Evaluation of rational extent lymphadenectomy for local advanced gastric cancer

Deep learning-based radiomics model can predict extranodal soft tissue metastasis in gastric cancer

BACKGROUND

The potential prognostic value of extranodal soft tissue metastasis (ESTM) has been confirmed by increasing studies about gastric cancer (GC). However, the gold standard of ESTM is determined by pathologic examination after surgery, and there are no preoperative methods for assessment of ESTM yet.

PURPOSE

This multicenter study aimed to develop a deep learning-based radiomics model to preoperatively identify ESTM and evaluate its prognostic value.

METHODS

A total of 959 GC patients were enrolled from two centers and split into a training cohort (N = 551) and a test cohort (N = 236) for ESTM evaluation. Additionally, an external survival cohort (N = 172) was included for prognostic analysis. Four models were established based on clinical characteristics and multiphase computed tomography (CT) images for preoperative identification of ESTM, including a deep learning model, a hand-crafted radiomic model, a clinical model, and a combined model. C-index, decision curve, and calibration curve were utilized to assess the model performances. Survival analysis was conducted to explore the ability of stratifying overall survival (OS).

RESULTS

The combined model showed good discrimination of the ESTM [C-indices (95% confidence interval, CI): 0.770 (0.729-0.812) and 0.761 (0.718-0.805) in training and test cohorts respectively], which outperformed deep learning model, radiomics model, and clinical model. The stratified analysis showed this model was not affected by patient's tumor size, the presence of lymphovascular invasion, and Lauren classification (p < 0.05). Moreover, the model score showed strong consistency with the OS [C-indices (95%CI): 0.723 (0.658-0.789, p < 0.0001) in the internal survival cohort and 0.715 (0.650-0.779, p < 0.0001) in the external survival cohort]. More interestingly, univariate analysis showed the model score was significantly associated with occult distant metastasis (p < 0.05) that was missed by preoperative diagnosis.

CONCLUSIONS

The model combining CT images and clinical characteristics had an impressive predictive ability of both ESTM and prognosis, which has the potential to serve as an effective complement to the preoperative TNM staging system.

Postoperative mortality and morbidity after D2 lymphadenectomy for gastric cancer: A retrospective cohort study

BACKGROUND

Surgery for gastric cancer is a complex procedure and lymphadenectomy is often mandatory. Postoperative mortality and morbidity after curative gastric cancer surgery is not insignificant.

AIM

To evaluate the factors determining mortality and morbidity in a population of patients undergoing R0 resection and D2 lymphadenectomy for gastric cancer.

METHODS

A retrospective analysis of clinical data and pathological characteristics (age, sex, primary site of the tumor, Lauren histotype, number of positive lymph nodes resected, number of negative lymph nodes resected, and depth of invasion as defined by the standard nomenclature) was conducted in patients with gastric cancer. For each patient we calculated the Kattan’s score. We arbitrarily divided the study population of patients into two groups based on the nomogram score (< 100 points or ≥ 100 points). Prespecified subgroups in these analyses were defined according to age (≤ 65 years or > 65 years), and number of lymph nodes retrieved (≤ 35 lymph nodes or > 35 lymph nodes). Uni- and multivariate analysis of clinical and pathological findings were performed to identify the factors affecting postoperative mortality and morbidity.

RESULTS

One-hundred and eighty-six patients underwent a curative R0 resection with D2 lymphadenectomy. Perioperative mortality rate was 3.8% (7 patients); a higher mortality rate was observed in patients aged > 65 years (P = 0.002) and in N+ patients (P = 0.04). Following univariate analysis, mortality was related to a Kattan’s score ≥ 100 points (P = 0.04) and the presence of advanced gastric cancer (P = 0.03). Morbidity rate was 21.0% (40 patients). Surgical complications were observed in 17 patients (9.1%). A higher incidence of morbidity was observed in patients where more than 35 lymph nodes were harvested (P = 0.0005).

CONCLUSION

Mortality and morbidity rate are higher in N+ and advanced gastric cancer patients. The removal of more than 35 lymph nodes does not lead to an increase in mortality.

D2 vs D2 Plus Para-aortic Lymph Node Dissection for Advanced Gastric Cancer

Objectives

Gastric cancer is a common malignancy worldwide. Effective treatment by interdisciplinary cooperation is important, and surgery still plays an important role.

Material and Methods

In a ten-year period, 355 patients were diagnosed to have gastric cancer. One hundred and sixty-two patients with a median (range) age of 58 (23-83) years were eligible for the study. There were 107 patients in D2 and 55 patients in D2 lymphadenectomy plus para-aortic lymph node (PALN) dissection group. The two groups were compared in terms of complications, morbidity, mortality and long-term survival.

Results

Length of stay was 12 (8-34) days for D2 and 14 (8-42) days for D2 plus PALND. Total number of operative mortality was 8/162 (5%), and it was not different between the groups. Twenty patients (18%) had complications in D2 group and 9 (17%) patients in D2 plus PALND group. Overall survival was also similar between the groups, but patients with T3-T4 tumors, patients with stage IIIA and IIIB disease had better survival with D2 plus PALN dissection. We found that the depth of invasion, PLN, ratio (PLN/TLN), stage and LND were all prognostic variables.

Conclusion

This study showed that D2 plus PALN dissection for advanced gastric cancer can be performed as safely as a standard D2 dissection by experienced surgeons without increasing postoperative morbidity and mortality. D2 plus PALN dissection should be preferred in the advanced stage of the disease (IIIA-IIIB) as it increases the rate of survival.

Clinical Significance of Metastasis or Micrometastasis to the Lymph Node Along the Superior Mesenteric Vein in Gastric Carcinoma: A Retrospective Analysis

Background

The validity of lymphadenectomy of the lymph node along the superior mesenteric vein (LN14v) in gastric cancer remains controversial. The study investigated the characteristics and prognosis of gastric cancer with metastasis or micrometastasis to LN14v.

Methods

A retrospective study of 626 patients undergoing radical gastrectomy in our center from January 2003 to December 2015 was analyzed. In total, 303 patients had lymphadenectomy of LN14v, and lymph node micrometastasis was evaluated by immunohistochemical staining for cytokeratin nodes CK8/18. A logistic regression model was applied to confirm the predictive factors of micrometastasis. Survival analysis was performed to evaluate the effect of micrometastasis or metastasis on prognosis.

Results

The metastatic rate of the LN14v lymph node was 15.8%, and the micrometastatic rate was 3.3%. Multivariate analysis showed site, Borrmann classification, postoperative lymph node metastasis (pN), and metastasis in LN6 and LN9 were predictive factors for LN14v micrometastasis or metastasis (P < 0.05). The 5-year survival rate in the positive group (LN14v micrometastasis or metastasis) was 12.4%. The prognosis of patients without LN14v lymph node micrometastasis was better than that of the positive group, whereas the difference between group of LN14v micrometastasis and LN14v metastasis was not obvious. In matched analysis, patients with stage III gastric cancer L/M area, pN2-3, and LN6(+) who underwent lymphadenectomy of LN14v had better survival than those without lymphadenectomy of LN14v.

Conclusion

Lymph node micrometastasis may provide accurate prognostic information for patients with gastric cancer. Moreover, lymphadenectomy of LN14v might improve the survival of patients with stage III gastric cancer of L/M area, pN2-3, and LN6(+).

Current status of extended 'D2 plus' lymphadenectomy in advanced gastric cancer

The extent of lymph node (LN) dissection has been a topic of interest in gastric cancer (GC) surgery. D2 lymphadenectomy is considered the standard surgical procedure for most resectable advanced GC cases. The value and indications of more extended lymphadenectomy than D2 remain unclear. Currently, the controversial stations beyond the D2 range are mainly focused on no. 14v, no. 16a2/b1 and no. 13 LN stations. The metastatic rate of no. 14v LN is relatively high in advanced distal GC, particularly in patients with suspicious no. 6 LN metastasis. D2 plus no. 14v LN dissection may be attributed to improved survival outcomes for patients with obvious no. 6 LN metastasis. Although GC with para-aortic lymph node (PALN) metastases is considered an M1 disease beyond surgical cure, patients with limited PALN metastases may benefit from the treatment strategy of adjuvant chemotherapy followed by D2 plus no. 16a2-b1 LN dissection. In addition, D2 plus no. 13 LN dissection may be an option in a potentially curative gastrectomy for GC with duodenal invasion. The present review discusses the current status and future perspectives of D2 plus lymphadenectomy.

Safety and Feasibility of No.12a Lymph Node Dissection by Portal Vein Approach in Radical Laparoscopic Gastrectomy for Gastric Cancer

Background:

Traditional laparoscopic No.12a lymph node dissection in radical gastrectomy for gastric cancer may damage the peripheral blood vessels, and is not conducive to the full exposure of the portal vein and the root ligation of the left gastric vein. We recommend a new surgical procedure, the portal vein approach, to avoid these problems.

Methods:

25 patients with advanced gastric cancer underwent radical laparoscopic gastrectomy and No.12a lymph node were dissected by portal vein approach, including 7 cases with total gastrectomy, 18 cases with distal gastric resection, 14 males and 11 females. Operative time, intraoperative blood loss, time to first flatus, postoperative hospital stay, number of total lymph node dissection and No.12a lymph node dissection, No.12a lymph node metastasis rate and postoperative complications were statistically observed.

Results:

All the patients were operated successfully and No.12a lymph node were cleaned by portal vein approach. A total of 683 lymph nodes were dissected, with the average number of lymph nodes dissection and positive lymph nodes were (27.3 ± 12.7) and (3.8 ± 5.6) respectively. The average number of No.12a lymph node dissection was (2.4 ± 1.95) and the metastasis rate of No.12a lymph node was 16% (4/25). The average operation time of radical laparoscopic distal and total gastrectomy were (239.2 ± 51.4) min and (295.1 ± 27.7) min respectively. The mean intraoperative blood loss was (134.0 ± 65.7) ml, and postoperative first anal exhaust time was (2.24 ± 0.86) d. The mean time to fluid intake was (4.2 ± 1.7) d, and postoperative hospitalization time was (9.6 ± 5.0) d. Without portal vein injure, anastomotic leakage, gastrointestinal bleeding, intestinal obstruction and other complications were observed in all patient.

Conclusion:

Our results show that the laparoscopic No.12a lymph node dissection by portal vein approach for gastric cancer is safe, feasible and has certain clinical application value.

Impact of retrieved lymph node count on short-term complications in patients with gastric cancer

BACKGROUND

It is well established that retrieved lymph node (RLN) counts were positively correlated with better overall survival in gastric cancer (GC). But little is known about the relationship between RLN count and short-term complications after radical surgery.

METHODS

A total of 1487 consecutive GC patients between January 2016 and December 2018 at Nanjing Drum Tower Hospital were retrospectively analyzed. Univariate analyses were performed to elucidate the association between RLN count and postoperative complications. We further identified clinical factors that might affect the RLN count.

RESULTS

Among all of the patients, postoperative complications occurred in 435 (29.3%) patients. The mean RLN count was 25.1, and 864 (58.1%) patients were diagnosed with lymph node metastasis. Univariate analyses showed no significant difference between RLN count and postoperative complications (both overall and stratified by CDC grade). Univariate and multivariate analyses further revealed that type of resection, tumor invasion, and lymph node metastasis were associated with RLN count.

CONCLUSIONS

The current study demonstrated that RLN count was not associated with postoperative short-term complications following gastrectomy of GC, which provided a rationale for the determination of a proper RLN count of curative gastrectomy.

Advances in para-aortic nodal dissection in gastric cancer surgery: A review of research progress over the last decade

Approximately 17%-40% of para-aortic lymph node (PAN) metastasis occurs in patients with advanced gastric cancer. As the third tier of lymphatic drainage of the stomach and the final station in front of the systemic circulation, PAN infiltration is defined as distant metastasis and plays a key role in the evaluation of the prognosis of advanced gastric cancer. Many clinical factors including tumor size ≥ 5 cm, pT3 or pT4 depth of tumor invasion, pN2 and pN3 stages, the macroscopic type of Borrmann III/IV, and the diffuse/mixed Lauren classification are indicators of PAN metastasis. Whether PAN dissection (PAND) should be performed on patients with or without the macroscopic PAN invasion remains unascertained, regardless of the numerous retrospective comparative studies reported on the improved prognosis over D2 alone. Another paradoxical result from many other studies showed no significant difference in the overall survival between these two lymphadenectomies. A phase II trial launched by the Japan Clinical Oncology Group indicated that two or three courses of S-1 and cisplatin preoperatively followed by radical surgery with D2 + PAND and postoperative S-1 is the current standard strategy for the treatment of patients with extensive lymph node metastasis, and this regimen could be substituted by a promising strategy with effective combination chemotherapy or suitable chemotherapy duration. This review focuses on the advances in radical gastrectomy plus PAND with or without chemotherapy for patients with advanced gastric cancer.

Evaluation of D2-plus radical resection for gastric cancer with pyloric invasion

Background

The optimal lymphadenectomy for gastric cancer (GC) with pyloric invasion is controversial because the pattern of lymph node metastasis is different from that of distal GC. The rate of lymph node metastasis into the posterior area of the pancreatic head and hepatoduodenal ligament is high. This study evaluated the estimated benefit of radical gastrectomy with D2-plus lymphadenectomy in patients with pyloric invasion.

Methods

All patients with GC invading the pylorus who underwent curative surgical resection with D2-plus lymphadenectomy between February 2013 and September 2015 were enrolled in the study. The index of estimated benefit from lymph node dissection (IEBLD) was calculated by multiplying the incidence of metastasis to each lymph node station by the 3-year overall survival (OS) rate of patients with metastasis to that station.

Results

In total, 128 patients were eligible. The rate of lymph node metastasis and the 3-year OS rate (and IEBLD) of the patients with metastasis to lymph nodes were 14.3 and 44.4% (5.56) for No. 8p, 10.9 and 35.7% (3.89) for No. 12b, 9.5 and 33.3% (3.13) for No. 12p, 18.8 and 54.2% (10.19) for No. 13, and 21.8 and 53.6% (11.68) for No. 14v, respectively.

Conclusions

In radical gastrectomy for GC with pyloric invasion, some survival benefit was observed with dissection of the No. 13 and No. 14 lymph nodes, but there was no survival benefit with dissection of the No. 8p lymph nodes. The No. 12b and No. 12p lymph nodes may be better to dissect in cT3 GC patients with pyloric invasion.

Trial registration

http://ClinicalTrials.gov Identifier: NCT01836991. Date of registration: April 17, 2013.

Prognostic significance of 14v-lymph node dissection to D2 dissection for lower-third gastric cancer

BACKGROUND

Radical gastrectomy with D2 lymph node (LN) dissection is the standard surgical procedure for patients with resectable gastric cancer (GC). In the fifteenth edition of the Japanese Classification of Gastric Carcinoma, the 14v LN (LNs along the root of the superior mesenteric vein) was defined as the regional gastric LN. The efficacy of 14v LN dissection during radical distal gastrectomy for lower-third GC remains controversial.

AIM

To analyze whether the addition of 14v LN dissection improved the survival of patients with lower-third GC.

METHODS

The data from 65 patients who underwent 14v LN dissection and 65 patients treated without 14v LN dissection were selected using the propensity score-matched method from our institute database constructed between 2000 and 2012. Overall survival was compared between the groups.

RESULTS

Overall survival was similar between patients with 14v LN metastasis and those with distant metastasis (P = 0.521). Among patients with pathological stage IIIA disease, those who were treated with 14v LN dissection had a significantly higher overall survival than those treated without it (P = 0.020). Multivariate analysis showed that age < 65 years and pT2-3 stage were independent favorable prognostic factors for prolonged overall survival in patients with pathological stage IIIA disease. Patients with No. 1, No. 6, No. 8a, or No. 11p LN metastasis were at higher risk of having 14v LN metastasis.

CONCLUSION

Adding 14v LN dissection to D2 dissection during radical distal gastrectomy may improve the overall survival of patients with pathological stage IIIA lower-third GC.

Should All Stage N3b Patients with Advanced Gastric Cancer Be Considered Equivalent? A 30-Year Single Center Study

PURPOSE

To investigate the survival of stage N3b patients with advanced gastric cancer (AGC) after radical surgery and to evaluate the TNM staging of subgroups of stage N3b patients.

METHODS

We reviewed the data of 222 stage N3b patients with AGC who underwent D2/D3 radical surgery. Depending on the number of metastatic lymph nodes (MLNs), we divided N3b patients into several groups and compared the survival differences among them. We found that survival of patients with 16-20 MLNs was better than that of patients with ≥ 21 MLNs. Therefore, we divided the N3b patients into two subgroups and defined patients with 16-21 MLNs as N3b1 and patients with ≥ 21 MLNs as N3b2. Then, we compared survival differences between the two groups and their subgroups. Patients who underwent palliative surgery served as the reference group. In addition, we selected stage IIIB, IIIC, and IV patients from the same database to properly re-classify the N3b subgroups in the TNM staging system.

RESULTS

Survival differed significantly between the new N3b1and N3b2 groups and between the new N3b1 group and the palliative group. However, the survival of the new N3b2 group was similar to that of the palliative group. Comparisons of survival according to T staging revealed similarities between the following groups: (1) stages T2-3N3b1 and IIIB, (2) stages T4N3b1 and IIIC, and (3) stages T2-4N3b2 and IV.

CONCLUSIONS

All stage N3b patients with AGC should not be considered equivalent. A significant difference in survival was observed between stage N3b1 and N3b2 patients after radical surgery, while the survival of stage N3b2 patients was similar to that of patients who undergo palliative surgery. We recommend re-classifying stage T2-3N3b1 as TNM stage IIIB, stage T4N3b1 as stage IIIC, and T2-4N3b2 as stage IV.

Comparison of D2 and D2 plus radical surgery for advanced distal gastric cancer: a randomized controlled study

BACKGROUND

The optimal extent of lymph node (LN) dissection for advanced distal gastric cancer remains controversial. The present study compared the safety and efficacy of extended LN dissection (D2 plus) with standard D2 radical surgery for advanced distal gastric cancer.

METHODS

Eligible patients were enrolled and randomly assigned into two groups: D2 group and D2 plus group. Patients in the D2 group received standard D2 LN dissection, while patients in the D2 plus group received an additional nos. 8p, 12b, 13, and 14v LNs dissection. The clinicopathological and surgical data of these two groups were compared, and the factors that may influence survival were analyzed.

RESULTS

Seventy patients were enrolled, out of which 64 patients were analyzed. There were no significant differences in the operative time, blood loss, and complications between the two groups. In the D2 plus group, the positive rate of the nos. 12b, 13, and 14v LN was 3.1%, 9.4%, and 12.5%, respectively. The positive rate of the no. 13 LN correlated with the duodenal involvement, while the positive rate of the no. 14v LN correlated with no. 6 LN metastasis. The survival analysis indicated that among patients with duodenum involvement, the 3-year disease-free survival rate of the D2 plus group was significantly better than that of the D2 group.

CONCLUSION

Duodenum involvement and positive no. 6 LN were high-risk factors of advanced distal gastric cancer. D2 plus radical surgery turned out to be safe and feasible, and may improve the prognosis of these patients. However, further clinical trials are still warranted.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov as NCT01836991 , registered on 22 April 2013.

Para-aortic lymphadenectomy in surgery for gastric cancer: current indications and future perspectives

Involvement of para-aortic nodes (PAN) has been detected at pathological examination in 10-25% of locally advanced gastric cancer. Based on these data of nodal diffusion, the lymphadenectomy of para-aortic stations would be desirable in locally advanced gastric cancer. However, the debate on the oncological benefit of para-aortic nodes dissection is still not solved. A review of the literature was performed and papers reporting either the rate of para-aortic nodal metastases or the long-term survival outcomes after D2+ para-aortic nodes dissection (PAND) or D3 lymphadenectomy were descriptively reported. The literature survey yielded 14 studies. Most of the papers show the outcome of series of advanced gastric cancer treated with surgery alone, while starting from 2012, 3 articles report the outcomes of D2 + PAND or D3 lymphadenectomy after preoperative chemotherapy. The rate of PAN metastases ranges between 8.5 and 28% in surgical series. Survival outcomes largely improved in series of patients treated with multimodal approach compared to those of surgery alone. In patients with clinically detected para-aortic nodal metastases, preoperative chemotherapy followed by PAND is indicated. More data are needed to clarify the indication to prophylactic PAND in the era of multimodal treatment, anyway super-extended lymphadenectomies have to be performed by experienced surgeons in dedicated centres.

Validation of clinical significance of examined lymph node count for accurate prognostic evaluation of gastric cancer for the eighth edition of the American Joint Committee on Cancer (AJCC) TNM staging system

Objective

To validate the necessity of increasing the examined lymph node (ELN) count for enhancing the accuracy of prognostic evaluation of gastric cancer (GC) patients after curative gastrectomy in multiple medical centers of China.

Methods

The clinicopathological data of 7,620 patients who underwent the curative resection for GC between 2001 and 2011 were included to demonstrate whether the ELN count is indispensable for enhancing the accuracy of prognostic evaluation of GC patients after surgery. After a meticulous stratification by using the cut-point survival analysis, all included 7,620 patients were allocated into three groups as: less than 16 (<16), between 16 and 30 (16−30), and more than 30 (>30) ELNs. Survival differences among various subgroups of GC patients were analyzed to assess the impact of the ELN count on the stage migration in accordance with the overall survival (OS) of GC patients.

Results

Survival analyses revealed that the ELN count was positively correlated with the OS (P=0.001) and was an independent prognostic predictor (P<0.01) of 7,620 GC patients. Stratum analysis showed that the accuracy of prognostic evaluation could be enhanced when the ELN count was no less than 16 (≥16) for node-negative patients and >30 for node-positive patients. Stage migrations were mainly detected in the various subgroups of patients with specific pN stages as follows: pN0 with 16−30 ELNs (pN0₁₆₋₃₀) and pN0 with >30 ELNs (pN0 _>30), pN0 with <16 ELNs (pN0 _<16) and pN1_>30, pN1_<16 and pN2₁₆₋₃₀, pN1₁₆₋₃₀ and pN2_>30, pN3a_<16 and pN3b₁₆₋₃₀, and pN3a_<16 and pN3b_>30. These findings indicate that increasing the ELN count is a prerequisite to guarantee precisely prognostic evaluation of GC patients.

Conclusions

The ELN count should be proposed to be >30 for acquiring the accurate prognostic evaluation for GC patients, especially for node-positive patients.

Elevated preoperative plasma D-dimer dose not adversely affect survival of gastric cancer after gastrectomy with curative intent: A propensity score analysis

Objective

Elevated plasma D-dimer has been reported to be associated with advanced tumor stage and poor survival in several types of malignancies. The purpose of this study was to assess the potential impact of preoperative plasma D-dimer level (PDL) on overall survival (OS) of gastric cancer (GC) patients undergoing curative surgery by applying propensity score analysis.

Methods

A total of 1,025 curatively resected GC patients in Tianjin Medical University Cancer Institute & Hospital were enrolled. Patients were categorized into two groups based on preoperative PDL: the elevated group (EG) and the normal group (NG). To overcome bias due to the different distribution of covariates for the two groups, a one-to-one match was applied using propensity score analysis, after matching, prognostic factors were analyzed.

Results

In analysis for the whole study series, patients in the EG were more likely to have a larger proportion of tumor size ≥5 cm (67.5% vs. 55.8%, P=0.006), elder mean age (64.0±10.8 years vs. 60.5±11.6 years, P<0.001) and advanced tumor (T), node (N), and TNM stage. Patients with elevated PDL demonstrated a significantly lower 5-year OS than those with normal PDL (27.0%vs. 42.6%, P<0.001), however, the PDL was not an independent prognostic factor for OS in multivariate analysis [hazard ratio: 1.13, 95% confidence interval (95% CI): 0.92-1.39, P=0.236]. After matching, 163 patients in the EG and 163 patients in the NG had the same characteristics. The 5-year OS rate for patients in the EG was 27.0% compared with 25.8% for those in the NG (P=0.809, log-rank).

Conclusions

The poor prognosis of GC patients with elevated preoperative PDL was due to the advanced tumor stage and elder age rather than the elevated D-dimer itself.