Comparative genomic hybridization (CGH) is a molecular cytogenetic technique that allows the entire genome of a tumor to be surveyed for gains and losses of DNA copy sequences. A limited number of studies reporting the use of this technique in adult adrenocortical tumors have yielded conflicting results. In this study we performed CGH analysis on 13 malignant, 18 benign, and 1 tumor of indeterminate malignant potential with the aim of identifying genetic loci consistently implicated in the development and progression of adrenocortical tumors. Tissue samples from 32 patients with histologically proven adrenocortical tumors were available for CGH analysis. CGH changes were seen in all cancers, 11 of 18 (61%) adenomas, and the 1 tumor of indeterminate malignant potential. Of the adrenal cancers, the most common gains were seen on chromosomes 5 (46%), 12 (38%), 19 (31%), and 4 (31%). Losses were most frequently seen at 1p (62%), 17p (54%), 22 (38%), 2q (31%), and 11q (31%). Of the benign adenomas, the most common change was gain of 4q (22%). Mann-Whitney analysis showed a highly significant difference between the cancer group (mean changes, 7.6) and the adenoma group (mean changes, 1.1) for the number of observed CGH changes (P < 0.01). Logistic regression analysis showed that the number of CGH changes was highly predictive of tumor type (P < 0.01). This study has identified several chromosomal loci implicated in adrenocortical tumorigenesis. Activation of a protooncogene(s) on chromosome 4 may be an early event, with progression from adenoma to carcinoma involving activation of oncogenes on chromosomes 5 and 12 and inactivation of tumor suppressor genes on chromosome arms 1p and 17p.

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Serum PTH 1-h after total thyroidectomy is a reliable predictor of hypocalcaemia and can allow safe early discharge of patients from hospital.

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Endogenous histamine has been shown to effect growth mechanisms in experimental mammary carcinomas via H2 membrane receptors (Cricco et al, 1994). Both H1 and H2 binding sites are present in human mammary glands but only 75% malignant carcinomas express H2 receptors (Lemos et al, 1995). The presence of mast cells around tumour tissue raises questions concerning the source of histamine in breast tumour tissue. While cimetidine, an H2 antagonist, has been shown to influence the presence of tumour infiltrating lymphocytes (TIL) in colorectal cancer (Adams and Morris, 1994, 1997) that was not found to be the case in breast cancer (Ng et al, 1995). In recent studies tumour cell proliferation, as measured by Ki-67 antibody labelling, has been seen as an additional prognostic indicator in breast cancer (Railo et al, 1993, 1997; Ferno, 1998; Schauer et al, 1998). We investigated the possibility that cimetidine may influence tumour proliferation by blocking the growth-promoting effects of histamine. No relationship between preoperative cimetidine administration and tumour cell proliferation was seen overall. A weak correlation was seen between tissue histamine content and mast cell count which was not influenced by cimetidine. Tumour cell proliferation correlated well with other prognostic indicators such as grade and differentiation. © 2000 Cancer Research Campaign

Adrenal masses are a common problem affecting 3-7% of the population. The majority turn out to be benign adrenocortical adenomas, which may be functional or non-functional. Much more rarely, these masses represent a primary adrenal carcinoma. It is becoming increasingly recognized that of the benign functioning adenomas or hyperplasias, the majority will hypersecrete aldosterone and this will be more frequently detected when hypertensive populations are screened for this disease. In contrast, the incidence of primary adrenocortical carcinoma has remained steady and for this disease, surgery represents the mainstay of treatment. The advent of laparoscopic adrenal surgery has lowered the threshold size for recommending surgery for asymptomatic adrenal masses and as such, an increased proportion of adrenocortical cancers are being resected and detected at an earlier stage. Recent progress has been made in our understanding of the key genetic changes which underpin the biology of this disease. Progression from adrenal adenoma to carcinoma involves a monoclonal proliferation of cells which, among other defects, have undergone chromosomal duplication at the 11p15.5 locus leading to overexpression of the IGF2 gene and abrogation of expression of the CDKN1C and H19 genes. TP53 is involved in progression to carcinoma in a subset of patients and the frequency of ACTH receptor deletion needs to be more fully explored. Other key oncogenes and tumour suppressor genes remain to be identified although the chromosomal loci in which they lie can be identified at 17p, 1p, 2p16 and 11q13 for tumour suppressor genes and chromosomes 4, 5 and 12 for oncogenes.

Parathyroid surgery is indicated in patients presenting with primary hyperparathyroidism (PHPT) and osteoporosis (defined as bone mineral density more than 2 standard deviations below normal). Many are elderly women with complex medical problems, either unwilling or considered unfit for surgery. Estrogen replacement therapy (ERT) may potentially be an alternative form of therapy in this group. We studied 15 consecutive postmenopausal women presenting with PHPT and osteoporosis. Group 1 comprised 5 women who elected to be treated with ERT (conjugated equine estrogen, 0.3-0.625 mg/day). The other 10 women underwent successful parathyroidectomy. These 10 patients were randomly subdivided into group 2 (5 patients who received calcitriol 0.25 micrograms b.i.d. for 12 months following surgery) and group 3 (5 patients who received elemental calcium 1 g/day for 12 months following surgery). Lumbar spine and femoral neck bone mineral density (BMD) were measured prior to and after 12 months of therapy, using a dual-energy X-ray absorptiometer (Lunar DPX-L). The three groups did not differ with respect to their ages (group mean 71.8 years), or baseline serum calcium (group mean 2.77 mmol/l), serum parathyroid hormone (group mean 11.0 pmol/l), lumbar spine BMD (group mean 0.93 g/cm2) and femoral neck BMD (group mean 0.73 g/cm2). Serum calcium normalized in all patients who underwent surgery and none developed hypoparathyroidism. A non-significant decrease in serum calcium was seen in patients treated with ERT only. Lumbar spine (+5.3% per year; 95% CI, 1.1% to 9.6%) and femoral neck BMD (+5.5% per year; 95% CI, -2.1% to 13.2%) increased significantly after 12 months of ERT (p < 0.001 compared with pre-therapy values). These increases in BMD did not differ significantly from those in patients who underwent successful parathyroidectomy followed by either calcitriol therapy or calcium replacement (lumbar spine BMD increase of +6.2% per year, 95% CI 3.1% to 9.4%; and femoral neck BMD increase of +3% per year, 95% CI 0 to 6%). In summary, increases in lumbar spine and femoral neck BMD occur following treatment of PHPT. ERT appeared as effective as parathyroidectomy (combined with either calcitriol or calcium supplements) for the treatment of osteoporosis in elderly postmenopausal women presenting with PHPT.

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