

DNA was extracted from formalin-fixed, paraffin-embedded biopsy samples from a cohort of patients with locally advanced rectal adenocarcinoma (T3/4 or N1/2 disease) who received nCRT. High read-depth sequencing of > 400 cancer-relevant genes was performed. Tumor mutations and variant allele frequencies were used to calculate mutant-allele tumor heterogeneity (MATH) scores as measures of intratumoral heterogeneity. Response to nCRT was pathologically scored after surgical resection.

RESULTS

Biopsy samples from 21 patient tumors were analyzed. Eight patients had disease noted to have complete response, 2 moderate, 4 minimal, and 7 poor. Higher MATH scores correlated with poorer response to treatment, demonstrating significantly increased tumor heterogeneity compared to complete response (P = .039).

CONCLUSION

The application of MATH scores as a measure of tumor heterogeneity may provide a useful biomarker for treatment response in locally advanced rectal cancer.

The INTERACT Trial: Long-term results of a randomised trial on preoperative capecitabine-based radiochemotherapy intensified by concomitant boost or oxaliplatin, for cT2 (distal)-cT3 rectal cancer

BACKGROUND AND PURPOSE

Capecitabine-based radiochemotherapy (cbRCT) is standard for preoperative long-course radiochemotherapy of locally advanced rectal cancer. This prospective, parallel-group, randomised controlled trial investigated two intensification regimens. cT4 lesions were excluded.

PRIMARY OBJECTIVE

pathological outcome (TRG 1-2) among arms.

MATERIALS AND METHODS

Low-located cT2N0-2M0, cT3N0-2M0 (up to 12 cm from anal verge) presentations were treated with cbRCT randomly intensified by either radiotherapy boost (Xelac arm) or multidrug concomitant chemotherapy (Xelox arm). Xelac: concomitant boost to bulky site (45 Gy/1.8 Gy/die, 5 sessions/week to the pelvis, +10 Gy at 1 Gy twice/week to the bulky) plus concurrent capecitabine (1650 mg/mq/die). Xelox: 45 Gy to the pelvis + 5.4 Gy/1.8 Gy/die, 5 sessions/week to the bulky site + concurrent capecitabine (1300 mg/mq/die) and oxaliplatin (130 mg/mq on days 1,19,38). Surgery was planned 7-9 weeks after radiochemotherapy.

RESULTS

From June 2005 to September 2013, 534 patients were analysed: 280 in Xelac, 254 in Xelox arm. Xelox arm presented higher G ≥ 3 haematologic (p = 0.01) and neurologic toxicity (p < 0.001). Overall, 98.5% patients received curative surgery. The tumour regression grade distribution did not differ between arms (p = 0.102). TRG 1+2 rate significantly differed: Xelac arm 61.7% vs. Xelox 52.3% (p = 0.039). Pathological complete response (ypT0N0) rates were 24.4 and 23.8%, respectively (p non-significant). Median follow-up:5.62 years. Five-year disease-free survival rate were 74.7% (Xelac) and 73.8% (Xelox), respectively (p = 0.444). Five-year overall survival rate were 80.4% (Xelac) and 85.5% (Xelox), respectively (p = 0.155).

CONCLUSION

Xelac arm significantly obtained higher TRG1-2 rates. No differences were found about clinical outcome. Because of efficacy on TRG, inferior toxicity and good compliance, Xelac schedules or similar radiotherapy dose intensification schemes could be considered as reference treatments for cT3 lesions.