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The sexual practices of male homosexuals may lead to the development of a wide variety of colorectal and perianal diseases. This review describes the pathogenesis of these conditions, their management, and the influence of HIV infection on these conditions.

Gene transfer techniques have now achieved clinical realization in the wake of recent advances in recombinant DNA technology, together with increased understanding of the molecular biology and immunology of cancer. These novel treatments, and their applications and limitations merit intensive study.

Anal endosonography has been performed in 22 patients with fistula in ano and perianal sepsis and compared with the operative findings. Using a special hard cone attachment to a radial 7 MHz probe the examination was well tolerated, rapid and generally accurate, detecting two unsuspected foreign bodies and all seven complicated fistula in ano preoperatively.

Two hundred and twenty-eight patients with anal carcinoma treated between 1948 and 1984 were reviewed. Of 145 with anal canal carcinoma, 118 were treated by total anorectal excision, nine by local excision and 13 by radiotherapy. Fifteen patients were inoperable. There were five postoperative deaths. Crude and cancer-specific survival rates of 123 patients treated 5 or more years previously were 58 and 64 per cent. These rates for patients undergoing total anorectal excision were 62 and 65 per cent, and local excision 87 and 100 per cent. Eighty-three patients had carcinoma of the anal margin. Of these, 55 were treated by local excision, 18 by total anorectal excision and 20 by radiotherapy. Eight patients were inoperable. Crude and cancer-specific survival rates for 72 patients followed for 5 years were 55 and 57 per cent with respective rates of 65 and 69 per cent after local excision and 36 and 40 per cent after total anorectal excision. The 5-year survival rate of 27 patients with TNM N1stage was 48 per cent. Histological confirmation was obtained in only nine of these patients, however, but five (55 per cent) survived 5 years after block dissection or radiotherapy. Metachronous lymphadenopathy occurred in 25 patients. The 5-year survival rate in the 23 cases that were histologically confirmed was 35 per cent after block dissection (17 cases) and radiotherapy (four cases). Using a modification of Papillon's T classification for anal canal carcinoma, stage correlated with survival after combining T1with T2tumours and T2with T3tumours. Five-year survival rates in these groups were 60 and 54 per cent respectively. The TN M-UICC classification for anal margin carcinoma correlated with survival in a similar manner. The 5-year survival rate was 65 per cent for patients with T1and T2tumours and 33 per cent for those with T3and T4tumours.

Immunocytochemistry was used in parallel with conventional cytology to detect circulating malignant epithelial cells in 42 patients undergoing resection for colorectal cancer. Preoperative peripheral and peroperative mesenteric venous blood samples were taken. Tumour cells were isolated on a density gradient and cytospins prepared. Slides were stained by conventional cytology (May-Grünwald-Giemsa) and by an indirect immunoperoxidase technique with the anticytokeratin antibody KG8.13. Using conventional cytology, definite morphological evidence of malignancy was observed in three patients and suspicious features in a further seven. Immunocytochemistry confirmed these findings in all three of the malignant but in only one of the suspicious cases. Counts of immunostained cytospins showed the concentration of tumour cells in blood samples from these four patients to be in the range 0-954 cells/ml. This study supports the use of immunological markers to detect and enumerate malignant cells. This method provides a powerful tool to investigate one aspect of the metastatic process.

The blood supply of the human bile duct has been re-evaluated using high resolution resin casts prepared from 24 fresh human cadavers. The refined technique used yielded casts of all vessels, including capillaries, and produced a clear picture of the blood supply of the human bile duct for the first time. The arterial supply of the supraduodenal duct was shown to be axial, with the main vessels, which have been named the 3 o'clock and 9 o'clock arteries, running along the lateral borders. The retroportal artery, which has not been described by previous workers, was present in all complete casts and was a major source of the axial blood supply to the supraduodenal duct in 32 per cent of them.The major importance of this new knowledge of bile duct blood supply may well lie in the understanding of the aetiology of postoperative bile duct strictures and in their prevention. An explanation is proposed for the long strictures sometimes seen after minimal surgical trauma to the bile duct, based on damage to the small vessels supplying the duct; guidelines to prevent such damage are presented. Ischaemia of the bile duct may also explain some of the biliary problems that have followed human liver transplantation and other procedures involving biliary anastomosis, such as Whipple's operation.

Thirty patients with pyogenic liver abscess were admitted to King's College Hospital between 1967 and 1978. The overall mortality was 43 per cent (13 patients). The diagnosis was often difficult and in 10 patients the correct diagnosis was not made until post-mortem. Of the 20 patients diagnosed and treated, 17 had a unilocular abscess, of whom 16 survived. The remaining 3 had a multicentric abscess, and only 1 of them survived. Difficulty in diagnosis was sometimes increased by misleading results from special investigations. Clinical awareness leading to early diagnosis, drainage and broad spectrum antibiotic treatment remain the prerequisites for cure.

Guidelines for screening for colorectal cancer in subjects with a positive family history of the disease, without the use of DNA based screening, are outlined. These suggestions are derived from (a) the experience of screening 644 subjects at an estimated lifetime risk of dying from colorectal cancer of 10% or more, in the StMark's Family Cancer Clinic, over six years, and (b) a review of published studies, particularly incorporating the experience of the International Collaboration Group on Hereditary Non-polyposis Colorectal Cancer (HNPCC). Selection of subjects for surveillance depends upon the empirical evaluation of their risk of colorectal cancer, based upon family history details, with the exclusion of a diagnosis of familial adenomatous polyposis in the family.When DNA predictive tests for genes predisposing to HNPCC are available, surveillance can be directed at subjects with a germline mutation known to confer an increased genetic risk of colorectal cancer and discontinued in those at lower (or average) risk. In many subjects, however, DNA testing may still not be possible because of the failure to identify a predisposing mutation in an affected subject in their family. Any surveillance protocol can only be evaluated by long term follow up of those subjects in multiple centres.

PURPOSE: This study was designed to select the best monoclonal antibody to stain malignant cells in peritoneal wash fluid, and to investigate the incidence of free malignant cells in preresection and postresection colorectal cancer peritoneal washings using a combination of conventional cytology and immunocytochemistry. METHODS: Peritoneal washings were taken from 35 consecutive patients undergoing colorectal cancer resection. RESULTS: Malignant cells were isolated on a density gradient and identified by conventional cytology and an indirect immunoperoxidase stain. Malignant cells were identified in peritoneal washings from 15 patients (preresection only n=3, postresection only n=4, both n= 8). The origin of free malignant peritoneal cells in 11 preresection-positive washings must be the serosa. The origin of these cells in the four postresection-positive patients is uncertain: serosal and luminal spillage were considered unlikely and no circulating cells were found in the mesenteric vessels near the tumor. CONCLUSION: Tumor cells may have leaked out from lymphatics cut during the dissection.

To evaluate the potential effect of androgens on the development and growth of human colorectal adenomas, the prevalence and concentration of cytosolic androgen receptors (AR) were analysed in 26 adenomas and 19 samples of normal colonic mucosa by a hybrid ligand receptor-binding assay. AR were detected in 7 of the adenomas (26.9%), and in 6 of the normal mucosa samples (31.6%). In the adenomas, AR levels demonstrated were low, ranging from 6 to 31 fmol/mg cytosol protein, and dissociation constants (Kds) ranged from 0.17–2.7x10-9M. Of 13 adenomas excised from men, 6 (46%) had positive receptor activity, whereas only 1 of 13 (7.7%) from women was positive (P=0.03, Fisher's exact test). There was no correlation between AR titre and patient age, or between adenoma size and histological type or degree of dysplasia. In normal mucosa, AR levels ranged from 7 to 33 fmol/mg and Kds ranges from 0.24–3.1x10-9M. There was no significant difference between either AR prevalence or levels in the adenomas and normal mucosa. The sex difference was exclusive to the adenoma. Endogenous androgen may play a role in adenoma development early in the promotional process.

This study of radioimmunoscintigraphy (RIS) was primarily undertaken to determine how the imaging results related to surgical findings. Technetium-99m radiolabelled 1A3, a monoclonal antibody against a columnar cell surface antigen, was used. No adverse effects or thyroid uptake was observed in 127 studies. The 85 primary colorectal cancers were all image positive. In the assessment of recurrent tumour in the abdomen or pelvis, the accuracy was 33/35 (94%), including true-positive findings in some whose serum carcinoembryonic antigen was normal. There was a positive predictive value for abdominal or pelvic recurrence of 92% and a negative predictive value of 100%, at a prevalence of 66%. In those patients whose liver was able to be evaluated, the accuracy was 72/79 (91%). There was a positive predictive value for liver metastases of 88% and a negative predictive value of 93%, at a prevalence of 32%. The simple procedure for labelling antibody with 99mTc and its ready availability allow a completed report to be given within 24 h of the request.

The aetiology of anal squamous cell carcinoma (SCC) has recently been associated with a sexually transmissible agent — human papillomavirus (HPV) type 16. In this study clinical and pathological data from a prospective series of 67 anal SCC collected over a three year period were compared with the HPV type 16 DNA content of these tumours to determine whether any of the clinical or histological parameters might predict HPV DNA conten in a tumour specimen. Of twelve clinicopathological variables examined none was significantly correlated with HPV DNA content at the p=0.01 level.

Low compliance with faecal occult blood screening reduces the power of clinical trials, potential benefit, and efficiency. It has been proposed that the faecal manipulation required to perform conventional guaiac based tests may be an important factor in low compliance. The aim of this study was to evaluate whether use of a new method (vehicle) of stool collection for the faecal occult blood guaiac test would be preferred to the established standard. A novel self-interpreted test, Early Detector® (ED), requires the subject to apply a guaiac/peroxide spray to a stool sample collected simply by wiping the anus with a specimen pad. To determine whether this method would be preferred to the stool manipulation required by Haemoccult® (HO) and to compare test validity, employees at a London company were invited to use both tests. Eight-hundred and fifty-seven subjects were shown both tests. Before use, 48% indicated a preference for the method of Early Detector; 24% chose Haemoccult (p<0.001), while 28% indicated no immediate preference. Seven-hundred and one performed both tests. After use, 74% preferred ED; 5% preferred HO (p<0.001); 21% had no preference (NP). The preference for the ED test method was consistent by sex categories, age groups and occupational class. Logistics, aesthetics, and immediacy of results were the main reasons indicated for choosing ED. Whether the preference for ED could result in higher compliance remains to be proven. Its high positivity (14%), however, would preclude its use as a sole test to determine the need for endoscopic and/or radiologic investigation in the screened patient.

This prospective study of radioimmunoscintigraphy using111 In-labelled, C46, a monoclonal antibody against carcino embryonic antigen, CEA, was undertaken in 23 patients with colorectal cancer, 18 with primary carcinomas, 3 with recurrences and 2 with metastases. A sensitivity of 95% and an accuracy of 91% was found. New observations through the use of two administered doses of antibody and the analysis of surgical specimens showed that for the low dose of antibody (average 0.76 mg) tumour uptake was 1.14×10-2% of the injected dose per gram, whereas on the higher dose (average 4.67 mg) the average tumour uptake was 6.77% (same units)p<0.01. Thus a six-fold increase of antibody caused a sixfold increase in tumour uptake, but no change was seen in the tumour to mucosa ratio 4.8±0.5 (low dose) and 4.0±1.0 (high dose). A further observation was that well and moderately differentiated tumours took up about four times more than poorly differentiated tumours (p<0.05). It was also found that tumour free lymph nodes had a six-fold greater uptake than tumour involved nodes (p<0.05) confirming other work with anti-CEA monoclonal antibody. In conclusion, although biological factors influence its efficacy,111In labelled C46 anti-CEA is a suitable radiopharmaceutical for the radioimmunoscintigraphy of colorectal cancer.

The DNA content of 203 cases of rectal cancer, with at least 15 years follow-up, was analysed by flow cytometry. One hundred and twenty-nine (64%) were DNA aneuploid and corrected survivals were significantly influenced by ploidy distribution (p < 0.01). The DNA content and details of stage and grade were subjected to multivariate analysis using the Cox regression model. Ploidy was entered into models including Dukes' stage alone, tumour differentiation alone, Dukes' stage and differentiation in combination and a more comprehensive range of discrete stage- and grade-related parameters. All four models demonstrated its independent contribution to survival. However, its contribution was very small (5%, 18%, 5%, 4% respectively). These findings illustrate that results based on new technological developments should not be viewed in isolation, but their values must be assessed in combination with traditionally available data by means of multivariate analysis.

Haemorrhage from the small bowel is a serious diagnostic and therapeutic problem. The value of selective superior mesenteric angiography to localize the source accurately does not require emphasizing; (Athanasoulis et al., 1976; Casarella et al., 1974). However, many of the lesions demonstrated are notoriously difficult to find at operation unless they are actively bleeding at the time (Alfidi et al., 1971; Athanasoulis et al., 1976). We describe a simple method of intra-operative angiography which, because demonstration of the bleeding lesion on the operative films is not an essential requirement, does not involve the use of specialized angiographic equipment. Although only one case is offered to illustrate the method, it seems to possess sufficient versatility to be useful in most situations where intra-operative assistance in isolating a specific loop of small bowel for resection is anticipated.High-quality selective superior mesenteric angiography showing the actual or presumed source of haemorrhage in the small bowel pre-operatively is an essential requirement of the method. Once immediate operative management has been decided upon the intra-arterial catheter is left in the superior mesenteric artery (SMA) and the patient transferred from the radiology department to the operating theatre. For this purpose a catheter shape is chosen which will not easily displace from the SMA during transfer, such as a Sidewinder No. 7F (Cordis); it is kept patent in the interval by connection to a continuous arterial drugs infusion set.A radiologist and radiographer should be present in the operating theatre as well as the necessary surgical staff.

The incidence of anal intraepithelial neoplasia (AIN) was studied in a group of 210 homosexual and bisexual men. The presence of genital warts and human immunodeficiency virus (HIV) infection was assessed as risk factors for the development of AIN. In all, 74 (35 per cent) of the group had histological evidence of AIN. The relative risk of being positive for HIV on AIN (relative to being negative for HIV) was 1.58 (95 per cent confidence interval (c.i.) 1.01–2.48). The relative risk of anal warts on AIN (relative to absence of anal warts) was 4.70 (95 per cent c.i. 1.81–12.20). Logistic regression analysis showed no significant interactive effect between HIV and anal warts on the risk of AIN. It is concluded from the results of a Mantel-Haenzel analysis that the presence of anal warts and HIV infection are independent risk factors for the development of AIN in homosexual and bisexual men.

Conservative proctocolectomy was performed for ulcerative colitis in 19 patients, Crohn's disease in three and familial adenomatous polyposis in one. Healing was uncomplicated in only three patients (13 per cent). Eleven developed an anal discharge and nine an infected pelvic haematoma despite peranal drainage. Fourteen patients developed pelvic sepsis and, despite surgical curettage in 11, none healed. Six of these patients have had the anal sphincter divided, with healing in only one, and the anal canal has been excised in two. Eleven patients have ultimately healed at a median time of 28 months and eight have persistent sepsis after a median period of 45 months. Two patients with sepsis have had a successful ileoanal anastomosis. Conservative proctocolectomy cannot be recommended as a definitive operation for ulcerative colitis even though it may permit a subsequent restorative procedure.

It is essential to submit all lymph nodes from specimens of rectal cancer for histological examination. In a prospective study we compared the traditional method of dissection with the fat clearance technique in 20 operative specimens of rectal cancer. There was no significant difference in the lymph node harvest obtained by either method. The fat clearance technique resulted in a modest saving in dissection time (mean 4 min), but was expensive (£ 14.00 per specimen) and resulted in an unacceptable reporting delay (mean 3 days). The manual method was cheaper, as effective in identifying nodes and enabled much quicker reporting.