Squamous cell carcinoma of the thyroid gland: primary or secondary disease?

OBJECTIVE: To review the aetiopathogenesis, clinical characteristics, immunohistochemical profile, prognosis and treatment options for primary thyroid squamous cell carcinoma, and to compare it with squamous cell carcinoma metastatic to the thyroid, thus providing the reader with a framework for differentiating primary and secondary disease. METHOD: Review of English language literature from the past 25 years. SEARCH STRATEGY: A search of the Medline, Embase and Cochrane databases (April 1984 to April 2009) was undertaken to enable a comprehensive review. RESULTS: After applying strict criteria for the diagnosis of primary thyroid squamous cell carcinoma, 28 articles were identified reporting 84 cases. When reviewing secondary thyroid squamous cell carcinoma, we only analysed cases of squamous cell carcinoma metastatic to the thyroid gland, and found 28 articles reporting 78 cases. CONCLUSION: It is possible to differentiate between primary and secondary thyroid squamous cell carcinoma, on the basis of combined evidence from clinical examination and endoscopic, pathological and radiological evaluation. Such differentiation is important, as the prognosis for primary squamous cell carcinoma is uniformly poor irrespective of treatment, and the most suitable option may be supportive therapy. Treatment for secondary squamous cell carcinoma of the thyroid varies with the site and extent of spread of the primary tumour.

Neutrophils, Helicobacter pylori, and nonsteroidal anti-inflammatory drug ulcers.

BACKGROUND & AIMS: Gastric injury by nonsteroidal anti-inflammatory drugs (NSAIDs) is minimal in neutropenic animals. This study examined peptic ulcer development in the presence or absence of gastric neutrophils in patients requiring long-term use of NSAIDs. METHODS: Gastric histology, neutrophils, and Helicobacter pylori were assessed in 120 patients randomized to receive placebo or 20 or 40 mg famotidine twice daily as prophylaxis against NSAID-related ulcers and who underwent endoscopy at 0, 4, 12, and 24 weeks. RESULTS: In 43 patients without gastric neutrophils, ulcers developed in 1 of 14 (7.7%) taking placebo, 2 of 16 (12.5%) taking 20 mg famotidine, and none of 13 taking 40 mg famotidine. However, in 77 patients with neutrophils, ulcers developed in 13 of 28 (47. 4%) taking placebo (P < 0.001), 3 of 26 (12.6%) taking 20 mg famotidine, and 3 of 23 (13%) taking 40 mg famotidine. Eight of 46 patients (17%) without H. pylori had neutrophils compared with 69 of 74 (93%) with both H. pylori and neutrophils (P < 0.001). CONCLUSIONS: Gastric neutrophils increase the incidence of ulceration in long-term NSAID users. Because neutrophils exist with H. pylori, eradicating this infection might prevent NSAID-related peptic ulcers.

Helicobacter pylori infection and chronic gastric acid hyposecretion.

BACKGROUND & AIMS: We have identified a subgroup of Helicobacter pylori-infected subjects with low or absent gastric acid output. The aim of this study was to document the morphological and functional abnormalities in these subjects and to assess the effect of eradicating the infection. METHODS: The 16 hypochlorhydric subjects (6 men) had a mean age of 55 years (range, 36-79 years). They underwent a 14C-urea breath test, H. pylori serology, fasting gastrin, gastric autoantibodies, gastroscopy with antral and body biopsies, and measurement of peak acid output to pentagastrin (PAO(PG)). Their histology was compared with that of age- and sex-matched duodenal ulcer and nonulcer dyspepsia patients (16 each). H. pylori infection was eradicated in the hypochlorhydric subjects, and the investigations were repeated 6 months later. RESULTS: Compared with controls, the hypochlorhydric subjects had less dense H. pylori colonization, body-predominant colonization and gastritis, and increased prevalence of body atrophy and intestinal metaplasia. Median PAO(PG) before eradication in the hypochlorhydric subjects was 1.1 mmol/h and increased to 12.6 mmol/h after eradication (P < 0.001), with no significant change in body atrophy or intestinal metaplasia. CONCLUSIONS: In some subjects, chronic H. pylori infection produces a body-predominant gastritis and profound suppression of gastric acid secretion that is partially reversible with eradication therapy.

Collagen promotes perianastomotic tumour growth in an experimental animal model.

Local application of growth factors promote wound healing and may find clinical application for use in high-risk intestinal anastomoses such as that following anterior resection. Since viable tumour cells are present in the bowel lumen and circulation after curative colorectal cancer surgery, it is unclear what effect such factors may have on tumour recurrence. The aim of this study was to examine the effect of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) in a collagen suspension on perianastomotic tumour growth in an animal model. Significantly (P < 0.05) more animals in the collagen treated groups developed anastomotic tumours. The area of tumour growth at the anastomosis was also significantly greater for the collagen (median 14.7 mm2) and collagen + EGF (median 10.8 mm2) groups compared with controls (median 0.78 mm2). We were unable to demonstrate any promotion of tumour by growth factors alone. Collagen promotes perianastomotic tumour growth in this model and is not a suitable vehicle for growth factor application in colorectal cancer surgery.

Oesophageal histology in long term users of non-steroidal anti-inflammatory drugs.

AIMS: To study the oesophageal histological changes in long term users of non-steroidal anti-inflammatory drugs (NSAIDs) compared with patients not receiving these drugs. METHODS: Ninety eight patients were studied, 53 of whom had taken NSAIDs for three years; 45 had not. Oesophageal biopsy specimens were taken from healthy-looking mucosa in the lower third of oesophagus. The papillary length, the thickness of the basal cell layer, and the intensity of cells infiltrating the epithelium were all assessed blind. RESULTS: The NSAID group included four (7%) cases of papillary elongation and two (4%) cases of basal cell hyperplasia, compared with 13 (29%; p < 0.01) and eight (18%; p < 0.02), respectively, in patients not taking NSAIDs. The total histological scores were also lower in patients treated with NSAIDs. CONCLUSION: Long term NSAID users have fewer oesophageal histological abnormalities than patients not receiving NSAIDs. Macroscopic damage related to NSAID use is, therefore, unlikely to require pre-existing histological oesophagitis for its development.

Predicting NSAID related ulcers--assessment of clinical and pathological risk factors and importance of differences in NSAID.

Although ulcers are often associated with non-steroidal anti-inflammatory drugs (NSAIDs) little is known about the feasibility of predicting their development in patients taking NSAIDs. In addition, the ulcerogenic potentials of the newer NSAIDs, taken on long term basis, have not been compared with those of more established preparations. The aim of this study was to identify the clinical and pathological characteristics of patients at a higher risk of NSAID induced ulcers, measure the ulcerogenic potential of a variety of NSAIDs, and test the effect of these potentials on the predictability of ulceration. Altogether 190 long term NSAID users were studied. The presence of abdominal complaints, previous history of ulcers, arthritis related physical disability, anaemia, gastritis, and Helicobacter pylori status were all assessed as possible risk factors. NSAIDs were classified into established drugs (group I), and newer agents (group II). Group I included naproxen, indomethacin, diclofenac, ketoprofen, piroxicam, and flurbiprofen. Group II included fenbufen, nabumetone, ibuprofen, etodolac, azapropazone, and tiaprofenic acid. Of 63 ulcers identified in the study group, 51 (81%) were seen in group I NSAID patients (51 of 132, 39%) compared with 12 ulcers in group II (12 of 58, 21%), p < 0.02; estimated relative risk (ERR): 2.41). In group I, 25 ulcers were found in 38 patients with abdominal pain (25 of 38, 66%, p < 0.01, ERR: 5.03); 18 in 25 (72%) patients with a previous history of ulcers (p < 0.001, ERR: 5.77), 26 in 44 (59%) patients with debilitating arthritis (p < 0.001, ERR 3.64), and 35 in 73 (48%) patients with H pylori associated gastritis (p < 0.01, ERR: 2.48). The presence of these factors in group II patients did not influence the risk of ulceration. Group I NSAIDs were more likely to be associated with chemical gastritis and to intensify H pylori related damage. Although silent ulcers are not uncommon in patients taking NSAIDs, recognition of the risk factors might helps predict a significant number (up to 81%), especially in those receiving group I NSAIDs.

Effect of Helicobacter pylori and its eradication on gastric juice ascorbic acid.

The presence of ascorbic acid in gastric juice may protect against gastric carcinoma and peptic ulceration. This study examined the effect of Helicobacter pylori (H pylori) on the secretion of ascorbic acid into gastric juice by measuring fasting plasma and gastric juice ascorbic acid concentrations in patients with and without the infection and also before and after its eradication. Gastric juice ascorbic acid concentrations in 19 H pylori positive patients were significantly lower (median 2.8, range 0-28.8 micrograms/ml) than those in 10 H pylori negative controls (median 17.8, range 5.6-155.4 micrograms/ml) (p < 0.0005) despite similar plasma ascorbic acid concentrations in both groups. The median gastric juice:plasma ascorbic acid ratio in the H pylori positive patients was only 1.16 (range 0.02-6.67), compared with a median ratio of 4.87 (range 0.76-21.33) in H pylori negative controls (p < 0.01). In the patients with H pylori infection there was a significant negative correlation between the severity of the antral polymorphonuclear infiltrate and gastric juice ascorbic acid concentrations (correlation coefficient -0.52, p = 0.02). After eradication of H pylori in 11 patients, gastric juice ascorbic acid concentrations rose from 2.4 (0-12.8 micrograms/ml) to 11.2 (0-50 micrograms/ml) (p = 0.01). The median gastric juice: plasma ascorbic acid ratio also increased from 1.33 (0.05-6.67) to 2.89 (0.01-166) (p = 0.01). In conclusion, the high gastric juice:plasma ascorbic acid ratio in H pylori negative subjects shows active secretion of ascorbic acid into gastric juice. Secondly, H pylori infection causes a reversible lowering of gastric juice ascorbic acid concentrations, which may predispose to gastric carcinoma and peptic ulceration.

Duodenal histology, ulceration, and Helicobacter pylori in the presence or absence of non-steroidal anti-inflammatory drugs.

Duodenitis and gastric metaplasia, which is often colonised by Helicobacter pylori (H pylori), are increasingly recognised for their importance in the pathogenesis of duodenal ulcers. The situation is not clear in patients receiving non-steroidal anti-inflammatory drugs (NSAIDs), who have a higher risk of peptic ulceration. The aim of this study was to identify the duodenal histological abnormalities in the presence or absence of NSAIDs, H pylori, and duodenal ulceration. Endoscopic duodenal biopsy specimens were taken from healthy looking mucosa of 172 patients (74 took NSAIDs, and 98 did not). Duodenitis was graded according to the degree of neutrophilic and plasma cell infiltration, villus height, Brunner's gland prolapse, and gastric metaplasia. The activity of duodenitis was dependent on the neutrophilic infiltration. A global score covering all the above factors was constructed, and H pylori in both the stomach and duodenum, was also assessed. The results showed that duodenitis with varying degrees of neutrophilic infiltration and gastric metaplasia was found in 20 patients (27%) taking NSAIDs, compared with 56 patients (57%) not taking NSAIDs (chi 2 = 16.24, p < 0.001). This degree of duodenitis was also found in 20 of 25 patients (80%) with duodenal ulcers, regardless of NSAID intake (chi 2 = 15.38, p < 0.001). Gastric metaplasia was identified in 20 patients (27%) receiving NSAIDs and 38 (39%) not receiving NSAIDs. Duodenal H pylori was only seen in patients with gastric metaplasia 10 (50%) receiving NSAIDs, and 34 (89%) not receiving NSAIDs. H pylori positive gastritis, and the combination of active duodenitis and gastric metaplasia were independent predictors of duodenal ulceration. It is concluded that active duodenitis is less common in patients taking NSAIDs but is strongly associated with gastric metaplasia, H pylori positive gastritis, and duodenal ulceration. These findings are relevant to the pathogenesis and treatment of duodenal ulcers in patients taking NSAIDs.

Effect of fibrin sealant on perianastomotic tumor growth in an experimental model of colorectal cancer surgery.

Viable intraluminal tumor cells can penetrate a clinically intact rodent colonic anastomosis and give rise to perianastomotic tumor growth. The aim of this study was to determine whether transanastomotic cell migration can be prevented by fibrin-based tissue sealant. Following distal colonic transection and reanastomosis with 5/0 silk sutures, Fischer F344 rats were randomly allocated to three experimental groups. In Group A, a circumferential ring of tissue sealant was placed around the serosal surface of the anastomosis; in Group B, sealant was limited to 50 percent of the anastomotic circumference; and, in Group C, no sealant was applied. All rats then had 10(5) Mtln3 carcinoma cells injected into the proximal colonic lumen via a rectal catheter. The incidence of perianastomotic tumor at 21 days was significantly lower in Group A (3 of 14 animals) than in Group B (11 of 16 rats) (P = 0.012; Fisher's exact test) or Group C (10 of 14 rats; P = 0.011). A further experiment demonstrated that sealant did not protect the anastomosis when tumor cells were instilled directly into the peritoneal cavity. A topical carcinocidal action therefore appears unlikely, but our results suggest that a circumferential anastomotic ring of fibrin sealant forms an effective mechanical barrier preventing intraluminal tumor cells from reaching the peritoneal cavity.

A study of the pathogenesis of Helicobacter pylori negative chronic duodenal ulceration.

In the past five years 12 patients have been identified presenting with chronic duodenal ulcer (DU) disease and with no evidence of current or recent Helicobacter pylori (H pylori) infection. Four of them were taking regular non-steroidal anti inflammatory agents, one was subsequently found to have Crohn's disease of the duodenum, and one to have the Zollinger-Ellison syndrome. The remaining six patients with idiopathic DU disease were remarkable for their absence of the A1 blood antigen gene. Detailed studies of gastric function were performed in these six patients and compared with H pylori positive patients with DU and with healthy volunteers. The median integrated gastrin response in the patients with idiopathic DU (2810 (range 750-8750) ng/l min) was similar to that of the H pylori positive patients with DU (3355 (550-8725)) and higher than that of the H pylori negative healthy volunteers (560 (225-1125)). The median peak acid output in the patients with idiopathic DU (37 mmol/h, range 17-52) was similar to that of the H pylori positive patients with DU (40 (15-57)) and higher than that of the non-ulcer controls (22 (16-29)). The median percentage of a liquid meal retained in the stomach at 60 minutes was less in the patients with idiopathic DU (23 (15-33)) than in H pylori negative healthy volunteers (34 (30-53) p < 0.01). The median percentage of a solid meal retained at 60 minutes was less in the patients with idiopathic DU (54 (9-83)) than in either H pylori negative healthy volunteers (87 (49-95) p<0.01) or H pylori positive patients with DU (79 (51-100) p<0.01). In conclusion, three abnormalities of gastric function are prevalent in patients with H pylori negative idiopathic DU disease - hypergastrinaemia, increased acid secretion, and the one feature distinguishing them from H pylori positive patients with DU - rapid gastric emptying of both liquids and solids. Each of these abnormalities will increase the exposure of the duodenal mucosa to acid and thus explain its ulceration. The absence of the blood group A1 antigen gene is consistent with a genetic basis for the disturbed gastric function linked to the ABO blood group antigen genes.

Effect of Helicobacter pylori infection on intragastric urea and ammonium concentrations in patients with chronic renal failure.

AIM: To assess the value of measuring the gastric juice urea:ammonium ratio in detecting Helicobacter pylori infection in patients with chronic renal failure. METHODS: Twenty three (12 men) patients with established chronic renal failure and dyspepsia were studied. Gastric juice (2 ml) was aspirated during endoscopy to measure urea and ammonium. The upper gastrointestinal tract was routinely inspected and two antral biopsy specimens obtained. The 14C-urea breath test was conducted within 14 days of endoscopic examination to determine H pylori antibody response. RESULTS: The median (range) serum urea concentration in 11 patients with renal failure and H pylori infection was similar to that in 12 without H pylori infection. The median gastric juice urea concentration in subjects with infection was lower than that in the subjects without infection (p < 0.01). The median gastric juice ammonium concentration in subjects with the infection was higher compared with subjects without infection (p < 0.01). There was an overlap of the urea and ammonium concentrations in gastric juice from both H pylori positive and negative subjects. The urea:ammonium ratio was 0.16 (0.01-1.11) for subjects with H pylori compared with 1.63 (1.0-18.9) in subjects without infection (p < 0.001). CONCLUSION: The urea:ammonium ratio differentiated both groups, with the exception of one false negative result. The urea:ammonium ratio proved almost as effective in identifying the presence of H pylori infection in subjects with chronic renal failure as it had in subjects with normal renal function.

The diagnosis of Helicobacter pylori infection in uremic patients.

Two urease-based tests--the urease slide test and the radiolabeled urea breath test, are commonly used for the diagnosis of Helicobacter pylori infection of the stomach. The reliability of these tests in chronic uremia was compared with serological tests for H pylori antibodies, and with direct detection of the organism by microscopy or culture of gastric antral biopsies. Twenty-seven patients with chronic renal failure and dyspepsia underwent upper gastrointestinal endoscopy. Twelve of these patients (46%) were judged to be infected with H pylori on the basis of identification of the organism on microscopy or culture of antral biopsy. Both urease-based tests were able to determine H pylori status, despite the markedly increased concentrations of urea in the gastric juice found in chronic renal failure. The urease slide test performed on antral biopsies obtained at endoscopy proved reliable in determining H pylori status with no false-positive nor false-negative results after 20 minutes and 24 hours of incubation. The 14C-urea breath test also differentiated the infected from the uninfected patients. The 20-minute 14CO2 excretion (kg %dose/mmol CO2 x 100) ranged from 50 to 834 in the H pylori-infected patients, compared with 0.3 to 27 in the H pylori-noninfected patients (P < 0.0001); the 90-minute values ranged from 88 to 398 in the former, compared with 1 to 79 in the latter (P < 0.0001). The excretion of 14CO2 (derived from bacterial hydrolysis of ingested 14C-urea) was higher in all the uremic patients compared with nonuremic controls, and in half of the H pylori-noninfected uremic patients there was a late increase in 14CO2 excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of ammonia in the pathogenesis of the gastritis, hypergastrinaemia, and hyperpepsinogenaemia I caused by Helicobacter pylori infection.

Studies were performed in patients with and without renal failure to investigate the role of bacterial ammonia production in the pathogenesis of the mucosal abnormalities caused by Helicobacter pylori. The high rate of H pylori ammonia production in uraemic patients should accentuate any ammonia induced effects. The median (range) gastric juice ammonium concentration in the H pylori positive patients with renal failure was 19 mmol/l (II-43) compared with 5 mmol/l (1-11) in the H pylori positive patients without renal failure (p < 0.005). In the H pylori negative patients the values were 3 mmol/l (0.5-11) and 0.7 mmol/l (0.1-1.4) respectively in the patients with and without renal failure (p < 0.01). Despite the much higher ammonia production in the H pylori positive uraemic patients, the nature and severity of their gastritis was the same as that in the H pylori positive non-uraemic patients. The median (range) fasting serum gastrin concentration was raised in the uraemic patients compared with the non-uraemic patients but was similar in the uraemic patients with (95 pmol/l (52-333)) or without (114 pmol/l (47-533)) H pylori infection. The median (range) serum pepsinogen I concentration was also high in the uraemic compared with the non-uraemic patients and was significantly higher in uraemic patients with H pylori (352 ng/ml, range 280-653) than in those without H pylori infection (165 ng/ml, range 86-337) (p < 0.01). These findings indicate that the gastritis and hypergastrinaemia associated with H pylori infection are not the result of mucosal damage induced by the organism's ammonia production.

Is Helicobacter pylori associated hypergastrinaemia due to the bacterium's urease activity or the antral gastritis?

Eradication of Helicobacter pylori is associated with a fall in serum gastrin but the way in which the infection raises the serum gastrin concentration is not clear. It may be related to the ammonia produced by the bacterium's urease stimulating gastrin release by the antral G cells. Alternatively, the antral gastritis induced by the infection may modify the regulation of gastrin release. We have examined serum gastrin in 10 patients before and 24 hours after starting triple anti-H pylori treatment consisting of tripotassium dicitrato bismuthate 120 mg four times daily, metronidazole 400 mg three times daily, and amoxycillin 500 mg three times daily. The urease activity, assessed by the 20 minute value of the 14C-urea breath test, fell from a median of 176 (range 116-504) kg% dose/mmol CO2 x 100 pretreatment to 5 (2-15) at 24 hours (p less than 0.005). The median antral gastritis score was 6 (4-6) pretreatment and fell to 3 (2-5) at 24 hours (p less than 0.02), and this was due to resolution of the polymorphonuclear component. Despite this complete suppression of bacterial urease activity and partial resolution of antral gastritis the median basal gastrin concentration remained unchanged, being 57 ng/l (45-77) pretreatment and 59 ng/l (45-80) at 24 hours and the median integrated gastrin response to a standardised meal was also unaltered, being 4265 ng/l/min (range 1975-8350) and 4272 ng/l/min (range 2075-6495) respectively. These findings do not support a causal association between H pylori urease activity and hypergastrinaemia and show rapid improvement of antral gastritis after starting anti-H pylori treatment.

Plasma gastrin, daytime intragastric pH, and nocturnal acid output before and at 1 and 7 months after eradication of Helicobacter pylori in duodenal ulcer subjects.

Nine patients with Helicobacter pylori-related antral gastritis and history of duodenal ulceration were studied before and at 1 and 7 months after eradication of the infection by a 4-week course of tripotassium dicitrato bismuthate, metronidazole, and amoxycillin. The median basal gastrin concentration before eradication was 30 ng/l (range, 20-60) and fell to 20 ng/l (5-20) at 1 month (p less than 0.02) and 15 ng/l (5-20) at 7 months (p less than 0.01) after eradication. The integrated gastrin response to a peptide meal was 3650 ng/l.min (range, 1875-6025) before treatment compared with 1800 ng/l.min (range, 1200-3075) at 1 month (p less than 0.01) and 1312 ng/l.min (875-2625) at 7 months (p less than 0.03). Daytime intragastric pH (0900-2100 h) was similar before treatment (median, 1.4; range, 1.1-2.1) and at 1 month (1.4; 1.1-2.3) and 7 months (1.4; 1-2.2) after eradication. In five of the patients nighttime acid output (2300-0900 h) was also studied and was similar before (median, 86 mmol/10 h; range, 52-114) and at 1 month (76 mmol/10 h; 50-143) and 7 months (94 mmol/10 h; 63-106) after eradication. In conclusion, eradication of H. pylori is accompanied by a sustained fall in serum gastrin concentrations but is not accompanied by an early or late reduction of daytime intragastric acidity or nighttime acid output.