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

Decision-Making Strategy for Rectal Cancer Management Using Radiation Therapy for Elderly or Comorbid Patients

Rectal cancer predominantly affects patients older than 70 years, with peak incidence at age 80 to 85 years. However, the standard treatment paradigm for rectal cancer oftentimes cannot be feasibly applied to these patients owing to frailty or comorbid conditions. There are currently little information and no treatment guidelines to help direct therapy for patients who are elderly and/or have significant comorbidities, because most are not included or specifically studied in clinical trials. More recently various alternative treatment options have been brought to light that may potentially be utilized in this group of patients. This critical review examines the available literature on alternative therapies for rectal cancer and proposes a treatment algorithm to help guide clinicians in treatment decision making for elderly and comorbid patients.

Watch-and-Wait as a Therapeutic Strategy in Rectal Cancer

Purpose of Review

Pathological complete response is seen in approximately one fifth of rectal cancer patients following neoadjuvant chemoradiation. Since these patients have excellent oncological outcomes, there has been a rapidly growing interest in organ preservation for those who develop a clinical complete response. We review the watch-and-wait strategy and focus on all aspects of this hot topic, including who should be considered for this approach, how should we identify treatment response and what are the expected outcomes.

Recent Findings

The major challenges in interpreting the data on watch-and-wait are the significant heterogeneity of patients selected for this approach and of methods employed to identify them. The evidence available comes mostly from retrospective cohort studies, but has shown good oncological outcomes, including the rate of successful salvage surgery, locoregional control and overall survival.

Summary

There is currently not enough and not robust enough evidence to support watch-and-wait as a standard approach, outside a clinical trial, for patients achieving clinical complete response following neoadjuvant chemoradiation. Furthermore, there is a lack of data on long-term outcomes. However, the results we have so far are promising, and there is therefore an urgent need for randomised control studies such as the TRIGGER trial to confirm the safety of this strategy.

Preoperative short course radiotherapy with concurrent and consolidation chemotherapies followed by delayed surgery in locally advanced rectal cancer: preliminary results

PURPOSE

This study aimed to assess complications and outcomes of a new approach, that is, combining short course radiotherapy (SRT), concurrent and consolidative chemotherapies, and delayed surgery.

MATERIALS AND METHODS

In this single arm phase II prospective clinical trial, patients with T3-4 or N+ M0 rectal adenocarcinoma were enrolled. Patients who received induction chemotherapy or previous pelvic radiotherapy were excluded. Study protocol consisted of three-dimensional conformal SRT (25 Gy in 5 fractions in 1 week) with concurrent and consolidation chemotherapies including capecitabine and oxaliplatin. Total mesorectal excision was done at least 8 weeks after the last fraction of radiotherapy. Primary outcome was complete pathologic response and secondary outcomes were treatment related complications.

RESULTS

Thirty-three patients completed the planned preoperative chemoradiation and 26 of them underwent surgery (24 low anterior resection and 2 abdominoperineal resection). Acute proctitis grades 2 and 3 were seen in 11 (33.3%) and 7 (21.2%) patients, respectively. There were no grades 3 and 4 subacute hematologic and non-hematologic (genitourinary and peripheral neuropathy) toxicities and perioperative morbidities such as anastomose leakage. Grade 2 or higher late toxicities were observed among 29.6% of the patients. Complete pathologic response was achieved in 8 (30.8%) patients who underwent surgery. The 3-year overall survival and local control rates were 65% and 94%, respectively.

CONCLUSION

This study showed that SRT combined with concurrent and consolidation chemotherapies followed by delayed surgery is not only feasible and tolerable without significant toxicity but also, associated with promising complete pathologic response rates.

Identification of predictors for wound complications following preoperative or postoperative radiotherapy in extremity soft tissue sarcoma

INTRODUCTION

In extremity soft tissue sarcoma (ESTS), external beam radiotherapy (EBRT) has been used in addition to limb-sparing surgery (LSS). This study aims to identify predictors for major wound complication (MWC) development following EBRT and LSS in ESTS.

METHODS

This retrospective study includes ESTS patients treated with EBRT and LSS between 2005 and 2017. Two groups were formed; Group I included preoperatively irradiated patients, whereas Group II included patients who underwent postoperative EBRT. Multivariate logistic regression analyses were performed to create a prediction model for MWC development.

RESULTS

One hundred twenty-seven patients were included, 58 patients (45.7%) in Group I and 69 patients (54.3%) in Group II. Some differences in baseline characteristics were found between the groups, e.g. in tumor size and grade, histological subtype and total RT dose. Twenty-three patients (39.7%) in Group I and 14 patients (20.3%) in Group II developed a MWC (p = 0.02). Preoperative EBRT was identified as independent predictor for MWC development, OR 2.75 (95%CI 1.21-6.26), p = 0.02. Furthermore, a trend towards an increased MWC risk was shown for patients' age (OR 1.02 (0.99-1.04)), delayed wound closure (OR 3.20 (0.64-16.02)) and negative surgical margins (OR 2.26 (0.72-7.11)). The area under the curve (AUC) of the model was 0.68 (0.57-0.79).

CONCLUSIONS

This study corroborates the increased MWC risk following preoperative EBRT in ESTS. It remains important to carefully weigh the MWC risk against the expected long-term functional outcome, and to consider the liberal use of primary plastic surgical reconstructions in an individualized multidisciplinary tumor board prior to treatment.

Neoadjuvant radiotherapy provided survival benefit compared to adjuvant radiotherapy for hepatocellular carcinoma

BACKGROUND

This study compared the impact of neoadjuvant radiotherapy (RT) and adjuvant RT on survival for patients with hepatocellular carcinoma (HCC).

METHODS

Patients with HCC were identified from the Surveillance, Epidemiology and End Results (SEER) database. The Kaplan-Meier method and multivariate Cox regression analysis were used to compare the impact of neoadjuvant RT on survival with adjuvant RT. Subsequently, a propensity score-matched analysis was performed to confirm the result.

RESULTS

A total of 244 patients with HCC identified from the SEER database (2004-2014) received preoperative or post-operative radiation. A total of 151 patients received post-operative RT and 93 patients received preoperative RT. Preoperative RT had a clear superiority in terms of unadjusted overall survival and cancer-specific survival (P < 0.001 for log-rank test). After adjusting for confounding variables, hazard ratios (HRs) for all-cause (HR: 0.33; 95% CI: 0.19-0.53, P < 0.001) and cancer-specific (HR: 0.32; 95% CI: 0.19-0.53, P < 0.001) mortality risks in preoperative RT group were significantly lower than that of post-operative RT group. Subsequently, a propensity score-matched analysis was performed to confirm this result. Further univariate and multivariate survival analyses revealed that there was a persistent superiority of overall survival and cancer-specific survival in patients who received preoperative radiation than patients without RT.

CONCLUSION

We found that neoadjuvant RT was associated with improved long-term survival for patients with HCC versus adjuvant RT.

Clinical Cancer Advances 2018: Annual Report on Progress Against Cancer From the American Society of Clinical Oncology

A MESSAGE FROM ASCO'S PRESIDENT I remember when ASCO first conceived of publishing an annual report on the most transformative research occurring in cancer care. Thirteen reports later, the progress we have chronicled is remarkable, and this year is no different. The research featured in ASCO's Clinical Cancer Advances 2018 report underscores the impressive gains in our understanding of cancer and in our ability to tailor treatments to tumors' genetic makeup. The ASCO 2018 Advance of the Year, adoptive cell immunotherapy, allows clinicians to genetically reprogram patients' own immune cells to find and attack cancer cells throughout the body. Chimeric antigen receptor (CAR) T-cell therapy-a type of adoptive cell immunotherapy-has led to remarkable results in young patients with acute lymphoblastic leukemia (ALL) and in adults with lymphoma and multiple myeloma. Researchers are also exploring this approach in other types of cancer. This advance would not be possible without robust federal investment in cancer research. The first clinical trial of CAR T-cell therapy in children with ALL was funded, in part, by grants from the National Cancer Institute (NCI), and researchers at the NCI Center for Cancer Research were the first to report on possible CAR T-cell therapy for multiple myeloma. These discoveries follow decades of prior research on immunology and cancer biology, much of which was supported by federal dollars. In fact, many advances that are highlighted in the 2018 Clinical Cancer Advances report were made possible thanks to our nation's support for biomedical research. Funding from the US National Institutes of Health and the NCI helps researchers pursue critical patient care questions and addresses vital, unmet needs that private industry has little incentive to take on. Federally supported cancer research generates the biomedical innovations that fuel the development and availability of new and improved treatments for patients. We need sustained federal research investment to accelerate the discovery of the next generation of cancer treatments. Another major trend in this year's report is progress in precision medicine approaches to treat cancer. Although precision medicine offers promise to people with cancer and their families, that promise is only as good as our ability to make these treatments available to all patients. My presidential theme, "Delivering Discoveries: Expanding the Reach of Precision Medicine," focuses on tackling this formidable challenge so that new targeted therapies are accessible to anyone who faces a cancer diagnosis. By improving access to high-quality care, harnessing big data on patient outcomes from across the globe, and pursuing innovative clinical trials, I am optimistic that we will speed the delivery of these most promising treatments to more patients. Sincerely, Bruce E. Johnson, FASCO ASCO President, 2017 to 2018.

Neoadjuvant hyperfractionated accelerated radiotherapy plus concomitant 5-fluorouracil infusion in locally advanced rectal cancer: A phase II study

AIM

To evaluate the efficacy and tolerability of neoadjuvant hyperfractionated accelerated radiotherapy (HART) and concurrent chemotherapy in patients with locally advanced infraperitoneal rectal cancer.

METHODS

A total of 30 patients with histopathologically confirmed T2-3/N0+ infraperitoneal adenocarcinoma of rectum cancer patients received preoperative 42 Gy/1.5 Gy/18 days/bid radiotherapy and continuous infusion of 5-fluorouracil (325 mg/m2). All patients were operated 4-8 wk after neoadjuvant concomitant therapy.

RESULTS

In the early phase of treatment, 6 patients had grade III-IV gastrointestinal toxicity, 2 patients had grade III-IV hematologic toxicity, and 1 patient had grade V toxicity due to postoperative sepsis during chemotherapy. Only 1 patient had radiotherapy-related late side effects, i.e., grade IV tenesmus. Complete pathological response was achieved in 6 patients (21%), while near-complete pathological response was obtained in 9 (31%). After a median follow-up period of 60 mo, the local tumor control rate was 96.6%. In 13 patients, distant metastasis occurred. Disease-free survival rates at 2 and 5 years were 63.3% and 53%, and corresponding overall survival rates were 70% and 53.1%, respectively.

CONCLUSION

Although it has excellent local control and complete pathological response rates, neoadjuvant HART concurrent chemotherapy appears to not be a feasible treatment regimen in locally advanced rectal cancer, having high perioperative complication and intolerable side effects. Effects of reduced 5-fluorouracil dose or omission of chemotherapy with the aim of reducing toxicity may be examined in further studies.

Fluorescence of radiation-induced tissue damage

PURPOSE

The aim of this study was evaluating changes in the photosensitizer fluorescence in vivo in the radiation-induced damage area in comparison of intact areas with a simultaneous assessment of changes both in blood parameters and in histological data.

MATERIALS AND METHODS

The study was conducted in white outbred SHK mice (n = 21). Their right hindlimbs were irradiated with a dose of 25 Gy after the intraperitoneal injections of photosensitizer 'Photosens'. Fluorescence intensity was traced in vivo by a laser diagnostic system for seven weeks. Simultaneously, histological examination of the damaged areas and blood tests were performed.

RESULTS

An increased intensity of the laser-induced fluorescence of the photosensitizer 'Photosens' in the damaged areas, compared to the intact symmetrical ones was observed. Laboratory blood tests and histological examination showed changes that may indicate the occurrence of inflammation.

CONCLUSION

Enhanced intensity of the exogenous fluorescence of the photosensitizer in the radiation-induced inflammation of noncancerous tissues was observed. The obtained results may potentially affect an interpretation of the results of intraoperative tumors navigation that have been previously irradiated and can be used for selection of an individualized dose fractionation algorithm in radiology.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypI stage after neoadjuvant chemo-radiotherapy versus de novo stage pI cohort: A propensity score-matched analysis

Objective

Prognosis of patients with locally advanced rectal cancer (LARC) but achieving ypT1-2N0 stage after neoadjuvant concurrent chemo-radiotherapy (CRT) has been shown to be favorable. This study aims to determine whether the long-term outcome of ypT1-2N0 cases can be comparable to that of pT1-2N0 cohort that received definitive surgery for early disease.

Method

From January 2008 to December 2013, 449 consecutive patients with rectal cancer were treated and their outcome maintained in a database. Patients with LARC underwent total mesorectal excision (TME) surgery at 4-8 weeks after completion of CRT, and those achieving stage ypI were identified as a group. As a comparison, stage pI group pertains to patients whose initially limited disease was not upstaged after TME surgery alone. After propensity score matching (PSM), comparisons of local regional control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) were performed using Kaplan-Meier analysis and log-rank test between ypI and pI groups. Down-staging depth score (DDS), a novel method of evaluating CRT response, was used for subset analysis.

Results

Of the 449 patients, 168 matched cases were generated for analysis. Five-year LC, DMFS, DFS and OS for stage pI vs. ypI groups were 96.7% vs. 96.4% (P=0.796), 92.7% vs. 73.6% (P=0.025), 91.2% vs. 73.6% (P=0.080) and 93.1% vs. 72.3% (P=0.040), respectively. In the DDS-favorable subset of the ypI group, LC, DMFS, DFS and OS resulted in no significant differences in comparison with the pI group (P=0.384, 0.368, 0.277 and 0.458, respectively).

Conclusions

LC was comparable in both groups; however, distant metastasis developed more frequently in down-staged LARC than de novo early stage cases, reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response. DDS can be an indicator to identify a subset of the ypI group whose long-term oncologic outcomes are as good as those of stage pI cohort.

Controversial issues in radiotherapy for rectal cancer: a systematic review

The role of radiotherapy (RT) as an adjuvant to surgical options in the treatment of locally advanced rectal cancer has been established as it reduces local recurrence when combined with surgical resection and enhances survival when used in multidisciplinary treatment. However, many issues need to be addressed; some of these can render RT unnecessary, whereas others can reveal a new role of RT in rectal cancer. This review will discuss not only the basic role of RT but also the associated but controversial issues in detail in an attempt to find answers and determine future directions for the next decade.

Preoperative short-course radiotherapy in rectal cancer patients: results and prognostic factors

Objective

The purpose of this study was to evaluate the clinical outcome of preoperative short-course radiotherapy for rectal cancer patients.

Methods

The study group comprised 210 patients with pathologically proven resectable rectal cancer. Between 2001 and 2013, they were treated preoperatively with short-course radiotherapy (25 Gy delivered in five fractions), followed by total mesorectal excision. Adjuvant 5-fluorouracil-based chemotherapy was administered at the discretion of the treating physician, depending on the pathological stage.

Results

After a median follow-up of 57 months, the following 5-year survival rates were observed: overall survival-66.4%, disease-free survival-67.2%, locoregional relapse-free survival-91.7%, and distant metastases-free survival-71.5%. The local failure was observed in 15 patients. Ten patients (4.8%) achieved pathologic complete response. The multivariate analysis demonstrated the regional lymph node involvement to be statistically significant for unfavorable outcomes in terms of all estimated survival rates. Lymphovascular invasion was found to be a strong predictor of survival (HR = 1.68; 95% CI 1.29-3.55) and treatment failure (HR = 1.54; 95% CI 1.08-3.34). The presence of positive surgical circumferential margin was related to six times higher risk of locoregional recurrence. Early and late severe treatment-induced toxicity was reported in 1 and 7.6% patients, respectively.

Conclusions

Preoperative short-course radiotherapy followed by total mesorectal excision and adjuvant chemotherapy allows to achieve excellent local control and favorable survival rates. The treatment-induced toxicity is acceptable.

Advances in organ preserving strategies in rectal cancer patients

Treatment of rectal cancer patients has been subjected to change over the past thirty years. Total mesorectal excision is considered the cornerstone of rectal cancer treatment, but is also associated with significant morbidity resulting in an impaired quality of life. The addition of neoadjuvant chemoradiotherapy to surgery has shown to improve survival and local control and may lead to a partial or even complete response (CR). This raises questions regarding the necessity for subsequent radical surgery. After careful patient selection local excision and wait-and-see approaches are explored, aiming to improve quality of life without compromising oncological outcome. A multimodality diagnostic approach for optimal staging is crucial in determining the appropriate neoadjuvant treatment regimen. Adequate endoscopic restaging of rectal tumours after multimodality treatment will aid in selecting patients who are eligible for an organ preserving approach. The role and accuracy of imaging in the detection of the primary tumour, residual rectal cancer or local recurrence seems vital. Alternative neoadjuvant regimens are currently explored to increase the rate of clinical CRs, which may support organ preserving approaches. This review aims to generate insight into the advances in diagnostics and treatment modalities in all stages of rectal cancer and will highlight future studies that may support further implementation of organ preservation treatment in rectal cancer.

Cancer Radiosensitizers

Radiotherapy (RT) is a mainstay treatment for many types of cancer, although it is still a large challenge to enhance radiation damage to tumor tissue and reduce side effects to healthy tissue. Radiosensitizers are promising agents that enhance injury to tumor tissue by accelerating DNA damage and producing free radicals. Several strategies have been exploited to develop highly effective and low-toxicity radiosensitizers. In this review, we highlight recent progress on radiosensitizers, including small molecules, macromolecules, and nanomaterials. First, small molecules are reviewed based on free radicals, pseudosubstrates, and other mechanisms. Second, nanomaterials, such as nanometallic materials, especially gold-based materials that have flexible surface engineering and favorable kinetic properties, have emerged as promising radiosensitizers. Finally, emerging macromolecules have shown significant advantages in RT because these molecules can be combined with biological therapy as well as drug delivery. Further research on the mechanisms of radioresistance and multidisciplinary approaches will accelerate the development of radiosensitizers.

Current issues of preoperative radio(chemo)therapy and its future evolution in locally advanced rectal cancer

Neoadjuvant therapies are effective for local control and tumor downstaging. Up to date, preoperative long-course chemoradiotherapy and short-course radiotherapy are the two primary guideline-recommended neoadjuvant therapies for locally advanced rectal cancer patients. However, clinicians throughout the world are trying their best to further optimize the regimens and concepts of neoadjuvants. Hence, there is an urgent need to summarize evidence regarding indications of neaoadjuvant therapies and relative merits of current standard regimens. In addition, we also reviewed the optimized regimens mainly based on short-course radiotherapy with delayed surgery, consolidation chemotherapy, induction chemotherapy, chemotherapy alone without radiation and concepts in terms of organ preservation and personalized treatments to further explore the future evolution of neoadjuvant therapies in rectal cancer.

A novel mouse model of radiation-induced cancer survivorship diseases of the gut

A deeper understanding of the radiation-induced pathophysiological processes that develop in the gut is imperative to prevent, alleviate, or eliminate cancer survivorship diseases after radiotherapy to the pelvic area. Most rodent models of high-dose gastrointestinal radiation injury are limited by high mortality. We therefore established a model that allows for the delivering of radiation in fractions at high doses while maintaining long-term survival. Adult male C57/BL6 mice were exposed to small-field irradiation, restricted to 1.5 cm of the colorectum using a linear accelerator. Each mouse received 6 or 8 Gy, two times daily in 12-h intervals in two, three, or four fractions. Acute cell death was examined at 4.5 h postirradiation and histological changes at 6 wk postirradiation. Another group was given four fractions of 8 Gy and followed over time for development of visible symptoms. Irradiation caused immediate cell death, mainly limited to the colorectum. At 6 wk postirradiation, several crypts displayed signs of radiation-induced degeneration. The degenerating crypts were seen alongside crypts that appeared perfectly healthy. Crypt survival was reduced after the fourth fraction regardless of dose, whereas the number of macrophages increased. Angiogenesis was induced, likely as a compensatory mechanism for hypoxia. Four months postirradiation, mice began to show radiation-induced symptoms, and histological examination revealed an extensive crypt loss and fibrosis. Our model is uniquely suitable for studying the long-term trajectory and underlying mechanisms of radiation-induced gastrointestinal injury.NEW & NOTEWORTHY A novel mouse model for studying the long-term trajectory of radiation-induced gut injury. The method allows for the use of high doses and multiple fractions, with minor impact on animal health for at least 3 mo. Crypt loss and a slow progression of fibrosis is observed. Crypt degeneration is a process restricted to isolated crypts. Crypt degeneration is presented as a convenient proxy endpoint for long-term radiation-induced gut injury.

Screening candidate microRNA-mRNA regulatory pairs for predicting the response to chemoradiotherapy in rectal cancer by a bioinformatics approach

Extensive efforts have been undertaken in search of biomarkers for predicting the chemoradiotherapy response in rectal cancer. However, most attention on treatment efficiency prediction in carcinoma is addicted to single or limited molecules. Network biomarkers are considered to outperform single molecules in predictive power. In this study, candidate microRNAs (miRNAs) were identified from the PubMed citations and miRNA expression profiles. Targets of miRNAs were obtained from four experimentally confirmed interactions and three computationally predicted databases. Functional enrichment analysis of all the targets revealed their associations with chemoradiotherapy response, indicating they could be promising biomarkers. Two lists of key target mRNAs of the candidate miRNAs were retrieved from protein–protein interaction (PPI) network and mRNA expression profiles, respectively. Pathway analysis and literature validation revealed that the mRNA lists were highly related to the ionizing radiation. The above miRNAs along with the key miRNA targets provide potential miRNA-mRNA regulatory pairs as network biomarkers in which all the network components may be used for predicting the chemoradiotherapy response. These results demonstrated that the network biomarkers could provide a useful model for predicting the chemoradiotherapy response and help in further understanding the molecular basis of response differences, which should be prioritized for further study.

Gender-related prognostic significance of clinical and biological tumor features in rectal cancer patients receiving short-course preoperative radiotherapy

AIM

To study the prognostic value of clinical and biological features of rectal cancer and potential gender differences in patients' overall survival (OS), local recurrence-free survival (RFS) and metastasis-free survival (MFS) after short-course preoperative radiotherapy (SCRT) with short or long interval between RT and surgery (break).

BACKGROUND

The length of the interval between RT and surgery in SCRT is debatable and gender-related differences in patients survival are not established yet.

MATERIALS AND METHODS

126 patients received SCRT with 5 Gy dose per fraction during 5 days, followed by radical surgery after short break ≤17 days, and a long break >17 days. Pretreatment tumor proliferation (bromodeoxyuridine labeling index, BrdUrdLI and S-phase fraction) was evaluated by flow cytometry and proteins: CD34, Ki-67, GLUT-1, Ku70, BCL-2, P53 expression was studied immunohistochemically.

RESULTS

The studied group included 84 men and 42 women. There were 33, 76, and 17 cTNM (AJCC) tumor stages I, II, III, respectively. The median follow-up time was 53.3 months (range 2-142 months). For the whole group Cox multivariate analysis revealed that tumor grade (G > 1), interval between RT and surgery >17 days, pTNM stage >1 and P53 positivity + BrdUrdLI > 7.9% were negative prognostic factors for OS. Tumor aneuploidy and MVD > 140.8 vessels/mm² were important for RFS. pTNM stage > 1 and P53 positivity combined with BrdUrdLI > 7.9% were risk predictors for MFS. Based on tumor biological features, gender-related difference in OS, RFS, and MFS were observed. In multivariate analysis, male patients age > 62 years and break >17 days only appeared to be significant for OS.

CONCLUSIONS

In male rectal patients treated with SCRT, breaks between RT and surgery >17 days should be avoided because they negatively influence patients' survival.

Improved Metastasis- and Disease-Free Survival With Preoperative Sequential Short-Course Radiation Therapy and FOLFOX Chemotherapy for Rectal Cancer Compared With Neoadjuvant Long-Course Chemoradiotherapy: Results of a Matched Pair Analysis

PURPOSE

To compare treatment and toxicity outcomes between a phase 2 institutional trial of near total neoadjuvant therapy (nTNT) for locally advanced rectal cancer and a similar historical control cohort treated at Washington University in St. Louis with the current US standard of care, defined as neoadjuvant chemoradiotherapy (NCRT), total mesorectal excision (TME), and adjuvant FOLFOX chemotherapy; to expand the comparison to an additional institution, patients treated with similar NCRT at Stanford University were included.

METHODS AND MATERIALS

Sixty-nine patients with cT3-4N0-2M0 rectal adenocarcinoma enrolled on the Washington University in St. Louis phase 2 study of nTNT were included for analysis. Patients treated at the same institution with conventional NCRT and adjuvant FOLFOX were matched for exact cTNM stage. Forty-one patients treated with NCRT at Stanford University were included in a second analysis. Kaplan-Meier analysis with log-rank test was used to compare local control, distant metastasis-free survival, disease-free survival, and overall survival.

RESULTS

Median follow-up was 49 and 54 months for nTNT and NCRT, respectively. Pathologic complete response and T-downstaging rates were 28% versus 16% (P=.21) and 75% versus 41% (P<.001) in the nTNT and NCRT cohorts, respectively. Three-year disease-free survival (85% vs 68%, P=.032) was significantly better in the nTNT group. Actuarial 3-year local control (92% vs 96%, P=.36) and overall survival (96% vs 88%, P=.67) were similar. The Stanford cohort had significantly lower clinical stage. After controlling for clinical stage, age, tumor location, institution, and number of chemotherapy cycles, nTNT treatment remained significantly associated with lower risk of recurrence (P=.006).

CONCLUSIONS

Patients treated with nTNT had higher T-downstaging and superior distant metastasis-free survival and disease-free survival compared with conventional NCRT when matched for tumor location and exact cTNM stage. Near total neoadjuvant therapy remained a significant multivariate predictor for improved outcome when including patients treated with NCRT at another institution.