Are relatives of patients with multiple HNPCC spectrum tumours at increased risk of cancer?

BACKGROUND

Relatives of patients with early onset colorectal cancer, a feature of hereditary non-polyposis colorectal cancer (HNPCC), are at increased risk of colorectal cancer.

AIMS

To investigate risk in relatives of patients with multiple primary cancers, another feature of HNPCC.

METHODS

Details were obtained on patients from one region who had developed colorectal cancer and a separate primary from the HNPCC tumour spectrum (colorectal, stomach, urinary, ovary, endometrial). Overall, 157 patients had second primaries occurring between 1990 and 1995 and 128 completed family histories were obtained by structured interview (study group). A comparison group of 444 patients with a single colorectal cancer were similarly interviewed.

RESULTS

Fifteen families (13%) from the study group were suggestive of HNPCC compared with three (0.7%, p<0.0001) from the comparison group. Overall risk of colorectal cancer in close relatives of the study group was 3.4 times the general population rate compared with 1.8 times for the comparison group. Bowel cancer risk was even higher for relatives of bowel/ovary and bowel/endometrial subgroups, but was similar to the comparison group for the bowel/bowel subgroup. Finally, extracolonic HNPCC associated cancers were seen twice as frequently as expected in the general population in relatives of the study group.

CONCLUSION

This study highlights the importance of taking a family history in patients with multiple primary cancers and indicates the risk of malignancy in their relatives.

Frequency of replication errors in colorectal cancer and their association with family history

BACKGROUND

Replication errors (RERs) characterise tumours of hereditary non-polyposis colorectal cancer (HNPCC). RER status may therefore improve identification of such families previously diagnosed by family history alone.

AIMS

To assess RER and HNPCC frequency within a population of colorectal cancer patients and a regional population of family history defined (Amsterdam criteria) HNPCC families.

METHODS

Family history was assessed by personal interview in a population of 479 patients with colorectal cancer attending one follow up clinic. Seven fluorescently labelled microsatellites were used to investigate RER frequency in colorectal cancers from 89 patients of this population with varying degrees of family history and 20 Amsterdam criteria positive families (four with a known germline mutation, 16 with unknown mutation status) from the regional population.

RESULTS

Only four of the follow up population (0.8%) came from families meeting the Amsterdam criteria with only one showing RERs. The frequency of RERs was similar in the early onset cancer group (less than 50 years of age), those with a family history, and those with no family history of colorectal cancer. From the regional population, RERs were identified in 4/4 families with a mutation but only 8/16 families with unknown mutation status.

CONCLUSIONS

No correlation was seen between RER status and strength of family history except in HNPCC families. Results also indicate that half of the Amsterdam criteria defined families do not exhibit RERs, perhaps suggesting a different mechanism of tumorigenesis.

Circumferential margin involvement after mesorectal excision of rectal cancer with curative intent. Predictor of survival but not local recurrence?

PURPOSE

This study examines the prognostic significance of circumferential margin involvement by tumor in resected specimens after potentially curative rectal cancer surgery.

METHODS

During an eight-year period, all patients with rectal cancer were prospectively audited. For tumors of the middle and lower thirds of the rectum, a total mesorectal excision was performed; for tumor of the upper third, mesorectal excision proceeded at least 5 cm distal to the primary tumor. Resected specimens were subjected to careful histologic assessment, and patients undergoing curative procedures were entered into a surveillance program to detect both local and distant recurrence.

RESULTS

Of 218 patients in the cohort, 9 had no resection, 14 underwent local excision, 1 had pre-operative radiotherapy, and 42 patients (20 percent) had palliative resections and were excluded from further analysis. This left 152 patients having a curative resection, of whom 20 (13 percent) had tumor within 1 mm of the circumferential margin. After follow-up until death or a median period of 41 months, recurrent disease was seen in 24 percent of patients with a negative margin and 50 percent with a positive margin. Both disease-free survival and mortality were significantly related to margin involvement (log-rank, P = 0.01 and P = 0.005, respectively). Local recurrence, however, was not significantly different in the two groups (11 and 15 percent, respectively; log-rank, P = 0.38).

CONCLUSIONS

When mesorectal excision is performed, circumferential margin involvement is more an indicator of advance disease than inadequate local surgery. Patients with an involved margin may die from distant disease before local recurrence becomes apparent.

Rhinocerebral mucormycosis caused by Apophysomyces elegans

Mucormycosis is an uncommon fungal disease and one of the most fulminant infections known. This is the second report of rhinocerebral mucormycosis caused by Apophysomyces elegans, a newly recognized genus and species classified in the family Mucoraceae. The patient was a 54-year-old man being treated for a severe sinus infection with antibiotics and oral steroids. Recovery occurred in our patient after prompt surgical debridement and drainage of his maxillary sinuses. This case fits the reported characteristics of other A. elegans infections including warm climate, intimate contact with the soil, and an incubation period measured in days. Several reported cases indicate A. elegans can cause mucormycosis in immunocompetent individuals with no underlying medical problems.

Incidence of DNA replication errors in patients with multiple primary cancers

PURPOSE

Multiple primary cancers are a feature of hereditary nonpolyposis colorectal cancer in which defects in DNA repair mechanisms result in accumulation of replication errors within tumor DNA. We assessed replication error incidence in multiple primary cancer patients who may have similar genetic defects.

METHODS

DNA was obtained from 69 patients from the Yorkshire region who had developed colorectal cancer and one other primary tumor from the hereditary nonpolyposis colorectal cancer tumor spectrum (28 colorectal, 12 stomach, 15 ovary, and 14 uterus). DNA was also obtained from 86 sporadic, single primary cancer patients attending a colorectal cancer clinic. Replication error status was assessed at five microsatellite loci using fluorescent polymerase chain reaction and computer-assisted analysis.

RESULTS

The replication error phenotype was observed in 7 of 86 (8 percent) of the sporadic single primary patients. This compared with 23 of 69 (33 percent) of the multiple primary group (P < 0.001). Replication error was also observed more frequently in each subgroup. Even excluding patients from families meeting the Amsterdam criteria (likely to be hereditary nonpolyposis colorectal cancer and have the replication error phenotype), this increased frequency remained in both the multiple primary group (P < 0.005) and multiple colorectal and colorectal/uterine subgroups (P < 0.001).

CONCLUSIONS

Results suggest that genetic instability plays an important role in development of multiple primary cancers, particularly from certain cancer subsets. Testing for replication errors may be an appropriate way of identifying individuals at risk of multiple primary cancers.

Applications of the FIB lift-out technique for TEM specimen preparation

A site-specific technique for cross-section transmission electron microscopy specimen preparation of difficult materials is presented. A focused ion beam was used to slice an electron transparent membrane from a specific area of interest within a bulk sample. Micromanipulation lift-out procedures were then used to transport the electron-transparent specimen to a carbon-coated copper grid for subsequent TEM analysis. The FIB (focused ion beam) lift-out technique is a fast method for the preparation of site-specific TEM specimens. The versatility of this technique is demonstrated by presenting cross-sectioned TEM specimens from several types of materials systems, including a multi-layered integrated circuit on a Si substrate, a galvanized steel, a polycrystalline SiC ceramic fiber, and a ZnSe optical ceramic. These specimens have both complex surface geometry and interfaces with complex chemistry. FIB milling was performed sequentially through different layers of cross-sectioned materials so that preferential sputtering was not a factor in preparing TEM specimens. The FIB lift-out method for TEM analysis is a useful technique for the study of complex materials systems for TEM analysis.

Development and application of polymerase chain reaction (PCR) tests for the detection of subgroup J avian leukosis virus

Subgroup J avian leukosis virus (ALV) is a recently identified avian retrovirus associated with myeloid leukosis in meat-type chickens. The env gene of the HPRS-103 strain of ALV, the prototype of this subgroup, differs considerably from that of other subgroups, but shows close homology to the env-like sequences of members of the EAV family of endogenous retroviruses. Polymerase chain reaction (PCR) tests using two sets of primers were developed for the specific detection of the members of this new subgroup along with another pair of primers for detecting other subgroup viruses. The specificity and sensitivity of this detection system was compared with the conventional detection methods in experimentally and naturally infected samples. The use of PCR was found to be rapid, specific and more sensitive than the conventional diagnostic tests for the detection of ALV. Moreover, the two subgroup J ALV-specific PCR tests were found to be capable of differentiating between 'prototype-like' viruses and more recent isolates which show extensive antigenic and sequence variations. The use of this test as a rapid and sensitive method of detection of viruses in epidemiological studies and eradication programs is discussed.

Restorative proctocolectomy for idiopathic megarectum: postoperative recovery of hypotonic anal sphincters. Report of two cases

PURPOSE

Restorative proctocolectomy has been advocated in the treatment of idiopathic megacolon, provided there is normal sphincter function. We report two patients undergoing this procedure, despite abnormal sphincter function.

METHODS

Anorectal manometry and detailed symptom review were performed both preoperatively and at various stages postoperatively in two young patients with idiopathic megarectum.

RESULTS

Both patients had progressive sphincter recovery postoperatively, shown both manometrically and with symptomatic review.

CONCLUSION

Low preoperative sphincter pressures in young patients with idiopathic megarectum may not preclude successful outcome after restorative proctocolectomy.

Sigmoidoscopic neurosurgery? Treatment of an unusual complication of ventriculoperitoneal shunting

A 16-year-old male with acute hydrocephalus due to bilateral acoustic neuromata was treated successfully with a ventriculoperitoneal shunt before formal neuroma resection. However, 2 years postoperatively, he noticed the distal shunt per rectum while defaecating. Subsequent removal was successfully performed using a flexible sigmoidoscope.

Management of minor head injuries in the accident and emergency department: the effect of an observation ward

The management of 483 patients presenting with minor head injury to the accident and emergency (A&E) departments of two Scottish hospitals was studied prospectively. Such patients comprised 5.7 and 3.9% of the total attendances to each department. Of the 277 patients assessed in the former department, 83 (30%) fulfilled at least one of the currently accepted criteria for recommending admission to hospital and 49 (17.7%) patients were actually admitted. Patients in whom head injury was not the principal reason for admission were excluded from the study. In the same time period the second department dealt with 206 patients with minor head injury, 49 (24%) of whom had criteria for admission. However, significantly fewer, 10 (4.9%) patients, were actually admitted. The major relevant factor when comparing the two departments was the existence in the former of an observation ward. These results support the view that easy access to hospital beds is a major determinant of management in patients presenting with minor head injury to the A&E department and may be more influential than clinical findings.

Psychology of computer use: XXIX. Measuring computer users' stress: the Computer Hassles Scale

Measurement of computer users' stress was based on the Computer Hassles Scale. 65 questionnaires were returned from 113 mailed to users of accounting information systems who worked for manufacturing companies. Correlations were calculated for the total sample and subsamples divided by gender. The analysis indicated that persons with college degrees experienced greater computer users' stress than those who were without. Those persons who reported more computer hassles experienced more somatic complaints which indicated that the computer hassles were stressful. There were no significant mean differences between women and men on computer hassles or somatic complaints. The correlations of computer hassles with somatic complaints differed by gender. Women's computer hassles were significantly correlated .61 with somatic complaints, but men's computer hassles were not significantly correlated (r = .18) with somatic complaints. The gender differences suggest that there is a complex relationship between stressors (computer hassles) and stress reactions (somatic complaints).

Steven R. Brown on investigating kickbacks

(Steven R. Brown is the corporate security manager of the Southwest region for ARCO Oil and Gas. He primarily investigates and oversees investigations involving kickback and conflict of interest cases. He has travelled extensively to lecture on the topic. His 25 years of law enforcement experience includes serving as an instructor for the National Academy of the Federal Bureau of Investigation. While Brown speaks frankly about kickback problems in a large oil company, the nature of this kind of employee/vendor theft and the techniques for uncovering it apply equally to any sizable company or institution, public or private.

Is rectosigmoid response to food modulated by proximal colon stimulation?

Rectosigmoid motor activity and postprandial breath hydrogen levels were monitored in eight healthy males under basal conditions and for 3 1/2 hr after a meal (beefburger and breadroll and ice cream incorporating 20 g lactulose). Within minutes of ingestion there was a significant increase in motility index (P less than 0.05) and also an initial temporary rise in breath hydrogen. A late increase in motor activity occurred in seven of eight subjects 123 +/- 19 min after the meal and was temporally related to the beginning of a second, much larger rise in breath hydrogen (r = 0.99; P less than 0.01). The close association between the timing of the rises in breath hydrogen and rectosigmoid motor activity would support the possibility that the latter may be generated by chemical or mechanical stimulation of the proximal colon.

Temporal trends in the incidence of cutaneous malignant melanoma among Caucasians in the San Francisco-Oakland MSA

Temporal changes in the incidence of cutaneous malignant melanoma (CMM) were examined in the San Francisco-Oakland (California, United States) Metropolitan Statistical Area (MSA) between 1976 and 1987, using data from the population-based cancer registry. This analysis was conducted after the completion of a project designed to eliminate bias in the reporting of CMM due to changes in medical practice. The incidence of CMM is higher in the San Francisco-Oakland MSA than nationally. From 1976 through 1987, the incidence of invasive CMM increased from 9.8 +/- 0.9 to 16.5 +/- 1.1 per 100,000 (P = 0.0001) among men and from 9.3 +/- 0.8 to 12.7 +/- 0.9 per 100,000 (P = 0.001) among women. Age-specific, histologic-specific, and anatomic site-specific trends were also evaluated. The temporal patterns of CMM suggest that the recent increases are not accounted for solely by ascertainment bias due to reporting practices. The observed trends are consistent with early detection efforts and with changes in the prevalence of risk factors.

Recent trends in the incidence of salivary gland cancer

Beginning in 1985, a sudden and sustained doubling of salivary gland cancer incidence, among men only, is observed in the San Francisco-Oakland Metropolitan Statistical Area. Registry data are examined to determine the nature of this increase and its possible association with the AIDS epidemic. Changes in patient characteristics are assessed by comparing their distribution among recently diagnosed cases (1985-1988) to an expectation based on population growth and the age-specific incidence among patients diagnosed earlier (1973-1984). Based on the observed patterns, it is unlikely that the temporal increase in these tumours is a direct result of the AIDS epidemic or solely the result of a shift in the prevalence of established risk factors. The increase is predominantly seen in men over the age of 75 at diagnosis (O/E = 2.3, p = 0.02) and is observed among both those with and without a prior cancer (O/E = 2.7, p = 0.02 and O/E = 1.5, p = 0.06, respectively). Radiation for the prior cancer was not associated with increased occurrence. Military exposure is crudely approximated by examining birth cohorts. However, the cohort data do not support a hypothesis of military exposure.

A novel subgroup of exogenous avian leukosis virus in chickens

An avian leukosis virus with a wide host range belonging to a new subgroup for chickens was isolated from meat-type chicken lines. The virus, of which HPRS-103 strain is the prototype, was of low oncogenicity in chickens but appeared to behave like an exogenous leukosis virus. Neutralizing antibodies to the virus were found in three of five meat-type chicken lines, but not in seven layer lines. The virus and its Rous sarcoma virus pseudotype did not replicate in, or transform, mammalian cells.

Bringing the medical library to the office desktop

This demonstration illustrates LRC Remote Computer Services- a dual operating system, multi-protocol system for delivering medical library services to the medical professional's desktop. A working model draws resources from CD-ROM and magnetic media file services, Novell and AppleTalk network protocol suites and gating, LAN and asynchronous (dial-in) access strategies, commercial applications for MS-DOS and Macintosh workstations and custom user interfaces. The demonstration includes a discussion of issues relevant to the delivery of said services, particularly with respect to maintenance, security, training/support, staffing, software licensing and costs.

Effect of coffee on distal colon function

Ninety nine healthy young volunteers (58 men, 34 women, aged 17-27 years) answered a questionnaire concerning their bowel habit with particular reference to the effects of beverages. Twenty nine per cent (63% women) claimed that coffee induced a desire to defecate. The rectosigmoid motor responses to black, unsweetened coffee were then investigated by multiport manometry in 14 healthy-subjects (12 men, two women, eight of whom claimed coffee caused a desire to defecate (responders). Results revealed an increase in motility index within four minutes after ingestion of both regular and decaffeinated coffee (p less than 0.05) in the eight responders, but not in the six non-responders. The increase in rectosigmoid motility induced by coffee lasted at least 30 minutes. There was no increase in the motility index in any subject after a drink of hot water. These results suggest that drinking coffee can stimulate a motor response of the distal colon in some normal people.