Clinical tools to predict outcomes in patients with esophageal cancer treated with definitive chemoradiation: are we there yet?

Significance of intratreatment tumor volume change during chemoradiotherapy for potentially resectable thoracic esophageal squamous cell carcinoma

OBJECTIVE

The purpose of this study was to investigate the clinical significance of tumor response assessment at a twentieth fraction of radiotherapy when predicting the survival of patients with potentially resectable esophageal squamous cell carcinoma (ESCC).

METHODS

A total of 123 ESCC patients with clinical stages II to IV_a were enrolled and analyzed. Gross tumor volume (GTV) of the esophagus (GTV_e) and GTV of the metastatic lymph node (GTV_nd) were manually contoured by at least 2 senior professional radiotherapists on the simulated computed tomography (CT) images in a process that followed the delineating rules for ESCC.

RESULTS

The GTV_e reduction ratio (RR) and GTV_nd RR were calculated based on the evaluation of the tumor volume at a twentieth fraction of radiotherapy. Univariate analysis showed that GTV_e and GTV_nd before treatment, and GTV_e RR and GTV_nd RR at the twentieth fraction of radiotherapy were all significantly associated with complete clinical response (cCR) and overall survival (OS). The Kaplan-Meier method was used to estimate OS and locoregional recurrence-free survival (LRRFS).

CONCLUSIONS

The GTV_e RR ≥27.92% and GTV_nd RR ≥21.49% at a twentieth fraction of radiotherapy are positive predictive factors of LRRFS, and according to multivariate analysis, only GTV_e RR at the twentieth fraction of radiotherapy ≥27.92% is prognostic for a favorable OS.

Intratreatment Tumor Volume Change During Definitive Chemoradiotherapy is Predictive for Treatment Outcome of Patients with Esophageal Carcinoma

BACKGROUND

This study aimed to assess the predictive value of tumor volume changes of esophagus evaluated by serial computed tomography (CT) scans before, during, and after radical chemoradiotherapy (CRT) for treatment outcomes in patients with esophageal cancer (EC).

METHODS

Fifty-three patients with histologically confirmed EC were included for analysis. Gross tumor volume of esophagus (GTVe) was manually contoured on the CT images before treatment, at a twentieth fraction of radiotherapy, at completion of CRT and three months after treatment. GTVe reduction ratio (RR) was calculated to reveal changes of tumor volume by time. The Kaplan-Meier method was used to estimate survival and for univariate analysis. The Cox regression model was performed for multivariate analysis.

RESULTS

Predominant reduction of GTVe was observed during the first 20 fractions of radiotherapy. Age, pretreatment GTVe, GTVe three months after treatment and GTVe RR at twentieth fraction of radiotherapy were all significantly associated with overall survival (OS) in a univariate analysis. Gender was correlated with locoregional recurrence-free survival (LRRFS) in univariate analysis. Multivariate analysis showed that GTVe ≤20 cc, GTVe RR at twentieth fraction of radiotherapy ≥35% were positive predictive factors of OS and pretreatment GTVe ≤20 cc was prognostic for a favorable LRRFS.

CONCLUSION

Pretreatment tumor volume and intratreatment volume reduction ratio are reliable prognostic factors for esophageal cancer treated with definitive CRT.

Barrett's Esophagus after Bimodality Therapy in Patients with Esophageal Adenocarcinoma

INTRODUCTION

Barrett's esophagus (BE) may be present in patients with esophageal adenocarcinoma (EAC) after bimodality therapy (BMT). There is no specific guidance for follow-up of these patients with regard to the presence of BE or dysplasia. In this study, we assessed the outcomes of patients who, after BMT, had BE and those who did not.

METHOD

Patients with EAC who had BMT were identified and analyzed retrospectively in two groups, with and without BE. We compared patient characteristics and outcome variables (local, distant, and no recurrence).

RESULTS

Of 228 patients with EAC, 68 (29.8%) had BE before BMT. Ninety-eight (42.9%) had BE after BMT, and endoscopic intervention was done in 11 (11.2%). With a median follow-up of 37 months, the presence of post-BMT BE was not significantly associated with overall survival (OS) and local recurrence-free survival (LRFS). Similarly, endoscopic intervention was not significantly associated with OS and LRFS. Fifty (73.5%) patients with BE before BMT had BE after BMT (p < 0.0001).

CONCLUSION

The presence of BE after BMT was not associated with increased risk of local recurrence. The local recurrence rate was not influenced by endoscopic intervention. Prospective studies are warranted to generate guidance for intervention, if necessary, for this group of EAC patients.

Radiotherapy response evaluation using FDG PET-CT-established and emerging applications

Radiation therapy is a common component of curative cancer treatment. However, there is a significant incidence of treatment failure. In these cases, salvage surgical options are sometimes appropriate. Accurate assessment of response and early recognition of treatment success or failure is therefore critical to guide treatment decisions and impacts on survival and the morbidity of treatment. Traditionally, treatment response has depended upon the anatomical measurement of disease. However, this may not correlate well with the presence of disease, especially after radiotherapy. Combined positron emission tomography (PET) and CT imaging employs radioactive tracers to identify molecular characteristics of tissues. PET imaging exploits the fact that malignancies have characteristic molecular profiles which differ compared with surrounding tissues. The complementary anatomical and functional information facilitates accurate non-invasive assessment of surrogate biomarkers of disease activity.

Prognostic Significance of 2-Deoxy-2-[18F]-Fluoro-D-Glucose PET/CT in Patients With Locally Advanced Esophageal Cancer Undergoing Neoadjuvant Chemoradiotherapy Before Surgery: A Nonparametric Approach

To investigate the prognostic value of tumor metabolism measurements on serial 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography and computed tomography scans in patients with locally advanced esophageal cancer undergoing neoadjuvant chemoradiotherapy. Forty-five patients (63 ± 7 years, 6 female) treated with concomitant chemoradiotherapy before surgery were followed up for 24 ± 18 months (range 4-71). Positron emission tomography and computed tomography scans were obtained within 1 week before the start (PET1) and 1 month after the completion of the treatment (PET2). Total body tumor metabolic activity was measured as the sum of the parameters: SUVmax, SUV corrected for lean body mass, and total lesion glycolysis (TLG40/50/70%). Then, delta values for the parameters between PET1 and PET2 were calculated and expressed as percentage of PET1 results. At the time of the analysis, 27 patients were dead and 18 were alive. There was no difference between the 2 groups in terms of age, sex, site of the disease, histology, and the presence/absence of linfonodal metastases (P = NS). Survival random forest analysis (20,000 trees) resulted in an estimate of error rate of 36%. The nonparametric approach identified ΔTLG40 as the most predictive factor of survival (relative importance 100%). Moreover, T (17%), N (5%), and M (5%) stage of the disease, cancer histology (11%), TLG70 (5%) at the end of chemioradioterapy, and ΔTLG(50-70) (17%-5%) were positively associated with patient outcome. The nonparametric analysis confirmed the prognostic importance of some clinical parameters, such as TNM stage and cancer histology. Moreover, ΔTLG resulted to be the most important factor in predicting outcome and should be considered in risk stratification of patients treated with neoadjuvant chemoradiotherapy.

Serum thymidine kinase 1 levels correlate with clinical characteristics of esophageal squamous cell carcinoma

Patients with esophageal cancer are often diagnosed at advanced stages, leading to poor prognosis. Biomarkers are needed to enable earlier detection as well as to aid in the prediction of prognosis, but to date these tools remain scarce. Thymidine kinase (TK1) has been shown to exhibit altered expression levels in esophageal tumor cells, therefore this study sought to determine whether serum TK1 levels are also altered and, if so, to assess the utility of TK1 as a biomarker in esophageal squamous cell carcinoma. Eighty patients with esophageal squamous cell carcinoma were included as the case group and 80 healthy persons were selected as the control group. Serum TK1 levels, postoperatively for cancer patients, were detected by chemiluminescence. Follow-up was performed for cancer patients to determine the progression free survival (PFS) and overall survival (OS). Serum TK1 levels were significantly higher in cases of esophageal cancer than in healthy control individuals (t=7.235, P<0.05). When cancer cases were sub-divided into lower and higher serum TK1 levels, based on the mean level of 3.38 pmol/L, statistically significant differences in TNM stage, tumor differentiation, and lymph node metastasis were observed between patients with ≥3.38 pmol/L and <3.38 pmol/L (χ(2)=28.134, 3.187, 7.234, P<0.05). The average OS of all esophageal cancer patients was 30.13 months, and the average PFS was 24.73 months. However, when the cases were divided by serum TK1 level, average OS of those with higher serum TK1 (≥3.38 pmol/L) was significantly lower (23.98 mo) than those with lower serum TK1 (32.96 mo) (χ(2)=5.439, P<0.05). Similarly, average PFS was significantly lower in patients with higher serum TK1 (17.65 mo versus 27.62) (χ(2)=4.640, P<0.05). OS was correlated with TNM stage (hazard ratio, HR=3.116), degree of tumor differentiation (HR=0.427), lymph node metastasis (HR=0.535), and serum TK1 level (HR=1.913) (Wald χ(2)=6.782, 6.228, 4.562, 5.681, P<0.05). Similarly, PFS was correlated with TMN stage (HR=2.153), degree of tumor differentiation (HR=0.627), and serum TK1 level (HR=1.632) (Wald χ(2)=7.035, 5.335, 4.887, P<0.05). Thus, patients with esophageal squamous cell carcinoma exhibit higher circulating TK1 levels, consistent with findings of increased TK1 expression in tumor cells. Further, the correlation of serum TK1 levels with clinical features of esophageal cancer and with patient survival suggest that serum TK1 may serve as a valuable biomarker for predicting patient prognosis.