What Is the Ideal Tumor Regression Grading System in Rectal Cancer Patients after Preoperative Chemoradiotherapy?

Purpose

Tumor regression grade (TRG) is predictive of therapeutic response in rectal cancer patients after chemoradiotherapy (CRT) followed by curative resection. However, various TRG systems have been suggested, with subjective categorization, resulting in interobserver variability. This study compared the prognostic validity of four different TRG systems in order to identify the most ideal TRG system.

Materials and Methods

This study included 933 patients who underwent preoperative CRT and curative resection. Primary tumors alone were graded according to the American Joint Committee on Cancer (AJCC), Dworak, and Ryan TRG systems, and both primary tumors and regional lymph nodes were graded according to a modified Dworak TRG system. The ability of each TRG system to predict recurrence-free survival (RFS) and overall survival (OS) was analyzed using chi-square and C statistics.

Results

All four TRG systems were significantly predictive of both RFS and OS (p < 0.001 each), however none was a better predictor of prognosis than ypStage. Among the four TRGs, the mDworak TRG system was a better predictor of RFS and OS than the AJCC, Dworak, and Ryan TRG systems, and both the chi-square and C statistics were higher for the former, although the differences were not statistically significant. The combination of ypStage and the modified Dworak TRG better predicted RFS and OS than ypStage alone.

Conclusion

The modified Dworak TRG system for evaluation of entire tumors including regional lymph nodes is a better predictor of survival than current TRG systems for evaluation of the primary tumor alone.

How to measure tumour response in rectal cancer? An explanation of discrepancies and suggestions for improvement

Various methods categorize tumour response after neoadjuvant therapy, including down-staging and tumour regression grading. Response categories allow comparison of different treatments within clinical trials and predict outcome. A reproducible response categorization could identify subgroups with high or low risk for the most appropriate subsequent treatments, like watch and wait. Lack of standardization and interpretation difficulties currently limit the usability of these approaches. In this review we describe these difficulties for the evaluation of chemoradiation in rectal cancer. An alternative approach of tumour response is based on patterns of residual disease, including fragmentation. We summarise the evidence behind this alternative method of response categorisation, which explains a number of very relevant clinical discrepancies. These issues include differences between downstaging and tumour regression, high local regrowth in advanced tumours during watchful waiting procedures, the importance of resection margins, the limited value of post-treatment biopsies and the relatively poor outcome of patients with a near complete pathological response. Recognition of these patterns of response can allow meaningful development of novel biomarkers in the future.

Diagnostic accuracy of MRI in assessing tumor regression and identifying complete response in patients with locally advanced rectal cancer after neoadjuvant treatment

BACKGROUND

The diagnostic accuracy of Magnetic Resonance Imaging (MRI) in restaging locally advanced rectal cancers (LARC) after neoadjuvant chemo-radio therapy (NCRT) has been under recent scrutiny. There is limited data on the accuracy of MRI and its timing in assessing tumor regression grade (TRG) and in identifying patients with complete response (CR). NCRT seems to cause tissue inflammation and oedema which renders reading the scans difficult for radiologist.

AIM

This study aims to assess the accuracy of MRI at different time intervals after NCRT in staging TRG and in identifying CR. Inter-observer agreement between 2 blinded radiologists will also be assessed.

METHOD

In this retrospective analysis, all patients diagnosed with LARC between January 2003 and 2014, who underwent long-course NCRT, who had at least one post-treatment MRI scan, and who underwent surgery with available pathology results are included. Histopathology staging is considered the reference standard. Accuracy of MRI in T staging and in TRG staging is assessed using weighted kappa. Accuracy, sensitivity, and specificity in identifying CR are calculated from a 2 × 2 contingency table. Inter-observer agreement between two-staging blinded radiologists is calculated using weighted kappa. These are calculated at 2 different time intervals after completion of NCRT.

RESULTS

114 patients were identified who had a first post-treatment MRI scan at an average of 6.2 weeks after completion of NCRT. A subgroup of 68 patients had a second post-treatment MRI at an average of 10.4 weeks. Pathology results were available for 103 patients. By the second post-treatment scan, an additional 25% of patients experienced downstaging; accuracy in T staging increased from 43% to 57.4%; accuracy in TRG staging rose from 28.2% to 38.1%; accuracy in identifying CR rose from 83.4% to 84.1%. Inter-observer agreement in T staging rose from 0.1 for first post-treatment MRI to 0.206 for second post-treatment MRI.

CONCLUSION

This study advocates that restaging should occur at 10 weeks rather than the standard 6 weeks. This results in higher complete response rates and higher concordance with pathological specimens. Our results also showed that it is easier for radiologists to stage the MRI scans, resulting in higher inter-rater agreements.

Survival landscape of different tumor regression grades and pathologic complete response in rectal cancer after neoadjuvant therapy based on reconstructed individual patient data

BACKGROUND

Neoadjuvant therapy can lead to different tumor regression grades (TRG) in rectal cancer after neoadjuvant therapy. The purposes of this study are to investigate the relationships among TRG, pathologic complete response (pCR) and long-term survival, on the basis of reconstructed individual patient data (IPD).

METHODS

The PubMed, Embase, Ovid and Cochrane CENTRAL databases were searched. The primary endpoint was to evaluate the survival landscape of different TRGs after neoadjuvant therapy and the secondary endpoint was to evaluate the associations between pCR and survival. IPD were reconstructed with Kaplan-Meier curves.

RESULTS

The 10-year overall survival (OS) and 5-year disease-free survival (DFS) were clearly higher in the pCR group than in the non-pCR (npCR) group (80.5% vs. 48.3, 90.1% vs. 69.8%). Furthermore, the OS and DFS increased with improvement in tumor regression after neoadjuvant therapy. According to the IPD, the pCR group had longer OS (HR = 0.240, 95% CI = 0.177-0.325, p < 0.001) and DFS (HR = 0.274, 95% CI = 0.205-0.367, p < 0.001) than the npCR group. Better tumor regression was associated with better survival outcomes (p < 0.005). Direct calculation of published HR values yielded similar results.

CONCLUSIONS

Our results indicate a positive relationship between better tumor regressions and improved survival benefits among the npCR group and patients with rectal cancer achieving pCR had much longer OS and DFS than patients achieving npCR, presenting a survival landscape of different TRGs and pCR in rectal cancer after neoadjuvant therapy.

Tumor Regression Grade in Gastric Cancer After Preoperative Therapy

BACKGROUND

The Cancer Staging Manual, 8th edition, now includes post-neoadjuvant therapy (ypTNM) staging for gastric cancer patients. Our purpose was to determine whether the tumor regression grade (TRG) of the primary tumor is useful for predicting the survival of these patients.

METHODS

We performed a retrospective review of an institutional database and identified patients with clinically non-metastatic gastric adenocarcinoma who underwent preoperative chemotherapy or chemoradiation therapy before gastrectomy. Pathology reports were reviewed, and TRG was classified as follows: 0 (complete response), 1 (viable tumor cells ≤ 1-2%), 2 (viable cells ≤ 50%), or 3 (viable cells > 50%).

RESULTS

Of the 356 patients identified, including 80 (23%) with a gastroesophageal junction tumor, 268 (75%) had undergone preoperative chemoradiation therapy. Fifty-six (16%) had TRG 0, 57 (16%) TRG 1, 128 (36%) TRG 2, and 115 (32%) TRG 3. No association between TRG and pretreatment factors was identified, except for signet-ring cell histologic type and tumor location. A higher TRG was associated with more advanced ypT and ypN categories (both p < 0.001), ypM1 (p = 0.004), and R1 resection (p = 0.052). The median overall survival (OS) duration was 6.6 years, and the 5-year OS rate was 54.1%. TRG 3 was associated with a shorter OS duration than were other TRG scores (p = 0.015), while the OS did not differ significantly among the TRG 0-2 groups (p = 0.803). On multivariable analysis, TRG was not associated with OS after adjustment for ypN status.

CONCLUSION

In gastric cancer patients who underwent preoperative therapy, TRG 3 was associated with advanced ypStage and R1 resection. Patients with TRG 3 had a shorter OS duration because of associated advanced ypStage, particularly ypN+ status.

Colorectal liver metastases: ADC as an imaging biomarker of tumor behavior and therapeutic response

PURPOSE

To correlate the ADC values of colorectal liver metastases, evaluated before (preADC) and after (postADC) neoadjuvant chemotherapy (ChT), as well as their difference (ΔADC), with the histological tumor regression grade (TRG) and to determine whether the preADC value can be predictive of the lesion ChT response.

METHOD

Twenty-four patients with colorectal liver metastases, who had undergone 3 T-MRI before and after ChT and were subsequently treated by parenchymal-spearing surgery, were retrospectively included. Diffusion-weighted MRI (DW-MRI) was performed using a spin-echo echo-planar sequence with multiple b values, obtaining an ADC map. Fitted ADC values were calculated for each lesion before and after ChT. The maximum diameter of each lesion in both examinations was recorded. Diameter variations and RECIST1.1 criteria were assessed. All MRI findings were histopathologically correlated to TRG of resected liver metastases. Statistical analysis was performed on a per-lesion basis.

RESULTS

A total of 58 colorectal liver metastases were analysed; after ChT, 8 out of 58 lesions disappeared. TRG1, TRG2, TRG3, TRG4 and TRG5 were observed in 6, 12, 12, 13 and 7 lesions, respectively. The preADC values showed a different distribution according to the TRG scores (p = 0.0027), even though the distribution was not linear. The postADC and ΔADC values were significant different based on the TRG system (both p < 0.0001). A significant correlation between the lesion TRG and the evaluation according to RECIST1.1 criteria was observed by a per-lesion analysis (p = 0.0009).

CONCLUSIONS

PostADC and ΔADC could be proposed as reliable biomarkers to assess tumor treatment response after preoperative ChT in patients with colorectal liver metastases.

Absolute CT perfusion parameter values after the neoadjuvant chemoradiotherapy of the squamous cell esophageal carcinoma correlate with the histopathologic tumor regression grade

PURPOSE

To analyze value of the computed tomography (CT) perfusion imaging in response evaluation of the esophageal carcinoma to neoadjuvant chemoradiotherapy (nCRT) using the histopathology as reference standard.

METHODS

Forty patients with the squamous cell esophageal carcinoma were re-evaluated after the nCRT by CT examination, which included low-dose CT perfusion study that was analyzed using the deconvolution-based CT perfusion software (Perfusion 3.0, GE). Histopathologic assessment of tumor regression grade (TRG) according to Mandard's criteria served as reference standard of response evaluation. Statistical analysis was performed using Spearman's rank correlation coefficient (r(S)) and Kruskal-Wallis's test.

RESULTS

The perfusion CT parameter values, measured after the nCRT in the segment of the esophagus that had been affected by neoplasm prior to therapy, significantly correlated with the TRG: blood flow (BF) (r(S)=0.851; p<0.001), blood volume (BV) (r(S)=0.732; p<0.001) and mean transit time (MTT) (r(S)=-0.386; p=0.014). Median values of BF and BV significantly differed among TRG 1-4 groups (p<0.001), while maximal esophageal wall thickness did not (p=0.102). Median BF and BV were gradually rose and MTT decreased as TRG increased, from 21.4 ml/min/100 g (BF), 1.6 ml/100 g (BV) and 8.6 s (MTT) in TRG 1 group, to 37.3 ml/min/100 g, 3.5 ml/100 g and 7.5 s in TRG 2 group, 81.4 ml/min/100 g, 4.1 ml/100 g and 3.8 s in TRG 3 group, and 121.1 ml/min/100 g, 4.9 ml/100 g and 3.7 s in TRG 4 group. In all 15 patients who achieved complete histopathologic regression (TRG 1), BF was <30.0 ml/min/100 g.

CONCLUSIONS

CT perfusion could improve the accuracy in response evaluation of the esophageal carcinoma to nCRT.

Tumor regression grades: potential outcome predictor of locally advanced rectal adenocarcinoma after preoperative radiotherapy

AIM

To analyze tumor regression grade (TRG) for prognosis of locally advanced rectal adenocarcinoma (LARA) treated with preoperative radiotherapy.

METHODS

One hundred and ninety patients with clinical stage II/III LARA were studied. All patients underwent radical surgery (between 2004 and 2010) after 30-Gy/10-fraction preoperative radiotherapy (pre-RT). All 190 patients received a short course of pre-RT and were reassessed for disease recurrence and survival; the slides of surgical specimens were reviewed and classified according to Mandard TRG. We compared patients with good response (Mandard TRG1 or TRG2) vs patients with bad/poor response (Mandard TRG3-5). Outcomes evaluated were 5-year overall survival (OS), 5-year disease-free survival (DFS), and local, distant and mixed recurrence. Fisher's exact test or χ(2) test, log-rank test and proportional hazards regression analysis were used to calculate the probability that Mandard TRG was associated with patient outcomes.

RESULTS

One hundred and sixty-six of 190 patients (87.4%) were identified as Mandard bad responders (TRG3-5). High Mandard grade was correlated with tumor height (41.7% < 6 cm vs 58.3% ≥ 6 cm, P = 0.050), ypT stage (75% ypT0-2 vs 25% ypT3-4, P = 0.000), and ypN stage (75% ypN0 vs 25% ypN1, P = 0.031). In univariate survival analysis, Mandard grade bad responders had significantly worse OS and DFS than good responders (TRG1/2) (OS, 83.1% vs 96.4%, P = 0.000; DFS, 72.3% vs 92.0%, P = 0.002). In multivariate survival analysis, Mandard bad responders had significantly worse DFS than Mandard good responders (DFS 3.8 years (95%CI: 1.2-12.2 years, P = 0.026).

CONCLUSION

Mandard grade good responders had a favorable prognosis. TRG may be a potential predictor for DFS in LARA after pre-RT.

Prediction of tumor response after neoadjuvant chemoradiotherapy in rectal cancer using (18)fluorine-2-deoxy-D-glucose positron emission tomography-computed tomography and serum carcinoembryonic antigen: a prospective study

PURPOSE

To investigate the association between (18)fluorine-2-deoxy-D-glucose positron emission tomography-computed tomography ((18)F-FDG PET/CT) parameters, serum carcinoembryonic antigen (CEA), and tumor response in patients with rectal cancer receiving neoadjuvant chemoradiotherapy (nCRT).

METHODS

Sixty-four patients with T3-4 and/or node-positive rectal cancer receiving nCRT followed by surgery were prospectively studied. PET/CT was performed before, and in 28 patients, both before and after nCRT. The pre-/post-nCRT maximum standardized uptake (SUVmax) values, differences between pre-/post-nCRT SUVmax (∆SUVmax), response index of SUVmax (RI-SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and CEA were measured. The ability of PET/CT parameters and CEA to predict Mandard's tumor regression grade (TRG) and pathological complete remission (pCR) were evaluated.

RESULTS

31 patients were identified as responders (TRG 1-2), and 19 exhibited pCR. For responders, significant differences were found for ΔSUVmax (24.88 vs. 15.39 g/ml, p = 0.037), RI-SUVmax (0.76 vs. 0.63, p = 0.025), ΔSUVmean (14.43 vs. 8.65 g/ml, p = 0.029), RI-SUVmean (0.77 vs. 0.63, p = 0.011), CEA-pre (6.30 vs. 27.86 μg/L, p < 0.001), CEA-post (2.22 vs. 5.49 μg/L, p = 0.002), ΔCEA (4.08 vs. 23.13 μg/L, p < 0.001), and RI-CEA (0.25 vs. 0.55, p = 0.002). Differences between pCR and non-pCR patients were noted as RI-SUVmean (0.77 vs. 0.65, p = 0.043), MTV-pre (9.87 vs. 14.62 cm(3), p = 0.045), CEA-pre (5.62 vs. 22.27 μg/L, p = 0.002), CEA-post (1.95 vs. 4.72 μg/L, p = 0.001), and ΔCEA (3.68 vs. 17.99 μg/L, p = 0.013). Receiver operating characteristic analysis revealed that RI-SUVmean exhibited the greatest accuracy in predicting responders, whereas CEA-post and ΔCEA exhibited the greatest accuracy in predicting pCR.

CONCLUSIONS

(18)F-FDG PET/CT parameters and CEA are accurate tools for predicting tumor response to nCRT in rectal cancer.

Combined value of apparent diffusion coefficient-standardized uptake value max in evaluation of post-treated locally advanced rectal cancer

AIM: To assess the clinical diagnostic value of functional imaging, combining quantitative parameters of apparent diffusion coefficient (ADC) and standardized uptake value (SUV)max, before and after chemo-radiation therapy, in prediction of tumor response of patients with rectal cancer, related to tumor regression grade at histology.

METHODS: A total of 31 patients with biopsy proven diagnosis of rectal carcinoma were enrolled in our study. All patients underwent a whole body ¹⁸FDG positron emission tomography (PET)/computed tomography (CT) scan and a pelvic magnetic resonance (MR) examination including diffusion weighted (DW) imaging for staging (PET1, RM1) and after completion (6.6 wk) of neoadjuvant treatment (PET2, RM2). Subsequently all patients underwent total mesorectal excision and the histological results were compared with imaging findings. The MR scanning, performed on 1.5 T magnet (Philips, Achieva), included T2-weighted multiplanar imaging and in addition DW images with b-value of 0 and 1000 mm²/s. On PET/CT the SUVmax of the rectal lesion were calculated in PET1 and PET2. The percentage decrease of SUVmax (ΔSUV) and ADC (ΔADC) values from baseline to presurgical scan were assessed and correlated with pathologic response classified as tumor regression grade (Mandard’s criteria; TRG1 = complete regression, TRG5 = no regression).

RESULTS: After completion of therapy, all the patients were submitted to surgery. According to the Mandard’s criteria, 22 tumors showed complete (TRG1) or subtotal regression (TRG2) and were classified as responders; 9 tumors were classified as non responders (TRG3, 4 and 5). Considering all patients the mean values of SUVmax in PET 1 was higher than the mean value of SUVmax in PET 2 (P < 0.001), whereas the mean ADC values was lower in RM1 than RM2 (P < 0.001), with a ΔSUV and ΔADC respectively of 60.2% and 66.8%. The best predictors for TRG response were SUV2 (threshold of 4.4) and ADC2 (1.29 × 10^-3 mm²/s) with high sensitivity and specificity. Combining in a single analysis both the obtained median value, the positive predictive value, in predicting the different group category response in related to TRG system, presented R² of 0.95.

CONCLUSION: The functional imaging combining ADC and SUVmax in a single analysis permits to detect changes in cellular tissue structures useful for the assessment of tumour response after the neoadjuvant therapy in rectal cancer, increasing the sensitivity in correct depiction of treatment response than either method alone.

The Effects of Neoadjuvant Treatment on the Tumor Microenvironment in Rectal Cancer: Implications for Immune Activation and Therapy Response

BACKGROUND

Because more than one neoadjuvant treatment is available for advanced rectal cancer, the aim of this study was to compare the differential clinical and pathologic effects of different combinations of chemoradiation regimens, treatment sequencing, and timing to surgery on patient outcomes.

PATIENTS AND METHODS

Between January 2015 and October 2018, 126 newly diagnosed patients with rectal cancer with magnetic resonance imaging-based cT3-4 or N+ rectal disease for curative-intent treatment received 1 of 4 neoadjuvant regimens, followed by immediate surgery or delayed surgery. Whole post-neoadjuvant surgical specimens were assessed by 3-dimensional digital whole-tumor microarray imaging and immunostaining in pathology to analyze the global tumor pathologic regression grades, residual tumor distribution patterns, the extent of lymphovascular permeation, lymph node positivity, and the overall density of lymphocyte infiltration in the tumor microenvironment. These factors were further examined to identify possible correlations with clinical outcomes.

RESULTS

Among the 4 neoadjuvant treatment groups, including 2 conventional regimens, we found a significant increase of stromal CD3+ and CD8+ immune infiltrates in the postneoadjuvant tumor microenvironment in the 3 groups with delayed surgery after different chemoradiation regimens compared with the group with immediate surgery after a short course of RT alone. Independent of neoadjuvant chemoradiation regimens, the post-induction high-intermediate-low stromal-infiltrating CD8+ T-cell densities corresponded to tumor regression grades, distant metastasis rates, and disease-free survival and were prognostic factors for the further stratification of patients with American Joint Committee on Cancer stage III rectal cancer into different risk groups after surgery.

CONCLUSION

The effectiveness of induction strategies on tumor remission and disease recurrence in advanced rectal cancer was significantly correlated with an enhanced cytotoxic immune response in the tumor microenvironment.

Clinical significance of tumor regression grade in rectal cancer with preoperative chemoradiotherapy

Purpose

Neoadjuvant chemoradiotherapy applied to the locally advanced rectal cancer reduces local recurrence and improves survival. We assessed tumor regression grade (TRG) and its influence on survival in rectal cancer patients treated with chemoradiotherapy followed by surgical resection.

Methods

We studied 108 patients that were seen at our hospital between August 2004 and December 2008. Patients received preoperative chemoradiotherapy consisting of 5-fluorouracil and leucovorin by continous infusion during the first and fifth week, delivered with concurrent pelvic radiation of 50.4 Gy, followed by radical surgery at 6-8 weeks. The TRG was determined by the amount of fibrosis in the tumor embedding area and was divided into 5 grades based on the relative amount of fibrosis. We analyzed all preoperative clinicopathologic factors, postoperative pathologic stages, TRG and prognosis, retrospectively.

Results

Downstaging of rectal cancer through neoadjuvant chemoradiotherapy occurred in 64 (59%) patients. The numbers of total regressions (TRG4), good regressions (TRG3), moderate regressions (TRG2), minor regressions (TRG1), and no regression (TRG0) were 19 (18%), 65 (60%), 17 (16%), 6 (5%), and 1 (1%) respectively. The TRG was inversely correlated with perineural invasion and lymphovascular invasion (P = 0.008, P = 0.032). The local recurrence rate declined as the tumor regression grade increased (P = 0.032). The 19 patients with TRG4 had a better three-year disease free survival than the 89 patients with TRG0-3 (P = 0.034). The 16 patients with pathologic complete remission (pCR) had a better three-year disease free survival than the 92 patients with non-pCR (P = 0.025).

Conclusion

Higher TRG after preoperative chemoradiotherapy for rectal cancer closely correlates with better survival and low local recurrence. The TRG is considered to be a significant prognostic factor.

Evaluation and Comparison of Predictive Value of Tumor Regression Grades according to Mandard and Becker in Locally Advanced Gastric Adenocarcinoma

Purpose

Tumor regression grade (TRG) has been widely used in gastrointestinal carcinoma to assess pathological responses to neoadjuvant chemotherapy (NCT). There are various standards without a consensus, and it is still unclear which kind of system has better predictive value. This study aims to investigate and compare the predictive ability of the Mandard and Becker TRGs in patients with locally advanced gastric cancer.

Materials and Methods

A total of 290 patients with locally advanced gastric adenocarcinoma who underwent NCT and curative surgery were studied. Survival analysis for overall survival (OS) and disease-free survival (DFS) were based on the Kaplan-Meier method and Cox proportional hazards method. Predictive values of TRGs and models were assessed by time-dependent receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), nomogram, and calibration curve.

Results

In multivariable analysis, the Mandard TRG was associated with OS (hazard ratio [HR], 1.806; p=0.026) and DFS (HR, 1.792; p=0.017). The Becker TRG was also related to OS (HR, 1.880; p=0.014) and DFS (HR, 1.919; p=0.006). The Mandard and Becker TRG AUCs for 5-year survival were 0.72 and 0.71, respectively. The whole models showed an increased predictive value, with AUCs of 0.85 and 0.86, respectively. There was no significant difference between the two TRGs and two models.

Conclusion

TRG was an independent predictor for survival, and there was no significant difference between these two systems.

Comparison of tumor regression grading systems for locally advanced gastric adenocarcinoma after neoadjuvant chemotherapy

BACKGROUND

Current tumor regression grade (TRG) evaluations are based on various systems which brings confusion for oncologists and pathologists when interpreting results. The recent six-tier system (JGCA2017-TRG) recommended by the Japanese Gastric Cancer Association (JGCA) is worth investigating, as four-tier TRG systems are favored in various parts of the world.

AIM

To compare the predictive accuracies of five published TRG systems.

METHODS

Data were retrospectively collected from patients with locally advanced gastric cancer (LAGC) who underwent neoadjuvant chemotherapy followed by D2 Lymphadenectomy between January 2005 and January 2014 at our institution. Outcomes were overall survival (OS) and disease-free survival (DFS), which were evaluated separately using the following TRG systems: JGCA2017, JGCA, Becker, AJCC/CAP, and Mandard.

RESULTS

All five published TRG systems were independent predictors for OS and DFS. Concordance indices of the JGCA2017, JGCA, Becker, AJCC/CAP-TRG, and Mandard systems were 0.651/0.648 0.652/0.649, 0.693/0.695, 0.688/0.685, and 0.674/0.675 for OS and DFS, respectively. The four-tier Becker system showed the highest c-index, which was significantly greater than that of the six-tier JGCA2017 and five-tier JGCA systems (P < 0.05 in OS and DFS). When residual tumor percentages were reset as: “no residual tumor”, < 10%, < 100%, and “no response”, the rearranged cutoff values achieved a maximum c-index with 0.728 for OS and 0.737 for DFS, which was superior to the other five systems.

CONCLUSION

The newly introduced six-tier JGCA-TRG system cannot increase prognostic stratification. The four-tier Becker system is more suitable for LAGC patients. A population-based study is warranted to define the optimal criterion for TRG in LAGC patients.

Degree of tumor regression after preoperative chemo-radiotherapy in locally advanced rectal cancer-Preliminary results

AIM

The aim of this investigation is to determine the degree of tumor regression by histopathological evaluation of surgical specimen after neoadjuvant chemo-radiotherapy for patients with stage IIIB rectal cancer.

BACKGROUND

The standard therapy for rectal carcinoma is surgical, however, preoperative radiochemotherapy will play an increasing role especially in locally advanced disease. To estimate the prognosis and the effect of radiochemotherapy the postradiochemotherapeutical pathological features are important to assess.

MATERIALS AND METHODS

Ten patients with cT3-4, cN1 stage rectal cancer received preoperative chemo-radiotherapy. A total tumor dose of 50 Gy was applied to all patients, with a daily fraction of 2 Gy, 5 times a week, with concomitant Capecitabine 1650 mg/m(2). A pathomorphologic assessment of the therapeutic response of the residual tumor volumes and estimation of tumor control were performed using Dworak's system of tumor regression grading (TRD) from no regression (0) to a complete tumor control (4).

RESULTS

Dworak's TRD for the examined patients is as follows: in 20% of the patients no tumor regression was observed - Grade 0, in 30% - Grade 1, in 20% - Grade 2 and in 30% a complete tumor regression was achieved - Grade 4. Four of the patients (40%) presented with borderline resectable tumors before the neoadjuvant chemo-radiotherapy. Nine of the patients (90%) underwent radical surgery. In one case (10%) a radical surgery was not possible. One patient (10%) developed severe radiation enteritis in both the early and late postoperative period, with her tumor regression evaluated as Grade 4.

CONCLUSION

Accurate evaluation of local tumor control using Dworak's tumor regression grading scale after preoperative chemo-radiotherapy gives the basis for a larger investigation and search for a correlation with the prognosis of the disease and individual choice of adjuvant treatment.

Interobserver agreement of a gastric adenocarcinoma tumor regression grading system that incorporates assessment of lymph nodes

Perioperative chemotherapy is increasingly used in combination with surgery for the treatment of patients with locally advanced, resectable gastric cancer. Histologic tumor regression grade (TRG) has emerged as an important prognostic factor; however, a common standard for its evaluation is lacking. Moreover, the clinical significance of regressive changes in metastatic lymph nodes (LNs) remains unclear. We conducted an international study to examine the interobserver agreement of a TRG system that is based on the Becker system for the primary tumors and additionally incorporates regression grading in LNs. Twenty observers at different levels of experience evaluated the TRG in 60 histologic slides (30 primary tumors and 30 LNs) based on the following criteria: for primary tumors, grade 1 represented complete response (no residual tumor), grade 2 represented <10%, grade 3 represented 10-50%, and grade 4 represented >50% residual tumor, as described by Becker et al. For LNs, grade "a" represented complete, grade "b" represented partial, and grade "c" represented no regression. The interobserver agreement was estimated using the Kendall's coefficient of concordance (W). Regarding primary tumors, agreement was good irrespective of the level of experience, reaching a W-value of 0.70 overall, 0.71 among subspecialized, and 0.71 among nonsubspecialized observers. Regarding LNs, interobserver agreement was moderate to good, with W-values of 0.52 overall, 0.64 among subspecialized, and 0.45 among nonsubspecialized observers. These findings indicate that the combination of the Becker TRG system with a three-tiered grading of regression in LNs generates a system that is reproducible. Future studies should investigate whether the additional information of TRG in LNs adds to the prognostic value of histologic regression grading in gastric cancer specimens.

Neutrophile-to-lymphocyte, lymphocyte-to-monocyte, and platelet-to-lymphocyte ratios as prognostic and response biomarkers for resectable locally advanced gastric cancer

BACKGROUND

Perioperative fluorouracil plus leucovorin, oxaliplatin, and docetaxel (FLOT) improves prognosis in locally advanced gastric cancer (LAGC). Neutrophil-to-lymphocyte (NLR), lymphocyte-to-monocyte (LMR), and platelet-to-lymphocyte (PLR) ratios are prognostic biomarkers but not predictive factors.

AIM

To assess blood ratios’ (NLR, LMR and PLR) potential predictive response to FLOT and survival outcomes in resectable LAGC patients.

METHODS

This was a multicentric retrospective study investigating the clinical potential of NLR, LMR, and PLR in resectable LAGC patients, treated with at least one preoperative FLOT cycle, from 12 Portuguese hospitals. Means were compared through non-parametric Mann-Whitney tests. Receiver operating characteristic curve analysis defined the cut-off values as: High PLR > 141 for progression and > 144 for mortality; high LMR > 3.56 for T stage regression (TSR). Poisson and Cox regression models the calculated relative risks/hazard ratios, using NLR, pathologic complete response, TSR, and tumor regression grade (TRG) as independent variables, and overall survival (OS) as the dependent variable.

RESULTS

This study included 295 patients (mean age, 63.7 years; 59.7% males). NLR was correlated with survival time (r = 0.143, P = 0.014). PLR was associated with systemic progression during FLOT (P = 0.022) and mortality (P = 0.013), with high PLR patients having a 2.2-times higher risk of progression [95% confidence interval (CI): 0.89-5.26] and 1.5-times higher risk of mortality (95%CI: 0.92-2.55). LMR was associated with TSR, and high LMR patients had a 1.4-times higher risk of achieving TSR (95%CI: 1.01-1.99). OS benefit was found with TSR (P = 0.015) and partial/complete TRG (P < 0.001). Patients without TSR and with no evidence of pathological response had 2.1-times (95%CI: 1.14-3.96) and 2.8-times (95%CI: 1.6-5) higher risk of death.

CONCLUSION

Higher NLR is correlated with longer survival time. High LMR patients have a higher risk of decreasing T stage, whereas high PLR patients have higher odds of progressing under FLOT and dying. Patients with TSR and a pathological response have better OS and lower risk of dying.

Quantitative RECIST derived from multiparametric MRI in evaluating response of esophageal squamous cell carcinoma to neoadjuvant therapy

OBJECTIVE

To develop a quantitative Response Evaluation Criteria in Solid Tumors (qRECIST) for evaluating response to neoadjuvant therapy (nT) in ESCCs relying on multiparametric (mp) MRI.

METHODS

Patients with cT2-T4a/N0-N3/M0 ESCC undergoing pre-nT and post-nT esophageal mpMRI before radical resection were prospectively included. Images were reviewed by two experienced radiologists. qRECIST was redefined using four methods including conventional criterion (cRECIST) and three model-dependent RECIST relying on quantitative MRI measurements at pre-nT, post-nT, and delta pre-post nT, respectively. Pathological tumor regression grades (TRGs) were used as a reference standard. The rates of agreement between four qRECIST methods and TRGs were determined with a Cronbach's alpha test, area under the curve (AUC), and a diagnostic odds ratio meta-analysis.

RESULTS

Ninety-one patients were enrolled. All four methods revealed high inter-reader agreements between the two radiologists, with a Kappa coefficient of 0.96, 0.87, 0.88, and 0.97 for cRECIST, pre-nT RECIST, post-nT RECIST, and delta RECIST, respectively. Among them, delta RECIST achieved the highest overall agreement rate (67.0% [61/91]) with TRGs, followed by post-nT RECIST (63.8% [58/91]), cRECIST (61.5% [56/91]), and pre-nT RECIST (36.3% [33/91]). Especially, delta RECIST achieved the highest accuracy (97.8% [89/91]) in distinguishing responders from non-responders, with 97.3% (34/35) for responders and 98.2% (55/56) for non-responders. Post-nT RECIST achieved the highest accuracy (93.4% [85/91]) in distinguishing complete responders from non-pCRs, with 77.8% (11/18) for pCRs and 94.5% (69/73) for non-pCRs.

CONCLUSION

The qRECIST with mpMRI can assess treatment-induced changes and may be used for early prediction of response to nT in ESCC patients.

KEY POINTS

• Quantitative mpMRI can reliably assess tumor response, and delta RECIST model had the best performance in evaluating response to nT in ESCCs, with an AUC of 0.98, 0.95, 0.80, and 0.82 for predicting TRG0, TRG1, TRG2, and TRG3, respectively. • In distinguishing responders from non-responders, the rate of agreement between delta RECIST and pathology was 97.3% (34/35) for responders and 98.2% (55/56) for non-responders, resulting in an overall agreement rate of 97.8% (89/91). • In distinguishing pCRs from non-pCR, the rate of agreement between MRI and pathology was 77.8% (11/18) for pCRs and 94.5% (69/73) for non- pCRs, resulting in an overall agreement rate of 91.2% (83/91).

Phosphatidylinositol 3-kinase CB association with preoperative radiotherapy response in rectal adenocarcinoma

AIM

To examine the correlation of phosphatidylinositol 3-kinase (PIK3) CB expression with preoperative radiotherapy response in patients with stage II/III rectal adenocarcinoma.

METHODS

PIK3CB immunoexpression was retrospectively assessed in pretreatment biopsies from 208 patients with clinical stage II/III rectal adenocarcinoma, who underwent radical surgery after 30-Gy/10-fraction preoperative radiotherapy. The relation between PIK3CB expression and tumor regression grade, clinicopathological characteristics, and survival time was statistically analyzed. Western blotting and in vitro clonogenic formation assay were used to detect PIK3CB expression in four colorectal cancer cell lines (HCT116, HT29, LoVo, and LS174T) treated with 6-Gy ionizing radiation. Pharmacological assays were used to evaluate the therapeutic relevance of TGX-221 (a PIK3CB-specific inhibitor) in the four colorectal cancer cell lines.

RESULTS

Immunohistochemical staining indicated that PIK3CB was more abundant in rectal adenocarcinoma tissues with poor response to preoperative radiotherapy. High expression of PIK3CB was closely correlated with tumor height (P < 0.05), ypT stage (P < 0.05), and high-degree tumor regression grade (P < 0.001). High expression of PIK3CB was a potential prognostic factor for local recurrence-free survival (P < 0.05) and metastasis-free survival (P < 0.05). High expression of PIK3CB was also associated with poor therapeutic response and adverse outcomes in rectal adenocarcinoma patients treated with 30-Gy/10-fraction preoperative radiotherapy. In vitro, PIK3CB expression was upregulated in all four colorectal cancer cell lines concurrently treated with 6-Gy ionizing radiation, and the PIK3CB-specific inhibitor TGX-221 effectively inhibited the clonogenic formation of these four colorectal cancer cell lines.

CONCLUSION

PIK3CB is critically involved in response to preoperative radiotherapy and may serve as a novel target for therapeutic intervention.

Clinical impact of tumor regression grade after preoperative chemoradiation for locally advanced rectal cancer: subset analyses in lymph node negative patients

BACKGROUND

We investigated the prognostic significance of tumor regression grade (TRG) after preoperative chemoradiation therapy (preop-CRT) for locally advanced rectal cancer especially in the patients without lymph node metastasis.

METHODS

One-hundred seventy-eight patients who had cT3/4 tumors were given 5,040 cGy preoperative radiation with 5-fluorouracil/leucovorin chemotherapy. A total mesorectal excision was performed 4-6 weeks after preop-CRT. TRG was defined as follows: grade 1 as no cancer cells remaining; grade 2 as cancer cells outgrown by fibrosis; grade 3 as a minimal presence or absence of regression. The prognostic significance of TRG in comparison with histopathologic staging was analyzed.

RESULTS

Seventeen patients (9.6%) showed TRG1. TRG was found to be significantly associated with cancer-specific survival (CSS; P = 0.001) and local recurrence (P = 0.039) in the univariate study, but not in the multivariate analysis. The ypN stage was the strongest prognostic factor in the multivariate analysis. Subgroup analysis revealed TRG to be an independent prognostic factor for the CSS of ypN0 patients (P = 0.031). TRG had a stronger impact on the CSS of ypN (-) patients (P = 0.002) than on that of ypN (+) patients (P = 0.521). In ypT2N0 and ypT3N0, CSS was better for TRG2 than for TRG3 (P = 0.041, P = 0.048), and in ypN (-) and TRG2 tumors, CSS was better for ypT1-2 than for ypT3-4 (P = 0.034).

CONCLUSION

TRG was found to be the strongest prognostic factor in patients without lymph node metastasis (ypN0), and different survival was observed according to TRG among patients with a specific histopathologic stage. Thus, TRG may provide an accurate prediction of prognosis and may be used for f tailoring treatment for patients without lymph node metastasis.

Morphologic changes associated with neoadjuvant-treated pancreatic ductal adenocarcinoma and comparison of two tumor regression grading systems

Pancreatic ductal adenocarcinoma (PDAC) is aggressive, with an overall five-year survival rate of 9%, and few patients are candidates for pancreatectomy at presentation. The role of neoadjuvant therapy (NAT) is evolving, especially for high-risk potentially resectable tumors. Owing to the increasing number of NAT resection specimens, we aim to characterize the histologic changes associated with NAT and to compare two tumor regression grading schemes. One hundred eighteen resections for PDAC were selected from the cases between 2011 and 2018, 59 not treated and 59 treated with NAT. All H&E stained tumor slides were reviewed for histologic changes and graded using the four-tier modified Ryan score (recommended by College of American Pathologists) and the three-tier MD Anderson (MDA) score. The histologic changes evaluated included blue/grey fibrosis, islet cell hyperplasia, dystrophic calcification, amyloid deposition, cholesterol clefts, nerve hypertrophy, elastotic stromal/vascular change, abscess formation, and eosinophilic tumor cell changes. There were statistically significant differences for dystrophic calcification, eosinophilic tumor cell changes, elastotic stromal/vascular change, islet cell hyperplasia, and nerve hypertrophy between the two groups, with these features seen more frequently in NAT cases. Blue/grey stromal fibrosis was present in all cases regardless of NAT, except few complete regression cases and one treated case with intraneural invasion only. Blue/grey fibrosis is a useful histologic visual clue to suggest the possibility of adjacent tumor in the majority of PDAC cases regardless of NAT. By Kaplan-Meier analysis, neither grading scheme correlated with overall survival in our cohort. However, the MDA score was significantly correlated with both time to primary tumor recurrence (p = 0.002) and time to distant recurrence (p = 0.04), whereas the modified Ryan score was not.

High CFP score indicates poor prognosis and chemoradiotherapy response in LARC patients

BACKGROUND

Preoperative tumor markers, inflammation, and nutritional status are considered important predictors of prognosis and tumor response in locally advanced rectal cancer (LARC) patients. This study aims to explore the prognostic and predictive role of carcinoembryonic antigen (CEA), the Fibrinogen-Albumin Ratio Index (FARI), the Prognostic Nutritional Index (PNI) in LARC patients and compared them with a novel combined CEA-FARI-PNI (CFP) scoring system.

METHODS

A total of 138 LARC patients undergoing radical surgery following neoadjuvant chemoradiotherapy (NCRT) between January 2012 and March 2019 were enrolled. The X-tile program was used to determine the optimal cut-off values of CEA, FARI, and PNI, and CFP scoring system was constructed accordingly. The prognostic ability of these factors was assessed by the time-dependent receiver operating characteristic (ROC) curve, Kaplan-Meier, Cox regression, and logistic regression. Nomogram was established to evaluate the predictive role of these factors in tumor response.

RESULTS

The optimal cut-off values of CEA, FARI, and PNI were 5.15 ng/l, 10.56%, and 42.25 g/L, respectively. The time-dependent ROC curve showed that compared to CEA, FARI, and PNI, CFP showed stable predictive efficacy for overall survival (OS) and disease-free survival (DFS). In multivariate analysis, CFP was the only factor that could independently predict OS (HR = 8.117, p = 0.001) and DFS (HR = 4.994, p < 0.001). Moreover, high CFP (OR = 3.693, p = 0.002) was also an independent risk factor of poor response. The area under the ROC curve (AUC) of the nomograms for predicting tumor response was better including CFP (0.717) than without CFP (0.656) (p < 0.05).

CONCLUSIONS

The CFP score was a more reliable marker for predicting OS, DFS, and NCRT efficacy in LARC patients, and the score could apparently improve predicted efficacy of the nomogram.

Evaluation of diffusion kurtosis and diffusivity from baseline staging MRI as predictive biomarkers for response to neoadjuvant chemoradiation in locally advanced rectal cancer

PURPOSE

To evaluate the role of diffusion kurtosis and diffusivity as potential imaging biomarkers to predict response to neoadjuvant chemoradiation therapy (CRT) from baseline staging magnetic resonance imaging (MRI) in locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

This retrospective study included 45 consecutive patients (31 male/14 female) who underwent baseline MRI with high b-value sequences (up to 1500 mm/s²) for LARC followed by neoadjuvant chemoradiation and surgical resection. The mean age was 57.4 years (range 34.2-72.9). An abdominal radiologist using open source software manually segmented T2-weighted images. Segmentations were used to derive diffusion kurtosis and diffusivity from diffusion-weighted images as well as volumetric data. These data were analyzed with regard to tumor regression grade (TRG) using the four-tier American Joint Committee on Cancer (AJCC) classification, TRG 0-3. Proportional odds regression was used to analyze the four-level ordinal outcome. A sensitivity analysis was performed using univariable logistic regression for binary TRG groups, TRG 0/1 (> 90% response), or TRG 2/3 (< 90% response). p < 0.05 was considered significant throughout.

RESULTS

In the univariable proportional odds regression analysis, higher diffusivity summary (D_sum) values were observed to be significantly associated with higher odds of being in one or more favorable TRG group (TRG 0 or 1). In other words, on average, patients with higher D_sum values were more likely to be in a more favorable TRG group. These results are mostly consistent with the sensitivity analysis, in which higher values for most D_sum values [all but region of interest (ROI)-max D median (p = 0.08)] were observed to be significantly associated with higher odds of being TRG 0 or 1. Tumor volume of interest (VOI) and ROI volume, ROI kurtosis mean and median, and VOI kurtosis mean and median were not significantly associated with TRG.

CONCLUSION

Diffusivity derived from the baseline staging MRI, but not diffusion kurtosis or volumetric data, is associated with TRG and therefore shows promise as a potential imaging biomarker to predict the response to neoadjuvant chemotherapy in LARC.

CLINICAL RELEVANCE STATEMENT

Diffusivity shows promise as a potential imaging biomarker to predict AJCC TRG following neoadjuvant CRT, which has implications for risk stratification. Patients with TRG 0/1 have 5-year disease-free survival (DFS) of 90-98%, as opposed to those who are TRG 2/3 with 5-year DFS of 68-73%.

Prognostic value of tumor regression grade following the administration of neoadjuvant chemotherapy as treatment for gastric/gastroesophageal adenocarcinoma: A meta-analysis of 14 published studies

INTRODUCTION

The efficacy of neoadjuvant chemotherapy (NAC) for advanced gastric cancer (GC) has recently been revealed. The use of tumor regression grade (TRG) has also been reported, where TRG has been positively correlated with prognosis. However, previous studies included several types of GC and treatments. The prognostic value of TRG in a specific population has not been well investigated. Therefore, a meta-analysis of studies on gastric adenocarcinomas treated with NAC that evaluate the prognostic impact of TRG on overall survival (OS) must be conducted to provide more accurate evidence.

METHODS

A meta-analysis of studies reporting gastric cancer/gastroesophageal junction (GC/GEJ) adenocarcinoma treated with NAC was performed. Studies that calculate the number of responders and non-responders were considered eligible. The risk ratio (RR) was obtained from the eligible studies, and a random-effects model was used for pooled analysis.

RESULTS

Fourteen studies, which included a total of 1660 patients, were included in the current study. The responders showed better OS (RR: 0.53, 95% confidence interval (CI): 0.46-0.60, P < 0.001). All subgroup analyses (Asian vs. non-Asian populations, different TRGs, GC/GEJ vs. GC) also revealed the statistical dominance of better TRG over better OS. However, the possibility of some publication bias remained.

CONCLUSIONS

In this meta-analysis, better TRG was associated with better OS. However, the histology, configuration, and location of GC varied. Hence, a more subdivided analysis is recommended to obtain more solid evidence.

Predictive factors of histological response of colorectal liver metastases after neoadjuvant chemotherapy

BACKGROUND

Colorectal cancer is the third most common cancer in men and the second most common in women worldwide. Almost a third of the patients has or will develop liver metastases. Neoadjuvant chemotherapy (NAC) has recently become nearly systematic prior to surgery of colorectal livers metastases (CRLMs). The response to NAC is evaluated by radiological imaging according to morphological criteria. More recently, the response to NAC has been evaluated based on histological criteria of the resected specimen. The most often used score is the tumor regression grade (TRG), which considers the necrosis, fibrosis, and number of viable tumor cells.

AIM

To analyze the predictive factors of the histological response, according to the TRG, on CRLM surgery performed after NAC.

METHODS

From January 2006 to December 2013, 150 patients who had underwent surgery for CRLMs after NAC were included. The patients were separated into two groups based on their histological response, according to Rubbia-Brandt TRG. Based on their TRG, each patient was either assigned to the responder (R) group (TRG 1, 2, and 3) or to the non-responder (NR) group (TRG 4 and 5). All of the histology slides were re-evaluated in a blind manner by the same specialized pathologist. Univariate and multivariate analyses were performed.

RESULTS

Seventy-four patients were classified as responders and 76 as non-responders. The postoperative mortality rate was 0.7%, with a complication rate of 38%. Multivariate analysis identified five predictive factors of histological response. Three were predictive of non-response: More than seven NAC sessions, the absence of a radiological response after NAC, and a repeat hepatectomy (P < 0.005). Two were predictive of a good response: A rectal origin of the primary tumor and a liver-first strategy (P < 0.005). The overall survival was 57% at 3 yr and 36% at 5 yr. The disease-free survival rates were 14% at 3 yr and 11% at 5 yr. The factors contributing to a poor prognosis for disease-free survival were: No histological response after NAC, largest metastasis > 3 cm, more than three preoperative metastases, R1 resection, and the use of a targeted therapy with NAC (P < 0.005).

CONCLUSION

A non-radiological response and a number of NAC sessions > 7 are the two most pertinent predictive factors of non-histological response (TRG 4 or 5).