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Comparison between fluorescent images of gastric cancer with an endoscopic autofluorescence imaging system and the histological findings
A554 AGA ABSTRACTS
GASTROENTEROLOGY Vol. 114, No. 4 I
~
l i n l i i fflk~ fl i i H l i l J
• G2265 AMPLIFICATION OF 17q12-21 IN SPORADIC GASTRIC CARCINOMAS BUT NOT IN GASTRIC CARCINOMA FROM PATIENTS WITH HEREDITARY NONPOLYPOSIS COLORECTAL CANCER. M. Aarnio*, A. Kokkola*, P.Puolakkainen*, ML Larramendy, W E1-Rifail, O. Monni, E. Kivilaakso*, S. Knuutila. Second Department of Surgery*, Helsinki University Central Hospital and Dept. of Medical Genetics, Haartman Institute, University of Helsinki, Finland Background. It has been suggested that there are differences in tumorgenesis between sporadic and hereditary nonpolyposis colorectal cancer (HNPCC) associated gastric cancers. The aim of this study was to compare the pattern of DNA copy number changes in these two types of gastric carcinoma. Materials. A total of 25 patients with gastric cancer were included in this study. There were 12 HNPCC patients originating from 12 separate families. A mutated M L H ] gene has been detected in 10 families and the remaining two families fulfilled the Amsterdam criteria for HNPCC. The 13 sporadic gastric cancer patients were operated in our department during 1994-1995. The sporadic carcinomas were of intestinal type. A comparative genomic hybridization (CGH) was used to analyze DNA copy number changes of gastric cancer samples. Results. Three (25%) out of the 12 HNPCC samples showed gains of DNA sequences copy numbers affecting 19q, Xp and chromosome 22. Neither high-level amplifications nor losses of DNA copy number were detected. However, 10 (77%) of the 13 sporadic gastric carcinoma samples had multiple DNA copy number changes. The minimal common overlapping regions of the most frequent gains were at 1q22-q31, 8q23-gter, 9q33-gter, 17pl 1.2-q22 and 20q, all at a frequency of 31%. Highlevel amplifications were also seen at 17q21 in three cases (23%). Losses of DNA copy number were rare. Conclusions. Multiple changes in DNA copy numbers seem to have an important role in developing sporadic gastric cancer, whereas gastric cancer in HNPCC may relate to the specific tumorgenesis involving DNA mismatch repair dysfunction.
G2266 COMPARISON BETWEEN FLUORESCENT IMAGES OF GASTRIC CANCER WITH AN ENDOSCOPIC AUTOFLUORESCENCE IMAGING SYSTEM AND THE HISTOLOGICAL FINDINGS. S. Abe, H.Tajiri, K. Izuishi, M. Muto, N. Boku, A. Ohtsu, T. Fujii, K. Hosokawa, T. Kinoshita, S. Yoshida. National Cancer Center Hospital East, Kashiwa, Chiba, Japan Gastrointestinal neoplastic tissue has been reported to exhibit intrinsic autofluorescence that differs from the autofluorescence of normal tissue when excited with blue or violet light. An endoscopic autofluorescence imaging system (LIFE-GI system; Xilliix technology Corp., Canada and Olympus optical Co., Japan) that uses mercury light for excitation has been newly developed for imaging lesions of dysplasia and carcinoma in the gastrointestinal tract. However, it was unclear Which LIFE-GI color was characteristic of cancer lesions, or whether the LIFE-GI system could accurately detect cancer lesions. The purpose of this study was to clarify the relationship between L1FE-GIimages of gastric cancer and the histological findings. Methods: Human gastric cancer tissue was obtained from 22 resected specimens, and a total 108 surface areas were examined. Images of the resected specimens of gastric cancer were produced with the LIFE-GI system (excitation: 437nm). Tumor extension and depth of cancer invasion were investigated histologically, and each lesion was mapped to the images produced with the LIFE-GI system. Results: The images of gastric cancer obtained with the LIFE-GI system were classified as "dark red", "bright red", and "white" in comparison with "light blue" of normal mucosa. Most of the cancer lesions exhibited dark red fluorescence. Three areas showing bright red fluorescence in the center of gastric cancer corresponded to necrotic tissue histologically. Two areas exhibiting white fluorescence corresponded to exposed parts of the submucosal layer infiltrated by cancer cells on the surface. Additionally, at 4 areas showing light blue fluorescence in gastric cancer, infiltration of cancer cells was limited to the mucosal layer alone, where the thickness of the mucosal and submucosal layers was the same as in the surrounding normal tissue. Conclusion: Four types of fluorescent images were recognized in gastric cancer, and most of the cancer lesions could be distinguished from normal areas. However, in clinical use, it should be remembered that when cancer cells have infiltrated to the mucosal layer alone and there is no change in the thickness of the mucosal and submucosal layers, the lesion may not be visible with the LIFE-GI system. • G2267 SMOKING AND RISK OF COLORECTAL POLYPS. C Adams. NR Cmickshank,S Sanders, 13(3Morton. Queen Elizabeth Hospital, Birmingham,UK Introduction It is accepted that colorectal adenomas may progress to carcinoma within the large bowel. The significance of hyperplastic polyps is more obscure although it has been suggested that they may be a marker for carcinogen exposure. Previous studies have defined the association of smoking with adenomatous polyps; but very few have analysed this relationship further to determine the relationship with adenomas at low or
l|~ll lip!
high risk of malignant change; or with hyperplastic polyps. Aim To determine the comparative risk of smoking for polyps of varying clinical significance. Patients and Setting An ongoing prospective trial with five hundred and eight asymptomatic volunteers aged 55-64 attending for screening flexible sigmoidoscopy at our institution. Methods All patients completed a questionnaire on smoking habits. At flexible sigmoidoscopy all polyps
NONE
359
HYPER PLASTIC ONLY 87
LOW RISK ADENOM AS 31
HIGH RISK ADENOM AS 20
No PATIENTS AV YEARS SMOKED
10.98 *o
17.91"
15.06
19.45 °
There was a statistically significant difference (p<0.05) between average number of years smoked by those with no polyps and those with metaplastic polyps; any adenoma; or high risk adenomas. When corrected for sex this held true for males with mctaplastic adenomas although small numbers resulted in other comparisons failing to reach significance. Conclusions Our interim results suggest that smoking is a significant risk factor for hyperplastic polyps as well as for adenomatous polyps. It is known that the geographical distribution of hyperplastic polyps within the large bowel is similar to that of colorectal cancer and adenomatous polyps. This study suggests that hyperplastic polyps may be a marker for exposure to colorectal carcinogens. G2268 LOVASTATIN-INDUCED SENSITIZATION OF COLON CANCER CELLS TO APOPTOSIS IS INDEPENDENT OF ras AND IS REVERSED BY GERANYLGERANIOL BUT NOT BY FARNESOL. B A~,arwal, B Halmos S Bhendwal, *WG Ramey, SF Moss, PR Holt. Division of Gastroenterology and *Department of Surgery, St. Luke's-Roosevelt Hospital Center, Columbia University, New York, NY 10025. The efficacy of currently available chemotherapy for colon cancer is limited and there is a need for better combinations. We have studied the effect of using lovastatin with 5-FU or cisplatinum in colon cancer cell lines for its potential role in combination chemotherapy for colon cancer. Apoptosis was assessed by TUNEL staining and electron microscopy and quantified with flow cytometry using 1) BrdU/TdT staining 2) Annexin/PI staining 3) subdiploid peak on DNA histogram. In HT-29 cells, lovastatin (0, 10, 30 and 100 ~aM) increased apoptosis in a dose dependent manner from 0.2% to 8.0%. Pretreatment with lovastatin for 48 hours greatly potentiated the apoptosis induced by 75 pg/ml 5-flourouracil and cisplatinum 30 pg/ml: 100
~'~i ~'0 *~
[] Cispl~:inum ~ 0
~ 10
Iova 30
Iova 100
On Westem blotting, there was decreased expression of bcl-2 and increased expression of bax after lovastatin treatment. Lovastatin also induced apoptosis and potentiated 5-FU induced apoptosis in SW 480 ceils, which have a mutation on codon 12 of the ras oncogene. We then studied the relative role of various isoprenoids in lovastatin induced apoptosis. Mevalonate 100 laM and geranylgeraniol lpM completely prevented and farnesol 50 pM partially prevented lovastatin induced-apoptosis and also inhibited the potentiation of 5-FU induced apoptosis by lovastatin. To conclude, lovastatin sensitizes the colon cancer cell lines HT-29 and SW 480 to apoptosis induced by chemotherapeutic agents. This effect appears to be largely independent of inhibition of famesylation of ras and is most likely due to geranylgeraniol bound protein(s), possibly rho. Our data suggest that adding lovastatin to 5-FU may improve the efficacy of chemotherapy for colon cancer. G2269 MORPHOMETRIC ANALYSIS OF TIlE "MUCOCELLULAR LAYER" OVERLYING COLORECTAL CANCER AND NORMAL MUCOSA: RELEVANCE TO EXFOLIATED STOOL SCREENING MARKERS, D. A. Ahlquist, J. J. Harrington, L. J. Burgart, P. C. Roche. Colorectal Neoplasia Group. Divisions of Gastroenterology and Hepatology and of Pathology, Mayo Clinic, Rochester, MN. The pathology of colorectal cancer (CRC) has focused historically on the structure of anchored ceils and their invasion into tissue with surprisingly little descriptive detail on the histomorphometry of the "mucocellular layer" (MCL) at the luminal interface. Yet, the histology of the MCL provides a snapshot of shed cellular elements, which are transiently entrapped in this viscous supraepithelial amalgam. Characterization of the constitutional
GASTROENTEROLOGY Vol. 114, No. 4 I
~
l i n l i i fflk~ fl i i H l i l J
• G2265 AMPLIFICATION OF 17q12-21 IN SPORADIC GASTRIC CARCINOMAS BUT NOT IN GASTRIC CARCINOMA FROM PATIENTS WITH HEREDITARY NONPOLYPOSIS COLORECTAL CANCER. M. Aarnio*, A. Kokkola*, P.Puolakkainen*, ML Larramendy, W E1-Rifail, O. Monni, E. Kivilaakso*, S. Knuutila. Second Department of Surgery*, Helsinki University Central Hospital and Dept. of Medical Genetics, Haartman Institute, University of Helsinki, Finland Background. It has been suggested that there are differences in tumorgenesis between sporadic and hereditary nonpolyposis colorectal cancer (HNPCC) associated gastric cancers. The aim of this study was to compare the pattern of DNA copy number changes in these two types of gastric carcinoma. Materials. A total of 25 patients with gastric cancer were included in this study. There were 12 HNPCC patients originating from 12 separate families. A mutated M L H ] gene has been detected in 10 families and the remaining two families fulfilled the Amsterdam criteria for HNPCC. The 13 sporadic gastric cancer patients were operated in our department during 1994-1995. The sporadic carcinomas were of intestinal type. A comparative genomic hybridization (CGH) was used to analyze DNA copy number changes of gastric cancer samples. Results. Three (25%) out of the 12 HNPCC samples showed gains of DNA sequences copy numbers affecting 19q, Xp and chromosome 22. Neither high-level amplifications nor losses of DNA copy number were detected. However, 10 (77%) of the 13 sporadic gastric carcinoma samples had multiple DNA copy number changes. The minimal common overlapping regions of the most frequent gains were at 1q22-q31, 8q23-gter, 9q33-gter, 17pl 1.2-q22 and 20q, all at a frequency of 31%. Highlevel amplifications were also seen at 17q21 in three cases (23%). Losses of DNA copy number were rare. Conclusions. Multiple changes in DNA copy numbers seem to have an important role in developing sporadic gastric cancer, whereas gastric cancer in HNPCC may relate to the specific tumorgenesis involving DNA mismatch repair dysfunction.
G2266 COMPARISON BETWEEN FLUORESCENT IMAGES OF GASTRIC CANCER WITH AN ENDOSCOPIC AUTOFLUORESCENCE IMAGING SYSTEM AND THE HISTOLOGICAL FINDINGS. S. Abe, H.Tajiri, K. Izuishi, M. Muto, N. Boku, A. Ohtsu, T. Fujii, K. Hosokawa, T. Kinoshita, S. Yoshida. National Cancer Center Hospital East, Kashiwa, Chiba, Japan Gastrointestinal neoplastic tissue has been reported to exhibit intrinsic autofluorescence that differs from the autofluorescence of normal tissue when excited with blue or violet light. An endoscopic autofluorescence imaging system (LIFE-GI system; Xilliix technology Corp., Canada and Olympus optical Co., Japan) that uses mercury light for excitation has been newly developed for imaging lesions of dysplasia and carcinoma in the gastrointestinal tract. However, it was unclear Which LIFE-GI color was characteristic of cancer lesions, or whether the LIFE-GI system could accurately detect cancer lesions. The purpose of this study was to clarify the relationship between L1FE-GIimages of gastric cancer and the histological findings. Methods: Human gastric cancer tissue was obtained from 22 resected specimens, and a total 108 surface areas were examined. Images of the resected specimens of gastric cancer were produced with the LIFE-GI system (excitation: 437nm). Tumor extension and depth of cancer invasion were investigated histologically, and each lesion was mapped to the images produced with the LIFE-GI system. Results: The images of gastric cancer obtained with the LIFE-GI system were classified as "dark red", "bright red", and "white" in comparison with "light blue" of normal mucosa. Most of the cancer lesions exhibited dark red fluorescence. Three areas showing bright red fluorescence in the center of gastric cancer corresponded to necrotic tissue histologically. Two areas exhibiting white fluorescence corresponded to exposed parts of the submucosal layer infiltrated by cancer cells on the surface. Additionally, at 4 areas showing light blue fluorescence in gastric cancer, infiltration of cancer cells was limited to the mucosal layer alone, where the thickness of the mucosal and submucosal layers was the same as in the surrounding normal tissue. Conclusion: Four types of fluorescent images were recognized in gastric cancer, and most of the cancer lesions could be distinguished from normal areas. However, in clinical use, it should be remembered that when cancer cells have infiltrated to the mucosal layer alone and there is no change in the thickness of the mucosal and submucosal layers, the lesion may not be visible with the LIFE-GI system. • G2267 SMOKING AND RISK OF COLORECTAL POLYPS. C Adams. NR Cmickshank,S Sanders, 13(3Morton. Queen Elizabeth Hospital, Birmingham,UK Introduction It is accepted that colorectal adenomas may progress to carcinoma within the large bowel. The significance of hyperplastic polyps is more obscure although it has been suggested that they may be a marker for carcinogen exposure. Previous studies have defined the association of smoking with adenomatous polyps; but very few have analysed this relationship further to determine the relationship with adenomas at low or
l|~ll lip!
high risk of malignant change; or with hyperplastic polyps. Aim To determine the comparative risk of smoking for polyps of varying clinical significance. Patients and Setting An ongoing prospective trial with five hundred and eight asymptomatic volunteers aged 55-64 attending for screening flexible sigmoidoscopy at our institution. Methods All patients completed a questionnaire on smoking habits. At flexible sigmoidoscopy all polyps
NONE
359
HYPER PLASTIC ONLY 87
LOW RISK ADENOM AS 31
HIGH RISK ADENOM AS 20
No PATIENTS AV YEARS SMOKED
10.98 *o
17.91"
15.06
19.45 °
There was a statistically significant difference (p<0.05) between average number of years smoked by those with no polyps and those with metaplastic polyps; any adenoma; or high risk adenomas. When corrected for sex this held true for males with mctaplastic adenomas although small numbers resulted in other comparisons failing to reach significance. Conclusions Our interim results suggest that smoking is a significant risk factor for hyperplastic polyps as well as for adenomatous polyps. It is known that the geographical distribution of hyperplastic polyps within the large bowel is similar to that of colorectal cancer and adenomatous polyps. This study suggests that hyperplastic polyps may be a marker for exposure to colorectal carcinogens. G2268 LOVASTATIN-INDUCED SENSITIZATION OF COLON CANCER CELLS TO APOPTOSIS IS INDEPENDENT OF ras AND IS REVERSED BY GERANYLGERANIOL BUT NOT BY FARNESOL. B A~,arwal, B Halmos S Bhendwal, *WG Ramey, SF Moss, PR Holt. Division of Gastroenterology and *Department of Surgery, St. Luke's-Roosevelt Hospital Center, Columbia University, New York, NY 10025. The efficacy of currently available chemotherapy for colon cancer is limited and there is a need for better combinations. We have studied the effect of using lovastatin with 5-FU or cisplatinum in colon cancer cell lines for its potential role in combination chemotherapy for colon cancer. Apoptosis was assessed by TUNEL staining and electron microscopy and quantified with flow cytometry using 1) BrdU/TdT staining 2) Annexin/PI staining 3) subdiploid peak on DNA histogram. In HT-29 cells, lovastatin (0, 10, 30 and 100 ~aM) increased apoptosis in a dose dependent manner from 0.2% to 8.0%. Pretreatment with lovastatin for 48 hours greatly potentiated the apoptosis induced by 75 pg/ml 5-flourouracil and cisplatinum 30 pg/ml: 100
~'~i ~'0 *~
[] Cispl~:inum ~ 0
~ 10
Iova 30
Iova 100
On Westem blotting, there was decreased expression of bcl-2 and increased expression of bax after lovastatin treatment. Lovastatin also induced apoptosis and potentiated 5-FU induced apoptosis in SW 480 ceils, which have a mutation on codon 12 of the ras oncogene. We then studied the relative role of various isoprenoids in lovastatin induced apoptosis. Mevalonate 100 laM and geranylgeraniol lpM completely prevented and farnesol 50 pM partially prevented lovastatin induced-apoptosis and also inhibited the potentiation of 5-FU induced apoptosis by lovastatin. To conclude, lovastatin sensitizes the colon cancer cell lines HT-29 and SW 480 to apoptosis induced by chemotherapeutic agents. This effect appears to be largely independent of inhibition of famesylation of ras and is most likely due to geranylgeraniol bound protein(s), possibly rho. Our data suggest that adding lovastatin to 5-FU may improve the efficacy of chemotherapy for colon cancer. G2269 MORPHOMETRIC ANALYSIS OF TIlE "MUCOCELLULAR LAYER" OVERLYING COLORECTAL CANCER AND NORMAL MUCOSA: RELEVANCE TO EXFOLIATED STOOL SCREENING MARKERS, D. A. Ahlquist, J. J. Harrington, L. J. Burgart, P. C. Roche. Colorectal Neoplasia Group. Divisions of Gastroenterology and Hepatology and of Pathology, Mayo Clinic, Rochester, MN. The pathology of colorectal cancer (CRC) has focused historically on the structure of anchored ceils and their invasion into tissue with surprisingly little descriptive detail on the histomorphometry of the "mucocellular layer" (MCL) at the luminal interface. Yet, the histology of the MCL provides a snapshot of shed cellular elements, which are transiently entrapped in this viscous supraepithelial amalgam. Characterization of the constitutional