Androgen and progesterone receptors in colonic and rectal cancers

Sex steroid metabolism and action in colon health and disease

The colon is the largest hormonally active tissue in the human body. It has been known for over a hundred years that various hormones and bioactive peptides play important roles in colon function. More recently there is a growing interest in the role the sex steroids, oestrogens and androgens, may play in both normal colon physiology and colon pathophysiology. In this review, we examine the potential role oestrogens and androgens play in the colon. The metabolism and subsequent action of sex steroids in colonic tissue is discussed and how these hormones impact colon motility is investigated. Furthermore, we also determine how oestrogens and androgens influence colorectal cancer incidence and development and highlight potential new therapeutic targets for this malignancy. This review also examines how sex steroids potentially impact the severity and progression of other colon disease, such as diverticulitis, irritable bowel syndrome, and polyp formation.

Estrogen and Progesterone Receptors in Human Colorectal Tumour Cells (Study of 70 Cases)

Estrogen and progesterone receptors were studied in 70 cases of human colorectal cancer by a cytochemical technique. 28.5% of the cases were estrogen-receptor positive and 42.8% progesterone-receptor positive.

There was no difference between the sexes for estrogen receptors but the women had more tumours with progesterone receptors than men.

The presence of receptors is unrelated to the differentiation of the tumour. More colon tumours were positive than those of the sigma and rectum. The concentration of cells with receptors in positive cancer cases tended to be low or medium-low.

Estrogen Receptors in Colorectal Adenocarcinomas and in Other Large Bowel Diseases

Seventy-two patients with tumor and ten with non-neoplastic colon disease were studied for the presence of estrogen receptors (ER) by three different methods. Only seven specimens (six primary adenocarcinomas and one recurrent cancer) had an ER concentration above 3 fm/mg of cytosolic protein, with no sex, age and tumor stage correlation. Our results suggest that the large bowel does not contain a cytosolic receptor for estradiol.

Androgen receptor (AR) expression is an independent unfavorable prognostic factor in gastric cancer

PURPOSE

To investigate the expression of sex steroid receptors in gastric cancer and to correlate their tumor expression profile with the clinicopathological parameters and overall survival of the patients.

METHODS

Immunohistochemical methodology was employed in formalin-fixed paraffin-embedded sections from 86 patients with gastric carcinoma. Monoclonal antibodies against androgen (AR), estrogen (ER), and progesterone (PR) receptors were used. Survival rates were estimated by the Kaplan-Meier method and compared using the log-rank test. Multivariate analysis was performed by the Cox proportional hazards model.

RESULTS

Fifteen (17.4%) cases of gastric adenocarcinomas were positive for AR, two (2.3%) were positive for PR and three (3.5%) were positive for ER. Significantly higher AR expression was found in tumors with metastases to lymph nodes (P = 0.03). Patients with AR-positive tumors (AR+) had worse prognosis than (AR-) patients (median survival 9 months vs 24 months, P = 0.03). Patients with AR- and heat shock protein 27 (HSP27)-positive tumors (AR+/HSP27+) had a median survival of 6 months, whereas (AR-/HSP27-) patients had a median survival of 42 months (P = 0.017). Multivariate analysis revealed that AR expression and UICC stage were independent factors of unfavorable prognosis (P = 0.037 and P = 0.0055, respectively).

CONCLUSIONS

Identification of AR-positive gastric carcinomas in gastric biopsies may warrant a more aggressive therapeutic approach and anti-androgen or AR-targeted agents may represent a novel strategy in tackling this devastating malignancy.

Colon cancer during pregnancy

The medical community should become mobilized to diagnose colon cancer earlier in pregnancy to improve prognosis. The primary care physician or obstetrician should refer the pregnant patient with significant gastrointestinal complaints to the gastroenterologist for evaluation. Likewise, the gastroenterologist should be prepared to perform sigmoidoscopy, preferably without endoscopic medications, for significant lower gastrointestinal symptoms such as persistent rectal bleeding. Sigmoidoscopy is particularly sensitive in identifying colon cancer in pregnant patients because their cancers are usually distal and within reach of the sigmoidoscope.

Somatic alterations of the androgen receptor CAG repeat in human colon cancer delineate a novel mutation pathway independent of microsatellite instability

The human androgen receptor gene contains a polymorphic CAG repeat region ranging from 8 to about 35 repeats in the normal human population. The repeat length is inversely related to the transactivation potential of the receptor. We have analyzed the repeat length in 50 sporadic colon cancer samples in comparison to surrounding healthy mucosa and have found somatic reductions of up to 10 repeats in 5 cases (10%), 3 of which were complex, probably involving both alleles. Alterations occurred in tumors with and without microsatellite instability indicating that they follow an independent mutation pathway. The similar repeat of the huntingtin gene did not show any somatic alterations in the same cases. No correlation to sex, tumor stage, location, or histology was evident. In the tumors that showed somatic reductions, the reduced allele was present in at least half of the cells and thus in most, if not all, of the tumor component of the sample. Somatic reductions of the androgen receptor CAG repeat thus occur frequently, through a pathway distinct from microsatellite instability and early during colon carcinogenesis. The receptor is expressed in most normal and neoplastic tissue samples analyzed. Apparent growth selection of cells bearing shortened AR alleles suggests that androgens contribute to colon carcinogenesis in a yet unknown way.

Cell surface molecules and their prognostic values in assessing colorectal carcinomas

OBJECTIVE

Carcinomas of the colon and rectum are the third leading cause of cancer-related deaths. Although advances in the surgical treatment of primary colorectal cancers have lead to improvements in patient survival at early tumor stages, treatment of more progressive cancers has not resulted in dramatic improvements in patient survival. However, the selection of patient subgroups based on their prognosis and other characteristics could result in improved outcomes from adjuvant therapies in patients with Dukes B and C carcinomas.

METHODS

The authors reviewed the available data on the value of cell surface molecules in assessing the prognosis of colorectal carcinomas, paying specific attention to the evaluation of statistical analysis and multivariate procedures.

RESULTS

Cell surface molecules have been identified on colorectal carcinoma cells whose expression appears to be related to malignant transformation, tumor progression, or patient prognosis. Among these cell surface molecules, various cell adhesion molecules, growth factor receptors, proteinases, and their receptors and inhibitors have been identified as potentially useful prognostic markers.

CONCLUSIONS

Although data exist on the prognostic values of certain cell surface markers, the use of multivariate analysis for the identification of valuable prognostic factors remains uncommon. Using reproducible and standardized multivariate analysis procedures, new tumor markers should be carefully examined for their biologic and prognostic relevance before being considered as potentially useful in the management of colorectal cancers.

Colon cancer during pregnancy. The gastroenterologist's perspective

Colon cancer during pregnancy is uncommon but not rare, with an estimated incidence of several hundred cases per year in the United States. This type of cancer tends to have a poor prognosis that is attributable to delays in diagnosis and advanced disease at diagnosis. The diagnosis frequently is delayed because symptoms of colon cancer, such as rectal bleeding, nausea and vomiting, and constipation, often are attributed to normal pregnancy or minor complications of pregnancy. Pregnancy affects the diagnostic evaluation and therapy of colon cancer because of fetal risks of diagnostic tests and therapy. Appropriate medical evaluation of significant lower gastrointestinal complaints during pregnancy can lead to an earlier and improved diagnosis.

Estrogens, androgens, and EGF receptor expression in gastric carcinoma induced by N-methyl-N'-nitro-N-nitrosoguanidine

Complex and conflicting relationships between epidermal growth factor (EGF), estrogens (E), androgens (A), and related receptors (EGF-R, E-R, A-R) have been reported in different biological situations associated with cell proliferation. There is also evidence that EGF and sex hormone receptors may be involved in normal and neoplastic growth of the gastrointestinal mucosa. In this study, we investigated the behavior of EGF receptors and sex hormone and related receptors, during N-methyl-N'-nitro-N-nitrosoguanidine (NG)-induced gastric carcinogenesis in Sprague-Dawley male rats. Four groups of 15 rats each (10 NG-treated and five controls) were sacrificed after 1, 20, 30, and 40 weeks of treatment. Gastric tissue from each rat was processed for receptor status (number and affinity) and proliferative activity. A significant and progressive decrease of A-R and EGF-R was observed starting from the 20th week, while no change of E-R occurred throughout the experiment. Cell proliferation in the gastric mucosa of NG-treated rats increased after 30 weeks of treatment. These data indicate that NG treatment is able to modify the receptor status of gastric mucosa in rats.

Colon and rectal cancer in pregnancy

Colorectal carcinoma presenting in pregnancy is an uncommon disease that is reported to be associated with an extremely poor prognosis. To better characterize this disease, we surveyed the membership of the American Society of Colon and Rectal Surgeons by mailed questionnaire and reviewed the literature. Forty-one new cases of women with large bowel cancer who presented during pregnancy or the immediate postpartum period were identified. The mean age at presentation was 31 years (range, 16-41 years). Tumor distribution was as follows: right colon-3, transverse colon-2, left colon-2, sigmoid colon-8, and rectum-26. Dukes stage at presentation was A = 0, B = 16, C = 17, and D = 6 (two patients were unstaged). Average follow-up was 41 months. Stage for stage, survival was found to be similar to patients with colorectal tumors in the general population. Large bowel cancer coexistent with pregnancy presents in a distal distribution (64 percent of tumors in the current series and 86 percent of those reported in the literature were located in the rectum) and presents at an advanced stage (60 percent were Stage C or more advanced at the time of diagnosis). While patient survival is poor, it is no different stage for stage from the general population with colorectal tumors.

Estradiol is trophic for colon cancer in mice: effect on ornithine decarboxylase and c-myc messenger RNA

The mitogenic role of estradiol on the growth of colon cancer was examined in mice. Sham-operated or ovariectomized mice were injected with cancer cells and received estradiol treatment. Tumor growth was noted: tumor weights were higher in female than male mice. The growth of the tumors was least in ovariectomized mice and highest in estradiol-treated ovariectomized mice. Tumor messenger RNA (mRNA) levels for ornithine decarboxylase (ODC) and proto-oncogenes c-myc, c-fos, and H-ras were examined. Two transcripts (2.2 and 2.7 kilobase pairs) of ODC were observed. The steady-state mRNA levels for ODC paralleled the changes observed in the weight of the tumors in all groups of animals. Less dramatic changes were observed in c-myc mRNA levels. No significant differences were observed in the mRNA levels for H-ras and c-fos. It thus appears likely that an increase in the ODC mRNA levels and, to a lesser extent, an increase in c-myc mRNA levels may be some of the important mechanisms by which estradiol mediates its growth effects on colon cancer cells in vivo.

Sex steroid hormone receptors, epidermal growth factor receptor, and polyamines in human colorectal cancer

We assayed the estrogen and progesterone cytosolic receptors by using the enzyme immunoassay method, the epidermal growth factor (EGF) cell surface receptors by using 125I-labeled hormone, and the levels of polyamines (putrescine, spermine, and spermidine) by using a high-pressure liquid chromatography (HPLC) procedure in neoplastic and surrounding normal tissues of patients with colorectal cancer. Our findings show that mean polyamine levels in neoplastic tissue were approximately two-fold greater than the levels in normal colonic mucosa. Estrogen and progesterone receptorial content in normal mucosa were twofold greater than those in neoplastic tissue. No significant differences in EGF receptors were found between colonic cancer tissue and the surrounding normal tissues. The correlations we found between 1) estrogen and polyamine levels and 2) estrogen and EGF binding suggest the existence of a modulation of the estrogens on colonic mucosa cell proliferation. Furthermore, there was no significant dependency of polyamine and receptor concentrations from the tumor site, the histologic differentiation, or the age and sex of patients.

Oestrogen receptor D5 antibody is an independent negative prognostic factor in gastric cancer

Recent studies have demonstrated oestrogen receptors in tissues other than those considered to be sex hormone responsive, for instance in gastric cancer. In vitro experiments have shown oestradiol to be trophic to gastric cancer cell lines. The effect of D5 (an oestrogen receptor-related protein) status on survival was therefore studied in a group of 188 consecutive patients undergoing surgery for gastric cancer. Ninety-two patients (49 per cent) were positive for the D5 antibody. There were no differences between the D5-positive and D5-negative groups for age or adverse prognostic features such as high grade tumours or advanced stage. The D5-negative patients had a significant survival advantage over the D5-positive patients. The 95 per cent confidence interval for survival in the patients with D5-negative tumours was 63-101 weeks compared with 39-66 weeks for the patients with D5-positive tumours (Mantel-Cox statistic = 4.15, P = 0.042). Prognostic factor analysis with a Cox proportional hazards model showed tumour stage (P = 0.001) and D5 status (P = 0.003) to be significant independent factors in gastric cancer. Laurén type, grade and gender were not significant independent factors in this small series.

Influence of sex hormones on pancreatic cancer

A possible new approach to treating pancreatic cancer has been suggested, since the presence of estrogen receptors, estrogen binding proteins, estramustin binding protein, and androgen receptors have been demonstrated in human pancreatic adenocarcinomas of ductular origin. Moreover, there is some evidence that there is a dysfunction of the hypothalamic-sex-organ axis, resulting in low values of gonadotropins as well as testosterone in serum. Confirmatory evidence that all these findings have therapeutic implications in humans is still lacking, but in experimental studies, inhibition as well as growth potentiation of pancreatic cancer can be demonstrated after hormonal manipulations.

Oestrogen receptors in colorectal carcinoma

The oestrogen receptor content of colorectal adenocarcinoma was investigated using an established ligand binding biochemical assay and two more recently introduced techniques using specific monoclonal antibodies (Abbott ER-EIA and ER-ICA assay kits). Twenty nine tumours were investigated by the ligand binding assay. Only one (3.4%) tumour gave a weakly positive result (11 fmol/mg cytosol protein); the rest were all negative. Where sufficient tissue was available, the receptors were also determined by a quantitative immunoassay in 18 patients and an immunohistochemical method in 13 patients. The results were similarly all negative. It is concluded that most colorectal carcinomas, irrespective of sex, are oestrogen receptor negative, and it is thus unlikely that hormonal manipulation would have an influence on the course of the disease.

Colorectal cancer. The bases for a comprehensive follow-up

The purpose of this article was to review the effectiveness of follow-up in patients with colorectal cancer submitted to curative treatment. A comprehensive follow-up involves rational initial management of the primary tumor, knowledge of prognostic factors, selection of the patient to be followed, determination of the time for follow-up, use of the most appropriate tests for early diagnosis of recurrence, and eventual curative treatment. The updated answers to all these questions are given through an extensive review of the world literature and confronted with the authors' experience of eight years of follow-up in a series of 170 colorectal cancer patients treated for cure. Although the future might be more promising, past world experience suggests only a few patients could be saved. It is concluded that there is no place for incomplete and disperse screening tests, and only comprehensive, intensive, and very well-coordinated follow-up programs should be undertaken if better results are hoped to be achieved.

Nuclear and cytosolic estrogen receptors in human colon carcinoma and in surrounding noncancerous colonic tissue

The measurement of estrogen as well as progesterone receptors has been applied clinically to predict the effectiveness of endocrine therapy in patients with breast or endometrial carcinoma. The presence of cytosolic estrogen receptors in human colorectal carcinomas has been reported by several different groups during the past 10 yr. The aim of our current study was to evaluate the estrogen binding activity in the nuclear and cytosolic fractions of these carcinomas, as well as in surrounding noncancerous colonic tissue. Twenty-six patients, operated on for colorectal carcinoma, were studied: 16 were men and 10 were postmenopausal women, mean age 61 yr (range 43-78 yr). In neoplastic tissue, cytosolic estradiol receptors were detected in 42.3% of the patients (women 40%, men 43.7%). The values for cytosolic estrogen receptor ranged from 118 to 1214 fmol/g wet colon. Nuclear estrogen receptors were detectable in 46.1% of the patients (women 40%, men 50%) and their values displayed a range from 3.4 to 2554 fmol/g wet colon. In 30.7% of the patients, both nuclear and cytosolic receptors were demonstrated. In 38.4% of the patients, receptors were found in neither cytosol nor nuclei. Receptor positivity in men was most frequently associated with tumors removed from the rectum, and those with Dukes' classification of C1. In the surrounding noncancerous tissue cytosolic estrogen receptors were also detected (range 133-1105 fmol/g wet colon) and were present in 34.6% of the patients (women 30%, men 37.5%). Nuclear estrogen receptors (range 225-1105 fmol/g wet colon) were detected in 57.6% of the patients (women 40%, men 68.7%). In 23% of the patients, both nuclear and cytosolic receptors were demonstrated. In 30.7% of the patients, no receptors were found in either cytosol or nucleus. Therefore, the presence of cytosolic or nuclear estrogen receptors, or both, in 61.6% of human colorectal cancer specimens emphasizes the need to evaluate both forms of these receptors for studies of potential hormone dependence in these tumors.