Patterns of response after preoperative treatment in gastric cancer

Nomogram for predicting pathological response to neoadjuvant treatment in patients with locally advanced gastric cancer: Data from a phase III clinical trial

PURPOSE

This study aimed to establish a nomogram using routinely available clinicopathological parameters to predict the pathological response in patients with locally advanced gastric cancer (LAGC) undergoing neoadjuvant treatment.

MATERIALS AND METHODS

We conducted this study based on the ongoing Neo-CRAG trial, a prospective study focused on preoperative treatment in patients with LAGC. A total of 221 patients who underwent surgery following neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy (nCRT) at Sun Yat-sen University Cancer Center between June 2013 and July 2022 were included in the analysis. We defined complete or near-complete pathological regression and ypN0 as good response (GR), and determined the prognostic value of GR by Kaplan-Meier survival analysis. Eventually, a nomogram for predicting GR was developed based on statistically identified predictors through multivariate logistic regression analysis and internally validated by the bootstrap method.

RESULTS

GR was confirmed in 54 patients (54/221, 24.4%). Patients who achieved GR had a longer progression-free survival and overall survival. Then, five independent factors, including pretreatment tumor differentiation, clinical T stage, monocyte count, CA724 level, and the use of nCRT, were identified. Based on these predictors, the nomogram was established with an area under the curve (AUC) of 0.777 (95% CI, 0.705-0.850) and a bias-corrected AUC of 0.752.

CONCLUSION

A good pathological response after neoadjuvant treatment was associated with an improved prognosis in LAGC patients. The nomogram we established exhibits a high predictive capability for GR, offering potential value in devising personalized and precise treatment strategies for LAGC patients.

Establishment of prognostic models for adenocarcinoma of oesophagogastric junction patients with neoadjuvant chemoradiotherapy: a real-world study

BACKGROUND

Multimodal therapies based on surgical resection have been recommended for the treatment of adenocarcinoma of the oesophagogastric junction (AEG). We aimed to evaluate prognostic factors in AEG patients receiving neoadjuvant chemoradiotherapy and to build predictive models.

METHODS

T3 - T4N + M0 AEG patients with resectable Siewert type II/III tumours were enrolled in this study. All patients underwent neoadjuvant chemoradiation, followed by radical surgery or systemic therapy according to clinical response. Survival analysis was performed using the Kaplan-Meier method; multivariate analysis using the Cox proportional hazards method was also conducted. The Harrell concordance index (C-index) was used to test the prognostic value of models involving prognostic factors, and consistency between actual and predicted survival rates was evaluated by calibration curves.

RESULTS

From February 2009 to February 2018, 79 patients were treated with neoadjuvant chemoradiotherapy; 60 patients of them underwent radical surgery. The R0 resection rate was 98.3%, and 46.7% of patients achieved a major pathologic response (MPR), namely, a residual tumour issue less than 10%. The 5-year overall survival (OS) rate was 63%, and the 5-year progression-free survival (PFS) rate was 48%. The incidence of grade 3 complications was 21.5%, and no grade 4 complications were reported. According to the results of univariate and multivariate analyses, we included the neutrophil-lymphocyte ratio (NLR), prognostic nutrition index (PNI), eosinophilic granulocyte (EOS) and postoperative pathologic stage in nomogram analysis to establish prediction models for OS and PFS; the C-index of each model was 0.814 and 0.722, respectively. Both the C-index and calibration curves generated to validate consistency between the actual and predicted survival indicated that the models were well calibrated and of good predictive value.

CONCLUSIONS

AEG patients achieved favourable downstaging and pathologic response after neoadjuvant chemoradiation, with acceptable adverse effects. Inflammation-based and nutrition-related factors and postoperative pathologic stage had a significant influence on OS and PFS, and the predictive value was verified through prognostic models.

Histopathologic Features are more Important Prognostic Factors than Primary Tumour Location in Gastro-oesophageal Adenocarcinoma Treated with Preoperative Chemoradiation and Surgery

The aim of present study was to evaluate the impact of primary tumour location and other factors on the outcome of preoperative chemoradiation followed by surgery in adenocarcinomas of distal oesophagus, gastro-oesophageal junction and stomach. We retrospectively reviewed the institutional patient database. The therapeutic response was re-evaluated as a percentage of residual tumor cells in surgical resection specimens. Overall survival (OS) and disease-free survival (DFS) were assessed. The effect primary tumour location, clinical and pathological TNM stage, and histopathological factors (histological type, grade, angioinvasion, perineural invasion, tumour response) on treatment outcome were evaluated. A total of 108 patients underwent preoperative chemoradiation for adenocarcinoma of distal oesophagus, gastro-oesophageal junction or stomach. The median prescribed dose of radiation was 45 Gy. The concurrent chemotherapy consisted of 5-fluorouracil +/- cisplatin +/- taxanes. R0 resection was achieved in 80 patients (74%). The complete response was observed in 19%. The median follow-up was 50.8 months. Three-year and 5-year OS and DFS were 36.2% and 25.3%; and 28.1% and 23.7%, respectively. Pretreatment T-stage, pathological N-stage, radicality of resection, histological subtype, grade, angioinvasion and perineural invasion, were identified as statistical significant OS predictors in univariate analysis; pathological N-stage, radicality of resection and angioinvasion, in multivariate analysis. The primary tumor location did not influence the prognosis. The pathologic response to chemoradiation had borderline significance. In conclusion, no prognostic impact of primary tumour location, in contrast to other investigated factors, was evident in the present study. The most important predictors of prognosis were angioinvasion status and pN-stage.

Role of histological regression grade after two neoadjuvant approaches with or without radiotherapy in locally advanced gastric cancer

Background:

The degree of histopathological response after neoadjuvant therapy in locally advanced gastric cancer (GC) is a key determinant of patients' long-term outcome. We aimed to assess the pattern of histopathological regression after two neoadjuvant approaches and its impact on survival times.

Methods:

Regression grade of the primary tumour (Becker criteria) and the degree of nodal response by a 4-point scale (grades A–D) were assessed. Grade A—true negative lymph nodes (LNs); grade B and C—infiltrated LNs with any or little evidence of nodal response; and grade D—complete pathological response in a previously infiltrated LN. A favourable pathological response was defined as Becker Ia–b and grade D.

Results:

From 2004 to 2014, 80 patients with GC (cT3–4/N+ by CT-scan/EUS) were treated with either preoperative chemotherapy (ChT, n=34) or chemoradiation (CRT, n=46). Patients in the CRT group had a higher likelihood of achieving a Becker Ia–b response (58 vs 32%, P=0.001), a grade D nodal regression (30 vs 6%, P=0.009) and a favourable pathological response (23 vs 3% P=0.019). Patients with a grade D nodal response had a longer 5-year PFS and OS compared with those with a grade B or C response. Patients with a baseline negative LN status had similar outcomes irrespective of the preoperative therapy received (5-year OS; ChT vs CRT, 58 vs 51%, P=0.92).

Conclusions:

Preoperative chemoradiation increases the likelihood of achieving favourable histopathological features that correlate with a 5-year OS>70% in GC patients.

Tumor regression grade in gastric cancer: Predictors and impact on outcome

BACKGROUND

The clinical value and prognostic implications of histologic response to neoadjuvant chemotherapy in gastric cancer is unknown.

METHODS

Tumor regression grade (TRG) was recorded in 58 gastric cancer patients identified from two institutional surgical databases. TRG 1a/b represented histologic responders (<10% viable tumor), while TRG 2/3 represented non-responders (>10% viable tumor).

RESULTS

TRG 1a/b was recorded in 10 patients (17%), while 48 patients (83%) had a TRG 2/3 response. Larger tumor size (OR 0.24; 95%CI 0.09, 0.64; P = 0.004) and clinical downstaging (OR 30.0; 95%CI 3.26, 276; P = 0.003) were the only factors predictive of histologic response. TRG 1a/b responders had 3-year survival of 70.0% and an estimated overall survival of >69.8 months compared to 38.2% and 22.8 months in non-responders; however, this trend was not statistically significant (P = 0.535). While TRG could not predict survival (OR 2.40; 95%CI 0.46, 12.57; P = 0.300), patient age (OR 1.06; 95%CI 1.00, 1.11; P = 0.035), and the number of positive lymph nodes (≥7; OR 0.05; 95%CI 0.07, 0.27; P < 0.001) were independent predictors of survival.

CONCLUSIONS

Few gastric cancers demonstrate histologic response to neoadjuvant chemotherapy. While TRG may be a valid marker for treatment response, its predictive value and clinical application in gastric cancer remains unclear. J. Surg. Oncol. 2016;114:434-439. © 2016 Wiley Periodicals, Inc.

Advanced gastric cancer: What we know and what we still have to learn

Gastric cancer is a common neoplastic disease and, more precisely, is the third leading cause of cancer death in the world, with differences amongst geographic areas. The definition of advanced gastric cancer is still debated. Different stadiating systems lead to slightly different stadiation of the disease, thus leading to variations between the single countries in the treatment and outcomes. In the present review all the possibilities of treatment for advanced gastric cancer have been analyzed. Surgery, the cornerstone of treatment for advanced gastric cancer, is analyzed first, followed by an investigation of the different forms and drugs of chemotherapy and radiotherapy. New frontiers in treatment suggest the growing consideration for intraperitoneal administration of chemotherapeutics and combination of traditional drugs with new ones. Moreover, the necessity to prevent the relapse of the disease leads to the consideration of administering intraperitoneal chemotherapy earlier in the therapeutical algorithm.

Determination of the optimal cutoff percentage of residual tumors to define the pathological response rate for gastric cancer treated with preoperative therapy (JCOG1004-A)

BACKGROUND

Pathological response rate (pathRR) is a common endpoint used to assess the efficacy of preoperative therapy for gastric cancer. PathRR is estimated based on the percentage of the residual tumor area in the primary tumorous bed. Various cutoff definitions used in previous trials (e.g., 10, 33, 40, 50, 67 %) often impair the comparability of pathRRs between trials.

METHODS

Individual patient data were used from four JCOG trials evaluating preoperative chemotherapy (JCOG0001, JCOG0002, JCOG0210, JCOG0405). Pathological specimens were evaluated from 173 out of 188 patients (92 %) who underwent surgery. Residual tumor area and primary tumorous beds were traced on a virtual microscopic slide by one pathologist and another confirmed these areas. The hazard ratio (HR) in overall survival was calculated for each cutoff percentage by stratified Cox regression analysis, including the study as a stratification factor, and concordance probability estimates (CPE) were calculated.

RESULTS

The numbers of patients with 0%, 1-10 %, 11-33 %, 34-50 %, 51-66 %, and 67-100 % residual tumors were 8, 35, 33, 27, 23, and 47, respectively. HRs in 10, 33, 50, and 67 % cutoffs were 1.91, 1.70, 1.55, and 1.71 for the overall population, and CPEs were 0.56, 0.56, 0.55, and 0.55, respectively. In patients with R0 resection, HRs in 10, 33, 50, and 67 % cutoffs were 1.87, 1.54, 1.24, and 1.38, and CPEs were 0.56, 0.55, 0.52, and 0.52. In subgroup analyses, the 10 % cutoff did not predict survival well for type 4 (linitis plastica) tumors.

CONCLUSIONS

The 10 % cutoff should be the global standard cutoff of %residual tumor to determine pathRR. PathRR might not be recommended for clinical trials where the main subjects are type 4 tumors.

Adjuvant Chemoradiation Therapy in Gastric Cancer: Critically Reviewing the Past and Visualizing the Next Step Forward

Gastric cancer remains one of the most common malignancies worldwide. Despite the significant advances in surgical treatment and multimodality strategies, prognosis has modestly improved over the last two decades. Locoregional relapse remains one of the main issues and the combined chemoradiation treatment seems to be one of the preferred approaches. However, more than ten years after the hallmark INT-0116 trial, minimal progress has been made both in terms of effectiveness and toxicity. Moreover, new regimens added to combined therapy failed to prove favourable results. Herein, we attempt a thorough literature review comparing pros and cons of all relative studies and potential bias, targeting well-designed future approaches.

Preoperative treatment with radiochemotherapy for locally advanced gastroesophageal junction cancer and unresectable locally advanced gastric cancer

Background.

To purpose of the study was to analyze the results of preoperative radiochemotherapy in patients with unresectable gastric or locoregionally advanced gastroesophageal junction (GEJ) cancer treated at a single institution.

Patients and methods.

Between 1/2004 and 6/2012, 90 patients with locoregionally advanced GEJ or unresectable gastric cancer were treated with preoperative radiochemotherapy at the Institute of Oncology Ljubljana. Planned treatment schedule consisted of induction chemotherapy with 5-fluorouracil and cisplatin, followed by concomitant radiochemotherapy four weeks later. Three-dimensional conformal external beam radiotherapy was delivered by dual energy (6 and 15 MV) linear accelerator in 25 daily fractions of 1.8 Gy in 5 weeks with two additional cycles of chemotherapy repeated every 28 days. Surgery was performed 4–6 weeks after completing radiochemotherapy. Following the surgery, multidisciplinary advisory team reassessed patients for the need of adjuvant chemotherapy. The primary endpoints were histopathological R0 resection rate and pathological response rate. The secondary endpoints were toxicity of preoperative radiochemotherapy and survival.

Results.

Treatment with preoperative radiochemotherapy was completed according to the protocol in 84 of 90 patients (93.3%). Twenty patients (22.2%) did not undergo the surgery because of the disease progression, serious comorbidity, poor performance status or still unresectable tumour. In 13 patients (14.4%) only exploration was performed because the tumour was assessed as unresectable or diffuse peritoneal carcinomatosis was established. Fifty-seven patients (63.4%) underwent surgery with the aim of complete removal of the tumour. Radical resection was achieved in 50 (55.6%) patients and the remaining seven (7.8%) patients underwent non-radical surgery (R1 in five and R2 in two patients). In this group of patients (n = 57), pathological complete response of tumour was achieved in five patients (5.6% of all treated patients or 8.8% of all operated patients). Down-staging was recorded in 49 patients (86%), in one patient (1.8%) the stage after radiochemotherapy was unchanged while in seven patients (12.3%) the pathological stage was higher than clinical, mainly due to higher pN stage. No death was recorded during preoperative radiochemotherapy. Most grade 3 and 4 toxicities were due to vomiting, nausea and bone marrow suppression (granulocytopenia). Twenty-six (45.6%) patients died due to GEJ or gastric carcinoma, one died because of septic shock following the surgery and a reason for two deaths was unknown. Twenty-eight patients (49.1%) were disease free at the time of analysis, while 29 patients (50.9%) developed the recurrence, mostly as distant metastases. At two years, locoregional control, disease-free survival, disease-specific survival and overall survival were 82.9%, 43.9%, 56.9% and 53.9%, respectively.

Conclusions.

Preoperative radiochemotherapy was feasible in our group of patients and had acceptable toxicity. Majority of patients achieved down-staging, allowing greater proportion of radical resections (R0), which are essential for patients’ cure.

Neoadjuvant chemoradiotherapy followed by D2 gastrectomy in locally advanced gastric cancer

AIM: To investigate the efficacy of neoadjuvant chemoradiotherapy (NACRT) for resectability of locally advanced gastric cancer (LAGC).

METHODS: Between November 2007 and January 2014, 29 patients with LAGC (clinically T3 with distal esophagus invasion/T4 or bulky regional node metastasis) that were treated with NACRT followed by D2 gastrectomy were included in this study. Resectability was evaluated with radiologic and endoscopic exams before and after NACRT. Using three-dimensional conformal radiotherapy, patients received 45 Gy, with a daily dose of 1.8 Gy. The entire tumor extent and the regional metastatic lymph nodes were included in the gross tumor volume. Patients presenting with a resectable tumor after NACRT received a total or subtotal gastrectomy with D2 dissection. The pathologic tumor response was evaluated using Japanese Gastric Cancer Association histologic evaluation criteria. Postoperative morbidity was evaluated using the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.0. Overall survival (OS) and progression-free survival (PFS) rates were estimated using a Kaplan-Meier analysis and compared using the log-rank test.

RESULTS: All patients were assessed as unresectable cases. Twenty-four patients (24/29; 82.8%) showed LAGC on positron emission tomography-computed tomography (CT) and contrast-enhanced CT, whereas four patients (4/29; 13.8%) with vague invasion or abutment to an adjacent organ underwent diagnostic laparoscopy. One patient (1/29; 3.4%), initially assessed as a resectable case, underwent an “open and closure” after the tumor was found to be unresectable. Abutment to an adjacent organ (34.5%) was the most common reason for NACRT. The clinical response rate one month after NACRT was 44.8%. After NACRT, 69% (20/29) of patients had a resectable tumor. Of the 20 patients with a resectable tumor, 18 patients (62.1%) underwent a D2 gastrectomy. The R0 resection rate was 94.4% and two patients (2/18; 11.1%) showed a complete response. The median follow-up duration was 13.5 mo. The one-year OS and PFS rates were 72.4 and 48.9%, respectively. The one-year OS, PFS, local failure-free survival, and distant metastasis-free survival were higher in patients with a resectable tumor after NACRT (P < 0.001, P < 0.001, P < 0.001, and P = 0.078, respectively). No grade 3-4 late treatment-related toxicities or postoperative mortalities were observed.

CONCLUSION: NACRT with D2 gastrectomy showed a high rate of R0 resection and promising local control, which may increase the R0 resection opportunity resulting in survival benefit.

Comparison between better and poorly differentiated locally advanced gastric cancer in preoperative chemotherapy: a retrospective, comparative study at a single tertiary care institute

BACKGROUND

Gastric cancer is the third leading cause of cancer-related mortality in China, and the long-term survival for locally advanced gastric cancer is very poor. Simple surgery cannot yield an ideal result because of the high recurrence rate after tumor resection. Preoperative chemotherapy could help to reduce tumor volume, improve the R0 resection rate (no residual tumor after surgery), and decrease the risk of local tumor recurrence. The aim of this study was to evaluate the influence of pathological differentiation in the effect of preoperative chemotherapy for patients with locally advanced gastric cancer.

METHODS

Patients with locally advanced gastric cancer (n = 32) received preoperative chemotherapy under the XELOX (capecitabine plus oxaliplatin) regimen. According to pathological examination, patients' tumors were classified into better (well and moderate) and poorly differentiated (lower differentiated and undifferentiated) groups, and the clinical response rate, type of gastrectomy, and negative tumor residual rate were compared between the two groups of patients. Morphological changes and toxic reactions were monitored after chemotherapy.

RESULTS

The results showed that the clinical response rate in the better differentiated group was significantly higher than that in the poorly differentiated group (100% versus 25%, P = 0.000). The partial gastrectomy rate in the better differentiated group was significantly higher than that in the poorly differentiated group (87.5% versus 25% P = 0.000). A significant shrinking of tumor and necrosis of tumor tissues caused by chemotherapy could be observed.

CONCLUSIONS

In conclusion, the better differentiated group with locally advanced gastric cancer is suitable for preoperative chemotherapy under the XELOX regimen, and as a result of effective preoperative chemotherapy, much more gastric tissue can be preserved for the better differentiated group.

Preoperative chemoradiotherapy for locally advanced gastric cancer

BACKGROUND

To examine toxicity and outcomes for patients treated with preoperative chemoradiotherapy (CRT) for gastric cancer.

METHODS

Patients with gastroesophageal (GE) junction (Siewert type II and III) or gastric adenocarcinoma who underwent neoadjuvant CRT followed by planned surgical resection at Duke University between 1987 and 2009 were reviewed. Overall survival (OS), local control (LC) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Toxicity was graded according to the Common Toxicity Criteria for Adverse Events version 4.0.

RESULTS

Forty-eight patients were included. Most (73%) had proximal (GE junction, cardia and fundus) tumors. Median radiation therapy dose was 45 Gy. All patients received concurrent chemotherapy. Thirty-six patients (75%) underwent surgery. Pathologic complete response and R0 resection rates were 19% and 86%, respectively. Thirty-day surgical mortality was 6%. At 42 months median follow-up, 3-year actuarial OS was 40%. For patients undergoing surgery, 3-year OS, LC and DFS were 50%, 73% and 41%, respectively.

CONCLUSIONS

Preoperative CRT for gastric cancer is well tolerated with acceptable rates of perioperative morbidity and mortality. In this patient cohort with primarily advanced disease, OS, LC and DFS rates in resected patients are comparable to similarly staged, adjuvantly treated patients in randomized trials. Further study comparing neoadjuvant CRT to standard treatment approaches for gastric cancer is indicated.

Pilot feasibility study of neoadjuvant chemoradiotherapy with S-1 in patients with locally advanced gastric cancer featuring adjacent tissue invasion or JGCA bulky N2 lymph node metastases

BACKGROUND

To improve the prognosis of locally advanced gastric cancer, clinical trials of neoadjuvant chemotherapy (NAC) are being performed. Although neoadjuvant chemoradiotherapy (NACRT) generally achieves superior local tumor control to NAC, its efficacy for locally advanced gastric cancers remains unclear. Therefore, a prospective trial was conducted to explore the feasibility and safety of NACRT with oral S-1 in a series of cases.

METHODS

Patients who had Japanese Gastric Cancer Association (JGCA) cStage IIIB gastric cancer were enrolled onto this study and received oral S-1 (65 mg/m(2)/day) administration and 50-Gy radiotherapy followed by radical surgery. The primary end points were completion of therapy and safety.

RESULTS

Between October 2005 and September 2008, 12 eligible patients were enrolled. Two could not complete the chemotherapy because of grade 3 toxicity. R0 resections were performed in 11 patients (91.7 %) (95 % confidence interval 61.5-99.8). Although operative morbidity was observed in two cases, there were no postoperative deaths. A pathologic response was observed in 10 patients (83.3 %). In five (62.5 %) of eight gastric cancers with invasion to adjacent structures, microscopic tumor deposits were not found in the affected organs. The 3-year survival rate was 58.3 % during a median follow-up period of 36 months.

CONCLUSIONS

Although this study is preliminary, the present regimen seems to be feasible and safe as a treatment for locally advanced gastric cancers featuring adjacent tissue invasion or JGCA bulky N2 disease. This treatment approach should now be tested using the new tumor, node, metastasis staging system in a large clinical trial.

Neoadjuvant chemotherapy for locally advanced gastric cancer: With or without radiation

The role of perioperative chemotherapy for gastric cancer has been established for gastric cancers in their advanced stage. In most parts of the world, even in Japan and Korea, local recurrence of gastric cancer following curative resection remains a problem. Should radiation be added to chemotherapy to achieve better local and regional control? What is the current evidence? What are the concerns regarding neoadjuvant chemoradiation in terms of safety, efficacy and survival benefit? After a serious review of the literature, the authors conclude that it is still too early to get a definitive answer but radiation seems promising. It may bring a higher pathological response rate. Rationally, more high level clinical trials are needed to confirm the role of radiotherapy in the neoadjuvant setting or to ascertain subsets of patients who may benefit from it. It is of note that surgeons should pay attention to possible complicated circumstances following radiotherapy, maintain proper nutrition status and minimize the occurrence of postoperative complications. As few data are available in Japan and Korea, interpretation and implementation of neoadjuvant radiation or chemoradiation should be done with caution.