Subclassification of pT2 gastric adenocarcinoma according to depth of invasion (pT2a vs pT2b) and lymph node status (pN)

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

Recent Advances in the Diagnosis, Staging, Treatment, and Prognosis of Advanced Gastric Cancer: A Literature Review

Gastric cancer is one of the most common cause of cancer related deaths worldwide which results in malignant tumors in the digestive tract. The only radical treatment option available is surgical resection. Recently, the implementation of neoadjuvant chemotherapy resulted in 5-year survival rates of 95% for early gastric cancer. The main reason of treatment failure is that early diagnosis is minimal, with many patients presenting advanced stages. Hence, the greatest benefit of radical resection is missed. Consequently, the main therapeutic approach for advanced gastric cancer is combined surgery with neoadjuvant chemotherapy, targeted therapy, or immunotherapy. In this review, we will discuss the various treatment options for advanced gastric cancer. Clinical practice and clinical research is the most practical way of reaching new advents in terms of patients' characteristics, optimum drug choice, and better prognosis. With the recent advances in gastric cancer diagnosis, staging, treatment, and prognosis, we are evident that the improvement of survival in this patient population is just a matter of time.

Low expression of CD80 predicts for poor prognosis in patients with gastric adenocarcinoma

AIM

To study the expression and prognostic significance of CD80 in patients with gastric adenocarcinoma. Materials & methods: Real-time quantitative PCR, western blot and immunohistochemistry were performed to detect the expression of CD80 in gastric cancer tissues and matched adjacent normal tissues. Double immunohistochemical staining was performed to preliminary examine the relationship between CD80⁺ cells and CD8⁺ cytotoxic T lymphocytes.

RESULTS

The expression of CD80 was downregulated in tumor tissues compared with normal tissues (p = 0.002). Immunohistochemistry analysis showed that 49 (39.8%) of 123 patients with gastric cancer demonstrated reduced CD80 expression, which was correlated with the tumor differentiation grade.

CONCLUSION

Our data suggest that reduced CD80 expression independently predicts a poor prognosis in patients with gastric adenocarcinoma.

Prognostic factors for survival in patients with pT1 N+ or T2–3 N0 gastric cancer in Japan

Background

The outcome for pT1 N+ or pT2–3 N0 gastric cancer is favourable, but some patients suffer from recurrent disease. The aim of this study was to identify prognostic factors in patients with pT1 N+ or pT2–3 N0 gastric cancer.

Methods

This was a multicentre, retrospective cohort study. All patients with pT1 N+ or pT2–3 N0 gastric cancer who underwent curative gastrectomy at five high-volume, specialized cancer centres in Japan between 2000 and 2008 were included. Demographic, clinical, surgical and pathological data were collected. Independent prognostic factors were identified using a Cox proportional hazards regression model.

Results

Some 1442 patients were included. The 5-year overall survival rate for patients with pT1 N+ or pT2–3 N0 gastric cancer was 92·0 per cent. Multivariable analysis for overall survival identified age (hazard ratio (HR) 2·67, 95 per cent c.i. 2·09 to 3·43), sex (HR 0·57, 0·39 to 0·83) and clinical tumour depth (cT) (HR 1·45, 1·06 to 1·98) as independent prognostic factors.

Conclusion

Survival of patients with pT1 N+ or pT2–3 N0 gastric cancer is good. Age 65 years or above, male sex and cT2-4 category are associated with worse overall survival.

Comparison between superficial muscularis propria and deep muscularis propria infiltration in gastric cancer patients: A retrospective cohort study

This study aimed to investigate the clinicopathological characteristics and survival outcomes of the subclassification of pT2 gastric cancers according to the depth of tumor involvement. We retrospectively collected clinicopathological data and survival outcomes for pT2 gastric cancer patients from 2006 to 2011. Patients were classified into the superficial muscularis propria (sMP) and deep muscularis propria (dMP) groups. Eighty-nine patients had sMP gastric cancers and 90 patients had dMP gastric cancers. The rates of lymph node metastasis for the sMP and dMP groups were 55.1% and 64.4%, respectively, P = 0.202. The 5-year overall survival (OS) of patients in the sMP group was significantly better than patients in the dMP group (76% vs 61%, P = 0.018). Multivariate analysis demonstrated that the depth of tumor invasion, lymph node metastasis, and postoperative chemotherapy were prognostic risk factors for the OS. For patients with pN0 stage tumor(s), the sMP group had a significantly better 5-year OS rate than the dMP group (92% vs 62%, P = 0.004); for patients with pN1-N3 stages, the 5-year OS rates were comparable between the sMP and dMP groups (64% vs 61%, P = 0.540). The subclassification of pT2 gastric cancer into the sMP and dMP groups can demonstrate different survival outcomes according to the lymph node status. However, the pT2 stage subclassification in the next tumor, node, metastasis (TNM) staging system is pending and requires more large sample size studies to confirm its importance.

Prognostic significance of intraoperative macroscopic serosal invasion finding when it shows a discrepancy in pathologic result gastric cancer

Purpose

Depth of wall invasion is an important prognostic factor in patients with gastric cancer, whereas the prognostic significance of intraoperative macroscopic serosal invasion (mSE) findings remain unclear when they show a discrepancy in pathologic findings. This study, therefore, assessed the prognostic significance of mSE.

Methods

Data from cohort of 2,835 patients with resectable gastric cancer who underwent surgery between 1990 and 2010 were retrospectively reviewed.

Results

The overall accuracy of mSE and pathologic results was 83.4%. The accuracy of mSE was 75.5% in pT2. On the other hand, the accuracy of pT3 dropped to 24.5%. According to mSE findings (+/–), the 5-year disease-specific survival (DSS) rate differed significantly in patients with pT2 (+; 74.2% vs. –; 92.0%), pT3 (+; 76.7% vs. –; 91.8%) and pT4a (+; 51.3% vs. –; 72.8%) (P < 0.001 each), but not in patients with T1 tumor. Multivariate analysis showed that mSE findings (hazard ratio [HR], 2.275; 95% confidence interval [CI], 1.148–4.509), tumor depth (HR, 6.894; 95% CI, 2.325–20.437), nodal status (HR, 5.206; 95% CI, 2.298–11.791), distant metastasis (HR, 2.881; 95% CI, 1.388–6.209), radical resection (HR, 2.002; 95% CI, 1.017–3.940), and lymphatic invasion (HR, 2.713; 95% CI, 1.424–5.167) were independent predictors of 5-year DSS rate.

Conclusion

We observed considerable discrepancies between macroscopic and pathologic diagnosis of serosal invasion. However, macroscopic diagnosis of serosal invasion was independently prognostic of 5-year DSS. It suggests that because the pathologic results could not be perfect and the local inflammatory change with mSE(+) could affect survival, a combination of mSE(+/–) and pathologic depth may be predictive of prognosis in patients with gastric cancer.

Ectopic expression of B and T lymphocyte attenuator in gastric cancer: a potential independent prognostic factor in patients with gastric cancer

It has been confirmed that B and T lymphocyte attenuator (BTLA; also known as CD272) is a novel co--inhibitory molecule that exhibits a critical role in restraining cell-mediated antitumor immunity. The present study aimed to investigate the expression and prognostic significance of BTLA in gastric adenocarcinoma. Immunohistochemical (IHC) staining was performed to investigate BTLA expression in gastric cancer tissues and normal mucosal tissues. In total, 123 pathologically confirmed specimens were obtained from stage IIIa gastric cancers. A correlation test, Kaplan-Meier curves, and a Cox proportional hazards regression model were used to analyze the data. No BTLA staining in the normal tissues was found, while BTLA-stained gastric carcinoma cells were detected in 75.6% (93/123) of the gastric cancer specimens. High expression levels of BTLA were detected in 31.7% (39/123) of the specimens, while low expression levels were detected in 68.3% (84/123) of the specimens. High BTLA expression levels were associated with shorter survival time, as confirmed by univariate and multivariate analyses. These findings provide a basis for the concept that high BTLA expression levels in gastric cancer, identified by IHC, are an independent biomarker for the poor prognosis of patients with gastric cancer.

Sixth and seventh tumor-node-metastasis staging system compared in gastric cancer patients

AIM: To investigate the clinical relevance and prognosis regarding survival according to the changes of the tumor-node-metastasis (TNM) in gastric cancer patients.

METHODS: We retrospectively studied 347 consecutive subjects who underwent surgery for gastric adenocarcinoma at the Division of General Surgery, Hospital of Busto Arsizio, Busto Arsizio, Italy between June 1998 and December 2009. Patients who underwent surgery without curative intent, patients with tumors of the gastric stump and patients with tumors involving the esophagus were excluded for survival analysis. Patients were staged according to the 6^th and 7^th edition TNM criteria; 5-year overall survival rates were investigated, and the event was defined as death from any cause.

RESULTS: After exclusion, our study population included 241 resected patients with curative intent for gastric adenocarcinoma. The 5-year overall survival (5-year OS) rate of all the patients was 52.8%. The diagnosed stage differed in 32% of 241 patients based on the TNM edition used for the diagnosis. The patients in stage II according to the 6^th edition who were reclassified as stage III had significantly worse prognosis than patients classified as stage II (5-year OS, 39% vs 71%). According to the 6^th edition, 135 patients were classifed as T2, and 75% of these patients migrated to T3 and exhibited a significantly worse prognosis than those who remained T2, regardless of lymph node involvement (37% vs 71%). The new N1 patients exhibited a better prognosis than the previous N1 patients (67% vs 43%).

CONCLUSION: 7^th TNM allows new T2 and N1 patients to be selected with better prognosis, which leads to different staging. New stratification is important in multimodal therapy.

Improved survival after adding dissection of the superior mesenteric vein lymph node (14v) to standard D2 gastrectomy for advanced distal gastric cancer

BACKGROUND

Extended lymph node dissection in gastric cancer (D3) was proven to have no survival benefit compared with a D2 dissection, but whether adding the superior mesenteric nodes (No. 14v) to the dissection provides survival benefit for gastric cancer patients remains controversial.

METHODS

From April 2001 to June 2007, 1,661 patients underwent curative resection for middle or lower third gastric cancer. Patients were grouped according to No. 14v lymphadenectomy (14vD+/14vD-). Clinicopathologic characteristics and treatment-related factors were compared between the groups. Overall survival according to the clinical stage (Union for International Cancer Control tumor-node-metastasis staging 6th edition) was analyzed using the Cox proportional hazard model.

RESULTS

The incidence of No. 14v lymph node metastasis was 5.0%. There was no difference in morbidity or mortality between the 14vD+ and the 14vD- groups. The proportion of locoregional recurrence was greater in 14vD- group (P = .018). In clinical stages I and II, 14v lymph node dissection did not affect overall survival; in contrast, 14v lymph node dissection was an independent prognostic factor in patients with clinical stage III/IV gastric cancer (hazard ratio, 0.58; 95% confidence interval, 0.38-0.88; P = .01).

CONCLUSION

Extended D2 gastrectomy including No. 14v lymph node dissection seems to be associated with improved overall survival of patients with clinical stage III/IV gastric cancer in the middle or lower third of the stomach.

Gastric cancer staging with radiologic imaging modalities and UICC staging system

There are two major stage classification systems for gastric cancer: the tumor-node-metastasis (TNM) stages by the International Union against Cancer (UICC) and the Japanese Classification of Gastric Carcinoma by the Japanese Gastric Cancer Association (JGCA). Preoperative stage classification using either of these systems is essential for deciding on the treatment strategy in the era of various multimodal therapeutic options. Evolution of multidetector computerized tomography with isotropic volumetric imaging and various 3D images has increased the accuracy of T and N staging in patients with gastric cancer, although detection of peritoneal deposits and nodal metastasis in the absence of lymphadenopathy remain problematic with the imaging tools currently available. The TNM and JGCA classifications have undergone revisions independent of each other, and the discrepancies were not helpful when international comparisons and cooperation were needed. More recently, the JGCA and TNM classifications were merged to have identical T and N categories, in addition to the more straightforward M categories that indicate the presence of distant metastasis. The result of these efforts is that researchers in Japan and the rest of the world are now looking at a similar disease when they discuss cancer that belongs to the same stage. A nomogram that incorporates other established prognostic determinants in addition to the TNM component may be a future direction for a more sophisticated means of predicting outcome. The increasing incidence of junctional (esophagogastric junction) cancer in the Far East has spurred researchers from this region to adequately stage the disease and to consider suitable treatment modalities for this disease entity, whereas Western researchers are more inclined to treat this disease as esophageal cancer. This could be an area for future international debate. For the next more accurate staging, we suggest the collaboration between Eastern and Western high-volume centers in gastric cancer because the inconsistency of surgical approaches, especially with respect to nodal resection, remains a barrier to mutual understanding.

A New Subclassification of pT4 Gastric Cancers According to the Width of Serosal Invasion

OBJECTIVE

The purpose of this study was to propose a novel subclassification of pT4 gastric cancers according to the width of serosal changes and to investigate the validity and clinical utility of this subclassification as a predictor of prognosis.

METHODS

A total of 780 pT4 stage gastric cancer patients classified according to the 7th American Joint Committee on Cancer (AJCC) staging system were reviewed. Clinicopathologic features were compared between patients with narrow serosal changes (nSE), wide serosal changes (wSE) and invasions of adjacent structures (SI). Prognostic factors were evaluated by univariate and multivariate analyses. The 7th AJCC and novel pT4 subclassification were compared for prognostic performance using the linear trend chi-square test, likelihood ratio chi-square test, and Akaike information criterion (AIC) in the Cox regression analysis.

RESULTS

The appropriate serosa infiltrate cutoff value was 8 cm. Most of the evaluated clinicopathologic features significantly differed between nSE and SI cancers. Only 3 factors were significantly different between wSE and SI cancers. The 5-year survival rates for patients with the novel pT4a and pT4b cancers were 47.2% and 14.52%, respectively, while they were 41.66% and 16.34% for the 7th AJCC pT4a and pT4b cancers, respectively. The novel pT4 subclassification had better discriminatory ability, monotonicity of gradients, and homogeneity and had smaller AIC values compared with the 7th AJCC pT4.

CONCLUSIONS

It is reasonable to subclassify pT4 to pT4a (nSE) and pT4b (wSE/SI) because the novel pT4 subclassification had more potential to identify the different prognoses for patients with gastric cancer.

A comparison between the seventh and sixth editions of the American Joint Committee on Cancer/International Union Against classification of gastric cancer

OBJECTIVE

To evaluate the prognostic significance of the seventh edition TNM staging classification for gastric cancer.

BACKGROUND

The seventh edition TNM staging system for gastric cancer was adopted by the American Joint Committee on Cancer/International Union Against Cancer on January 1, 2010, and included major revisions.

METHODS

The authors analyzed data retrospectively collected on patients with gastric cancer who underwent surgery at the Affiliated Hospital of Qingdao University Medical College between 2000 and 2008. A total of 964 patients with gastric cancer who underwent R0 surgical resection were included.

RESULTS

The relative risk (RR) for the seventh edition T classification was found to increase steadily and reasonably compared with the sixth edition. However, the RR for the sixth edition N classification was found to increase steadily and reasonably compared with the seventh edition classification. Cox regression multivariate analysis showed that the sixth edition N classification was superior to the seventh edition N classification as an independent prognostic factor. In survival analysis, the seventh edition TNM classification provided a more detailed classification; however, some subgroups of the seventh edition TNM classification did not demonstrate significantly different survival rates. The combination of the seventh edition T classification and the sixth edition N classification, with ideal RR results, showed significantly different survival rates except for IA and IB.

CONCLUSIONS

The combination of the seventh edition T classification and the sixth edition N classification seems to provide the optimal prognosis.

Prognostic value of the seventh AJCC/UICC TNM classification of non-cardia gastric cancer

Background

The TNM staging criteria for gastric carcinoma have seen numerous revisions, the most recent of which are reflected in the seventh edition AJCC TNM cancer staging manual.

Methods

A retrospective evaluation of the sixth and seventh TNM classification of gastric cancer on a prospective database, regarding patients operated on for primary gastric cancer, was conducted. The end point of the study was prognosis evaluation in terms of overall survival.

Patients operated on for primary gastric cancer between September 2003 and March 2012 at our Department of Emergency and General Surgery, were consecutively retrieved in this study; a total of 114 patients were considered. Cardia gastric cancers, gastric lymphomas and gastrointestinal stromal tumors (GIST) were excluded. Median and mean follow-up periods were 22.5 and 27.7 months (range 15 days to 5 years). Both TNM6 and TNM7 were used to evaluate our patients. Overall survival and survival rates at different stages were analyzed using the Kaplan-Meier method and differences were determined using a log-rank test. Cox’s proportional hazard model was used to identify significant factors related to prognosis in a multivariate analysis.

Results

Overall survival between the sixth and seventh TNM classification was not significantly different. Both the Kaplan-Meier analysis and the multivariate analysis showed that the major negative prognostic factor was lymphovascular invasion (P < 0.001 in the univariate analysis and P = 0.035 to 0.048 in the multivariate analysis). Stage distribution and stage-related survival changed from the sixth to the seventh edition, especially in T3 stage where median survival for the sixth edition was 720 days versus 1,200 days for the seventh edition. Moreover, differences were shown in the survival rate of N1 versus N2 stages within the seventh TNM.

Conclusions

Even though further studies are needed in order to increase the number of patients studied, the seventh edition seems to provide a more accurate prognosis, especially regarding N1 and N2 tumors, showing that the most important prognostic factor is lymphovascular invasion.

Clinical experience of 528 laparoscopic gastrectomies on gastric cancer in a single institution

BACKGROUND

Laparoscopic gastrectomy (LG) for locally advanced gastric cancer (AGC) as well as early gastric cancer (EGC) has gradually gained popularity. However, long-term experiences of LG for AGC as well as EGC rarely have been reported.

METHODS

A total of 528 patients with gastric cancer were enrolled in the study, and clinical experiences of LG were evaluated.

RESULTS

The study included 332 men and 196 women. The mean age was 61.3 ± 11.8 years. Of the 528 patients, 432 underwent distal gastrectomy, 87 had a total gastrectomy, and 9 had a proximal gastrectomy. There were 198 T1a, 139 T1b, 63 T2, 83 T3, and 45 T4a lesions. In 127 patients, lymph node metastasis was observed, and the rate of it was 1.5% in T1a, 12.2% in T1b, 34.9% in T2, 59.0% in T3, and 80.0% in T4a. The median follow-up period was 24 months (range, 1-83 months). The 5-year survival and disease-free survival rates according to the stage of tumor were 99.3% and 97.8% in stage I, 95.4% and 89.7% in stage II, and 44.4% and 31.3% in stage III, respectively. Operation related morbidities occurred in 45 patients, and there were 2 mortalities. Tumors recurred in 36 patients consisting of 2 in T1a, 2 T1b, 2 T2, 12 T3, and 18 T4a. Carcinomatosis peritonei was observed most commonly.

CONCLUSION

In our experience, oncologic results and the safety of LG for EGC and serosa-negative AGC were acceptable. This treatment may be considered as an alternative operative approach.

Comparação da sobrevivência e dos fatores prognósticos em pacientes com adenocarcinoma gástrico T2 e T3

OBJETIVO: Comparar a sobrevivência e os fatores prognósticos, após o tratamento cirúrgico de pacientes com adenocarcinoma gástrico que compromete a camada muscular própria (T2), e de pacientes cujo tumor invade a subserosa (T3). MÉTODOS: Estudo retrospectivo de 122 pacientes com câncer gástrico invadindo a muscular própria e subserosa, submetidos ao tratamento cirúrgico no período de janeiro de 1997 a dezembro de 2008 e acompanhados até dezembro de 2010. Foram analisadas variáveis demográficas, cirúrgicas e anatomopatológicas. RESULTADOS: Dos 122 pacientes, 22 (18%) foram excluídos da análise final porque apresentaram: margem positiva, mortalidade pós-operatória, segundo tumor primário e menos de 15 linfonodos na peça cirúrgica. Entre os 100 pacientes incluídos, 75 apresentavam tumores com invasão da muscular própria (T2) e 25 com invasão da subserosa (T3). A sobrevivência global foi 83,8%, sendo 90,6% no T2 e 52,1% no T3. Na análise univariada apresentaram significância: metástase linfonodal (p=0,02), tamanho do tumor (p=0,000), estadiamento patológico do tumor (p=0,000), estadiamento patológico linfonodal (p=0,000) e estadiamento por grupos da classificação TNM-UICC/AJCC, 2010 (p=0,000) Na análise multivariada, os fatores prognósticos independentes foram o tamanho do tumor e o estadiamento patológico linfonodal (pN). CONCLUSÃO: O comprometimento linfonodal e o tamanho do tumor são fatores prognósticos independentes nos tumores com invasão da muscular própria e nos tumores com invasão da subserosa. O T2 apresenta menor tamanho, menor taxa de linfonodos metastáticos e consequentemente, melhor prognóstico que o T3.

Comparative study of laparoscopy-assisted versus open subtotal gastrectomy for pT2 gastric cancer

PURPOSE

Laparoscopy-assisted distal gastrectomy (LADG) is a widely accepted surgery for early gastric cancer. However, its use in advanced gastric cancer has rarely been studied. The aim of this study is to investigate the feasibility and survival outcomes of LADG for pT2 gastric cancer.

MATERIALS AND METHODS

Between January 2004 and December 2009, we evaluated 67 and 52 patients who underwent open distal gastrectomy (ODG) and LADG, respectively, with diagnosis of pT2 gastric cancer. The clinicopathological characteristics, postoperative outcomes, and survival were retrospectively compared between the two groups.

RESULTS

There were statistically significant differences in the proximal margin of the clinicopathological parameters. The operation time was significantly longer in LADG than in ODG (207.7 vs. 159.9 minutes). There were 6 (9.0%) and 5 (9.6%) complications in ODG and LADG, respectively. During follow-up periods, tumor recurrence occurred in 7 (10.4%) patients of the ODG and in 4 (7.7%) patients of the LADG group. The 5-year survival rate of ODG and LADG was 88.6% and 91.3% (p=0.613), respectively. In view of lymph node involvement, 5-year survival rates were 96.0% in ODG versus 97.0% in LADG for patients with negative nodal metastasis (p=0.968) and 80.9% in ODG versus 78.7% in LADG for those with positive nodal metastasis (p=0.868).

CONCLUSION

Although prospective study is necessary to compare LADG with open gastrectomy for the treatment of advanced gastric cancer, laparoscopy-assisted distal gastrectomy might be considered as an alternative treatment for some pT2 gastric cancer.

Comparison of the survival difference between AJCC 6th and 7th editions for gastric cancer patients

BACKGROUND

The AJCC 7th edition changes the classification of T- and N-factors and the TNM stage of gastric cancer. We evaluated its prognostic impact.

METHODS

From December 1987 to December 2006, a total of 1,380 patients underwent curative surgery for gastric cancer at the Department of Surgery, Taipei Veterans General Hospital, with a retrieved lymph node number ≥ 15. Survival was compared for disease classified according to the AJCC 6th and 7th editions.

RESULTS

There is a significant difference in 5-year survival between T2 and T3 gastric cancer classified according to the AJCC 7th edition (75.2 vs. 54.9%, p < 0.001), as well as between N1 and N2 (71.4 vs. 44.1%, p < 0.001). Although patients with N3a had a better 5-year survival than did those with N3b (27.6 vs. 11.3%, p < 0.001), the N3 categories were combined and not applied in the TNM stage in the 7th edition. Multivariate analysis using Cox's proportional hazards model with a forward logistics regression stepwise procedure demonstrates that age, N category of 6th edition, and T and N categories of 7th edition are independent prognostic factors; however, T category of 6th edition is no longer significant. Furthermore, the discriminative power of survival difference between each TNM stage seems to be comparable between the 6th and 7th editions.

CONCLUSIONS

The AJCC 7th edition provides a more stratified survival difference in staging of gastric cancer. Future division of N3a and N3b in the classification of the TNM stage is recommended.

[The Comparison between 6th and 7th International Union Against Cancer/American Joint Committee on Cancer Classification for Survival Prognosis of Gastric Cancer]

BACKGROUND/AIMS

The tumor-node-metastasis (TNM) staging is an useful system to assess the prognosis of any solid cancer. As new TNM staging classification of 7th stomach cancer was revised in 2009, we evaluated the prognostic predictability of the 7th International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) TNM classification compared to 6th UICC/AJCC TNM classification in gastric cancer.

METHODS

From January 2000 to December 2009, 5-year survival rates of 266 patients with gastric cancer were calculated by the 6th and 7th UICC/AJCC TNM classification.

RESULTS

Using the 7th UICC/AJCC TNM classification, there was no significant difference in the 5-year cumulative survival rates (5 YSR) between stage IIA and IIB, IIB and IIIA, and IIIA and IIIB (70% vs. 71%, p=0.530; 71% vs. 80%, p=0.703; 80% vs. 75%, p=0.576, respectively) though significant differences of the survival rates were observed among stages of 6th edition. Using T stage of 7th edition, 5 YSR was not different between T2 and T3 (86% vs. 82%, p=0.655). Using N stage of 7th edition, 5 YSR were not different between N1 and N2, N3a and N3b (79% vs. 81%, p=0.506; 41% vs. 17%, p=0.895, respectively).

CONCLUSIONS

The 7th UICC/AJCC TNM classification had poor prognostic predictability in gastric cancer compared to the 6th edition.

Evaluation of the seventh edition of American Joint Committee on Cancer TNM staging system for gastric cancer: results from a Chinese monoinstitutional study

BACKGROUND

To investigate the validity of the 7th edition of American Joint Committee on Cancer (AJCC) TNM staging system for gastric cancer with special attention paid to pT2/pT3, pN1/pN2, and pN3a/pN3b category.

MATERIALS AND METHODS

Clinicopathologic data of 1998 patients underwent R0 surgery for histologically proven gastric cancers with >15 lymph nodes retrieved were retrospectively reviewed.

RESULTS

Prognoses were significantly different between pT2 and pT3 categories, between pN1 and pN2 categories, or between pN3a and pN3b categories. Each stage in the 6th edition was divided into the 7th edition stage with different survival rates. Moreover, stage IIIA, IIIB, and IIIC in the 7th edition system was divided into the 6th edition stage with different survival rates. Prognoses for patients in 7th edition T4aN1M0/T3N2M0/T2N3aM0, T4bN0-1M0/T4aN2M0/T3N3aM0, and T4aN3aM0/T4bN2M0 were similar to that of patients in T1N3bM0, T2N3bM0, and T3N3bM0, respectively, but significantly better than that of patients in T2N3bM0, T3N3bM0, and T4aN3bM0, respectively. However, no significant difference could be observed among patients in T4bN3aM0, T4aN3bM0, T4bN3bM0, and stage IV. A revised TNM system was proposed, in which T1N3bM0 was incorporated into stage IIIA, T2N3bM0 into stage IIIB, T3N3bM0 into stage IIIC, T4bN3aM0/T4aN3bM0/T4bN3bM0 into stage IV. Further analyses revealed the revised TNM system had better homogeneity, discriminatory ability, and monotonicity of gradients than the 6th and the 7th edition system.

CONCLUSIONS

It is reasonable to subclassify the 6th edition pT2 category and pN1 category into the 7th edition pT2/pT3 category and pN1/pN2 category, respectively. However, for better prognostic stratification, it might be more suitable for pN3a and pN3b categories to be considered individual determinants of the 7th edition TNM staging system.

Validation of the updated 7th edition AJCC TNM staging criteria for gastric adenocarcinoma

INTRODUCTION

The recently published 7th edition of the American Joint Committee on Cancer (AJCC) TNM staging criteria for gastric adenocarcinoma contains important revisions to T and N classifications, as well as overall stage grouping. Our goal was to validate the new staging system using a cancer registry.

METHODS

Retrospective review of gastric cancer patients from Surveillance, Epidemiology, and End Results (SEER) registry data (2004-2007). Patients were staged according to both 6th and 7th edition criteria, and 3-year disease-specific survival was compared.

RESULTS

Thirteen thousand five hundred forty-seven patients with gastric adenocarcinoma were identified with complete staging information. When using 7th edition criteria, there was an increase in the number of patients classified as stage III (23% vs. 13%), and a decrease in patients classified as stage IV (47% vs. 53%). Statistically significant differences in 3-year disease-specific survival were observed for all T and N categories and re-staging the same population according to the 7th edition criteria improved survival discrimination. Multivariate analysis revealed statistically significant differences in survival and linear progression of hazard ratios for each stage grouping.

CONCLUSIONS

The 7th edition AJCC staging criteria for gastric adenocarcinoma demonstrate better survival discrimination and risk stratification than previous criteria.

Is subdivision of pT2 tumors superior to lymph node metastasis for predicting survival of patients with gastric cancer? Review of 224 patients from four centers

BACKGROUND

The prognostic significance of the subclassification of pT2 tumors and the association of these categories with other clinicopathological factors in gastric cancer patients were investigated.

METHODS

A total of 224 patients with pT2 gastric cancer who had undergone curative gastrectomy and lymph node dissection were retrospectively analyzed. The prognostic role of the subclassification of pT2 tumors was evaluated by univariate and multivariate analysis.

RESULTS

Of 224 patients, 75 (33.5%) were classified as having pT2a tumors and 149 (66.5%) as having pT2b tumors. The prevalence of large-sized tumors (P < 0.003), lymph node involvement (P < 0.018), and lymphatic (P = 0.016), blood vessel (P = 0.001), and perineural invasion (P = 0.001) was significantly higher for pT2b tumors than for pT2a tumors. The rate of recurrence for pT2a cancers was significantly lower than that for pT2b cancers (P = 0.001).Median overall survival (OS) times and three-year OS of patients with a pT2b tumor were significantly worse than for patients with a pT2a tumor (P < 0.001).When patients were analyzed according to lymph node involvement, the prognosis of patients with pT2aN(1) cancers was significantly better than that of patients with pT2bN(1) (P < 0.001). Multivariate analysis indicated that the pT2 subdivision was an independent prognostic factor for OS (P = 0.006), as were pN stage, clinical stage, and recurrence.

CONCLUSION

Our results showed that subclassification of pT2 tumors into pT2a or pT2b was an important prognostic indicator for patients with pT2 gastric cancers who underwent curative gastrectomy. In the TNM staging system, subdivision of pT2 tumors should be undertaken routinely to detect gastric cancer patients who have a poor prognosis and to define patients more accurately in terms of their mortality after curative resection in accordance with the new 2010 AJCC TNM staging classification. This may also help as a guide to more appropriate therapy for tumors with subserosal invasion (old pT2b or new pT3).

Is the new seventh AJCC/UICC staging system appropriate for patients with gastric cancer?

BACKGROUND

The purpose of this study was to compare the clinical usefulness of the seventh Union Internationale Contre le Cancer/American Joint Committee on Cancer (AJCC/UICC) staging system vs the sixth AJCC/UICC staging system in patients with gastric cancer.

STUDY DESIGN

Included were 1,799 patients who underwent surgery for gastric cancer between January 2001 and June 2005 at the National Cancer Center (South Korea). For the sixth and seventh AJCC/UICC staging systems, survival outcomes stratified by stage, by T classification, and by N classification were summarized using Kaplan-Meier curves and compared statistically using a log rank test; survival differences were quantified using hazard ratios estimated from a Cox regression model. The 2 systems were compared in terms of prognostic performances using the linear trend chi-square test, likelihood ratio chi-square test, and Akaike information criterion (AIC) in the Cox regression analysis.

RESULTS

Significant survival differences between each stage were not found using the seventh staging system, especially for stages IB, IIA, and IIB (p = 0.14 and p = 0.11). The sixth staging system had higher linear trend chi-square score and likelihood ratio chi-square score, which means better discriminatory ability, monotonicity, and homogeneity, and had smaller AIC, which indicates better optimistic prognostic stratification, especially in the N classification. The modified staging system combining the T classification of the seventh AJCC/UICC system and the N classification of the sixth system showed better prognostic performance compared with each separate version (sixth or seventh) of the staging system.

CONCLUSIONS

The seventh AJCC/UICC staging system is not more clinically useful than the sixth system in surgically treated patients with gastric cancer because of an inappropriate N classification. A new TNM system is required with a different N classification.

Validation of seventh edition AJCC gastric cancer staging modifications

BACKGROUND AND OBJECTIVES

The seventh edition of the AJCC has more detailed staging categories for gastric cancer than does the sixth edition. The aim of our study was to compare the prognostic accuracies of the sixth and seventh AJCC editions for gastric cancer patients.

METHODS

We analyzed survival rates by category using the sixth and seventh editions of the AJCC in 10,060 patients with gastric cancer who had undergone gastrectomy between 1994 and 2007 at Samsung Medical Center.

RESULTS

Significant differences in prognosis were seen when comparing the new stages of the seventh edition of the AJCC that are subgroups of stages IB, II, IIIA, and IV in the sixth edition. In particular, stage IV of the AJCC sixth edition is divided into stages IIB, IIIA, IIIB, IIIC and IV in the seventh edition, and the 5-year survival rates of these respective stages were 80.2%, 45.3%, 23.5%, 17.2%, and 10.1% (P < 0.001).

CONCLUSIONS

Each category of the AJCC sixth edition has been divided into multiple stages in the AJCC seventh edition, each with a different prognosis. The newly divided subgroups from AJCC sixth edition stage IV showed more accurate outcome classification based on AJCC seventh edition staging stratification.

Validation of the new AJCC TNM staging system for gastric cancer in a large cohort of patients (n = 2,155): focus on the T category

BACKGROUND

The prognostic value of T subclassification in patients with gastric carcinoma has been just implemented in the new AJCC TNM staging system, which has reclassified T2a and T2b into T2 and T3 tumors, respectively. The aim of the present study was to validate the prognostic significance of the new T categorization within the frame of the latest TNM staging system.

METHODS

We retrospectively reviewed the records of 686 T2/T3 patients among 2155 subjects who underwent radical resection for gastric carcinoma at six Italian centers from 1988 through 2006.

RESULTS

Upon multivariate analysis, the new T categories, extent of lymph node dissection (D) and patient's age were retained by the survival model as independent prognostic factors. In particular, the death risk for patients with T3 tumors was higher than that of patients with T2 tumors (HR: 1.42, P = 0.005). Among the 686 patients previously classified as having T2 tumors, patients with T2 and T3 disease were 270 (39.4%) and 416 (60.6%), respectively. After a median follow-up of 55 months, the 5-year overall survival rates were 67.3% and 52.3% for patients with T2 and T3 tumors, respectively (P < 0.001). The survival advantage for the T2 as compared to T3 category was maintained even when N0 and N+ patients were separately considered (P = 0.0154 and P < 0.001, respectively).

CONCLUSIONS

Our data confirm the prognostic difference between the newly proposed T2 and T3 categories, which should be implemented in the routine clinical practice to improve risk stratification of patients with gastric cancer.

A novel insight of sentinel lymph node concept based on 1-3 positive nodes in patients with pT1-2 gastric cancer

Background

Sentinel node (SN) biopsy has been practiced in gastric cancer in recent years, and many studies focused on the distribution of solitary lymph node metastasis (SLM) to assess the pattern of SN. In fact, there is usually more than one SN existing in gastric cancer. The distribution of SNs needs to be further re-evaluated.

Methods

A total of 289 patients in pT1-2 stage with 1-3 positive nodes confined to same compartment were included in this study with informed consents. The primary lesion was solitary (≤ 5.0 cm in diameter) and D2 or D3 lymph node dissection had been performed. The location of metastatic lymph nodes was analyzed retrospectively.

Results

Most positive nodes occurred in N1 compartment, with frequency of 79.6% to 85.7% based on site of tumor. In the lower third of stomach, no. 6 was the most common metastatic site and no. 3 was the second; the order was reversed for SLM. With increasing depth of tumor invasion, a progressively augmented nodal involvement was shown. Nearly a half appeared transverse metastasis when the tumor located at the lesser or greater curvature. Among skip metastasis, no. 7, 8a, 9 and 11p were the most common metastatic sites and the prognosis was as similar as that of patients with N1 involved only.

Conclusions

The 1-3 positive nodes in the same compartment should be possible SNs, and most of which are restricted in N1 in pT1-2 gastric cancer. Transversal and 2 stations lymph node metastasis are common.

Validation of the seventh edition of the American Joint Committee on Cancer TNM staging system for gastric cancer

BACKGROUND

The seventh edition of the American Joint Committee on Cancer (AJCC) TNM classification for gastric cancer was published in 2010 and included major revisions. The aim of the current study was to evaluate the validity of the seventh edition TNM classification for gastric cancer based on an Asian population.

METHODS

A total of 2916 gastric cancer patients who underwent R0 surgical resection from 1989 through 2008 in a single institute were included, and were analyzed according to the seventh edition of the TNM classification for validation.

RESULTS

When adjusted using the seventh edition of the TNM classification, upstaging was observed in 771 patients (26.4%) and downstaging was observed in 178 patients (6.1%) compared with the sixth edition of the TNM classification. The relative risk (RR) of seventh edition pT classification was found to be increased with regular intensity compared with the sixth edition pT classification. The RR of seventh edition pN classification was found to be increased with irregular intensity compared with the sixth edition pN classification. In survival analysis, there were significant differences noted for each stage of disease, but only a marginal difference was demonstrated between stage IA and stage IB (P = .049). In the hybrid TNM classification, which combines the seventh edition pT classification and the sixth edition pN classification, both pT and pN classifications demonstrated a more ideal distribution of the RR, and 5-year survival rates also showed a significant difference for each stage (P <.01).

CONCLUSIONS

The seventh edition of the TNM classification was considered valid based on the results of the current study. However, the hybrid TNM classification, comprised of a combination of the seventh edition pT classification and sixth edition pN classification, should be considered for the next edition.

Comparison of the 6th and 7th editions of the UICC TNM staging system for gastric cancer: results of a Chinese single-institution study of 1,503 patients

AIM

To evaluate the prognostic efficacy of the 7th edition tumor-node-metastasis (TNM) classification compared with the 6th edition in gastric cancer patients.

METHODS

A total of 1,503 gastric cancer patients undergoing surgical resection were staged using the 6th and 7th edition staging systems. Homogeneity, discriminatory ability, and monotonicity of gradients of the two systems were compared using linear trend χ(2), likelihood ratio χ(2) statistics, and Akaike information criterion (AIC) calculations.

RESULTS

Significant differences in 5-year survival rates were observed for the T, N, and M subgroups using the 7th edition system, except for stage N2 and N3 patients in the 6th edition system. There were no significant differences in survival between IB and IIA in the 7th edition system. Patients with stage IV disease due to T4/N3 in the 6th edition system who were downstaged to stage III in the 7th edition system had significantly better survival than those who remained at stage IV. The 7th edition system had higher linear trend and likelihood ratio χ(2) scores, and smaller AIC values compared with those for the 6th edition, which represented the optimum prognostic stratification.

CONCLUSIONS

Our study suggests that the 7th edition system performs better than the 6th edition in several aspects.

Evaluation of the seventh American Joint Committee on Cancer/International Union Against Cancer Classification of gastric adenocarcinoma in comparison with the sixth classification

BACKGROUND

The seventh TNM staging system for gastric cancer of the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) had a more detailed classification than the sixth TNM staging system for both the tumor (T) and lymph nodes (N). The authors compared survival rates assessed by the seventh staging system with those by the sixth system.

METHODS

The authors analyzed the prospectively collected database on patients with gastric cancer who underwent surgery at Seoul National University Hospital between 1986 and 2006, and calculated the survival rates of 9998 cases with primary cancer, R0 resection, and >14 retrieved lymph nodes.

RESULTS

The 5-year cumulative survival rates (5YSR) according to the seventh edition T or N classifications were significantly different. The 5YSR according to seventh edition of the TNM staging system were 95.1% (stage IA), 88.4% (stage IB), 84.0% (stage IIA), 71.7% (stage IIB), 58.4% (stage IIIA), 41.3% (stage IIIB), and 26.1% (stage IIIC), which were significantly different from each other. The 5YSR of the seventh edition T2 and T3 classifications had significant differences in patients with every N classification, and the 5YSR of seventh edition N1 and N2 classifications had significant differences in T2 patients, T3 patients, and T4 patients. Each stage in the sixth edition was divided into the seventh edition stage with different survival rates. In addition, the number of homogenous groupings in seventh edition TNM stages was increased from 1 to 2.

CONCLUSIONS

The seventh system provided a more detailed classification of prognosis than the sixth system, especially between T2 and T3 tumors and N1 and N2 tumors, although further studies were found to be needed for the N3a and N3b classification.

[Gastric cancer screening and diagnosis]

Gastric cancer is the most common cancer in Korea and has overall survival rate of around 50%. Gastric cancer detected in early stage can be cured by endoscopic resection or less invasive surgical treatment and the subsequent prognosis is excellent. National cancer screening program for gastric cancer has been available for several years. The evaluation for efficacy of our screening strategy is strongly needed in terms of mortality reduction and cost-effectiveness. Accurate diagnosis and staging evaluation is important for proper management and prediction of a patients prognosis. It is recommended to understand the advantages and limitations of currently available guidelines and diagnostic modalities. The 7th edition of gastric cancer staging system from AJCC may have significant effect on our knowledge and patient management.

A novel subclassification of pT2 gastric cancers according to the depth of muscularis propria invasion: superficial muscularis propria versus deep muscularis propria/subserosa

PURPOSE

To propose a novel subclassification of pT2 gastric cancers according to the depth of muscularis propria (MP) invasion (superficial MP vs. deep MP/subserosa [SS]) and to investigate its impact in prognostic assessment.

SUMMARY BACKGROUND DATA

The major change in the sixth edition of the International Union Against Cancer (UICC)/American Joint Committee on Cancer (AJCC) TNM classification concerned the pT (primary tumor) category. Specifically, pT2 lesions were divided into pT2a (invading the MP) and pT2b (invading the SS) to discriminate these intramural locations. However, the value of the modification is still debated.

METHODS

One thousand two hundred fifty-six patients with pT2 cancers classified according to the UICC/AJCC pT staging system were reviewed. Among them, 214 (17.0%) were classified as invasion of the superficial MP (sMP) or inner circular muscle, 163 (13.0%) as invasion of the deep MP (dMP) or outer longitudinal muscle, and 879 (70.0%) as invasion of SS. Clinicopathologic features were compared between patients with sMP, dMP, and SS invasion. Overall survival rates were compared between the pT2a and pT2b stage cancers, according to the UICC/AJCC and the novel pT2 system. Two-step multivariate analysis was performed to identify the significantly important prognostic factors.

RESULTS

There was significant difference in most of the clinicopathologic features between sMP and SS cancers. Although, only 5 factors (tumor location, tumor size, Borrmann type, metastasis number, and metastasis ratio) were significantly different between dMP and SS cancers. In step 1 of the multivariate analysis, the UICC/AJCC pT2 system was an independent factor that correlated with prognosis, but was substituted by the novel pT2 system in step 2 of the multivariate analysis. With a certain metastasis ratio of lymph nodes, the novel pT2 system discriminated 2 subsets of patients with significantly different prognoses, whereas the UICC/AJCC pT2 system did not.

CONCLUSIONS

The novel pT2 staging system, which was subclassified as sMP and dMP/SS cancers, had more potential to identify the different prognoses for patients with pT2 gastric cancers.

Prognostic value of subclassification of T2 tumours in patients with gastric cancer

BACKGROUND

This study was designed to evaluate the prognostic value of tumour stage T2 subcategorization (T2a and T2b) in patients with gastric carcinoma.

METHODS

Clinicopathological details of a prospective series of patients who had radical resection of gastric adenocarcinoma in a single institution were analysed. Univariable and multivariable survival analyses were performed with the log rank test and Cox's model respectively.

RESULTS

Of 373 evaluable patients, 49 (13.1 per cent) had a T2a and 143 (38.3 per cent) a T2b tumour. At a median follow-up of 35.5 months, the 5-year overall survival rate was 73 and 31.1 per cent for patients with T2a and T2b lesions respectively (P < 0.001). On multivariable analysis, T stage remained an independent prognostic factor. Compared with T1a, the mortality risk for patients with T1b (hazard ratio (HR) 1.00; P = 0.992) and T2a (HR 0.97; P = 0.916) tumours was similar; by contrast, the risk of death associated with T2b (HR 1.81; P = 0.031) and T3 (HR 1.89; P = 0.038) lesions was significantly greater than for T1a tumours.

CONCLUSION

Subclassification of T2 tumours should be undertaken routinely in order to stratify patients with gastric cancer more accurately in terms of their mortality risk.

Clinicopathological Variables Associated with Lymph Node Metastasis and Prognostic Factors in pT2 Gastric Cancer

This retrospective study investigated the clinicopathological variables associated with lymph node metastasis and prognosis in 325 patients with pT2 gastric cancer in order to set out a foundation for the surgical management of this condition. Univariate and multivariate analyses identified factors that were predictive of lymph node metastasis. Cox regression analysis evaluated the effect of prognostic factors on survival. Tumour location, maximum tumour diameter, lymphatic invasion and total retrieved lymph nodes (tLN) were revealed as independent factors for lymph node metastasis in pT2a gastric cancer, whereas histological type, lymphatic invasion and tLN were associated with lymph node metastasis in patients with pT2b gastric cancer. Maximum tumour diameter, lymphatic invasion and metastatic lymph node (mLN) ratio, but not tLN, were independent prognostic factors in pT2a cancer. Maximum tumour diameter and mLN ratio, but not tLN, were independent prognostic factors in pT2b cancer. Overall, it is concluded that maximum tumour diameter and mLN ratio are important prognostic factors in pT2 gastric cancer.

Laparoscopy-assisted distal gastrectomy with D2 lymphadenectomy for T2b advanced gastric cancers: three years' experience

BACKGROUND

The application of laparoscopy-assisted distal gastrectomy (LADG) with advanced gastric cancer (AGC) is a controversial. The purpose of this study was to assess the possibility of using LADG application to AGC.

METHODS

Of 160 patients who underwent LADG with D2 lymphadenectomy between April 2004 and March 2007, 26 patients with stage pT2b were selected and compared to 25 patients of the same stage who underwent open distal gastrectomy (ODG) within same period. The comparison was based on the clinicopathologic characteristics, surgical outcome, and follow-up results.

RESULTS

There was no significant difference between LADG and ODG groups in most operation results including complication rates (15.4% vs. 16.0%, P = 1.000) except for less average loss of blood (160.0 ml vs. 215.0 ml, P = 0.012) and longer average operating time (255.0 min vs. 190.0 min, P < 0.001) in LADG. Three-year overall survival rates (88.2% vs. 77.2%; P = 0.246) and disease-free survival rates (71.4% vs. 53.4%; P = 0.757) were not significantly different in LADG and ODG groups.

CONCLUSIONS

The early results of current study suggest that LADG for AGC is technically safe and oncologically feasible. Therefore, LADG should be considered as a curative treatment for AGC not exposed to serosa.

Prognostic role of lymphatic vessel invasion in early gastric cancer: a retrospective study of 188 cases

BACKGROUND

Lymphatic vessel invasion is an important prognostic factor for the gastric cancer without lymph node metastasis. However, the studies on early gastric cancers is still sparse. Therefore, we carried out this study to determine clinicopathological and surgical prognostic factors, especially lymphatic vessel invasion, for early gastric cancers.

METHODS

Clinicopathological characteristics and prognostic outcomes of 188 patients who received a gastrectomy for early gastric cancer between 1980 and 2000 were retrospectively evaluated based on the subclassification of pN category. A multivariate analysis was performed by using the Cox regression model, where lymphatic vessel invasion and other potential prognostic factors were included.

RESULTS

Of the 188 patients, 158 had T1N0M0 and 30 T1N1M0 cancers. In patients with T1N0M0 cancers, the survival rate was significantly lower in those with lymphatic vessel invasion than in those without (chi(2)=4.025, P=0.045). However, in patients with T1N1M0 cancers, the survival rates were not significantly different between those with and those without lymphatic vessel invasion (chi(2)=0.253, P=0.615). The multivariate analysis identified that age (P=0.033) and lymph node metastasis (P=0.019) were independent prognostic factors for all early gastric cancers. However, age (P=0.042), tumor location (P=0.032), and lymphatic vessel invasion (P=0.010) were the independent prognostic factors for T1N0M0 cancers.

CONCLUSIONS

Lymphatic vessel invasion was an independent prognostic factor for T1N0M0 early gastric cancers, and thus may be a potential prominent factor that should be considered to be included in the category of lymphoid metastasis (both lymph node metastasis and lymphatic vessel invasion) in patients with early gastric cancer.

Impact of total retrieved lymph nodes on staging and survival of patients with gastric cancer invading the subserosa

PURPOSE

To investigate the impact of total retrieved lymph nodes (tLNs) on staging and survival in patients with pT2b gastric cancer according to the nodal status.

METHODS

Clinicopathological characteristics and prognostic outcomes of 392 patients with pT2b gastric cancer between 1980 and 2005 were retrospectively investigated based on the nodal status.

RESULTS

The number of metastatic lymph nodes (mLNs) was highly correlated with the number of tLNs (P<0.001). The overall 5-year and 10-year survival rates were 39.0% (153/392) and 17.9% (70/392), respectively. The survival rates in patients with pN0 cancers did not differ significantly from that in patients with pN1 cancer when the tLNs were 25 or less. However, the survival rate in patients with N0 cancers was significantly greater than that in patients with pN1 cancers when the tLNs were more than 25 (64.3% vs. 36.9%, chi(2)=4.339, P=0.037). Moreover, both 5- and 10-year survival rates differed significantly among patients with pN1, pN2 and pN3 gastric cancer regardless of tLNs. Multivariate analysis revealed that age, tumor focus number, tumor location, and mLN, but not tLNs, were independent prognostic predictors in patients with pT2b gastric cancer.

CONCLUSIONS

To improve the accuracy of staging, no less than 15 tLNs should be pathologically examined in patients with pN1-3, and 25 tLNs for the patients with N0. More tLNs may not be associated with a better prognosis in pT2b disease because the extent of lymph node dissection is pre-defined for the operation.

Prognostic significance of subclassification of pT2 gastric cancer: a retrospective study of 847 patients

PURPOSE

To investigate the prognostic significance of subclassification of pT2 gastric cancers according to the nodal status.

METHODS

Clinicopathological characteristics and prognostic outcomes of 847 gastric cancer patients who received a gastrectomy between 1985 and 2003 were retrospectively evaluated based on the subclassification of pT2 stage (i.e. pT2a and pT2b).

RESULTS

Of the patients, 244 and 603 had pT2a and pT2b stage cancers, respectively. Patients with pT2a cancers had a significantly longer disease-specific 5-year survival rate than those with pT2b cancers (P<0.001). The prognosis was significantly better in patients with pT2a cancers than in patients with pT2b cancers at pN0, pN1 and pN2 (P=0.036, 0.021, and 0.019 respectively), but not pN3 stages (P=0.775). Multivariate analysis identified age, tumor location, pT stages, pN stages, and adjuvant chemotherapy as independent prognostic factors for pT2 gastric cancers. The survival rates were similar between pT2aN1 (stage II) and pT2bN0 (stage IB) cancers (P=0.604), and between pT2aN2 (stage IIIA) and pT2bN1 (stage II) cancers (P=0.936).

CONCLUSIONS

Subclassification of pT2 gastric cancers into pT2a or pT2b is of prominent prognostic significance, and thus it is recommended that the current stage grouping conventions include subclassification of pT2, in order to more accurately predict the prognosis of patients.

Tumor diameter as a prognostic factor in patients with gastric cancer

BACKGROUND

The aim of this study was to evaluate the prognostic value of tumor diameter in gastric cancer.

METHODS

The study group comprised a series of 1215 patients who underwent curative gastrectomy. The appropriate tumor diameter cutoff value was determined. Prognostic factors were evaluated by univariate and multivariate analyses.

RESULTS

The tumor diameter cutoff value was 100 mm. Multivariate analysis showed that tumor site, macroscopic appearance, tumor diameter, depth of invasion, and presence of lymph node metastasis independently affected prognosis in all patients. Multivariate analysis of patients with larger tumors identified depth of invasion as an independent prognostic factor. A comparison between patients with smaller and larger tumors showed marked differences in the survival of those with stage II, IIIA, and IIIB tumors. A comparison of clinicopathological factors between stage II and III patients revealed that tumors occupying the entire stomach, ill-defined, undifferentiated, and serosa-penetrating tumors, and peritoneal metastases were far more frequent in patients with larger tumors.

CONCLUSIONS

Tumor diameter in gastric cancer is a reliable prognostic factor that might be a candidate for use in the staging system. To improve outcomes for patients with tumors >/=100 mm in diameter, it is necessary to establish therapeutic strategies for peritoneal metastasis, particularly in stage II and III tumors.