Prognostic factors of gastric cancer tumours of less than 2 cm in diameter: rationale for limited surgery

Significance of nodal dissection and nodal positivity in gastric cancer

Lymphadenectomy is a central component of surgery for gastric cancer. However, controversies over the optimal extent of lymphadenectomy in gastric cancer surgery have persisted for several decades. In Eastern countries where the incidence of gastric cancer is high, surgeons have performed extensive lymphadenectomy (D2 lymphadenectomy) with low morbidity and mortality, while most Western surgeons have advocated for more limited lymphadenectomies according to the results of Dutch trial and MRC trial. Initially, these trials had failed to show survival benefit of D2 procedure and instead, found pancreaticosplenectomy performed as part of the D2 procedure associated with high incidence of morbidity and mortality. Subsequently, superiority of D2 lymphadenectomy on survival was demonstrated based on updated results. Moreover, spleen and pancreas preserving D2 lymphadenectomy are being performed safely in Western countries. Today, there is an international consensus on performing D2 lymphadenectomy as the standard procedure for advanced gastric cancer and is widely accepted as the standard procedure for gastric cancer surgery. The significance of the extent of lymphadenectomy is intimately associated with the prognostic importance of nodal metastases as the most powerful indicator of recurrence and survival for patients after curative gastrectomy. Maruyama computer program could be used to estimate the risk of lymph node metastasis in each nodal station. The Maruyama Index could be used to assess the adequacy of lymphadenectomy in gastric cancer. Positive lymph node ratio is calculated as the ratio of positive lymph nodes to all harvested lymph nodes, which might be a more precise predictor of prognosis than the absolute number of positive lymph nodes. While D2 lymphadenectomy enables the accurate staging of the disease, reduces the incidence of locoregional recurrences and thus contribute to an improved overall survival; performing lymphadenectomy beyond D2 is unlikely to improve survival. Therapeutic D2+ lymphadenectomy for advanced gastric cancer requires further evaluations, especially for patients receiving neo-adjuvant or conversion treatments.

Is adjuvant chemotherapy necessary in pT1N1 gastric cancer?

Background

Due to a lack of consensus on adjuvant treatments for pT1N1 gastric cancer, surgeons face a dilemma when deciding treatments for patients with pT1N1 gastric cancer after gastrectomy. The objective of this study was to determine survival benefits of adjuvant chemotherapy and risk factors for tumor recurrence in gastric cancer patients with pT1N1.

Methods

Between 1996 and 2010, 510 patients who underwent curative resection for pT1N1 gastric cancer at three institutes were divided into two groups: adjuvant chemotherapy group (N = 150) and surgery-only group (N = 360). Disease-free survival rates and risk factors for tumor recurrence were analyzed.

Results

During the median follow-up of 78 months, 7.5% of patients experienced tumor recurrence (7.3% in adjuvant chemotherapy group and 7.5% in surgery-only group). The 5-year disease-free survival rate was 91.8% in the adjuvant chemotherapy group and 94.6% in the surgery-only group without significant difference between the two. In univariate analysis, older age (>65 years), male gender, body mass index <25 kg/m², elevated gross type, and differentiated histology were associated with tumor recurrence. Multivariate analysis showed that advanced age and male gender were independent risk factors for tumor recurrence. In addition, adjuvant chemotherapy showed no benefitial effect on tumor recurrence in pT1N1 gastric cancer.

Conclusions

Adjuvant chemotherapy did not show any oncologically benefitial effect on tumor recurrence, it might be unnecessary for pT1N1 gastric cancer after curative surgery.

Prognostic value of tumor size in gastric cancer: an analysis of 2,379 patients

Tumor size has been included into the staging systems of many solid tumors, such as lung and breast. However, tumor size is not integrated in the staging of gastric cancer, and its prognostic value for gastric cancer needs to be reappraised. A total of 2,379 patients who received radical resection for histopathologically confirmed gastric adenocarcinoma were enrolled in the present study. Tumor size, originally presented as continuous variable, was categorized into small gastric cancer (SGC) group and large gastric cancer (LGC) group using an optimal cutoff point determined by Cox proportional hazards model. The associations between tumor size and other clinicopathological factors were checked using Chi-square test. Survival of gastric cancer patients was estimated by using univariate Kaplan-Meier method, and the survival difference was checked by using the log-rank test. The significant clinicopathological factors were included into the Cox proportional hazards model to determine the independent prognostic factors, and their hazard ratios were calculated. With the optimal cutoff point of 4 cm, tumor size was categorized into SGC group (≤ 4 cm) and LGC group (>4 cm). Tumor size closely correlated with age, tumor location, macroscopic type, Lauren classification, and lymphatic vessel invasion. Moreover, tumor size was also significantly associated with depth of tumor invasion and status of regional lymph nodes. The 5-year survival rate was 68.7 % for SGC group which was much higher than 40.2 % for LGC group. Univariate analysis showed that SGC had a better survival than LGC, mainly for patients with IIA, IIB, and IIIA stage. Multivariate analysis revealed that tumor size as well as age, tumor location, macroscopic type, Lauren classification, lymphatic vessel invasion, depth of tumor invasion, and status of regional lymph nodes were independent prognostic factors for gastric cancer. Tumor size is a reliable prognostic factor for patients with gastric cancer, and the measurement of tumor size would be helpful to the staging and management of gastric cancer.

Poor prognostic factors in patients with stage I gastric cancer according to the seventh edition TNM classification: a comparative analysis of three subgroups

BACKGROUND AND OBJECTIVES

The purpose of this study was to investigate the prognosis of stage I gastric cancer and to compare clinicopathologic characteristics by subgroup.

METHODS

Between January 2000 and December 2006, 384 patients with gastric cancer were reclassified as stage I according to the seventh edition classification. A comparative analysis was performed between three subgroups. Univariate and multivariate analyses were conducted.

RESULTS

The 5-year overall survival rates in T1N0, T1N1, and T2N0 were 98.8%, 94.1%, 91.1%, respectively (P = 0.009). In patients with T2N0 gastric cancer, tumors in the upper third and larger tumors were more common than in patients with T1N0 and T1N1 gastric cancer (P < 0.001). In patients with T1N1 and T2N0 gastric cancer, the presence of lymphatic and/or blood vessel invasion (LBVI) and perineural invasion (PNI) were more common than in patients with T1N0 gastric cancer (P < 0.001). Univariate analysis showed tumor stage, depth of invasion, LBVI, and PNI were significant prognostic factors. However, multivariate analysis demonstrated that only tumor stage, LBVI, and PNI were significant variables.

CONCLUSIONS

Survival data support the accuracy of new TNM classification for stage I gastric cancer. Tumor stage, the presence of LBVI and PNI are important independent prognostic factors in stage I gastric cancer.

Impact of lymphovascular invasion in patients with stage I gastric cancer

BACKGROUND

Patients with stage I gastric cancer often suffer from tumor recurrence despite a generally favorable operative outcome. It is therefore important to determine the prognostic factors in order to improve such outcomes.

METHODS

Between April 1985 and March 2000, a total of 1,880 patients with histologically proven stage I gastric cancer were included in this study. Operative outcomes (survival time, prognostic factors, pattern of recurrence) were evaluated in these patients.

RESULTS

Multivariate analysis in patients with all stage I gastric cancer revealed that depth of invasion, lymph node metastasis, and lymphovascular invasion independently influenced prognosis. Moreover, advanced age was selected as an independent prognostic factor in patients with stage IA, and lymphovascular invasion in patients with stage IB gastric cancer by multivariate analyses. The 5-year survival rates in stage T1N1 patients with moderate to severe lymphovascular invasion, T2N0 with moderate to severe lymphovascular invasion, and II were 95.1%, 83.5%, and 76.9%, respectively. There was a significant difference in survival time between stage T1N1 and II (P = .0189) but not between stage T1N1 and T2N0 or stage T2N0 and II.

CONCLUSION

T2N0 gastric cancer patients with moderate to severe lymphovascular invasion may be suitable candidates for adjuvant chemotherapy.

Comparison of colorectal and gastric cancer: survival and prognostic factors

BACKGROUND/AIMS

Gastric and colorectal cancers are the most common gastrointestinal malignancies in Iran. We aim to compare the survival rates and prognostic factors between these two cancers.

METHODS

We studied 1873 patients with either gastric or colorectal cancer who were registered in one referral cancer registry center in Tehran, Iran. All patients were followed from their time of diagnosis until December 2006 (as failure time). Survival curves were calculated according to the Kaplan-Meier Method and compared by the Log-rank test. Multivariate analysis of prognostic factors was carried out using the Cox proportional hazard model.

RESULTS

Of 1873 patients, there were 746 with gastric cancer and 1138 with colorectal cancer. According to the Kaplan-Meier method 1, 3, 5, and 7-year survival rates were 71.2, 37.8, 25.3, and 19.5%, respectively, in gastric cancer patients and 91.1, 73.1, 61, and 54.9%, respectively, in patients with colorectal cancer. Also, univariate analysis showed that age at diagnosis, sex, grade of tumor, and distant metastasis were of prognostic significance in both cancers (P < 0.0001). However, in multivariate analysis, only distant metastasis in colorectal cancer and age at diagnosis, grade of tumor, and distant metastasis in colorectal cancer were identified as independent prognostic factors influencing survival.

CONCLUSIONS

According to our findings, survival is significantly related to histological differentiation of tumor and distant metastasis in colorectal cancer patients and only to distant metastasis in gastric cancer patients.

Current status of minimal access surgery for gastric cancer

BACKGROUND

The aim was to conduct a systematic review of the literature on the subject of laparoscopic gastrectomy (LG) and determine the relative merits of laparoscopic (LG) and open gastrectomy (OG) for gastric carcinoma.

MATERIAL AND METHODS

A search of the Medline, Embase, Science Citation Index, Current Contents and PubMed databases identified individual retrospective and prospective series on LG (proximal, distal and total). Furthermore, all clinical trials that compared LG and OG published in the English language between January 1990 and the end of December 2006 were also identified. A large number of outcome variables were analysed for individual series and comparative trials between LG and OG and results discussed and tabulated.

RESULTS

The majority of the literature is published from Japan showing both oncological adequacy and safety of LG. The majority of early series and comparative studies have utilized laparoscopic resection for early and distal gastric cancer. However, with increasing advanced laparoscopic experience, advancement in digital technology and improvement in instrumentation, more advanced gastric cancers and more extensive procedures such as laparoscopic-assisted total gastrectomy and laparoscopy-assisted D2 dissection are becoming more common. To date lymph node harvesting, resection margins and complication rates seem to be equivalent to open procedures. Furthermore, the earlier fears of port-site metastases have not been borne out.

CONCLUSIONS

The available data suggests that LG seems to be associated with quicker return of gastrointestinal function, faster ambulation, earlier discharge from hospital, and comparable complications and recurrence rate to OG. However, the operating time for LG remains significantly longer compared to its open counterpart, although with experience it is achieving parity with OG. However, the majority of the comparative trials (if not all) probably do not have the power to detect differences in the outcome. As far as the RCT's (LG vs. OG) are concerned, the numbers of patients in such trials are small and the majority of patients were operated upon for early distal gastric cancer and, therefore, any meaningful conclusions regarding the advantages or disadvantages of LG for both the ECGs and extensive and advanced gastric tumours are difficult to justify.

Minimally invasive treatment for gastric cancer: approaches and selection process

Minimally invasive treatment of gastric cancer has emerged as a result of the technical advances, better understanding of gastric physiology, and more knowledge of the biologic behavior of gastric cancer. This treatment results in improved quality of life embodied by smaller incisions, reduced length of hospital stay, and a faster return to productive life. However, minimally invasive treatment for gastric cancer must take into consideration the potential effects of these techniques on tumor dissemination at the time of the treatment procedure, as well as the rates of recurrence and overall survival. Several technical treatment approaches to gastric cancer have now become possible, utilizing endoscopy, laparoscopy, or an open method. Endoscopic mucosal resection (EMR), limited resection, and laparoscopic surgical resection are the currently practiced modalities as the minimally invasive treatment. Lymph node dissection with the minimally invasive techniques is a barrier to its wide application. Although it is not commonly performed in Western countries, the use of minimally invasive treatment for gastric cancer is growing, especially in Korea and Japan. Minimally invasive treatment for early gastric cancer (EGC) has already been shown to be safe and effective in many retrospective series though no prospective randomized studies comparing it to open resection have been performed. Therefore, routine implementation of these procedures must await confirmatory outcomes generated by well-done randomized prospective clinical trials.

Expressão da proteína P53 no adenocarcinoma gástrico: correlação clínica, anatomopatológica e significância prognostica

OBJETIVO: Avaliar a expressão da proteína p53 no adenocarcinoma gástrico e correlacioná-la com variáveis clínicas e anatomopatológicas, tais como: idade, sexo, infiltração da parede gástrica (T), tipo histológico (Laurén), grau de diferenciação histológica, comprometimento linfonodal, estadiamento (TNM) e sobrevida. MÉTODO: Foram analisados os registros médicos e reestudadas as lâminas de peças cirúrgicas de 45 doentes com adenocarcinomas gástricos submetidos à gastrectomia parcial e total no Serviço de Cirurgia Oncológica da Santa Casa de Misericórdia de Maceió-AL e no Hospital Universitário da Universidade Federal de Alagoas, no período de 1991 a 2002. A expressão da proteína p53 foi avaliada pelo método imunohistoquímico com o anticorpo monoclonal DO-7 e comparada com idade, sexo, infiltração na parede gástrica, tipo histológico, grau de diferenciação, comprometimento linfonodal, estadiamento e sobrevida. RESULTADOS: Dos 45 doentes, 27 eram do sexo masculino (60%). A média das idades foi 53,9 anos (26 - 75 anos), e mediana de 57 anos. Em 40 doentes (88,9%) o tumor foi classificado como bem diferenciado. Quanto à infiltração na parede gástrica, em 28 doentes (62,2%) foram classificados como profundos. Em 25 doentes (55,6%) não havia comprometimento linfonodal. O estudo histológico revelou que 29 doentes (64,4%) apresentavam tumores classificados como tipo intestinal de Laurén. O estadiamento TNM demonstrou que 33 (73,3%) doentes apresentavam tumores avançados. Quanto à expressão da p53, 18 doentes (40%) foram considerados positivos. O tempo médio de seguimento foi de 1020,4 dias (63 - 3920 dias) e mediana de 798 dias. Trinta e um (68,9%) doentes evoluíram para óbito. As variáveis: idade, estadiamento, comprometimento linfonodal e infiltração do tumor na parede gástrica, foram fatores prognósticos relacionados à sobrevida com significado estatístico (p<0,05). Não houve correlação estatística significativa da proteína p53 com as variáveis estudadas. A análise estatística multivariada identificou apenas o comprometimento linfonodal como fator prognóstico independente. CONCLUSÕES: Os autores concluíram que dezoito (40%) dos doentes expressaram a reação imunohistoquímica para p53. Não houve correlação estatística significativa da expressão da proteína p53 com os fatores prognósticos estudados. A expressão da proteína p53 não foi fator prognóstico independente.

Treatment strategy of limited surgery in the treatment guidelines for gastric cancer in Japan

Surgical practice for gastric cancer in Japan is based on the Gastric Cancer Treatment Guidelines issued in 2001 by the Japanese Gastric Cancer Association. These recommendations list options for treatment of each stage of cancer, with clear distinctions between interventions recommended for routine use and those that should be confined to trial settings until further evidence for their curative potential becomes available. In this review, we discuss standard surgery, local resection, segmental resection, and pylorus-preserving gastrectomy (PPG) as examples of limited resection and describe in detail the indications for limited lymph-node dissection in cases of early-stage gastric cancer. At present, evidence does not support the conclusion that limited surgery is effective for local resection or for improving quality of life. Thus, use of limited surgery should be considered an experimental approach both in Japan and the West. We conclude that surgeons who are familiar with the criteria for selecting surgical procedures should decide on a case-by-case basis which technique is most appropriate. Choices should be made with consideration of the stage of the cancer, invasiveness of the surgical procedure, and the patient's history. For all procedures, the patient must give informed consent and the surgeons must accurately assess the success of the operation after surgery.

Early and late recurrences after gastrectomy for gastric cancer: a multiple logistic regression analysis

PURPOSE

Although many studies have focused on clinical risk factors for prognosis of patients with surgically treated gastric cancer, little information is available regarding the timing of recurrent malignant disease. The purpose of this study was to determine the factors that are predictive of early and late recurrences after gastrectomy.

PATIENTS AND METHODS

We reviewed the hospital records of patients with hisotological proof of gastric cancer who were admitted to Sendai National Hospital during the period from 1985 to 1995. A total of 923 records were examined, and 251 patients with recurrent disease were identified. The patients were divided into an "early recurrence group" consisting of 195 patients (died within one year after surgery) and a "late recurrence group" of 56 patients (died two years or more after surgery). Clinicopathological characteristics were examined, and independent risk factors influencing the timing of recurrence were determined by a multiple logistic regression analysis.

RESULTS

The mean tumor size of early recurrence cases was larger than that of late recurrence cases (p=0.0294). Tumors penetrating the serosa with direct invasion to continuous structures were found more frequently in the early recurrence group than in the late recurrence group. The patients with early recurrence showed a higher tendency to have nodal involvement, lymphatic invasion and vascular invasion. The relative risks of early and late recurrences associated with different variables were estimated by a multiple logistic regression method. The following variables were found to be significant risk factors for early recurrence: male gender (p=0.0382), lymph node metastasis (p=0.0016), and vascular invasion (p=0.0006).

CONCLUSION

Male patients who have node-positive gastric cancer with vascular invasion have a high risk of early recurrence.