[Etiology of colorectal cancer]

Colorectal cancer affect the 15% of general population in developed countries. Cancer is a multistep process in which multiple genetic alterations must usually occur in several years. The premalignant step consists of one or multiple aberrant crypts due to hyperproliferation of cells and its shift from the deep third of the crypt to its surface. It has been suggested that abnormality in the APC gene is responsible for this. Furthermore, there exists DNA hypometilation, activation of the gene K-ras and ornithine decarboxylase activity. There is also a loss of MCC gene, that seems to interact with the APC gene. Entire alterations described make possible the Class I adenoma formation. This adenoma, needs the loss of the DCC gene (late stage in the carcinogenesis process), to become a Class II adenoma. The following alteration is deleted and mutation of the p53 gene. There is also an activation of the c-myc oncogene. These two genes are important mechanisms for the conversion of a benign adenoma to a malignant one, adenoma with in situ carcinoma or Class III adenoma. This type of adenoma becomes carcinoma and metastatic stage, throughout inactivation of several tumor suppressor genes. Besides the hereditary APC alteration and other acquired genetic changes as described above there are other associated genetics, antigenics, and enzymes that have an important role in the adenoma-carcinoma sequence. Several carcinogenic factors have been described which also contribute in the adenoma and carcinoma formation: ulcerative colitis, acromegaly, familial history of colonic neoplasia, certain professions, smoking and drinking, consumption of red or processed meat, etc.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma of the uterine cervix and schistosomiasis

OBJECTIVES

To determine the incidence of carcinoma of the uterine cervix and its relationship to schistosomiasis infection.

METHODS

A retrospective analysis of a 10-year period (1980-1990) at the department of histopathology (cancer registry) of the University of Dar es Salaam using statistical evaluation of the proportional rate of histomorphological diagnosis, clinical symptoms and epidemiological aspects.

RESULTS

There were 4520 cases classified as cervical carcinoma. Unexpectedly, only 76 of these (1.7%) revealed an association with schistosomiasis. Precancerous lesions of the squamous epithelium of the uterine cervix were a relatively common feature in carcinoma of both groups. Furthermore, epidemiological analysis indicates that the occurrence of cancer and schistosomiasis infection of the cervix is not strictly confined to the population of rural regions, known as endemic areas, with low hygienic and socioeconomic standards. This fact is most probably due to the rural people moving into urban areas, hoping to improve their quality of life.

CONCLUSIONS

Our data do not support the assumption of an etiologic role of schistosomiasis in the oncogenesis of cervical carcinoma.

Cancer of the esophagus in Acadiana

Cancer of the esophagus is a frequently fatal cancer whose incidence appears to be increasing. In Acadiana, esophageal cancer occurs predominantly in males, with a higher incidence in black males. Results of surgical treatment, with or without other therapy, are dismal. Combined treatment with chemotherapy and radiotherapy improved survival when compared to surgery. Survival benefits with chemotherapy and radiotherapy are, unfortunately, modest at present.

Carcinoma in situ in boys with cryptorchidism: when can it be detected?

OBJECTIVE

To investigate the possibility of a pre-invasive phase of adult germ cell tumours being detectable in childhood.

PATIENTS AND METHODS

Seventy testicular biopsies were examined which had been taken at orchidopexies from 57 patients aged 1 to 16 years during the period 1951-1973, and for whom follow-up data on cancers and deaths up to 1989 were available.

RESULTS

Malignant germ cell tumours had developed in three testes from which biopsies were available: a right-sided teratoma and left-sided mixed germ cell tumour in one patient and a left-sided teratoma in a second patient. Carcinoma in situ was seen in only one of the 70 biopsies. This biopsy was taken from a patient aged 16 years and preceded the appearance of a teratoma by 4 years. Carcinoma in situ was not seen in a biopsy of this testis carried out 11 years before tumour diagnosis. Carcinoma in situ was also not seen in a biopsy of the contralateral testis in this patient carried out 22 years before tumour diagnosis in the testis, nor was it observed in a biopsy 17 years before the development of malignancy in the second patient.

CONCLUSION

These findings bring into question the extent to which the appearance of testicular biopsies taken during childhood orchidopexy can exclude the development of a tumour in adult life. No evidence has been found in this study for histological pre-malignant changes occurring before the onset of puberty.

Cervicovaginal screening in women with HIV infection: a need for increased vigilance?

OBJECTIVE

To review the current literature on cervical disease (dysplasia, cervical intraepithelial neoplasia [CIN] or carcinoma) in women with HIV infection and to assess recommendations for cervicovaginal screening in these patients.

DATA SOURCES

MEDLINE and AIDSLINE were searched for relevant articles published in English or French between January 1987 and February 1993, abstracts presented at international AIDS conferences from 1989 to 1993 were evaluated, and pertinent agencies and organizations were consulted.

STUDY SELECTION

A total of 92 reports of gynecologic disease in women with HIV infection were examined; 32 studies were retained that reported pertinent findings on cervical dysplasia, CIN or cervical carcinoma.

DATA EXTRACTION

The following criteria were used to extract data: study design (descriptive v. comparative), sample size, heterogeneity of the study population, presence of immunodeficiency indicators (i.e., absolute CD4+ lymphocyte count) and presence of concomitant vaginal infections. Recommendations were assessed for their specific application to women with HIV infection.

DATA SYNTHESIS

Data on the associations between stage of cervical disease and response to treatment at varying levels of CD4+ lymphocyte depletion were incomplete. Recommendations by official bodies for cervicovaginal screening in women with HIV infection differed little from recommendations for standard care of all women of reproductive age.

CONCLUSIONS

The consequences of a missed or delayed diagnosis of cervical disease for women with HIV infection can be severe. Pending further research, more frequent cervicovaginal screening through Papanicolaou testing and colposcopy in women with HIV infection is warranted.

Cigarette smoking and other risk factors for cervical dysplasia in southwestern Hispanic and non-Hispanic white women

To assess smoking-related and other risk factors for high-grade cervical dysplasia in southwestern Hispanic and non-Hispanic white women in New Mexico, we conducted a clinic-based case-control study among attendees at university-affiliated gynecology clinics. We collected data on cigarette use, sexual behavior, past and current sexually transmitted diseases, hygienic practices, contraception, and diet. For both ethnic groups combined, after adjustment for the effects of human papillomavirus, sexual behavior, and other risk factors, cigarette smoking at the time of diagnosis was associated with high-grade dysplasia (odds ratio, 1.7; 95% confidence limits, 1.0-2.8). In contrast, former smoking was not associated with cervical dysplasia (odds ratio 0.9; 95% confidence limits, 0.5-1.5). Analyses showed dose-response relationships for the amount of cigarettes smoked per day and for cumulative exposure (pack-years of use) in association with cervical dysplasia. Although our study lacked the power to show statistically significant ethnic differences in smoking-related risks for dysplasia, smoking at the time of diagnosis, high pack-years of use, and smoking at the time of menarche were associated with dysplasia only for non-Hispanic white versus Hispanic women. Our data support hypotheses that implicate cigarette use as an etiological factor in the development of high-grade cervical dysplasia and suggest ethnic differences in risks for dysplasia among women attending the same clinics.

[Cancer of the uterine cervix. Historical perspective]

This paper describes the existing etiological paradigms which explain the development of cervical cancer (CACU), and particular, is a review of the historical attempts to explain the occurrence of the disease. Previous analysis concerning the prevalence of CACU in populations has been based on empirical work which can be summarized in several public health models, including: biomedical, hygienist-preventive, epidemiologic, ecologic, and social medical. We conclude that the existing paradigms must be reoriented in order to formulate organized social responses for the control of CACU.

Risk of secondary cutaneous malignancies in patients with long-standing mycosis fungoides

BACKGROUND

Patients with mycosis fungoides (MF) are frequently treated with UV light and psoralen (PUVA), nitrogen mustard, and electron beam irradiation, modalities known to predispose persons to development of cutaneous malignancies.

OBJECTIVE

We assessed the relation between these therapeutic modalities and the development of secondary cutaneous malignancies.

METHODS

We reviewed the charts of all patients observed during the past year.

RESULTS

We found that 7 of 71 patients had cutaneous neoplasms in an average follow-up time of 8.3 years. Orthovoltage radiation was used in five of seven cases and PUVA in four of seven. Five of seven patients had multiple neoplasms.

CONCLUSION

The risk of the development of second malignancies from the treatment of MF is relatively small and appears to be related to the type of therapy.

Verruca vulgaris and radiation exposure are associated with squamous cell carcinoma of the finger

BACKGROUND

Factors associated with the development of squamous cell carcinoma (SCC) of the finger are verruca vulgaris, radiation exposure, burns, and arsenic ingestion.

OBJECTIVES

We wish to further document the relationship between human papillomavirus (HPV) and roentgen exposure to squamous cell carcinoma of the finger.

METHODS

A retrospective study of 32 cases of digital squamous cell carcinoma seen at UCLA Medical Center was performed.

RESULTS

Ten patients (31%) had histories of verrucae at the site of the carcinoma. Eight patients (25%) had histories of x-ray therapy to the hand.

CONCLUSION

Our study further supports the association of verruca vulgaris and radiation exposure in the development of squamous cell carcinoma of the finger.

[A combination of spermatocytic and classic seminoma, mature teratoma and carcinoma in situ of the testis. An attempt at an etiologic explanation]

We report of a 39 years old patient with a large testicular tumor found during an examination for infertility. The tumor consisted of a spermatocytic seminoma (SS) and a differentiated teratoma (TD). Furthermore, two small foci of seminoma were seen in the surrounding testicular tissue, several testicular tubuli contained carcinoma in situ (CIS). The diagnosis was based on the results obtained with various immunohistochemical markers: keratin, vimentin, desmin, LCA, CD3, CD20, CD45R, ferritin, PLAP, AFP. On the basis of the macroscopic and histopathological features, we propose the following etiology: CIS progressed in an earlier phase to the (larger) TD and later to the (smaller) classical seminoma; likewise, in an earlier phase, SS developed from a still unknown precursor stage. Our case of a mixed tumor as well as other cases reported in the last years do not allow the explanation of a differing etiology for SS. On the contrary, it may be presumed that the origins of seminoma and teratoma on the one hand and SS on the other hand are less divergent than hitherto thought.

Serum micronutrients and the subsequent risk of cervical cancer in a population-based nested case-control study

A nested case-control study was conducted in Washington County, MD, to determine whether low serum micronutrients are related to the subsequent risk of cervical cancer. Among the 15,161 women who donated blood for future cancer research during a serum collection campaign in 1974, 18 developed invasive cervical cancer and 32 developed carcinoma in situ during the period January 1975 through May 1990. For each of these 50 cases, two matched controls were selected from the same cohort. The frozen sera of the cases and their matched controls were analyzed for a number of nutrients. The mean serum levels of total carotenoids, alpha-carotene, beta-carotene, cryptoxanthin, and lycopene were lower among cases than they were among controls. When examined by tertiles, the risk of cervical cancer was significantly higher among women in the lower tertiles of total carotenoids (odds ratio 2.7; 95% confidence limit, 1.1-6.4), alpha-carotene (odds ratio, 3.1; 95% confidence limit, 1.3-7.6), and beta-carotene (odds ratio, 3.1; 95% confidence limit, 1.2-8.1) as compared to women in the upper tertiles and the trends were statistically significant. Cryptoxanthin was significantly associated with a lower risk of cervical cancer when examined as a continuous variable. Retinol, lutein, alpha- and gamma-tocopherol, and selenium were not related to cervical cancer risk. Smoking was also strongly associated with cervical cancer. These findings are suggestive of a protective role for total carotenoids, alpha-carotene and beta-carotene in cervical carcinogenesis and possibly for cryptoxanthin and lycopene as well.

[Degree of familiarity with carcinoma in situ of the testis. A study of a representative selection of established urologists]

METHOD

By a telephone poll conducted among 143 selected representative urologists in private practice throughout the west German Länder.

BASIC REMARKS

Via a search for carcinoma in situ of the testicles (CIS, or testicular intra-epithelial neoplasia, TIN), active early detection of testicular germ cell tumors is now possible.

RESULTS

Among 143 urologists questioned, 62 claimed to be familiar with testicular CIS. However, only 52% were able correctly to answer one question as to its significance, and only 33% could correctly answer a question on the diagnosis of CIS. Only 28% of all those questioned were able to answer correctly 2 questions about CIS. Knowledge about CIS proved to be inversely correlated with the interval in years since obtaining a licence to practice as a specialist.

CONCLUSION

The poll reveals that, at the present time, too few urologists are familiar with carcinoma in situ of the testicles, and the possibilities of active early detection of testicular tumors.

Is HIV infection associated with an increase in the prevalence of cervical neoplasia?

OBJECTIVE

To test the hypotheses: (1) that HIV infection predisposes to cervical intraepithelial neoplasia (CIN); (2) that this CIN is a result of HIV related immunosuppression; and (3) that this CIN is a result of immunosuppression causing increased expression of the potentially oncogenic viruses, human papilloma virus (HPV), Epstein Barr virus (EBV) and herpes simplex virus (HSV).

DESIGN

A matched cross sectional study.

SETTING

The Department of Gynaecological Oncology, The Samaritan Hospital, London; the Department of Genitourinary Medicine, St Mary's Hospital, London; and the Family Planning Clinic, Claremont Terrace, Glasgow.

SUBJECTS

Fifty HIV seropositive women enrolled from the Genitourinary Medicine Department and the Drug Dependency Unit at St Mary's Hospital, London, and the Unit of Infectious Diseases at Ruchill Hospital, Glasgow. Forty-three HIV seronegative controls enrolled from the Department of Genitourinary Medicine at St Mary's Hospital, matched against 43 of the seropositive women for age, age at first intercourse, lifetime number of sexual partners, and smoking habit.

MAIN OUTCOME MEASURES

Associations between CIN, as detected by cytology and histology, and HIV infection. Association was also sought between CIN and immunosuppression, as measured clinically by T4 cell number, beta-2-microglobulin and p24 antigen. Associations of these with: (1) HPV, as detected by Southern blot testing and the polymerase chain reaction; (2) EBV, as detected by Southern blot testing; and (3) HSV, as detected by tissue culture of endocervical swabs, was also studied.

RESULTS

There was no significant difference in the prevalence of CIN or oncogenic viruses between HIV seropositive and seronegative women in the absence of immunosuppression. If the HIV infected women showed signs of immunosuppression, the prevalence of CIN was increased. No association was shown between detection of HPV, EBV and HSV and immunosuppression or CIN.

CONCLUSION

HIV infection may only be associated with an increased risk of CIN when immunosuppression is present.

History of circumcision, medical conditions, and sexual activity and risk of penile cancer

BACKGROUND

Epidemiological evidence suggests lack of neonatal circumcision as the strongest risk factor for penile cancer, but the role of sexually transmitted diseases in the etiology of penile cancer has remained unclear.

PURPOSE

To further clarify risk factors for penile cancer, we examined the role of circumcision, personal characteristics and habits (such as smoking), sexually transmitted diseases, past sexual activity, and medical conditions of the penis.

METHODS

A population-based, case-control study was conducted in western Washington state and in the province of British Columbia. We interviewed 110 men with penile cancer diagnosed from January 1979 to July 1990 and 355 control subjects from the general population, frequency matched to case subjects on age and date of diagnosis. Tumor tissue from 67 case subjects was tested for human papillomavirus (HPV) DNA by polymerase chain reaction. Results of blood tests from 69 case subjects and 208 control subjects were available for study. STATISTICALLY SIGNIFICANT RESULTS: Relative to men circumcised at birth, the risk for penile cancer was 3.2 times greater among men who were never circumcised and 3.0 times greater among men who were circumcised after the neonatal period. For current smokers, the risk was 2.8 times that of men who never smoked. The risk among men reporting a history of genital warts was 5.9 times that of men reporting no such history. Of 67 tumors tested for HPV DNA, 49% were positive; the majority of these positive tumors (70%) were type 16, which has been associated with anogenital carcinoma. Relative risks (RRs) associated with a reported history of penile rash or penile tear were 9.4 and 3.9, respectively. Among men not circumcised at birth, RRs associated with presence of smegma and difficulty in retracting the foreskin were 2.1 and 3.5, respectively. Twenty-eight percent of case subjects, compared with only 10% of control subjects, reported 30 or more sexual partners, and men with HPV-positive tumors were more likely to report a greater number of sexual partners.

CONCLUSIONS

These results suggest that the absence of neonatal circumcision and potential resulting complications are associated with penile cancer. Additionally, medical conditions of the penis, sexual activity, infection with HPV, and smoking may increase the risk for penile cancer.

IMPLICATIONS

A larger study would allow examination of interrelationships of circumcision, infection with HPV, and smoking as risk factors.

[Occult cervical cancer developing after diagnostic-therapeutic conization of CIN 3]

A case of the so called occult cervical cancer which developed 2 years after the conisation performed in a 45-year old woman on account of CIN 3 has been described. Cancer was detected in the operative specimen of the removed uterus. Hysterectomy was performed on account of the progressive form of the myomas. The multiple colposcopy and cytological follow-up examination after conisation was always negative, just as the histological examination of the tissue specimen of the cervical canal. The hypothetical course of the development of the cancer has been discussed. In connection with the above findings a modification of the conisation technique, especially in older women, is suggested.

Detection of dysplasia and carcinoma in situ by ratio fluorometry

Fluorescence bronchoscopy was performed in 82 volunteers recruited from occupational groups at risk of exposure to asbestos and/or diesel fumes to determine whether differences in tissue autofluorescence between normal and malignant bronchial tissues can be used to improve the sensitivity of standard fiberoptic bronchoscopy in detecting dysplasic and carcinoma in situ (CIS). This study consisted of 25 nonsmokers, 40 exsmokers, and 17 current smokers with mean ages of 52, 55, and 49 yr, respectively. Tissue autofluorescence was induced by a blue light from an He-Cd laser coupled to the illumination channel of the bronchoscope and analyzed by a ratiofluorometer. One or more sites of moderate or severe dysplasia were found in 12% of the exsmokers and current smokers but in none of the nonsmoker volunteers. CIS was found in two of the exsmokers. The sensitivity of fluorescence bronchoscopy (86%) was found to be 50% better than that of conventional white-light bronchoscopy (52%) in detecting dysplasia and CIS. Pre- and post-bronchoscopy sputum cytology failed to detect these precancerous lesions. Our results suggest that fluorescence bronchoscopy may be an important new method that can improve the ability to detect and localize precancerous and/or CIS lesions.

[A cohort study on cancer of uterine cervix in Jingan county, Jiangxi province]

A cohort study on 24,628 married women beyond 30 years of age in Jingan county, Jiangxi province was carried out from 1974 to 1985. It was equivalent to 207,490 person-year. The results showed that the earlier the first sexual intercourse the higher the risk of cervical cancer. There was a significant linear trend. The relative risk (RR) of cervical cancer in women increased from 1.63 to 6.85 with increase in the number of sex partners from one to two or more. The risk also increased from 1.44 to 5.38 and 2.69 as their husband had one, two or three and more extramarital sex partners. Irregular menstruation and insanitary mentrual pads were also risk factors. Risk factors of menarche age, age of first delivery, number of children, smoking and drinking were balanced in the present analysis by the logistic regression model.

Hyperplasia of mouse mammary epithelium induced by expression of the Wnt-1 (int-1) oncogene in reconstituted mammary gland

We have expressed the Wnt-1 (formerly int-1) oncogene in Balb/c mouse mammary epithelium in vivo, using a tissue reconstitution method in which primary cultures of mammary epithelial cells are infected with a retrovirus vector and then transplanted into mouse mammary fat pads from which the natural epithelium has been removed. Transplants carrying the Wnt-1 gene grew in a hyperplastic pattern, the duct epithelium showing abundant fine side-branches, but without development of clusters of alveoli. The hyperplasias were similar, but not identical, to transplants of normal epithelium in a mid-pregnant host. Transplants of epithelium that expressed Wnt-1 into mammary fat pads of male or ovariectomized females grew to form a similar three-dimensional pattern, but the extent of growth, and so presumably the rate of growth, was slower than in intact females, and there were no terminal end buds at the edges of the outgrowths. Thus, although Wnt-1 may enhance growth of epithelium in the male or ovariectomized-female environment, it does not restore the major mode of growth in the intact female, the extension of major ducts from terminal end buds. Normal epithelium showed no change in morphology when in close proximity to hyperplasia induced by Wnt-1, confirming the limited range of diffusion of Wnt-1 protein in vivo. Our results are consistent with the hypothesis that Wnt-1 acts principally by mimicking the signal that causes ducts to develop side-branches in pregnancy.