Imaging aspects of the tumor stroma with therapeutic implications

Cancer cells rely on extensive support from the stroma in order to survive, proliferate and invade. The tumor stroma is thus an important potential target for anti-cancer therapy. Typical changes in the stroma include a shift from the quiescence promoting-antiangiogenic extracellular matrix to a provisional matrix that promotes invasion and angiogenesis. These changes in the extracellular matrix are induced by changes in the secretion of extracellular matrix proteins and glucose amino glycans, extravasation of plasma proteins from hyperpermeable vessels and release of matrix modifying enzymes resulting in cleavage and cross-linking of matrix macromolecules. These in turn alter the rigidity of the matrix and the exposure and release of cytokines. Changes in matrix rigidity and vessel permeability affect drug delivery and mediate resistance to cytotoxic therapy. These stroma changes are brought about not only by the cancer cells, but also through the action of many cell types that are recruited by tumors including immune cells, fibroblasts and endothelial cells. Within the tumor, these normal host cells are activated resulting in loss of inhibitory and induction of cancer promoting activities. Key to the development of stroma-targeted therapies, selective biomarkers were developed for specific imaging of key aspects of the tumor stroma.

Bodily habitus and mitral valve prolapse

We investigated the hypothesis that patients with idiopathic mitral valve prolapse (MVP) have distinctive anthropometric characteristics as part of an ill-defined connective tissue abnormality. In 100 consecutive patients with MVP identified at echocardiography, 56 women and 44 men (age range 28-78 years), we compared measurements of height, weight, arm span, upper and lower body segments, anteroposterior chest diameter, anteroposterior chest diameter/height index, body mass index, and metacarpal index with those from an age and sex matched control group. We also compared the frequency of thoracic asymmetry in MVP patients and controls. Both male and female MVP patients had lower body mass indices than their controls (p less than 0.01 and p less than 0.01 and p less than 0.001, respectively). Women with MVP were lighter than their controls (p less than 0.001) and the same trend was seen in men (p = 0.14). There were no significant differences with any of the other measurements or in the frequency of thoracic asymmetry. We conclude that patients of both sexes with idiopathic MVP are leaner than control subjects but do not otherwise have a specific bodily habitus or an increased frequency of thoracic cage abnormalities. The findings do not support the hypothesis of an underlying generalised connective tissue abnormality but raise the interesting question of why MVP patients should be lean.

Is pancreatic duct obstruction or stricture a major cause of pain in calcific pancreatitis?

Forty-seven patients with calcific pancreatitis were submitted to ERCP, 24 of whom were designated 'painless' and 23 'painful', according to whether or not pain had occurred during the previous year. The pancreatic duct was cannulated in 39 of these patients. The incidence of pancreatic duct obstruction or stricture was of the same order in the painless (13/20, 65 per cent) and painful (15/19, 79 per cent) groups. Alcohol was the aetiological factor in 46 patients. Twenty-four (52 per cent) continued to drink, and were equally divided between the painless (12) and painful (12) groups. Four out of 13 in the painless and 7 out of 14 in the painful groups, with a stricture or obstruction, continued to drink. The difference was statistically not significant. These results suggest that ERCP findings of pancreatic duct obstruction or stricture need not necessarily be pertinent to the pain in patients with chronic pancreatitis.

Histamine H2-receptor antagonists in the treatment of duodenal ulcers

A double-blind trial of histamine H2-receptor antagonists and placebo was carried out in 46 patients with endoscopically proven duodenal ulceration. H2-receptor antagonists (metiamide and cimetidine) produced a significantly greater degree of completely healed ulcers and fewer complete failures than placebo. The results of the trial indicate that H2-receptor antagonists promote the healing of ulcers. The action of these compounds would appear to be related to the inhibition of acid secretion. Neither the duration of the illness, rate of recurrence of the ulcers of level of gastric acid secretion materially affected the healing rate in indvidual patients. There were no serious side-effects over the 6-week period of drug administration, but the metiamide was replaced by cimetidine because reports from other centrea indicated that agranulocytosis was associtated with metiamide therapy.

Endoscopic retrograde cholangiopancreatography in the evaluation of pancreatic disease

Endoscopic retrograde cholangiopancreatography (ERCP) was carried out in 98 patients with unexplained abdominal pain or known pancreatitis with recurrent pain. Patients with jaundice were excluded from the study. In 38 patients with a clinical diagnosis of pancreatitis, the radiological findings on ERCP were graded according to the criteria of Kasugai et al. Advanced pancreatitis was found in 20 patients (52,5%), moderate changes in 7 (18,4%) and minimal-change pancreatitis in 6 (15,8%). ERCP had normal pancreatic function tests. In 35 patients investigated for unexplained abdominal pain, changes consistent with pancreatitis were found in 7, pancreatic carcinoma in 5, a duodenal ulcer in 2, gallstones in 1 and a duodenal tumour in 1. ERCP was normal in 19 patients. A comparison of the findings on ERCP and the standard secretin-cholecystokinin pancreatic function test was available in 52 patients. There was a good agreement between the two tests in the patients with advanced or moderate pancreatitis as revealed by ERCP, but less agreement in the patients with minimal-change pancreatitis. A few patients with clinical pancreatitis and abnormal ERCP had normal pancreatic function tests. ERCP increases the diagnostic yield in patients suspected of having pancreatitis and is at present the only reliable method of diagnosing pancreatic carcinoma which is not evident by other non-operative techniques. ERCP is also of value in the assessment of the severity of pancreatitis and is a necessary investigation before pancreatic surgery to confirm or exclude cyst formation or the site of duct obstruction. The finding of an unsuspected cyst at ERCP necessitates early operation because of the danger of introducing infection during the procedure.