Journal of Surgical Oncology 47:79-81 (1991)
Elevated Serum Gastrin levels in Patients With Gastric Cancer SRDJAN RAKIC, MD,
RONALD A. HINDER, MD, PhD, GORDANA ADANJA, PharmD, AND TOM R. DEMEESTER,MD From the Department of Surgery, lnstitute of Digestive Diseases, University School of Medicine, Belgrade, Yugoslavia (S.R., C.A.); and the Department of Surgery, Creighton University School of Medicine, Omaha, Nebraska (R.A.H., J.R.D.) PhD,
Elevated plasma gastrin levels have been found in patients with colorectal cancer. We measured fasting serum gastrin levels in control subjects (n = 12), patients with gastric cancer (n = 43), and patients with carcinoma of the esophagus (n = 55). Serum gastrin levels were significantly higher in patients with gastric cancer compared to normal controls (P < 0.005) and those with esophageal cancer ( P < 0.05). This information may add to our understanding of the pathogenesis of gastric cancer. ~
KEYWORDS:gastric cancer, stomach, gastrinemia
INTRODUCTION
MATERIALS AND METHODS
Hormones have been shown to have a modulating effect on various tumors. Recently it has been shown that gut tumors, both in vivo and in vitro, respond to gastrin and that gastrin may have a trophic effect upon the growth of human gastric and colorectal tumors [I-31. The hypergastrinemia associated with the inhibition of gastric acid secretion during long-term omeprazole therapy has been shown to produce gastric enterochromaffinlike (ECL) tumors in rats [4,5]. Exogenous gastrin is trophic to the gastric mucosa and is also associated with increased thymidine uptake which suggests increased DNA activity [6,7]. The role of gastrin in tumor initiation and promotion, however, remains unclear. The recent observation that colorectal cancer patients have higher circulating gastrin levels than control subjects suggests that an abnormality of gastrin production may be related to tumor development [8,9]. This stimulated us to measure serum gastrin levels in patients with gastric cancer in an attempt to define whether such a relationship could be demonstrated for gastric tumors. Serum pepsinogen I levels were measured in some patients simultaneously as an indicator of the gastric acid secretory status [lo]. The control group consisted of normal subjects and patients with tumor in a nearby organ with less probability of hormonal modulation of the tumor. For this purpose patients with squamous cell carcinoma of the esophagus were studied. 0 1991 Wiley-Liss, Inc.
The study population consisted of 43 patients with gastric cancer, 12 normal subjects (controls), and 55 patients with squamous cell carcinoma of the esophagus. The demographic information on these subjects is shown in Table I. All subjects with a potential cause for hypergastrinemia such as previous gastric surgery or vagotomy , H,-blocker therapy, peptic ulcer disease, and gastric outlet obstruction were excIuded from the study, as were subjects with adenocarcinoma of the esophagus. Venous blood samples were obtained from each subject after an overnight fast. Serum gastrin concentrations were determined by radioimmunoassay using a commercial kit from Oris Industrie (Gif-Sur-Yvette, France). The assay was performed directly on unheparinized serum. When performed within 24 h the samples were kept at 2 4 ° C ; otherwise they were stored at -20°C. The antiserum used in the assay presents a correct recognition of G-17. Sensitivity has been determined as being to 10 pg/ml . Pepsinogen I serum concentrations were determined in 25 randomly chosen patients with gastric cancer and 17 of those with esophageal cancer. Radioimmunoassay was Accepted for publication January 27, 1991. Address reprint requests to Srdjan Rakic, M.D., Department of Surgery, Institute of Digestive Diseases, Belgrade University School of Medicine, Ulica Visegradska 26, Belgrade 1 1000, Yugoslavia.
80
Rakic et al.
TABLE I. Demographic Data on the Study Group Group
No.
Sex (MIF)
Mean age
Range
Controls Gastric cancer Esophageal cancer
12 43 55
715 28/15 4718
53.4 58.3 58.8
29-77 30-78 37-73
851.7 547.8 4 1 1.3 226.2
663.6
1501
perfornied using a commercial kit from Sorin Biomedica (Saluggia, Italy). With this test no significant crossreaction has been found for human gastrin and sensitivity has been determined as being 0.8 t 0.2 ngiml.
100 -
Statistical Analysis The ANOVA test was used for comparing the subjects’ age. For the remaining, not normally distributed data, median values were calculated and statistical comparisons were made using the Kruskal-Wallis and MannWhitney tests. The relationship between gastrin and pepsinogen I serum levels was assessed using the Pearson correlation coefficient.
RESULTS The groups were found to be well matched for age on statistical analysis. The serum gastrin values for the three groups are shown in Figure 1. Patients with gastric cancer had significantly higher gastrin levels compared to controls ( P < 0.005) and those with esophageal cancer ( P < 0.05). There was no difference in gastrin levels between controls and those with esophageal cancer. The serum gastrin values were above normal (mean 2 2 SD) in 19 of 43 patients with gastric cancer and 18 of 55 with esophageal cancer. The means of pepsinogen I level in those with gastric cancer (63.0 k 48.0) and those with esophageal cancer (49.8 t 34.6) were not significantly different. No significant correlation between gastrin and pepsinogen I values was demonstrated either in gastric or esophageal cancer.
DISCUSSION In this study we have shown that hypergastrinemia is associated with gastric cancer. This raises the question whether hypergastrinemia promotes the growth of gastric tumors or whether the observed hypergastrinemia is a consequence of the tumor. They also may not be related. Both exogenous and endogenous gastrin are known to cause gastric mucosal hypertrophy or tumor formation [ 1-31. In rats subjected to hypergastrinemia it has been shown that exogenously administered gastrin produced hyperplasia and thickening of the gastric mucosa [6]. Failure of normal acid secretion or severe inhibition of gastric acid secretion results in endogenous hypergastrinemia, which h a repeatedly been shown to act as a stimulus to proximal gastric mucosal ECL cell hyperpla-
+
4-* + v
CONTROL
QASTRIC CANCER
ESOPHAQIEAL CANCER
Fig. 1. Values of serum gastrin in controls (n = 12) and patients with gastric cancer (n = 43) and esophageal cancer (n = 55). Horizontal bars represent the median values. The dotted line represents the control group mean Ifr 2 SD. Values of gastrin above 150 pgiml are shown numerically.
sia and tumor formation [4,5]. This has become of particular interest recently with the availability of the drug omeprazole which strongly inhibits acid secretion, and has been shown in rats to produce hypergastrinemia and gastric carcinoid tumors. There is also evidence in humans that hypergastrinemia results in tumor formation in the stomach which regresses after antrectomy and a concomitant fall in the raised serum gastrin [I 13. There is good evidence that gastrin acts as a modulator of human gastrointestinal tumors. Watson et al. [3] have shown that 55% of human colonic tumors grown in culture and 69% of gastric tumors in culture show significant trophic effect to the physiological doses of gastrin. Elevated serum gastrin levels are associated with benign polyps and cancers of the colon [8,9]. There is, however, no direct evidence that these are causally related. Our study has shown that such a relationship also exists for gastric cancer. G-cell hyperplasia and hypergastrinemia are produced when the antrum is chronically in a low acid environment or alkalinized. Thus hypergastrinemia is frequently seen in association with atrophic gastritis which is also related to gastric cancer [12]. This could also occur in the presence of duodenogastric reflux where bile acids may
Serum Gastrin in Gastric Cancer
be carcinogenic or even promoters of gastric mucosal hyperplasia or tumor formation [ 13,141. It is possible that the elevated gastrin levels could be due to tumor hormone secretion. Gastric tumors have been shown by immunohistochemistry to produce gastrin 1151. Watson et al. [16,17] have shown recently that a gastrin-like substance is produced in vitro by human gastric and colorectal cancer cells. Immunoperoxidase studies of the tumor cells staining for gastrin compared to samples of the pancreas in the same patient would be useful to see where gastrin originates in our patients. It is of interest that in vitro studies have shown that gastric and colonic tumor cells have gastrin receptors [ 181. This suggests a possible etiologic role of gastrin in stimulating or promoting tumor growth. A potential for therapy of these tumors by using gastrin blockers is suggested and may gain attention in the future [19]. It is therefore not clear from our study whether hypergastrinemia is the cause or effect of the tumor or the result of an event such as achlorhydria. If the hypergastrinemia observed in our study was due to achlorhydria we would have expected to find lower serum pepsinogen I levels in our patients with the highest serum gastrin levels. This was not found to be the case with gastric cancer. It therefore seems unlikely that the raised serum gastrin in this group is a consequence of hypochlorhydria in our study. Direct measurement of acid secretion might provide more convincing evidence of whether the elevation in serum gastrin levels in gastric cancer is a primary or a secondary phenomenon. Stomach cancer may prove to be a hormonally responsive tumor. This may have important implications in the prophylaxis against gastric cancer and may become useful in the future treatment of this condition.
REFERENCES 1. Winsett OE, Townsend CM, Glass EJ, Thompson JC: Gastrin stimulates growth of colon cancer. Surgery 99:302-307, 1986. 2. Kusyk CJ, McNeil NO, Johnson RL: Stimulation of growth of a colon cancer line by gastrin. Am J Physiol 251:G597-G601, 1986.
81
3. Watson SA, Durrant LG, Crosbie JD, Morris DL: The in vitro growth response of primary human colorectal and gastric cancer cells to gastrin. Int J Cancer 43:692496, 1989. 4. Tielemans Y, Hakanson R, Sundler F, Willems G: Proliferation of enterochromaffinlike cells in omeprazole-treated hypergastrinernic rats. Gastroenterology 96:723-729, 1989. 5. Havu N: Enterochromaffin-like carcinoids of gastric mucosa in rats after life-long inhibition of gastric secretion. Digestion 35(S~ppl1):42-55, 1986. 6. Ryberg B, Axelson J, Hakanson R , Sundler F, Mattsson H: Trophic effect of continuous infusion of [Le~'~]-gastrin-17 in the rat. Gastroenterology 98:33-38, 1990. 7. Johnson LR: New aspects of the trophic action of gastrointestinal hormones. Gastroenterology 72:788-792, 1977. 8. Smith JP, Wood JG, Solomon TE: Elevated gastrin levels in patients with colon cancer or adenomatous polyps. Dig Dis Sci 341171-174, 1989. 9. Seitz JF, Giovannini M, Gauthier A: Elevated gastrin levels in patients with colorectal cancer. J Clin Gastroenterol 11:362-363, 1989. 10. Samloff IM, Secrist DM, Passaro E: A study of the relationship between serum group I pepsinogen levels and gastric acid secretion. Gastroenterology 69:1196--1200, 1975. 11. Richards AT, Hinder RA, Harrison AC: Gastric carcinoid tumors associated with hypergastrinaemia and pernicious anaemiaRegression of tumours by antrectomy. S Afr Med J 72:51-53, 1987. 12. Sipponen, Kekki M, Siurala M: Increased risk of gastric cancer in males affects the intestinal type of cancer and is independent of age, location of the tumor and atrophic Br J Cancer . gastritis " 51:332-336, 1988. 13. Chomchai C. Bhadrachari N. Niero ND: The effect of bile on the induction of experimental intessnal tumors in rats. Dis Colon Rectum 17:31&312, 1974. 14. Moorehead RJ, Kernohan RM, Patterson CC, McKelvey STD, Parks TG: Does cholecvstectomv oredisDose to colorectal cancer? Dis Colon Rectum 29:36-38, 1386. 15. Tahara E, Ho H, Nakagami K, Shimamoto F, Yamamoto M, Sumi K: Scirrhous argyrophil cell carcinoma of the stomach with multiple production of polypeptide hormones, amine, CEA, lysozyme and HCG. Cancer 49:1904-1915, 1982. 16. Watson SA, Durrant L, Morris DL: Gastrin dependence of human colonic and gastric tumors [Abstract]. Gut 29:A738, 1988. 17. Morris DL, Watson SA, Durrant LG, Harrison JD: Hormonal control of gastric and colorectal cancer in man. Gut 30:425-429, 1989. 18. Sing P, Rae-Venter 8, Townsend CM Jr, Khalil T, Thompson JC: Gastrin receptors in normal and malignant gastrointestinal mucosa: Age associated changes. Am J Physiol249:761-769, 1985. 19. Beauchamp RD, Townsend CM, Singh P, Glass EJ, Thompson JC: Proglumide, a gastrin receptor antagonist, inhibits growth of colon cancer and enhances survival in mice. Ann Surg 202:303309. 1985.
Elevated Serum Gastrin levels in Patients With Gastric Cancer SRDJAN RAKIC, MD,
RONALD A. HINDER, MD, PhD, GORDANA ADANJA, PharmD, AND TOM R. DEMEESTER,MD From the Department of Surgery, lnstitute of Digestive Diseases, University School of Medicine, Belgrade, Yugoslavia (S.R., C.A.); and the Department of Surgery, Creighton University School of Medicine, Omaha, Nebraska (R.A.H., J.R.D.) PhD,
Elevated plasma gastrin levels have been found in patients with colorectal cancer. We measured fasting serum gastrin levels in control subjects (n = 12), patients with gastric cancer (n = 43), and patients with carcinoma of the esophagus (n = 55). Serum gastrin levels were significantly higher in patients with gastric cancer compared to normal controls (P < 0.005) and those with esophageal cancer ( P < 0.05). This information may add to our understanding of the pathogenesis of gastric cancer. ~
KEYWORDS:gastric cancer, stomach, gastrinemia
INTRODUCTION
MATERIALS AND METHODS
Hormones have been shown to have a modulating effect on various tumors. Recently it has been shown that gut tumors, both in vivo and in vitro, respond to gastrin and that gastrin may have a trophic effect upon the growth of human gastric and colorectal tumors [I-31. The hypergastrinemia associated with the inhibition of gastric acid secretion during long-term omeprazole therapy has been shown to produce gastric enterochromaffinlike (ECL) tumors in rats [4,5]. Exogenous gastrin is trophic to the gastric mucosa and is also associated with increased thymidine uptake which suggests increased DNA activity [6,7]. The role of gastrin in tumor initiation and promotion, however, remains unclear. The recent observation that colorectal cancer patients have higher circulating gastrin levels than control subjects suggests that an abnormality of gastrin production may be related to tumor development [8,9]. This stimulated us to measure serum gastrin levels in patients with gastric cancer in an attempt to define whether such a relationship could be demonstrated for gastric tumors. Serum pepsinogen I levels were measured in some patients simultaneously as an indicator of the gastric acid secretory status [lo]. The control group consisted of normal subjects and patients with tumor in a nearby organ with less probability of hormonal modulation of the tumor. For this purpose patients with squamous cell carcinoma of the esophagus were studied. 0 1991 Wiley-Liss, Inc.
The study population consisted of 43 patients with gastric cancer, 12 normal subjects (controls), and 55 patients with squamous cell carcinoma of the esophagus. The demographic information on these subjects is shown in Table I. All subjects with a potential cause for hypergastrinemia such as previous gastric surgery or vagotomy , H,-blocker therapy, peptic ulcer disease, and gastric outlet obstruction were excIuded from the study, as were subjects with adenocarcinoma of the esophagus. Venous blood samples were obtained from each subject after an overnight fast. Serum gastrin concentrations were determined by radioimmunoassay using a commercial kit from Oris Industrie (Gif-Sur-Yvette, France). The assay was performed directly on unheparinized serum. When performed within 24 h the samples were kept at 2 4 ° C ; otherwise they were stored at -20°C. The antiserum used in the assay presents a correct recognition of G-17. Sensitivity has been determined as being to 10 pg/ml . Pepsinogen I serum concentrations were determined in 25 randomly chosen patients with gastric cancer and 17 of those with esophageal cancer. Radioimmunoassay was Accepted for publication January 27, 1991. Address reprint requests to Srdjan Rakic, M.D., Department of Surgery, Institute of Digestive Diseases, Belgrade University School of Medicine, Ulica Visegradska 26, Belgrade 1 1000, Yugoslavia.
80
Rakic et al.
TABLE I. Demographic Data on the Study Group Group
No.
Sex (MIF)
Mean age
Range
Controls Gastric cancer Esophageal cancer
12 43 55
715 28/15 4718
53.4 58.3 58.8
29-77 30-78 37-73
851.7 547.8 4 1 1.3 226.2
663.6
1501
perfornied using a commercial kit from Sorin Biomedica (Saluggia, Italy). With this test no significant crossreaction has been found for human gastrin and sensitivity has been determined as being 0.8 t 0.2 ngiml.
100 -
Statistical Analysis The ANOVA test was used for comparing the subjects’ age. For the remaining, not normally distributed data, median values were calculated and statistical comparisons were made using the Kruskal-Wallis and MannWhitney tests. The relationship between gastrin and pepsinogen I serum levels was assessed using the Pearson correlation coefficient.
RESULTS The groups were found to be well matched for age on statistical analysis. The serum gastrin values for the three groups are shown in Figure 1. Patients with gastric cancer had significantly higher gastrin levels compared to controls ( P < 0.005) and those with esophageal cancer ( P < 0.05). There was no difference in gastrin levels between controls and those with esophageal cancer. The serum gastrin values were above normal (mean 2 2 SD) in 19 of 43 patients with gastric cancer and 18 of 55 with esophageal cancer. The means of pepsinogen I level in those with gastric cancer (63.0 k 48.0) and those with esophageal cancer (49.8 t 34.6) were not significantly different. No significant correlation between gastrin and pepsinogen I values was demonstrated either in gastric or esophageal cancer.
DISCUSSION In this study we have shown that hypergastrinemia is associated with gastric cancer. This raises the question whether hypergastrinemia promotes the growth of gastric tumors or whether the observed hypergastrinemia is a consequence of the tumor. They also may not be related. Both exogenous and endogenous gastrin are known to cause gastric mucosal hypertrophy or tumor formation [ 1-31. In rats subjected to hypergastrinemia it has been shown that exogenously administered gastrin produced hyperplasia and thickening of the gastric mucosa [6]. Failure of normal acid secretion or severe inhibition of gastric acid secretion results in endogenous hypergastrinemia, which h a repeatedly been shown to act as a stimulus to proximal gastric mucosal ECL cell hyperpla-
+
4-* + v
CONTROL
QASTRIC CANCER
ESOPHAQIEAL CANCER
Fig. 1. Values of serum gastrin in controls (n = 12) and patients with gastric cancer (n = 43) and esophageal cancer (n = 55). Horizontal bars represent the median values. The dotted line represents the control group mean Ifr 2 SD. Values of gastrin above 150 pgiml are shown numerically.
sia and tumor formation [4,5]. This has become of particular interest recently with the availability of the drug omeprazole which strongly inhibits acid secretion, and has been shown in rats to produce hypergastrinemia and gastric carcinoid tumors. There is also evidence in humans that hypergastrinemia results in tumor formation in the stomach which regresses after antrectomy and a concomitant fall in the raised serum gastrin [I 13. There is good evidence that gastrin acts as a modulator of human gastrointestinal tumors. Watson et al. [3] have shown that 55% of human colonic tumors grown in culture and 69% of gastric tumors in culture show significant trophic effect to the physiological doses of gastrin. Elevated serum gastrin levels are associated with benign polyps and cancers of the colon [8,9]. There is, however, no direct evidence that these are causally related. Our study has shown that such a relationship also exists for gastric cancer. G-cell hyperplasia and hypergastrinemia are produced when the antrum is chronically in a low acid environment or alkalinized. Thus hypergastrinemia is frequently seen in association with atrophic gastritis which is also related to gastric cancer [12]. This could also occur in the presence of duodenogastric reflux where bile acids may
Serum Gastrin in Gastric Cancer
be carcinogenic or even promoters of gastric mucosal hyperplasia or tumor formation [ 13,141. It is possible that the elevated gastrin levels could be due to tumor hormone secretion. Gastric tumors have been shown by immunohistochemistry to produce gastrin 1151. Watson et al. [16,17] have shown recently that a gastrin-like substance is produced in vitro by human gastric and colorectal cancer cells. Immunoperoxidase studies of the tumor cells staining for gastrin compared to samples of the pancreas in the same patient would be useful to see where gastrin originates in our patients. It is of interest that in vitro studies have shown that gastric and colonic tumor cells have gastrin receptors [ 181. This suggests a possible etiologic role of gastrin in stimulating or promoting tumor growth. A potential for therapy of these tumors by using gastrin blockers is suggested and may gain attention in the future [19]. It is therefore not clear from our study whether hypergastrinemia is the cause or effect of the tumor or the result of an event such as achlorhydria. If the hypergastrinemia observed in our study was due to achlorhydria we would have expected to find lower serum pepsinogen I levels in our patients with the highest serum gastrin levels. This was not found to be the case with gastric cancer. It therefore seems unlikely that the raised serum gastrin in this group is a consequence of hypochlorhydria in our study. Direct measurement of acid secretion might provide more convincing evidence of whether the elevation in serum gastrin levels in gastric cancer is a primary or a secondary phenomenon. Stomach cancer may prove to be a hormonally responsive tumor. This may have important implications in the prophylaxis against gastric cancer and may become useful in the future treatment of this condition.
REFERENCES 1. Winsett OE, Townsend CM, Glass EJ, Thompson JC: Gastrin stimulates growth of colon cancer. Surgery 99:302-307, 1986. 2. Kusyk CJ, McNeil NO, Johnson RL: Stimulation of growth of a colon cancer line by gastrin. Am J Physiol 251:G597-G601, 1986.
81
3. Watson SA, Durrant LG, Crosbie JD, Morris DL: The in vitro growth response of primary human colorectal and gastric cancer cells to gastrin. Int J Cancer 43:692496, 1989. 4. Tielemans Y, Hakanson R, Sundler F, Willems G: Proliferation of enterochromaffinlike cells in omeprazole-treated hypergastrinernic rats. Gastroenterology 96:723-729, 1989. 5. Havu N: Enterochromaffin-like carcinoids of gastric mucosa in rats after life-long inhibition of gastric secretion. Digestion 35(S~ppl1):42-55, 1986. 6. Ryberg B, Axelson J, Hakanson R , Sundler F, Mattsson H: Trophic effect of continuous infusion of [Le~'~]-gastrin-17 in the rat. Gastroenterology 98:33-38, 1990. 7. Johnson LR: New aspects of the trophic action of gastrointestinal hormones. Gastroenterology 72:788-792, 1977. 8. Smith JP, Wood JG, Solomon TE: Elevated gastrin levels in patients with colon cancer or adenomatous polyps. Dig Dis Sci 341171-174, 1989. 9. Seitz JF, Giovannini M, Gauthier A: Elevated gastrin levels in patients with colorectal cancer. J Clin Gastroenterol 11:362-363, 1989. 10. Samloff IM, Secrist DM, Passaro E: A study of the relationship between serum group I pepsinogen levels and gastric acid secretion. Gastroenterology 69:1196--1200, 1975. 11. Richards AT, Hinder RA, Harrison AC: Gastric carcinoid tumors associated with hypergastrinaemia and pernicious anaemiaRegression of tumours by antrectomy. S Afr Med J 72:51-53, 1987. 12. Sipponen, Kekki M, Siurala M: Increased risk of gastric cancer in males affects the intestinal type of cancer and is independent of age, location of the tumor and atrophic Br J Cancer . gastritis " 51:332-336, 1988. 13. Chomchai C. Bhadrachari N. Niero ND: The effect of bile on the induction of experimental intessnal tumors in rats. Dis Colon Rectum 17:31&312, 1974. 14. Moorehead RJ, Kernohan RM, Patterson CC, McKelvey STD, Parks TG: Does cholecvstectomv oredisDose to colorectal cancer? Dis Colon Rectum 29:36-38, 1386. 15. Tahara E, Ho H, Nakagami K, Shimamoto F, Yamamoto M, Sumi K: Scirrhous argyrophil cell carcinoma of the stomach with multiple production of polypeptide hormones, amine, CEA, lysozyme and HCG. Cancer 49:1904-1915, 1982. 16. Watson SA, Durrant L, Morris DL: Gastrin dependence of human colonic and gastric tumors [Abstract]. Gut 29:A738, 1988. 17. Morris DL, Watson SA, Durrant LG, Harrison JD: Hormonal control of gastric and colorectal cancer in man. Gut 30:425-429, 1989. 18. Sing P, Rae-Venter 8, Townsend CM Jr, Khalil T, Thompson JC: Gastrin receptors in normal and malignant gastrointestinal mucosa: Age associated changes. Am J Physiol249:761-769, 1985. 19. Beauchamp RD, Townsend CM, Singh P, Glass EJ, Thompson JC: Proglumide, a gastrin receptor antagonist, inhibits growth of colon cancer and enhances survival in mice. Ann Surg 202:303309. 1985.
