The pre-operative assessment of advanced gastric cancer by computed tomography

Can serum interleukin-2 receptor alpha predict lymph node metastasis in early gastric cancer?

Purpose

Although local resection like endoscopic mucosal resection for early gastric cancer is accepted as a treatment option, one of the most important drawbacks of such an approach is the inability to predictlymph node metastasis. The aim of this study was to evaluate the serum soluble receptor alpha for interleukin-2 (IL-2Rα) level as a predictor of lymph node metastasis in the patients with early gastric cancer.

Methods

Assessment of pre-operative serum IL-2Rα levels was performed on 86 patients with early gastric cancer treated by gastrectomies combined with D2 lymph node resections and 20 healthy controls at Samsung Medical Center. Data on patient age and gender, tumor size, depth of invasion, histologic differentiation, and endoscopic findings were reviewed post-operatively. The submucosal lesions were divided into three layers (sm1, sm2, and sm3) in accordance with the depth of invasion.

Results

Lymph node metastasis was observed in 16 patients (18.6%). Statistically, the serum IL-2Rα level was an important predictive factor of lymph node metastasis in undifferentiated gastric cancer, and the cut-off point for the predictive value of serum IL-2Rα level was 200 U/mL.

Conclusion

The serum IL-2Rα level might be a good predictor of lymph node metastasis in undifferentiated early gastric cancer.

Gastric Adenocarcinoma: Is Computed Tomography (CT) Useful in Preoperative Staging?

BACKGROUND AND PURPOSE

Although multiple studies testing the accuracy of CT in the preoperative staging of gastric adenocarcinoma have been carried out, their results are controversial. Whilst some authors claim that CT is an accurate method for preoperatively staging gastric cancer, others have advocated the contrary. Because of this discrepancy we have retrospectively reviewed preoperative CT findings compared with histopathological results in patients with gastric adenocarcinoma.

PATIENTS AND METHODS

Seventy-two patients diagnosed with gastric cancer who underwent potentially curative surgery and preoperative staging CT of quality were included in the study. The size, gastric wall thickening, presence of lymphadenopathy, adjacent organ invasion and location of the gastric mass was recorded. Early tumors (T1 and T2) and more advanced tumors (T3 and T4) were grouped together. CT staging was correlated with the final histopathological stage (TNM). The global results were expressed as sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

Seventy-two cases were included with fifty-five being male and a median age of 67 years (range 33-91). CT correctly identified the location of the tumor in 56 (53% antropyloric, 18% subcardial). Median time from CT scan to surgery was fourteen days (range 2-49). In T detection: T1/T2 and T3/T4 with sensitivity of 70% and 61%. Lymph node involvement: Sensitivity 49%. Overstaged in 47% Understaged in 75%. Specificity of 53%. Nine patients with colon-mesocolon (5 patients) and pancreas (4 patients) invasion. Sensitivity 44% and specificity 96%.

CONCLUSION

Spiral CT is not an accurate method in predicting preoperative stages in gastric cancer.

Value of nonvisualized primary lesions of gastric cancer on preoperative MDCT

OBJECTIVE

The purpose of this study was to retrospectively determine the value of nonvisualized primary lesions on preoperative MDCT of patients with gastric cancer.

MATERIALS AND METHODS

The records of patients who had undergone radical gastrectomy for gastric cancer between August 2004 and August 2006 were retrospectively reviewed. Each patient was given 500-1,000 mL of water to drink, and 16-MDCT for preoperative staging was performed with i.v. contrast agents. Transverse and coronal reconstructed images had been prospectively interpreted as a part of daily practice. TNM stage, gross and histologic types, and location and size of the lesions were retrospectively analyzed for patients with primary lesions not visualized on preoperative MDCT.

RESULTS

In 44 patients with nonvisualized primary lesions, most (98%) of the lesions were stage pT1 confined to the mucosa (n = 27) or involving the submucosal layer (n = 16). Only one (2%) of the lesions had regional lymph node metastasis (pN1). Most (64%) of the lesions were located in the lower third of the stomach. Forty-one early gastric cancer lesions were flat, depressed, or excavated, and only two were elevated. Depending on the depth of invasion (mucosa or submucosa), there were no statistical differences (p > 0.05) in size, location, and gross or histologic type.

CONCLUSION

Almost all primary lesions of gastric cancer not visualized on preoperative MDCT with an optimized imaging protocol are early gastric cancer without regional lymph node metastasis. This negative finding may be helpful in planning minimally invasive management of gastric cancer.

Accuracy of endoscopic ultrasound staging of gastric cancer in routine clinical practice in Singapore

OBJECTIVE

Endoscopic ultrasound has emerged as the leading modality to assess the T and N stage in gastric cancer. This study aimed to assess the accuracy of TN staging by endoscopic ultrasound in routine clinical practice in Singapore.

METHODS

Over a period of 7 years, 77 patients (male: 70%; median age 62.8 years) with gastric cancer underwent preoperative staging with endoscopic ultrasound. Fifty-seven patients eventually underwent surgery with tissues available for histopathological staging and comparison.

RESULTS

The tumor locations were: cardia: 13; corpus: 20; incisura: 19; antrum: 25. The majority was poorly differentiated (57.1%); 26% were moderately differentiated and 16.9% were well differentiated adenocarcinoma. Compared to pathological staging, the overall accuracy of T staging by endoscopic ultrasound was 77.2% (17.5% under-staged: 5.3% over-staged). The staging accuracy of T1 (92.9%) and T3 (81.8%) was higher than T2 (57.1%) and T4. For N staging, the accuracy of endoscopic ultrasound was 59.6% (26.3% under-staged; 14% over-staged); this was significantly superior to computer tomography (43.9%).

CONCLUSION

Endoscopic ultrasound is useful for the T staging of gastric cancer, with an overall accuracy rate of 77%, and up to 93% for T1 lesions. Under-staging may occur due to microscopic tumor infiltration, while over-staging may arise due to inflammatory reactions. The accuracy of N staging is lower at 60%, but could be further improved with the use of fine needle aspiration.

CT and PET in stomach cancer: preoperative staging and monitoring of response to therapy

Stomach cancer is one of the leading causes of cancer mortality worldwide. Complete resection of a gastric tumor and adjacent lymph nodes represents the only potentially curative intervention. Computed tomography (CT) has remained the modality of choice for the preoperative staging of gastric cancer and for follow-up. A recently developed advanced CT technique that makes use of thin sections, optimal contrast material enhancement, and multiplanar reformation allows more accurate staging. However, CT may be limited in the identification of nonenlarged lymph node metastasis, peritoneal dissemination, and small hematogenous metastasis. Positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) has been recognized as a useful diagnostic technique in clinical oncology. FDG PET allows scanning of a larger volume than is possible with CT. Although FDG PET is not an appropriate first-line diagnostic procedure in the detection of stomach cancer and is not helpful in tumor staging, it may play a valuable role in the detection of distant metastases, such as those of the liver, lungs, adrenal glands, ovaries, and skeleton. FDG PET may also be helpful in the follow-up of patients undergoing chemotherapy, as it allows the identification of early response to treatment. Further studies are needed to determine the efficacy of FDG PET in the detection of local nodal metastases and peritoneal dissemination. Nevertheless, the combined use of CT and PET can be helpful in the preoperative staging of stomach cancer and in the therapeutic monitoring of affected patients.

Indications for gastrectomy after incomplete EMR for early gastric cancer

BACKGROUND

Although the number of patients with early gastric cancer (EGC) treated by endoscopic mucosal resection (EMR) has increased, the appropriate strategy for treating those with incomplete resection has not been established.

METHODS

This study analyzed 726 cases of EGC in patients treated by EMR between 1991 and 2000, in order to clarify the en-bloc and complete resection rates. We classified patients with incomplete resection into four groups according to the estimated risk of residual cancer or lymph node (LN) metastasis, determined from pathological findings of EMR specimens. We then analyzed 45 patients with EGC treated surgically after incomplete EMR, with the aim of eliciting the risk of residual cancer and LN metastasis.

RESULTS

Of the 726 patients, 529 (72.9%) had an en-bloc resection, while 378 (52.1%) had a complete resection. Three hundred and nine patients were found to have mucosal cancer and lateral cut-end-positive status with no LN metastasis (group A). In this group, 18 patients (5.8%) had residual cancer, with the lesions in the majority of patients being limited to the mucosal layer. Group B consisted of 14 patients with differentiated and submucosal (sm1) depth cancers, with 1 patient having residual cancer and 2 patients having LN metastasis. Fifteen patients were classified as group C, with sm2 or greater and vertical cut end-negative status, with 2 showing residual cancer and 1 showing LN metastasis. Group D included 10 patients with vertical cut end-positive status. Four of these patients had residual cancer while 1 had LN metastasis.

CONCLUSION

We recommend that patients in group A should have close follow-up or endoscopic treatment, while those in groups B, C, or D should be treated by gastrectomy associated with LN dissection.

Gastric cancer by multidetector row CT: preoperative staging

The role of computed tomography (CT) in the preoperative staging of gastric cancer, even if controversial, may be fundamental for evaluating the local extent and nodal involvement of the disease, especially in locally advanced cases. However, previous results of CT staging have not been satisfactory for predicting the invasive depth of the tumor or possible nodal metastases. Recently introduced multidetector row CT (MDCT) and three-dimensional (3D) imaging are expected to overcome the limitations in cancer staging by offering rapid and accurate information for space perception, detailed hemodynamics, and real-time 3D processing of volumetric data sets. In particular, virtual endoscopic imaging may be helpful for detecting early gastric cancer. In our experience, T and N stagings of gastric cancer were improved with 3D MDCT when using volume rendering and virtual endoscopic imaging compared with conventional axial two-dimensional (2D) CT (accuracy of T staging with 3D vs. 2D CT images, 84% vs. 77%; accuracy of N staging, 63% vs. 61% with 3D vs. 2D images, respectively). In particular, the detection rate of early gastric cancer was markedly increased up to 96% when using 3D MDCT. Therefore, we believe that 3D MDCT of the stomach may enhance the performance of CT in the preoperative evaluation of patients who have gastric cancer by offering easy early detection of lesions and accurate tumor staging through the 3D imaging process.

Evaluation of contrast-enhanced helical hydro-CT in staging gastric cancer

AIM: To discuss the helical computed tomography (CT) characteristics of gastric cancer and evaluate the diagnostic value of contrast-enhanced helical hydro-CT (HHCT) in staging gastric cancer.

METHODS: A total of 50 patients with gastric cancer were included in this study. The CT findings in them were retros-pectively analyzed and correlated with pathologic findings at surgery. All patients were preoperatively imaged by plain and contrast-enhanced helical CT after orally ingesting 1 000-1 500 mL water. Peristalsis was minimized by intra-venous administration of spasmolytics.

RESULTS: The foci of gastric cancer became more prominent in all the 50 patients and showed strong enhancement in contrast-enhanced HHCT. The tumor was located at the gastric cardia in 14 cases, at the gastric fundus in 3 cases, at the gastric body in 8 cases, at the gastric antrum in 4 cases, at the gastric fundus and the body in 8 cases, at the gastric body and antrum in 11 cases, and at three segments of the stomach in 2 cases. The CT features of gastric cancer were focal or diffuse mural thickening, soft tissue mass, cancerous ulcer, stenosis of stomach, infiltration to adjacent tissues, lymph node and distant metastases. Strong contrast enhancement of the gastric wall was closely related to gastric cancer. The accuracy rate of contrast-enhanced HHCT in staging gastric cancer was 86% (43/50). The detection rate of lymph node metastases by CT was 60% (12/20).

CONCLUSION: Contrast-enhanced HHCT is a reliable method to diagnose and stage gastric cancer.

Gastric cancer staging at multi-detector row CT gastrography: comparison of transverse and volumetric CT scanning

PURPOSE

To prospectively evaluate the accuracy of multi-detector row computed tomography (CT) gastrography for preoperative staging of gastric cancer, with pathologic and surgical results as the reference standard.

MATERIALS AND METHODS

This study was approved by the institutional review board, and patients gave written informed consent. One hundred six patients (72 male, 34 female; mean age, 56 years) with endoscopically proved gastric cancer underwent unenhanced and contrast material-enhanced multi-detector row CT gastrography, with effervescent granules used as oral contrast material. Two experienced radiologists independently evaluated the depth of tumor invasion into the gastric wall (tumor staging), the involvement of regional lymph nodes (nodal staging), and the presence or absence of metastasis (metastatic staging) on transverse and volumetric CT images, which included images produced with multiplanar reformation and a virtual endoscopic technique. TNM staging of each tumor was compared with the pathologic and surgical results. Diagnostic accuracy in TNM staging was analyzed.

RESULTS

Gastric cancer was detected in 92 (87%) of 106 study patients with transverse CT imaging and in 104 (98%) with volumetric CT imaging. The overall accuracy of the tumor staging was 77% with transverse CT imaging and 84% with volumetric CT imaging (P < .001). The overall accuracy for lymph node staging was 62% with transverse CT imaging and 64% with volumetric CT imaging (P = .057). For staging of metastases, there was no difference between transverse and volumetric CT imaging (86% for both) (P > .99).

CONCLUSION

Multi-detector row CT gastrography with multiplanar reformation and virtual endoscopy, compared with transverse CT imaging, can improve the accuracy of preoperative staging of gastric cancer. This difference was significant for tumor staging but not for the staging of lymph nodes and metastases.

Preoperative staging of gastric adenocarcinoma: comparison of helical CT and endoscopic US

PURPOSE

To compare the performance of helical computed tomography (CT) and endoscopic ultrasonography (US) in the preoperative staging of gastric cancer.

MATERIALS AND METHODS

Fifty-one consecutive patients with a primary malignant gastric tumor (stage T2-T4) were preoperatively evaluated with both helical CT and endoscopic US within 3 days. Each tumor was staged according to the TNM classification system with both modalities. All patients subsequently underwent surgery. Results of CT and endoscopic US were compared with histologic staging of tumor invasion depth and regional lymph node metastasis. For comparison of CT and endoscopic US data, the marginal homogeneity test was used, and a P value of less than.05 was determined to indicate statistical significance.

RESULTS

In comparison with histologic results, CT achieved correct T staging in 39 patients (76%) and correct N staging in 35 patients (70%). The corresponding results for endoscopic US achieved correct T staging in 44 patients (86%) and correct N staging in 45 patients (90%). There was no significant difference between T staging (P =.55) and N staging (P >.99). Because of challenging detection of wall layers, correct T staging was difficult for CT and endoscopic US in the differentiation of T2 and T3 lesions.

CONCLUSION

Compared with endoscopic US, helical CT focused on the stomach provides valuable results regarding T and N staging in patients with gastric cancer.

Two-phase dynamic contrast-enhanced computed tomography with water-filling method for staging of gastric carcinoma

The objective of the study was to evaluate the usefulness of two-phase incremental contrast-enhanced computed tomography (CT) with water-filling method in the preoperative assessment of stomach carcinoma. Dynamic CT was done in 20 patients with biopsy-proven gastric cancers and the findings were compared with surgery. A 150-ml ionic contrast medium was administered intravenously at a flow rate of 3.5 ml/s. CT scanning was done at 45 s (early phase) and 3 min (equilibrium phase) after the start of intravenous injection. Primary tumors were detected in all the cases. The overall accuracies of dynamic CT in determining depth of tumor invasion, pancreatic invasion, adjacent liver infiltration, and lymph node metastasis were 85% (17/20), 90% (18/20), 85% (17/20), and 69% (13/19), respectively. The early phase of dynamic CT is highly accurate in determining the depth of tumor invasion of advanced gastric cancers but has low sensitivity in the detection of nodal metastasis. The delayed phase scans do not add any additional information and hence, should not be routinely used for staging.

Two-phase helical CT for detection of early gastric carcinoma: importance of the mucosal phase for analysis of the abnormal mucosal layer

PURPOSE

To evaluate the efficacy of two-phase dynamic helical computed tomography (CT), including the gastric mucosal phase, for detection of early gastric carcinoma with typical hyperattenuating and atypical nonhyperattenuating enhancement patterns.

METHOD

Two-phase helical CT scanning was performed using the water-filling method as negative oral contrast material for 212 patients with proven adenocarcinoma on endoscopic biopsy. Two gastrointestinal radiologists prospectively analyzed the focal alterations of the inner hyperattenuating mucosal layer and the outer hypoattenuating layer before the information obtained at barium study and pathologic examination was available. The first, so-called mucosal phase was obtained at 38-45 seconds after the start of intravenous injection of contrast material for a total of 150 ml/sec at a rate of 4 ml/sec to obtain maximum enhancement of the inner mucosal layer. The second delayed phase was obtained at 3 minutes.

RESULTS

Fifty-four cases of early gastric cancer were suspected on two-phase helical CT preoperatively. Postoperatively, 49 cases of early gastric cancer were pathologically confirmed. The detection rate for the typical hyperattenuating early gastric cancer, that is the type I enhancement pattern defined as the localized thickening of the inner hyperattenuating layer, using two-phase helical CT was 18% (9/49 patients). The type 2 enhancement pattern, defined as the focal interruption of the inner hyperattenuating mucosal layer without abnormal enhancement of the outer hypoattenuating layer on the mucosal phase, was seen in 15 cases. These were pathologically confirmed as early gastric cancer IIb + IIc (three patients), IIc (four patients), IIc + IIa (one patient), IIc + III (three patients), IIb + IIc (one patient), and advanced cancer (T2) lesions (three patients). The type 3 enhancement pattern was defined as the focal polypoid protrusion of the inner hyperattenuating layer without abnormal enhancement of the outer thickened hypoattenuating layer on the mucosal phase, and was seen in seven patients who were pathologically confirmed with early gastric cancer IIb + IIc (three patients), IIc + IIa (one patient), and IIc + lIb (three patients). The lesions became less distinct on the delayed phase. Five T2 advanced gastric cancers were falsely interpreted as early gastric cancer. The detection rate for early gastric cancer after considering type 2 and 3 atypical enhancement patterns was increased to 57% (28/49 patients).

CONCLUSION

Helical CT with two-phase scan including the mucosal phase was efficient for identifying the enhancement patterns of early gastric cancer.

MRI in staging advanced gastric cancer: is it useful compared with spiral CT?

PURPOSE

During the last decade, rapid progress has been made in MR technology. Our objective was to evaluate the role of MRI in staging advanced gastric cancer (AGC; gastric cancer invading the muscularis propria) and to compare it with that of spiral CT.

METHOD

We prospectively performed both MR and CT examinations on 26 patients with AGC proven by endoscopic biopsy. Contrast-enhanced CT and nonenhanced MRI with a 1.0 T scanner using FLASH, HASTE, and true-FISP sequences were obtained in each patient after injection of antiperistaltic drug and ingestion of 1 L of tap water. Fifty-two sets of CT and MR images were analyzed by two radiologists in consensus without any information from other images. T and N staging of AGC was determined according to the TNM classification. All patients underwent surgery within 1 week after both examinations. Diagnostic accuracy of each staging of AGC on CT or MRI was evaluated by comparison with the pathologic results.

RESULTS

MRI was slightly superior to CT in T staging (81 vs. 73%, respectively; p < 0.05). Although MRI had a tendency to overstage the pathologic T2 cancer, positive predictability of T2 stage and sensitivity of T3 stage were high (100%, respectively). Regarding the N staging, CT was slightly superior to MRI (73 vs. 65%; p > 0.05). However, both CT and MRI demonstrated the tendency of understaging in N staging.

CONCLUSION

Although MRI was superior to spiral CT in T staging, MRI cannot completely replace spiral CT in staging AGC because of its limitation in N staging.

Dynamic CT in the preoperative evaluation of patients with gastric cancer: correlation with surgical findings and pathology

BACKGROUND

The use of diagnostic techniques in the preoperative staging of patients with gastric cancer must be better defined. To further clarify which technique is indicated, we applied a new modality of computed tomography (CT) scanning for patients with gastric cancer.

METHODS

Dynamic CT of the abdomen using water as oral contrast agent was performed in 30 patients with gastric adenocarcinoma. Patients without evidence of metastatic disease underwent exploratory laparotomy and intraoperative staging. Resectable patients had surgical excision and definitive pathologic staging.

RESULTS

Two patients (7%) had metastatic disease by CT and were considered inoperable. The remaining 28 underwent laparotomy. Of these, six (21%) were unresectable and 22 (79%) had surgical resection. Dynamic CT adequately suggested advanced stage disease in four (67%) of the 6 unresectable patients. Wall thickness in dynamic CT correlated with the risk of serosal involvement (P < .001). Both CT and surgery had an accuracy of 64% (P > .05) in predicting pathologic staging. CT overstaged only 4% of cases.

CONCLUSIONS

Dynamic CT is a useful modality that can indicate inoperable disease, obviating the need for laparotomy in patients with gastric adenocarcinoma. CT can modify the surgical approach by suggesting unresectable or advanced disease. The low percentage of patients that are overstaged by CT, combined with its similar staging accuracy when compared with laparotomy, support its preoperative use in these patients.

Evaluation of 18F-FDG positron emission tomography in gastric and oesophageal carcinoma

The aim of this study was to evaluate 18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) in gastric and oesophageal carcinoma. 16 patients with biopsy proven oesophageal or gastric carcinoma had PET scans. Four patients had advanced disease and received palliative treatment. The remaining 12 patients were randomized to immediate surgery or neoadjuvant chemotherapy. Three patients had repeat PET scans following chemotherapy. PET detected the primary tumour in all cases including stage T1 lesions. Involved locoregional nodes (N1, N2) were not identified separately from the primary tumour. Semiquantitative analysis was performed in the form of tumour to liver activity ratios (TLR). In general, the TLR values were higher in the higher T stages, although there was only one case each of T1 and T2 lesions. PET scanning using 18F-FDG is a sensitive method for detecting primary oesophageal and gastric cancers but is limited in locoregional staging.

Clinical results and prognostic factors of radiologically node-positive gastric carcinoma

Lymph node metastasis determined by histologic examination is an important prognostic indicator in gastric carcinoma. However, prognostic value of lymph node metastasis detected by computed tomography (CT) is unknown. The aim of this study was to evaluate clinical results and prognostic factors of patients with radiologically node-positive gastric carcinoma. The study included 78 patients with primary gastric carcinoma and lymph node metastasis confirmed by CT. The level of lymph node metastasis was simply graded as follows: level I included perigastric nodes; level II included intermediate nodes along the left gastric, common hepatic, and celiac arteries; and level III included distant nodes along the hepatoduodenal ligament, pancreas, spleen, and abdominal aorta. Sixty patients (79%) had stage IV tumors showing one or more of the following: level III lymph node metastasis in 37, pancreatic invasion in 27, peritoneal dissemination in 23, and liver metastasis in 19. Overall 1- and 5-year survival rates were 29% and 6%, respectively, and the 1-year survival rate was significantly influenced by the level of lymph node metastasis on CT (55% for level I, 27% for level II, 7% for level III, P < 0.01). In patients with gastrectomy, prognostic factors were tumor size (<10 cm versus >10 cm, P < 0.01), gross type (localized versus infiltrative, P < 0.01), histologic type (well differentiated versus poorly differentiated, P < 0.01), and curability of the disease (curative versus noncurative, P < 0.01). Our study indicates that prognosis of patients with radiologically node-positive gastric carcinoma is poor because of high frequency of extensive tumor spreads. Patients having only positive level I nodes on CT are candidates for curative gastrectomy, which may offer long-term survival.

Radiologic staging of gastrointestinal cancer

Pre-operative staging should define the probable course of a patient's disease, separate the resectable from the unresectable patients, and identify the patients who are candidates for induction therapy. Pre-operative staging must be well tolerated and should provide new or important information that will affect the proposed treatment plan. For some diseases such as colon cancer, pre-operative staging is largely unnecessary, but it can be of great value for other tumors such as pancreatic cancer. Currently, many imaging techniques are available to evaluate gastrointestinal cancers, and each provides information necessary for directing treatment. Although no individual technique can stage patients with complete accuracy, combinations of the various imaging techniques can be used to increase accuracy and promote appropriate decisions about an individual's treatment options. The use of current imaging techniques for staging primary lesions, regional spread, and the intra-abdominal metastatic spread of the most common gastrointestinal malignancies are reviewed.

Correlation of CT with histopathological findings in patients with gastric and gastro-oesophageal carcinomas following neoadjuvant chemotherapy

Gastric carcinoma is the fourth commonest cause of death from malignant disease in United Kingdom. In the Western hemisphere, it usually presents with advanced disease, which contributes to its very poor prognosis. Pre-operative (neoadjuvant) chemotherapy offers the possibility of down-staging such tumours and the potential to render tumours operable. Computed tomography (CT) plays a central role in the assessment of patients presenting with the disease, and in those who undergo chemotherapy, in evaluating their response.

OBJECTIVE

This study was undertaken to evaluate the role of CT in predicting loco-regional spread of tumour following neoadjuvant chemotherapy in non-metastatic gastric and gastro-oesophageal cancers.

METHODS AND MATERIALS

We correlated CT evidence of loco-regional spread with pathological findings following surgery in 21 patients who received pre-operative chemotherapy.

RESULTS

Residual masses were seen on CT in 19 patients, and 15 contained active tumour, although in four patients no viable tumour was demonstrated at histopathology. The overall accuracy of CT in assessing loco-regional disease was disappointing with sensitivities, specificities, positive and negative predictive values of 57%, 43%, 75% and 33%, respectively.

CONCLUSIONS

We conclude that CT is not accurate in identifying residual loco-regional spread and therefore should not preclude surgery in those patients who have received neoadjuvant chemotherapy.

Efficacy of helical CT in T-staging of gastric cancer

PURPOSE

The purpose of this study was to evaluate the performance of helical CT in preoperative T-staging in patients with gastric cancer.

METHOD

A total of 71 patients with an established diagnosis of gastric cancer [75 lesions, 46 early (T1) and 29 advanced (T2 or more) cancers] were evaluated with helical CT. Helical CT was performed with 5-mm slice thickness at 5-mm/s table incrementation. Using the volumetric data by helical scanning, axial CT images (5-mm slice thickness at 5-mm intervals) and multiplanar reconstruction (MPR) images were obtained. CT findings were compared with histopathologic studies of the resected specimen.

RESULTS

Sensitivity of helical CT for gastric cancer was 26% (12 of 46) for early and 100% (29 of 29) for advanced cancer. Three lesions were misdiagnosed as gastric cancer by helical CT. Histopathologically, all early gastric cancers detected by helical CT were either polypoid or elevated types or showed massive invasion of the submucosal layer. The differentiation between T1 cancer with massive submucosal invasion and advanced cancer was difficult. The differentiation between T2 and T3 cancer was possible in 73% (19 of 26) and between T1/T2 and T3/T4 (extraserosal invasion) in 83% (34 of 41). Overall T-staging was correct in 66% (27 of 41). MPR images improved the detection rate (three lesions) or increased confidence in T-staging (eight lesions) over axial CT images.

CONCLUSION

When helical CT detected gastric cancer that was not a polypoid or elevated type with underlying normal-appearing gastric wall, it was either T1 cancer with massive invasion of the cancer cells into the submucosal layer or advanced cancer. However, differentiation between these two stages was difficult on CT. Diagnosis of serosal invasion was not markedly improved by helical CT. MPR images increased confidence in the staging of certain gastric cancers, such as those in locations where CT images are susceptible to partial volume averaging effects.

Preoperative evaluation of the curative resectability of gastric cancer by abdominal computed tomography and ultrasonography: a prospective comparison study

OBJECTIVES

We compared the ability of preoperative abdominal computed tomography (CT) with that of preoperative abdominal ultrasonography (US) in predicting the extent of tumor growth and the curative resectability of gastric cancer.

METHODS

Abdominal CT and US were done in 95 patients with gastric adeno-carcinoma. The radiologic findings were prospectively compared with surgical and pathologic findings.

RESULTS

The sensitivities of abdominal CT and US in detecting the perigastric lymph node involvement were 26.6% and 20%, respectively. The sensitivity of abdominal CT in predicting the pancreatic invasion (60%) was better than that of abdominal US (20%). However, there were 6 false positive diagnosis of pancreatic invasion by abdominal CT; in contrast, there was no false positive diagnosis of pancreatic invasion by abdominal US. Of 95 patients who underwent surgical exploration, 14 were found to have unresectable tumors because of extragastric organ involvement and distant metastases. Abdominal CT falsely predicted 8 of 14 cases in which curative gastric resection was impossible as resectable. Moreover, abdominal CT falsely predicted 5 of 81 cases in which curative gastric resection was possible as unresectable. Abdominal US falsely predicted 12 of 14 cases in which curative surgery was impossible as resectable.

CONCLUSION

Preoperative abdominal Ct and US did not accurately predict the tumor extent and the curative resectability of the gastric cancer. Especially, abdominal CT finding of pancreatic invasion by gastric cancer should not be a contraindication for surgical exploration.

CT evaluation of treatment response in advanced gastric cancer

Ninety-one patients with advanced gastric carcinoma were followed by serial computed tomography (CT) in a phase II study using multi-agent chemotherapy. Regression of primary tumour was seen in 43, with complete resolution in 5 and > 50% regression in 29. Involvement of loco-regional lymph nodes was seen in 43 patients, with complete resolution in 16, and > 50% regression in 21. Hepatic metastases were seen in 40 patients, with complete resolution in three and > 50% regression in 17. Regression in other less common sites in the chest and abdomen were also documented. The pattern of maximum response in all sites of disease was seen within the first 12 weeks of chemotherapy. The difficulties of disease management are discussed and recommendations for CT evaluation in this group of patients are made.

A phase II study in advanced gastro-esophageal cancer using epirubicin and cisplatin in combination with continuous infusion 5-fluorouracil (ECF)

PURPOSE

A phase II study was performed in patients with unresectable or metastatic gastric cancer evaluating the efficacy of a new chemotherapy schedule combining epirubicin and cisplatin with a continuous ambulatory infusion of 5-fluorouracil (ECF).

PATIENTS AND METHODS

One hundred thirty-nine consecutive, previously untreated patients were given ECF. Of these, 128 had measurable disease. Epirubicin (50 mg/m2 i.v.) and cisplatin (60 mg/m2 i.v.) were administered every three weeks for 8 cycles during a 21 week continuous i.v. infusion of 5-fluorouracil (200 mg/m2/day). In total 773 cycles of chemotherapy were given.

RESULTS

Objective tumour responses was seen in 91 (71%) of the 128 patients with measurable disease, of which 15 (12%) had a complete response. Twenty patients with locally advanced disease responding to ECF had attempted resection of the primary--11 (55%) were completely removed, 4 of these had no residual tumour in the resected specimen. The overall median survival was 8.2 months with 1 and 2 year survivals of 30% and 10% respectively. Grade 3 or 4 emesis occurred in 13%, stomatitis in 7%, diarrhoea in 4%, infection in 6%, leucopenia in 21% and thrombocytopenia in 8% of patients. Myelosuppression delayed treatment in 39 (5%) of the 773 cycles. Six of the 139 patients (4.3%) had treatment related deaths. There was no measurable reduction in quality of life during chemotherapy, while 67% of the 66 patients with dysphagia had complete resolution of this symptom.

CONCLUSIONS

The ECF regimen displays high anti-tumour activity with moderate toxicity in patients with gastric cancer and in some cases enabled resection of previously inoperable tumours.

Does preoperative computed tomography scanning aid assessment of oesophageal carcinoma?

In this study 50 patients (36 male, 14 female) with oesophageal carcinoma have been examined preoperatively by computed tomography. Three parameters were assessed, nodal involvement, invasion of adjacent organs, and metastatic disease. For all patients the computed tomography findings were correlated with the subsequent surgical and pathological findings. Sensitivity for both invasion and node involvement is low (36% to 67%). Specificity however, is high (85% to 95%). Computed tomography is therefore relatively reliable when it predicts a 'negative result' for either invasion or node involvement. However, its predictive value for a positive result is not as reliable.

Acute haemorrhage from gastric malignancy

The presentation, pathology and treatment of 30 patients with acute bleeding from gastric malignancies has been reviewed. Patients usually have a history of symptoms of less than 6 months prior to bleeding. Adenocarcinoma was the commonest type of tumour, and 74 per cent were stage IV lesions. The proportion of lesions in the body of the stomach (57 per cent) was greater than expected, suggesting that these are different populations of gastric tumour. Laparotomy was undertaken in 20 patients, 12 of whom had a resection. Resection was associated with a median survival of 17.0 months. Those with unresectable tumours or who were treated only by supportive measures had a median survival of only 2.5 months (P less than 0.01). Evidence of peritoneal or liver involvement should contraindicate surgical intervention as these patients have a high postoperative mortality rate.

Computed tomography in the preoperative evaluation of gastric carcinoma

Computed tomography (CT) of the abdomen was done in 49 patients with gastric carcinoma. These cases were retrospectively staged and evaluated as to operability. Various staging parameters were also evaluated separately. The results were correlated to findings on surgery, liver scan, and cytology. Overall accuracy of CT staging and operability assessment was 72 and 82%, respectively. Among the various CT parameters, perigastric fat invasion had a positive predictive value of 91%. The demonstration of local node involvement and invasion of adjacent organs was unreliable. Since surgery is currently the only treatment for gastric carcinoma, CT staging has limited clinical value. The principal role of CT is in the assessment of operability in patients with carcinoma of the stomach.

Palliative surgery for gastric cancer

Most patients with gastric carcinoma have a disease that is too advanced for radical surgery. A Review was made of 13,175 cases of gastric carcinoma registered at the Birmingham Cancer Registry during the period of 1960-1969. Of the patients, 79.6% had disease that was not radically resected, and few of these patients survived to 2 years. Those who had a palliative resection or bypass had the lowest 30-day mortality rate when compared to all other palliative measures (P less than 0.001). Furthermore, palliative resection gave the best survival in the presence of both locally advanced and metastatic disease (P less than 0.001). This suggests that the best palliative procedure for those with a disease unsuitable for radical surgery is a resection.

Laparoscopy or scanning in oesophageal and gastric carcinoma?

A prospective study was undertaken of the accuracy in diagnosing intra-abdominal metastatic disease of the liver by scintigraphy, ultrasound scanning and laparoscopy. The effect of laparoscopy on management was also studied. Fifty patients were studied: 23 oesophageal carcinoma, 14 gastric carcinoma and 13 with suspected intra-abdominal metastatic spread. Accuracy was determined by laparoscopic biopsy, laparotomy and autopsy. The accuracy was 72 per cent for scintigraphy, 75 per cent for ultrasound and 96 per cent for laparoscopy (with 10 per cent failed ultrasound due to intra-abdominal gas). There was no morbidity or mortality associated with laparoscopy, with one failure due to adhesions. Thirteen patients without hepatic metastases had nodal and/or peritoneal spread diagnosed only by laparoscopy. Laparotomy was avoided in 58 per cent, and 74 per cent died in the 18 month follow-up period. Laparoscopy can obviate the need for laparotomy in inoperable cases of oesophageal carcinoma and allow better planning for potentially curable surgery. In gastric carcinoma the value of laparoscopy is doubtful as a high percentage require at least palliative surgery.