Pathologic complete response (pCR) rates and outcomes after neoadjuvant chemoradiotherapy with proton or photon radiation for adenocarcinomas of the esophagus and gastroesophageal junction

Low-Dose Radiation Yields Lower Rates of Pathologic Response in Esophageal Cancer Patients

BACKGROUND

Although neoadjuvant chemoradiation (nCRT) followed by surgery is standard treatment for locally advanced esophageal or gastroesophageal junction (E/GEJ) cancer, the optimal radiation dose is still under debate.

OBJECTIVE

The aim of this study was to assess the impact of different preoperative radiation doses (41.4 Gy, 45 Gy or 50.4 Gy) on pathologic response and survival in E/GEJ cancer patients.

METHODS

All consecutive patients with E/GEJ tumors, treated with curative intent between January 2009 and December 2016 in two referral centers were divided into three groups (41.4 Gy, 45 Gy and 50.4 Gy) according to the dose of preoperative radiotherapy. Pathologic complete response (pCR) rates, postoperative morbidity, overall survival (OS) and disease-free survival (DFS) were compared among the three groups, with separate analyses for adenocarcinoma (AC) and squamous cell carcinoma (SCC).

RESULTS

From the 326 patients analyzed, 48 were included in the 41.4 Gy group (14.7%), 171 in the 45 Gy group (52.5%) and 107 in the 50.4 Gy group (32.8%). Postoperative complication rates were comparable (p = 0.399). A pCR was observed in 15%, 30%, and 34% of patients in the 41.4 Gy, 45 Gy and 50.4 Gy groups, respectively (p = 0.047). A 50.4 Gy dose was independently associated with pCR (odds ratio 2.78, 95% confidence interval 1.10-7.99) in multivariate analysis. Within AC patients, pCR was observed in 6.2% of patients in the 41.4 Gy group, 29.2% of patients in the 45 Gy group, and 22.7% of patients in the 50.4 Gy group (p = 0.035). No OS or DFS differences were observed.

CONCLUSIONS

A pCR was less common after a preoperative radiation dose of 41.4 Gy in AC patients. Radiation dose had no impact on postoperative morbidity, long-term survival, and recurrence.

Neoadjuvant Chemoradiation Followed by Surgery for Locally Advanced Squamous Cell Carcinoma Esophagus: Demographics and Evaluation of Prognostic Factors at a Tertiary Care Center in India

Neoadjuvant chemoradiation followed by surgery has been the standard of care for locally advanced carcinoma esophagus. We present our experience and inference of various factors associated with the same treatment and the prognostic influence of the same. A retrospective analysis of a cohort of 132 squamous cell carcinoma esophagus patients post neoadjuvant chemoradiation operated with curative intent was carried out. The 2-year overall survival rate was 64.5%. A pathological complete response was achieved in 32.5% of patients and was the only factor that significantly determined overall survival (p = 0.048). Neoadjuvant chemoradiation before surgery for locally advanced squamous cell cancer of the esophagus remains the standard of care with a pathological complete response being a significant factor in predicting overall survival. More prospective randomized studies are necessary to analyze factors affecting and predicting a pathological complete response which would help organ preservation in patients with a complete response.

Concurrent chemoradiotherapy using proton beams can reduce cardiopulmonary morbidity in esophageal cancer patients: a systematic review

This systematic review was performed to investigate the superiority of proton beam therapy (PBT) to photon-based radiotherapy (RT) in treating esophageal cancer patients, especially those with poor cardiopulmonary function. The MEDLINE (PubMed) and ICHUSHI (Japana Centra Revuo Medicina) databases were searched from January 2000 to August 2020 for studies evaluating one end point at least as follows; overall survival, progression-free survival, grade ≥ 3 cardiopulmonary toxicities, dose-volume histograms, or lymphopenia or absolute lymphocyte counts (ALCs) in esophageal cancer patients treated with PBT or photon-based RT. Of 286 selected studies, 23 including 1 randomized control study, 2 propensity matched analyses, and 20 cohort studies were eligible for qualitative review. Overall survival and progression-free survival were better after PBT than after photon-based RT, but the difference was significant in only one of seven studies. The rate of grade 3 cardiopulmonary toxicities was lower after PBT (0-13%) than after photon-based RT (7.1-30.3%). Dose-volume histograms revealed better results for PBT than photon-based RT. Three of four reports evaluating the ALC demonstrated a significantly higher ALC after PBT than after photon-based RT. Our review found that PBT resulted in a favorable trend in the survival rate and had an excellent dose distribution, contributing to reduced cardiopulmonary toxicities and a maintained number of lymphocytes. These results warrant novel prospective trials to validate the clinical evidence.

Proton versus photon radiation therapy: A clinical review

While proton radiation therapy offers substantially better dose distribution characteristics than photon radiation therapy in certain clinical applications, data demonstrating a quantifiable clinical advantage is still needed for many treatment sites. Unfortunately, the number of patients treated with proton radiation therapy is still comparatively small, in some part due to the lack of evidence of clear benefits over lower-cost photon-based treatments. This review is designed to present the comparative clinical outcomes between proton and photon therapies, and to provide an overview of the current state of knowledge regarding the effectiveness of proton radiation therapy.

Proton Therapy in the Management of Luminal Gastrointestinal Cancers: Esophagus, Stomach, and Anorectum

While the role of proton therapy in gastric cancer is marginal, its role in esophageal and anorectal cancers is expanding. In esophageal cancer, protons are superior in sparing the organs at risk, as shown by multiple dosimetric studies. Literature is conflicting regarding clinical significance, but the preponderance of evidence suggests that protons yield similar or improved oncologic outcomes to photons at a decreased toxicity cost. Similarly, protons have improved sparing of the organs at risk in anorectal cancers, but clinical data is much more limited to date, and toxicity benefits have not yet been shown clinically. Large, randomized trials are currently underway for both disease sites.

Clinicopathological Characteristics and Survival Predictions for Adenocarcinoma of the Esophagogastric Junction: A SEER Population-Based Retrospective Study

Objective

Adenocarcinoma of the esophagogastric junction (AEJ) is a relatively rare malignancy in Western countries whose specific clinicopathological characteristics and associated prognosis have not been comprehensively described.

Methods

Data on patients with AEJ between 2005 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were extracted, evaluated, and compared with patients with gastric cancer (GC) in general. Overall survival (OS) was evaluated using the Kaplan–Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazards regression model to identify risk factors predictive for OS, and the results were used to construct a nomogram to predict 1-, 3-, and 5-year OS among patients with AEJ.

Results

A total of 8013 patients diagnosed with AEJ were identified from the records of 30,179 patients with GC. The mean age was 65.4 (SD = 12.0) years, 79.5% were men, 87.2% were Caucasian, 91.5% were moderately-to-poorly differentiated, 34.4% had AJCC stage I AEJ, and 28.8% had stage IV. The median OS was 18 months, and the 5-year OS was 25.8% (95% CI: 24.8–26.8%). Fewer patients with AEJ had undergone surgical resection, fewer had T+ and N+ (N2~N3) disease (P < 0.001), and fewer had distant metastases compared to the patients with GC (P < 0.05). In the univariate and multivariate analyses, age, race, summary stage, N stage, M stage, and surgery were identified as independent risk factors. The nomogram had a calibration index of 0.726.

Conclusion

AEJ was found to have distinct clinicopathological characteristics. Age, race, summary stage, N stage, M stage, and surgery were independently associated with OS. The nomogram accurately predicted 1-, 3-, and 5-year OS rates.

Treatment Options for T1 Stage Adenocarcinoma of Esophagogastric Junction: A Real-World Retrospective Cohort Study

Background

The number of patients diagnosed with T1 stage adenocarcinoma of esophagogastric junction (AEGJ) has been increasing. This study was conducted to investigate the effect of different treatment options (surgery, chemoradiation, and surgery+chemoradiation) on long-term survival in patients with T1-stage AEGJ.

Methods

We searched the Surveillance, Epidemiology, and End Results (SEER) database to identify the records of patients with T1-stage AEGJ between 2010 and 2018. Patient demographics and cancer parameters were compared among the three groups. The Kaplan–Meier method and Cox proportional hazard modeling were used to compare long-term survival.

Results

Data from 925 T1 stage AEGJ patients (surgery: n=516, surgery+chemoradiation: n=206, chemoradiation: n=203) were collected. We found that the OS and CSS rates of three treatment options had significant difference. Besides, positive nodal status also showed lower OS and CSS rat. Multivariate Cox regression analysis showed that surgery group has much lower risk of death compared with chemoradiation group and similar risk of death compared with surgery+chemoradiation group. Subgroup analysis suggested that in patients with N1–N3 status had higher OS and CSS rates in surgery+chemoradiation group.

Conclusion

Using SEER data, we identified a significant survival advantage with the use of surgery compared to chemoradiation in patients with T1-stage AEGJ while the long-term survival of patients after surgery+chemoradiation group was not significantly different and low risk of death in positive nodal status.

A Critical Review of Radiation Therapy: From Particle Beam Therapy (Proton, Carbon, and BNCT) to Beyond

In this paper, we discuss the role of particle therapy—a novel radiation therapy (RT) that has shown rapid progress and widespread use in recent years—in multidisciplinary treatment. Three types of particle therapies are currently used for cancer treatment: proton beam therapy (PBT), carbon-ion beam therapy (CIBT), and boron neutron capture therapy (BNCT). PBT and CIBT have been reported to have excellent therapeutic results owing to the physical characteristics of their Bragg peaks. Variable drug therapies, such as chemotherapy, hormone therapy, and immunotherapy, are combined in various treatment strategies, and treatment effects have been improved. BNCT has a high dose concentration for cancer in terms of nuclear reactions with boron. BNCT is a next-generation RT that can achieve cancer cell-selective therapeutic effects, and its effectiveness strongly depends on the selective ¹⁰B accumulation in cancer cells by concomitant boron preparation. Therefore, drug delivery research, including nanoparticles, is highly desirable. In this review, we introduce both clinical and basic aspects of particle beam therapy from the perspective of multidisciplinary treatment, which is expected to expand further in the future.

The Promise of Proton Beam Therapy for Oesophageal Cancer: A Systematic Review of Dosimetric and Clinical Outcomes

AIMS

Due to its physical advantages over photon radiotherapy, proton beam therapy (PBT) has the potential to improve outcomes from oesophageal cancer. However, for many tumour sites, high-quality evidence supporting PBT use is limited. We carried out a systematic review of published literature of PBT in oesophageal cancer to ascertain potential benefits of this technology and to gauge the current state-of-the-art. We considered if further evaluation of this technology in oesophageal cancer is desirable.

MATERIALS AND METHODS

A systematic literature search of Medline, Embase, Cochrane Library and Web of Science using structured search terms was carried out. Inclusion criteria included non-metastatic cancer, full articles and English language studies only. Articles deliberating technical aspects of PBT planning or delivery were excluded to maintain a clinical focus. Studies were divided into two sections: dosimetric and clinical studies; qualitatively synthesised.

RESULTS

In total, 467 records were screened, with 32 included for final qualitative synthesis. This included two prospective studies with the rest based on retrospective data. There was heterogeneity in treatment protocols, including treatment intent (neoadjuvant or definitive), dose, fractionation and chemotherapy used. Compared with photon radiotherapy, PBT seemed to reduce dose to organs at risk, especially lung and heart, although not for all reported parameters. Toxicity outcomes, including postoperative complications, were reduced compared with photon radiotherapy. Survival outcomes were reported to be at least comparable with photon radiotherapy.

CONCLUSION

There is a paucity of high-quality evidence supporting PBT use in oesophageal cancer. Wide variation in intent and treatment protocols means that the role and 'gold-standard' treatment protocol are yet to be defined. Current literature suggests significant benefit in terms of toxicity reduction, especially in the postoperative period, with comparable survival outcomes. PBT in oesophageal cancer holds significant promise for improving patient outcomes but requires robust systematic evaluation in prospective studies.

Epidemiology, Diagnosis, Staging and Multimodal Therapy of Esophageal and Gastric Tumors

Gastric and esophageal tumors are diverse neoplasms that involve mucosal and submucosal tissue layers and include squamous cell carcinomas, adenocarcinomas, spindle cell neoplasms, neuroendocrine tumors, marginal B cell lymphomas, along with less common tumors. The worldwide burden of esophageal and gastric malignancies is significant, with esophageal and gastric cancer representing the ninth and fifth most common cancers, respectively. The approach to diagnosis and staging of these lesions is multimodal and includes a combination of gastrointestinal endoscopy, endoscopic ultrasound, and cross-sectional imaging. Likewise, therapy is multidisciplinary and combines therapeutic endoscopy, surgery, radiotherapy, and systemic chemotherapeutic tools. Future directions for diagnosis of esophageal and gastric malignancies are evolving rapidly and will involve advances in endoscopic and endosonographic techniques including tethered capsules, optical coherence tomography, along with targeted cytologic and serological analyses.