The ypT category does not impact overall survival in node negative gastric cancer

Does the ypTNM-stage adequately predict long-term survival rates in gastric cancer patients receiving neoadjuvant chemotherapy followed by radical resection?

BACKGROUND

Following neoadjuvant chemotherapy (NAC) for resectable gastric cancer, the prognostic adequacy of the UICC staging system needs to be investigated. In particular to explore whether the ypTNM curves for radically resected gastric cancer patients receiving NAC follow the stage-matched survival curves of radically resected chemo-naïve patients (pTNM). Further, to disclose any interaction between the TNM-response mode to NAC and stage-specific survival rates, i.e., whether survival for a particular pathological disease stage was dependent on whether this was reached through a downstaging or as stable disease following NAC.

MATERIAL AND METHODS

Retrospective study on radically resected patients ≤ 75 years of age with gastric adenocarcinoma stages I-III diagnosed during 2001-2016. The patients constitute two population-based cohorts; the SURG-group with n = 121 patients treated before 2007 when NAC was introduced, and the NAC-group with n = 126 patients diagnosed since early 2007, receiving NAC and subsequent radical resection.

RESULTS

Long-term survival rates were similar when specific ypTNM-stages were compared to their corresponding pTNM chemo-naïve counterparts. The dichotomised N0 vs. N + had a substantial impact on the long-term survival rates in both groups, however, no discrepancy in long-term survival rates between pN0 vs. ypN0, and pN + vs. ypN + was found. The pathological stage determined long-term survival rates irrespective of the baseline disease stage, as no interaction between the response mode and stage-specific survival rates was found.

CONCLUSIONS

Survival curves for specific ypTNM-stages following NAC did not differ from the corresponding survival curves of their chemo-naïve pTNM counterparts. The interpretation is that NAC affected the gastric cancer, lymph nodes, and micrometastases, in such a way that the final ypTNM-stage provided similar prognostic information as the chemo-naïve pTNM-stages. Survival rates were contingent on the final ypTNM-stages alone, and not influenced by the response mode to reach that particular disease stage, or predetermined by the original clinical TNM-stage.

Independent Stage Classification for Gastroesophageal Junction Adenocarcinoma

In gastroesophageal junction (GEJ) adenocarcinoma cases, a prognosis based on ypTNM staging could be affected by preoperative therapy. Patients with esophageal adenocarcinoma and gastric adenocarcinoma who underwent preoperative therapy followed by surgical resection from 2006 through 2017 were identified in the National Cancer Database. To enable stage-by-stage OS comparisons, tumors were classified into four gross ypTNM groups: ypT1/2, N-negative; ypT1/2, N-positive; ypT3/4, N-negative; and ypT3/4, N-positive. Prognostic factors were examined, and an OS prediction nomogram was developed for patients with abdominal/lower esophageal and gastric cardia adenocarcinoma, representing GEJ cancers. We examined 25,463 patient records. When compared by gross ypTNM group, the abdominal/lower esophageal and gastric cardia adenocarcinoma groups had similar OS rates, differing from those of other esophageal or gastric cancers. Cox regression analysis of patients with GEJ cancers showed that preoperative chemoradiotherapy was associated with shorter OS than preoperative chemotherapy after adjustment for the ypTNM group (hazard ratio 1.31, 95% CI 1.24-1.39, p < 0.001), likely owing to downstaging effects. The nomogram had a concordance index of 0.833 and a time-dependent area under the curve of 0.669. OS prediction in GEJ adenocarcinoma cases should include preoperative therapy regimens. Our OS prediction nomogram provided reasonable OS prediction for patients with GEJ adenocarcinoma, and future validation is needed.

Trends of Oncological Quality of Robotic Gastrectomy for Gastric Cancer in the United States

Background

Robotic gastrectomy (RG) has been increasingly used for treatment of gastric cancer in the United States. However, it is unknown if there has been a nationwide improvement of short-term safety outcomes and oncological quality metrics over time.

Methods

We used the National Cancer Database to identify patients who underwent major gastrectomy from 2010 through 2018. The short-term safety outcomes and oncological metrics were compared between cases of open gastrectomy (OG), laparoscopic gastrectomy (LG), and RG. We also compared the indications and outcomes of RG between the three periods (2010 - 2012, 2013 - 2015, and 2016 - 2018).

Results

Of the 22,445 patients included, 1,867 (8%) underwent RG. Number of RG continued to increase from only 37 cases performed in 2010 to 412 cases performed in 2018. The number of lymph nodes (LNs) examined (OG, 16; LG, 17; and RG, 19) and the R0 rate (OG, 88%; LG, 92%; and RG 94%) were better for RG than for OG or LG (P < 0.001). In the RG group, the number of LNs examined (first period, 15; third period, 18; P < 0.001), R0 rate (first period, 88.6%; third period, 91.1%; P < 0.001), length of hospital stay (first period, 9 days; third period, 8 days; P < 0.001), 30-day readmission rate (first period, 10.1%; third period, 7.9%; P < 0.001), and 90-day mortality (first period, 7.3%; third period, 6.0%; P = 0.003) continued to improve cohort over time. The ratio of the robotic cases performed in academic institutions gradually increased (first period, 48.6%; third period, 54.3%; P < 0.001). In multivariable analyses, RG was associated with more than 15 LNs being examined (OR, 1.49; 95% CI, 1.34 - 1.65; P < 0.001). The indications for RG appeared expanding to include more advanced stage, high comorbidity, and patients who underwent preoperative therapy.

Conclusions

RG has been increasingly performed in the past decade. Although its indication was expanded to include more advanced tumors, we found that the oncological quality metrics and safety outcomes of RG have improved over time and were better than those of OG or LG.

Nodal downstaging to ypN0 after neoadjuvant chemotherapy positively impacts on survival of cT4N+ GC/GEJ patients

BACKGROUND

The prognostic value of histomorphologic regression in primary gastric and gastroesophageal cancers (GC/GEJ) has been previously established, however, the impact of lymph node (LN) regression on survival still remains unclear.

METHODS

A prospectively maintained database was reviewed to identify cT4N+ gastric and gastroesophageal cancers (GC/GEJ) after NAC (neoadjuvant chemotherapy). Patients were categorized into two groups based on LN status: cN+/ypN0 (downstaged N0) and cN+/ypN+ (persistent N+), long-term survival were analyzed using Kaplan-Meier survival estimates.

RESULTS

In total, 125 patients with cT4N+ GC/GEJ underwent NAC followed by surgery were enrolled. A total of 39 patients (31.2%) had cN+/ypN0 (ypN0) disease, 86 patients (68.8%) had cN+/ypN+ (ypN+) disease. Prognosis in ypN+ patients was significantly worse than those in ypN0 group for 3- and 5-year overall survival (OS) (p < 0.05). The 3-year OS was 83%, 44% in ypN0 and ypN+ group, respectively. The 5-year OS was 75%, 35% in ypN0 and ypN+ group, respectively. Multivariable analysis suggested that multivisceral resection (hazard ratio [HR] = 0.33, 95% confidence interval [CI]: 0.14-0.76, p = 0.009), and ypN+ (HR = 3.42, 95% CI: 1.15-10.13, p =0.027) were independent prognostic factors for OS.

CONCLUSION

Nodal downstaging is an important hallmark representing the effectiveness of NAC for GC/GEJ, and it positively impacts on survival of these patients.

Understanding the association between clinical staging accuracy, treatment response, and survival among gastric cancer patients through Bayesian analysis

BACKGROUND

Neoadjuvant therapy (NAT) improves survival among patients with locally advanced gastric cancer (GC), but it remains unclear whether its benefit is contingent on treatment response.

METHODS

This is a national cohort study of stage Ib-III GC patients in the National Cancer Data Base (2006-2015) treated with upfront resection or NAT followed by surgery. Bayesian analysis was used for NAT patients to ascertain staging concordance and to account for down-staging. We used multivariable Cox regression to evaluate the association between staging concordance, treatment, response to NAT, and survival.

RESULTS

The cohort included 13 340 patients treated at 1124 hospitals. Staging concordance ranged from 86.1% for cT3-4N+ to 34.7% for cT2N0 patients. Relative to accurately staged patients treated with upfront surgery, NAT was associated with a decreased risk of death if there was disease down-staging among those with cT1-2N+ (hazard ratio [HR]: 0.43 [0.30-0.61]), cT3-4N0 (HR: 0.69 [0.54-0.88]), and cT3-4N+ (HR: 0.51 [0.48-0.58]) tumors, and in the absence of down-staging among cT3-4N+ patients (HR: 0.83 [0.74-0.92]). Conversely, NAT without down-staging increased the risk of death among those with intermediate-stage disease.

CONCLUSIONS

NAT is associated with improved survival for GC, but it seems to be contingent on treatment response among patients with intermediate-stage disease.

Revisiting the 8th AJCC system for gastric cancer: A review on validations, nomograms, lymph nodes impact, and proposed modifications

Gastric cancer is the fifth most frequently diagnosed cancer worldwide, behind breast, lung, colorectal, and prostate cancers. In gastric cancer, multimodality treatment shows prospective benefits and also improves survival. Surgery, however, is the mainstay of curative treatment. The staging of gastric cancer patients is critical for harmonization of care. Accurate stages assure that informed clinical decisions are timely made. The American Joint Committee on Cancer (AJCC) staging system is the most widely applied system in to determine the disease's prognosis and survival prediction. The recently adopted 8th AJCC TNM staging system has been revised to enhance its survival predictive power. Subsequent studies have established the validity of the current edition, demonstrating improved stage stratification, discriminatory power, and survival prediction. However, other studies have cast doubt on the superiority of the new edition. Innovations aimed at further improving its prognosis have resulted in developing of novel models. Advances in our understanding of the tumor microenvironment and molecular categorization of cancer have resulted in proposals for their inclusion in TNM staging as potential complementary factors that enhance survival prediction and prognostic assessment ability. The purpose of this study is to conduct a review of the published literature regarding the validity of the 8th AJCC TNM staging system, proposed modifications, and nomograms.

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The 8th AJCC is valid in prognostic stratification of gastric cancer, however, revisions are still required.

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The yPT staging requires some modifications and inclusion of stages that currently don't exist in the 8th AJCC.

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High lymph nodes count and anatomical localization improve the prediction ability of the current AJCC.

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Nomograms comprising of individual prognostic factors are crucial to the current AJCC.

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Molecular markers positively influence survival prediction of gastric cancer.

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.

The Prognostic Value of Postoperative Lymph Node Ratio in Gastric Adenocarcinoma Patients Treated With Neoadjuvant Chemotherapy

Objective

In this study, we aimed to investigate the prognostic value of postoperative lymph node ratio (LNR)in locally advanced gastric cancer (GC) patients receiving neoadjuvant chemotherapy (NACT).

Methods

LNR was calculated as the ratio of positive LNs to the total LNs removed. The receiver operating characteristic (ROC) curve was plotted to estimate the cut-off value of LNR for recurrence. The area under the curve of LNR was 0.714 (95% CI: 0.604-0.825, p<0.001) with 60% sensitivity and >0.255 with 76% specificity. Patients were grouped as group I (≤0.255) and group II (>0.255).

Results

In this study, 157 GC patients were included (39.5% female and 60.5% male). Of the patients, 97 (61.8%) were in group I and 60 (38.2%) were in group II. Disease‑free survival (DFS) was not reached in group I, and it was 16 months in group II (p<0.001). Overall survival (OS) was 58 months in group I and 28 months in group II (p>0.001). In multivariate analysis, lymphovascular invasion, neoadjuvant response, adjuvant treatment, and LNR were found to be the factors associated with DFS and OS (p<0.05).

Conclusion

In our study, it was observed that LNR can predict survival rates better than LN staging.

Determinants of Survival for Patients with Neoadjuvant-Treated Node-Negative Gastric Cancer

BACKGROUND

This study sought to determine prognostic markers for disease recurrence and survival in a cohort of neoadjuvant-treated, node-negative gastric cancer patients (ypT0-4N0M0).

METHODS

Clinicopathologic data from patients treated with neoadjuvant therapy followed by curative-intent gastrectomy at the University of Texas MD Anderson Cancer Center from 1995 to 2017 were evaluated. Patients with AJCC TNM stage ypT0-4N0M0 were considered for analysis.

RESULTS

The inclusion criteria were met by 212 patients with a mean age of 58.3 years. Of these patients, 60 % were male, 53 % were Caucasian, 87 % received chemoradiation, and 13 % received chemotherapy. The findings showed a median overall survival (OS) rate of 11.3 years, a 5-year survival rate of 72 %, and a 10-year survival rate of 57 %. During a median follow-up period of 5.5 years, 38.2 % of the patients died. In the multivariable analysis, ypT4-stage and nodal yield fewer than 16 were significantly associated with reduced OS. Cancer classified as ypT4 had more aggressive biologic traits, including lymphovascular and perineural invasion, and was treated more aggressively with total gastrectomy and additional organ resection despite frequent positive margins. Depth of invasion remained significantly associated with worse outcome after the analysis controlled for nodal yield and possible stage migration. Compared with ypT0-3 tumors, ypT4 cancers were associated with significantly more recurrences (13 % vs. 45 %; p < 0.05), and the primary modes of failure for ypT4 lesions were local recurrence and peritoneal metastases (88 % of recurrences).

CONCLUSIONS

Depth of primary tumor invasion and nodal yield were significantly associated with OS among the patients with ypT0-4N0M0 gastric cancer. Serosal invasion (ypT4) was associated with a high rate of peritoneal recurrence, and trials of intraperitoneal therapy targeting these patients should be considered.

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.

Preoperative Therapy Regimen Influences the Incidence and Implication of Nodal Downstaging in Patients with Gastric Cancer

Purpose

Nodal downstaging after preoperative therapy for gastric cancer has been shown to impart excellent prognosis, but this has not been validated in a national cohort. The role of neoadjuvant chemoradiation (NACR) in nodal downstaging remains unclear when compared with that of neoadjuvant chemotherapy alone (NAC). Furthermore, it is unknown whether the prognostic implications of nodal downstaging differ by preoperative regimen.

Materials and Methods

Using the National Cancer Database, overall survival (OS) duration was compared among natural N0 (cN0/ypN0), downstaged N0 (cN+/ypN0), and node-positive (ypN+) gastric cancer patients treated with NACR or NAC. Factors associated with nodal downstaging were examined in a propensity score-matched cohort of cN+ patients, matched 1:1 by receipt of NACR or NAC.

Results

Of 7,426 patients (natural N0 [n=1,858, 25.4%], downstaged N0 [n=1,813, 24.4%], node-positive [n=3,755, 50.4%]), 58.2% received NACR, and 41.9% received NAC. The median OS durations of downstaged N0 (5.1 years) and natural N0 (5.6 years) patients were similar to one another and longer than that of node-positive patients (2.1 years) (P<0.001). In the matched cohort of cN+ patients, more recent diagnosis (2010–2015 vs. 2004–2009) (odds ratio [OR], 2.57; P<0.001) and NACR (OR, 2.02; P<0.001) were independently associated with nodal downstaging. The 5-year OS rate of downstaged N0 patients was significantly lower after NACR (46.4%) than after NAC (57.7%) (P=0.003).

Conclusions

Downstaged N0 patients have the same prognosis as natural N0 patients. Nodal downstaging occurred more frequently after NACR; however, the survival benefit of nodal downstaging after NACR may be less than that when such is achieved by NAC.

Does hipec improve outcomes in gastric cancer patients treated with perioperative chemotherapy and radical surgery? A propensity-score matched analysis

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) has been associated with improved survival when compared with surgery alone for non-metastatic gastric cancer patients in randomized trials and meta-analyses. However, little evidence is available regarding the use of HIPEC in nonmetastatic patients who are treated with perioperative chemotherapy and radical surgery. The aim of this study was to investigate the putative survival benefit of HIPEC in the subgroup of gastric cancer patients treated with perioperative chemotherapy and surgery.

PATIENTS AND METHODS

This was a retrospective cohort study that included gastroesophageal junction and gastric cancer patients who were treated with perioperative chemotherapy and curative resection in a single cancer center in the period between 2006 and 2017. In this time period, younger patients with diffuse-type tumors and serosa invasion or positive lymph node disease were often offered an adjuvant HIPEC protocol. This study compared the survival outcomes of these patients to the ones of those who received only perioperative chemotherapy and resection. A 2:1 propensity-score matched analysis for the two groups was also performed, and variables used were postchemotherapy T (ypT) and N (ypN) stages, histology and tumor site.

RESULTS

The study population comprised 269 subjects, 241 treated with chemotherapy and surgery and 28 who also received HIPEC. The mean age was 59 years old (standard deviation: 12.2) and 60% of all individuals were male. A total gastrectomy was performed in 137 patients and a distal resection in 132, with a D2-lymphadenectomy in 97.4% of the sample. Overall 60-day morbidity and mortality rates were 35.3% and 3.3%, respectively. In the HIPEC group, patients were younger, and more frequently had American Society of Anesthesiologists (ASA) 1 to 2 classification, tumors located in the gastric body, had diffuse histology, and ypN+ disease. Overall survival (OS; 5 years) results in the HIPEC and no HIPEC group were 59.5% vs 68.7% (P = .453), and disease-free survival (DFS) ones were 49.5% and 65.8% (P = .060), respectively. In the multivariable Cox regression model, ypT and ypN were independent overall and DFS predictors; also, ASA 3 to 4 classification and diffuse histology were associated with worse OS. In the matched analysis, HIPEC did not improve either overall (53.5% vs 59.5%; P = .517) or DFS (50.0% vs 49.5%; P = .993).

CONCLUSION

Treatment with HIPEC in patients who received perioperative chemotherapy and a D2-resection did not improve survival outcomes. Both ypT and ypN stages remained as the most important survival predictors in this cohort.

Characteristics and Survival of Gastric Cancer Patients with Pathologic Complete Response to Preoperative Therapy

BACKGROUND

Pathologic complete response of a primary tumor (ypT0) after preoperative therapy is associated with improved overall survival (OS). However, whether other variables are associated with outcome for gastric cancer patients with ypT0 status is unknown.

METHODS

This study reviewed an institutional database of patients who underwent resection of gastric or gastroesophageal adenocarcinoma after preoperative therapy and identified patients with ypT0 status. Cox regression models were used to identify clinicopathologic predictors of OS.

RESULTS

Of 77 patients with ypT0 status identified in this study, 36 (47%) had gastroesophageal junction tumors. At presentation, 62 patients (81%) had clinical T3 disease, and 7 (9%) had clinical T4 disease. The clinical nodal status was positive (cN+) for 45 patients (58%). Preoperative chemoradiation was administered to 75 patients (97%). The median follow-up duration was 3.54 years. The median OS was 10 years, and the 5-year OS rate was 61%. Univariable analysis identified age of 65 years or older at the time of diagnosis, histologic grade, and ypN status as significant predictors of OS. Multivariable analysis confirmed age of 65 years or older [hazard ratio (HR), 4.26; p < 0.001] and persistent nodal disease (ypN+ status; HR, 5.12; p < 0.001) to be independently associated with OS. Clinical stage was not associated with survival. In the subset of ypT0N0 patients, no clinicopathologic feature was predictive of survival.

CONCLUSION

For gastric or gastroesophageal adenocarcinoma patients with ypT0 status after preoperative therapy, ypN+ status substantially reduced survival. Pretreatment clinical stage had no impact on OS for patients with a pathologic complete response.

Impact of ypT, ypN, and Adjuvant Therapy on Survival in Gastric Cancer Patients Treated with Perioperative Chemotherapy and Radical Surgery

BACKGROUND

Perioperative chemotherapy and surgery is the standard of care in advanced gastroesophageal cancer patients, but its impact among those treated with radical surgery still needs further assessment. We present the results of this multimodality treatment approach in a gastric cancer patients cohort treated with D2 lymphadenectomy. We aimed to identify prognostic factors associated with improved survival.

PATIENTS AND METHODS

This retrospective cohort study enrolled patients treated with perioperative chemotherapy and resection in a single cancer center in Brazil between 2006 and 2016. Subjects presenting tumors of the gastric stump, esophageal tumors, or treated with intraperitoneal chemotherapy were excluded. Intention-to-treat survival analysis was performed for all subjects who started neoadjuvant chemotherapy, and prognostic factors were determined among those who had R0 resection.

RESULTS

This study included 239 patients, of whom 198 had R0 resection. The mean age was 59.9 years, and most had clinical stage IIB or III disease (88%). Among the 239 patients who started neoadjuvant chemotherapy, 207 (86.6%) completed all neoadjuvant treatment cycles, and surgical resection was performed in 225 subjects (94.1%). Overall 60-day morbidity and mortality rates were 35.6% and 4.4%, respectively. For the entire cohort, median survival was 78 months and the 5-year survival rate was 55.3%. Factors associated with worse survival were ypT3-4 stage, ypN + stage, extended resection, and no adjuvant chemotherapy.

CONCLUSIONS

Perioperative chemotherapy resulted in very good outcomes for patients treated with radical surgery, and downstaging after chemotherapy was shown to be a major determinant of prognosis.