Demographic characteristics, pigmentary and cutaneous risk factors for squamous cell carcinoma of the skin: a case-control study

We conducted a case-control study of squamous cell carcinoma of the skin (SCC) in a cohort of people followed from 1987 to 1994. Subjects were residents of Geraldton, Western Australia, who were between 40 and 64 years of age in 1987. On 2 occasions, in 1987 and 1992, dermatologists examined participants for skin cancers. Subjects were also asked on several occasions about skin cancers that they had had treated. Migrants to Australia had reduced risks of SCC. Furthermore, people who migrated to Australia early in life or, equivalently, lived in Australia for a long time had a higher risk than immigrants who arrived later in life or more recently. People who had southern European ancestry had a much lower risk of SCC than other subjects, most of whom were of British or northern European origin. Among Australian-born subjects of British or northern European ancestry, the skin's sensitivity to sunlight was strongly associated with SCC. The pigmentary traits of hair colour, eye colour and skin colour showed weaker associations. The degree of freckling on the arm was strongly predictive of risk. The risk of SCC increased strongly with increasing evidence of cutaneous solar damage and was most strongly associated with the number of solar keratoses. Our results show that sensitivity to sunlight and high levels of exposure to sunlight are important determinants of the risk of SCC.     

Skin cancers at Tertiary Referral Skin Hospital in Singapore

BACKGROUND: Skin cancer is the seventh most common cancer in Singapore. This study was performed to determine the pattern of skin cancers seen in a tertiary referral skin hospital. METHODS: Histologically confirmed skin cancers, seen between 1980 and 1991, were analyzed according to age, sex, race, site, and presence/absence of preexisting skin conditions. RESULTS: Of a total of 520 patients, the commonest skin cancer was basal cell carcinoma (BCC) (36.5%), followed by squamous cell carcinoma (SCC) (24.4%), Bowen's disease (16.7%), and mycosis fungoides (9.0%). Malignant melanomas (2.7%) were rare. The sharp increase (26.2%) in BCC in the recent 3 years was largely contributed by a fivefold increase of non-resident Caucasian patients with BCC. All types of skin cancers were more common in Chinese (78.1%) and less frequent in the more pigmented races (9.4%). The men to women ratio was 1.72:1. The peak age distribution was in the 51-70-year group, with the exception of mycosis fungoides (31-50 years). The commonest site involved in BCC was the head and neck (67.0%) and in Bowen's disease the trunk (33.3%). Squamous cell carcinoma was found on the head and neck and the lower extremities with equal frequency (29.3%) and 46.2% of all SCC on the lower extremities occurred in leprosy patients with chronic trophic ulcers. Of patients with Bowen's disease involving the nonsunexposed parts (trunk and upper extremities), 42.6% had probable arsenic exposure evident either from the history or clinical examination. Malignant melanomas were commonly located on the foot (71.4%). CONCLUSIONS: The commonest skin cancers seen were BCC, SCC, Bowen's disease, and mycosis fungoides. There were differences in the site distribution of SCC, Bowen's disease, and malignant melanomas in our study when compared to studies in Caucasians.     

Treatment of aggression and irritability after head injury

Epidemiological characteristics of colorectal cancer may differ by particular anatomical subsite, suggesting that the subsite-specific colorectal cancers may represent different disease entities. This study explored the time trends over a 23-year period in colorectal cancer incidence at various subsites by sex and age group. Data on the incidence of colorectal cancer were obtained from a population-based cancer registry in Shanghai, People's Republic of China. Between 1972 and 1994, 30,693 patients with colorectal cancer were registered at the Shanghai Cancer Registry. The overall age-adjusted colorectal cancer incidence rates increased > 50%, or 2% per year from 1972-1977 to 1990-1994, from 14 to 22 per 100,000 among men and from 12 to 19 per 100,000 among women. The increases in rates were considerably more rapid for colon cancer, with rates approximately doubling, than they were for rectal cancer. Proximal colon cancer was more common than distal colon cancer over the whole study period, whereas rates for both cancers rose with similar annual percentage changes (> 5% per year) and across virtually all age groups. The estimated annual increases rose from 2% at ages 35-44 years to 7% at ages 75-84 years for proximal colon cancer, but they were more uniform for distal colon cancer (5-6% per year). Age-adjusted and age-specific rectal cancer rates changed little. The male:female age-adjusted rate ratio for colorectal cancer was 1.19 in 1990-1994. The ratios increased over time and varied by subsites, with ratios increasing from the proximal colon to the distal colon and to the rectum. Furthermore, men had higher rates than women for distal colon and rectal cancers at ages 55 and older, whereas women had higher rates than men at younger ages for these two cancers. Male:female rate ratios for proximal colon cancer did not vary substantially with age. The findings from this study indicate that subsite-specific incidence rates of colorectal cancer differ by sex and age and in their time trends. Cancers arising in the proximal colon, distal colon, and rectum may have somewhat different disease etiologies.     

Descriptive epidemiology of vulvar and vaginal cancers in Vaud, Switzerland, 1974-1994

BACKGROUND: To analyse trends in incidence, survival and risk of second neoplasms following vaginal and vulvar cancers using data collected by the Swiss Cancer Registry of Vaud over the 21-year period 1974-1994. MATERIALS AND METHODS: Subjects were 257 vulvo-vaginal cancers. Of these, 69 were vaginal, 153 vulvar cancers, and 35 non-specified lower genital tract neoplasms; 94 in situ neoplasms were also registered (85 for the vulva). RESULTS: Invasive vaginal cancer incidence decreased from 0.8 in 1974-1984 to 0.4/100,000 women in 1985-1994, while invasive vulvar cancer incidence remained approximately stable around 1.2/100,000 (world standard); incidence of in situ vulvar cancer increased from 0.8 to 1.3/100,000, the rise being larger in younger women. Significant excesses for second primary neoplasms were observed for pro-pharyngeal and lung cancer, and for non-melanomatous skin neoplasms, as well as for invasive vulvar cancers following in situ cancers. CONCLUSIONS: This population-based dataset confirms that the incidence of in situ vulvar (but not invasive vulvar or vaginal cancer) has been increasing over the last 20 years. The excess second primary neoplasms supports the hypotheses that human papillomavirus and cigarette smoking are related to vulvo-vaginal neoplasms.     

Relation between the incidence of invasive cervical cancer and the screening interval: is a five year interval too long?

OBJECTIVE: To examine the incidence of invasive cervical cancer per 100,000 women years at risk and relative risk according to screening history among eligible women aged 25-69 in Southampton and South West Hampshire during the three years after completion of the first round of comprehensive screening. RESULTS: There was a significantly higher incidence of invasive cervical cancer in women who had not been screened during the preceding 0.5-5.5 years than in those who had been screened (relative risk (RR) 2.6; 95% confidence interval (CI) 1.6 to 4.3). Among the latter group of women (with interval cancers) there was a significantly higher incidence in those with a long interval of 3.5-5.5 years since their most recent smear than in those with a short interval of 0.5-3.5 years (RR 2.2; 95% CI 1.3 to 3.8). Among women with non-interval cancers, there was a significantly higher incidence among those who had no cytology record than among those who had been screened but were overdue for a smear (RR 3.0; 95% CI 1.2 to 7.3). When screen detected cancers were excluded from the figures the relative risks for all the comparative groups described above were greater, though the 95% confidence limits were wider because the numbers were smaller. The most pronounced difference in incidence was between symptomatic cancers in women with a short screening interval (5.8 per 100,000 women years at risk) and in women with no cytology record (71.3 per 100,000 years at risk). Most cancers were interval cancers (76%) because of the high screening coverage: 89.2% of eligible women aged 25-69 had been screened during the preceding 0.5-5.5 years. The overall incidence per 100000 women years at risk approached that of interval cancers, and was nearer to that observed in the short than the long interval because 74.7% of women had been screened within 3.5 years. CONCLUSION: The results confirm the effectiveness of screening but suggest that a five year screening interval may be too long, at least during the early rounds of screening.     

Cancer incidence and mortality in France in 1975-95

The aims of the European Network of Cancer Registries (ENCR) are to improve the quality, comparability and availability of cancer registry data in Europe. This paper on cancer incidence and mortality in France presents the most recent available data, with short-term projections to 1995, and a commentary based, where possible, on epidemiological research carried out in France. Cancer incidence in men in France increased throughout the study period 1975 to 1995, from 92,000 new cases in 1975 to about 135,000 in 1995. This increase was partly due to the ageing of the French population, but incidence rates have also increased, particularly from 1975 to 1985. The trend appears to be levelling off in the 1990s, with an incidence rate in 1995 of about 482 per 100,000 (this and subsequent rates quoted are standardized to the European Standard Population). Among women, the all-cancer incidence rates also increased during the 1970s and 1980s. Although the rate of increase was less pronounced than in men, the trend is continuing in the 1990s. The estimated age standardized rate in 1995 was 309 per 100,000, representing 104,000 new cases. The main components of these changes in the last decade were, for men, increases in large bowel and prostate cancer, which have been partly compensated for by decreases in oral cavity, larynx and stomach cancer. For women the trend was dominated by the continuing increase in breast cancer with increases also in large bowel and lung cancers. Of the numerically important cancers in women, only stomach cancer has shown a clear decline. The situation in 1995 was that breast cancer remained the predominant cancer affecting women in France, accounting for almost one third of all new cases of cancer diagnosed and one fifth of cancer deaths. The next most frequent cancers in women were those of the large bowel. Regrettably, incidence rates of both breast and bowel cancer are increasing in women. For men in France the most frequent cancers in 1995 were those of the prostate, large bowel and lung, all of which increased in incidence since 1975. Although it is estimated that there will be more newly diagnosed cases of prostate cancer than lung cancer in 1995, the latter will cause many more deaths, particularly of young men.     

Health risks

The health risks associated with ozone depletion will principally be those due to increased ultraviolet B (UV-B) radiation in the environment, i.e., increased damage to the eyes, the immune system, and the skin. Some new risks may also be introduced with the increased use of alternatives to the ozone-depleting substances (ODSs). Quantitative risk estimates are available for some of the UV-B-associated effects, e.g., cataract and skin cancer; however, the data are insufficient to develop similar estimates for effects such as immunosuppression and the toxicity of alternatives. Ocular damage from UV exposures includes effects on the cornea, lens, iris, and associated epithelial and conjunctival tissues. The most common acute ocular effect of environmental ultraviolet radiation (UVR) is photokeratitis. Also known as snowblindness in skiers, this condition also occurs in other outdoor recreationists. Chronic eye conditions likely to increase with ozone depletion include cataract, squamous cell carcinoma, ocular melanoma, and a variety of corneal/conjunctival effects, e.g., pterygium and pinguecula. Suppression of local (at the site of UV exposure) and systemic (at a distant, unexposed site) immune responses to a variety of antigens has been demonstrated in both humans and animals exposed to UV-B. In experiments with animals these effects have been shown to worsen the course/outcome of some infectious diseases and cancers. There is reasonably good evidence that such immunosuppression plays a role in human carcinogenesis; however, the implications of such immunosuppression for human infectious diseases are still unknown. In light-skinned populations, exposure to solar UVR appears to be the most important environmental risk factor for basal and squamous cell carcinomas and cutaneous melanoma. Originally it was believed that total accumulated exposure to UVR was the most important environmental factor in determining risk for these tumors. Recent information now suggests that only squamous cell carcinoma risk is related to total exposure. In the cases of both basal cell carcinoma and melanoma, new information suggests that increases in risk are tied to early exposures (before about age 15), particularly those leading to severe sunburns. Testing of a number of the chlorofluorocarbon (CFC) alternatives indicates that most of these chemicals have low acute toxicity, and low to moderate chronic toxicity. Some chemicals that were originally proposed as alternatives have been dropped from consideration because these tests raised concerns about toxicity and/or manufacturing difficulties. In one instance, high accidental occupational exposure was associated with liver damage, underlining the need for care in the use of these substitutes. Recent quantitative risk estimates have been developed for cataract, melanoma, and all skin cancers combined. These estimates indicate that under the Montreal Adjustments, cataract and skin-cancer incidence will peak mid-century at additional incidences of just under 3 per 100,000 and about 7 per 100,000, respectively.     

Malignant mesothelioma: incidence, survival and relative risks in selected municipalities 1943-1992

The development in incidence rates and survival in Denmark, and the rate-ratio in selected municipalities that had industries utilizing asbestos was studied in 1865 cases of malignant mesothelioma identified in the Danish Cancer Registry 1943-1992. For men a steady increase in the incidence to 1.6 per 100,000 personyears in 1992 was found, while the rate for women decreased to 0.28 per 100,000 personyears. Age-specific incidence rates were highest for the older age-groups. An unexplained difference in the distribution of pleural and peritoneal cancers was seen between men and women. The average survival was 6.9 months for men and 7.8 for women and had not changed during the period of observation. The average rate-ratio for the selected municipalities was 1.97 (95% confidence intervals: 1.73-2.24) for men and 1.35 (1.08-1.69) for women. Improvements in working conditions in terms of minimizing asbestos exposure were introduced in 1980. Considering the latency period from exposure to diagnosis of 25-30 years, the impact of this measure on the rate of incidence cannot be expected before the year 2000.     

Age standardized incidence rates of oral cancer in South Africa, 1988-1991

While numbers of papers on oral cancer in South Africa have been published, there have been very few studies on standardized morbidity rates. This paper has developed data collected by the National Cancer Registry from the entire country for the four year period 1988-1991 to present frequency, age standardized incidence rates (ASIRs) and life-time risk (LR) for histologically-diagnosed intra-oral cancers in female and male Asian, black, coloured and white South Africans. During this period 5396 cases of oral cancer were diagnosed in a total number of 157,307 cancer cases (3.4 per cent) excluding squamous cell carcinoma (SCC) and basal cell carcinoma (BSC) of the skin. Intra-oral cancer in all South African females and males accounted, respectively, for 1.8 per cent and 5.0 per cent of all cancers. There was a male preponderance in black, coloured and white groups but females were affected more frequently than men among Asians. The incidence in Asian women (6.66) was higher than those of the women in any of the other population groups, whereas the lowest incidence was found in black women (1.75). The incidence rate in coloured men was particularly high (13.13) whereas the incidence in white males (8.06) was not substantially lower than among black males (9.05). Differences between the eight groups were not significant (X2 = 6.24, df = 3, p > 0.1). The Cumulative Life Time Risk (LR) of developing intra-oral cancer for males and females in the four population groups ranged from 1:65 in coloured males to 1:455 for black females. Gender differences in LR in both black and coloured groups, signals substantial differences in exposure to known carcinogens for this disease. It is disturbing to note that the incidence in the period 1988-1991 was higher in Indian women that it was in 1964-1966, and that educative preventive measures have failed. Similarly, the incidence of intra-oral cancer in coloured men of 13.13 is substantially higher than the figure of 8.8 reported in 1979. If this is an accurately reflected trend, then a major educative programme needs to be pursued in this direction if the relative risk of one in 65 is to be reduced.     

Myocardial infarction in Girona, Spain: attack rate, mortality rate and 28-day case fatality in 1988. Regicor Study Group

This study was conducted to establish the attack rate, mortality rate and 28-day case-fatality rates of acute myocardial infarction (AMI) occurring in Girona, Spain, between October 1987 and September 1988. The study was carried out using a population register of AMI, and took place in one central hospital, and eight county hospitals in Girona (in the autonomous community of Catalonia, northeast Spain). Subjects comprised 222 fatal cases selected from 4069 death certificates, and 210 non-fatal cases from hospital records, among subjects aged between 25 and 74 years (reference population 263,778). The age standardized attack rate was 105.6 per 100,000 inhabitants in the age group 35-64 (193.6 in men and 17.6 in women). The age standardized mortality rate was 36.3 per 100,000 inhabitants in the age group 35-64 (63.1 among men and 9.9 among women). The age standardized 28-day case-fatality was 34.6% in men and 50.1% in women in this same age group. Attack and mortality rates of AMI in a region of Spain are presented for the first time. These rates are lower than in other developed countries, nevertheless the 28-day case-fatality is similar to that of these countries.     

Increased cutaneous toxicity to ionizing radiation in HIV-positive patients. Military Medical Consortium for the Advancement of Retroviral Research (MMCARR)

Little is known about the etiology of esophageal and gastric cardia adenocarcinoma (EGA), a cancer with one of the fastest-rising incidences in the developed world. To explore the etiology of this cancer, we conducted a retrospective cohort analysis using data from the Surveillance, Epidemiology and End Results Program of the United States National Cancer Institute to study EGA and esophageal squamous cell carcinoma (ESC), in association with cancers of other sites. Standardized incidence ratios, adjusted for age, sex, and time period, were calculated as a measure of the relative risk (RR) of developing a second primary cancer (EGA or ESC) following a given first primary site. We found a moderately elevated risk of EGA following cancers of the lung (RR = 1.9 in men and RR = 2.0 in women) and of the head and neck (RR = 2.1 in men and RR = 6.3 in women) and a strongly elevated risk of ESC following cancers of the lung (RR = 2.8 in men and RR = 5.1 in women) and of the head and neck (RR = 9.6 in men and RR = 38.8 in women). A significantly elevated risk following breast cancer in women was observed for both EGA (RR = 2.6; 95% confidence interval, 1.8-3.7) and ESC (RR = 1.4; 95% confidence interval, 1.1-1.9). We also found a significantly elevated risk of EGA following bladder (RR = 2.0), colorectal (RR = 1.7), and prostate (RR = 1.4) cancer in men and of ESC following colorectal cancer (RR = 1.7) in women in this study. The strong association with tobacco-related malignancies in this study reinforces the role of tobacco in the etiology of esophageal cancers, which appears stronger for squamous cell carcinoma than for adenocarcinoma and stronger in women than in men. The study also suggests a possible shared etiology between esophageal adenocarcinoma and colorectal cancer in men and provides new evidence about the association of both adenocarcinoma and squamous cell carcinoma of the esophagus with breast cancer in women. Findings of this study provide clues to the etiology of EGA and ESC.     

A description of age, sex, and site distributions of colon carcinoma in three geographic areas

BACKGROUND: Site of the carcinoma within the colon in relation to age and sex may provide clues into the etiology of the disease. Incidence of colon carcinoma by age, sex, and tumor site at a population-based level are reported infrequently. The goal of this study was to describe the distribution of colon carcinoma (excluding cancers of the rectosigmoid junction and rectum) by age at diagnosis, sex, and site of the tumor within the colon. These factors were also evaluated in conjunction with disease stage at the time of diagnosis. METHODS: Data from three geographically distinct populations were used to describe rates of colon carcinoma and the distribution of tumors by age, tumor site, and stage at diagnosis. All colon carcinoma cases diagnosed within a 3-year period within the areas are included. RESULTS: Approximately 50% of all cancers in men and greater than 50% of cancers in women were in the proximal segment of the colon. Men who were diagnosed prior to age 50 and both men and women diagnosed at age 70 or older had predominantly proximal cancers. People with proximal cancers and people diagnosed prior to age 50 were more likely to have more advanced disease. CONCLUSIONS: Both men and women have more proximal cancers with advancing age, which are associated with more advanced disease. Observed trends in cancer site distributions could reflect screening practices, environmental and genetic factors, or a combination of these variables.     

Prospective characterization of pathological features of prostatic carcinomas detected via serum prostate specific antigen based screening

PURPOSE: Many small (less than 0.5 cc), well differentiated, organ-confined prostate carcinomas remain clinically undetected during the life of the patient and are identified only at postmortem examination. Thus, these cancers are often called latent or autopsy cancers. There is concern that serum prostate specific antigen (PSA) based screening may preferentially detect these cancers. There are limited prospective data concerning the pathological features of carcinomas of the prostate detected in a screening program. We determined if prostatic carcinomas detected via PSA based screening resembled autopsy cancers. MATERIALS AND METHODS: We assessed the pathological features of carcinomas in 100 consecutive, completely embedded radical prostatectomy specimens from men whose cancer was detected in a PSA based screening program. The tumors were evaluated for pathological stage, surgical margin status, Gleason histological grade and intraglandular tumor extent (morphometrically quantified as percentage carcinoma and tumor volume). RESULTS: Of 100 carcinomas 68 (68%) were larger than 0.5 cc in volume (mean 1.7, range 0.1 to 10.7). Mean amount of carcinoma in the surgical specimen was 10.3% (range 0.1 to 41.6). Of the 100 carcinomas 94 had a Gleason score of 5 to 8 (mean 5.7) and only 6 (6%) were well differentiated (Gleason score of 4 or less). Locally advanced disease was noted in 41 cases (41%) as judged by the presence of extracapsular carcinoma and/or cancerous surgical margins. CONCLUSIONS: We concluded that the pathological features of most prostatic carcinomas detected via PSA based screening do not resemble those of autopsy cancers, and that most prostatic cancers detected in screening programs are likely to be clinically important.     

Breast cancer screening: first round in the population-based program in Valencia, Spain. Collaborative Group of Readers of the Breast Cancer Screening Program of the Valencia Community

PURPOSE: To analyze the results of round 1 of the population-based Valencia Breast Cancer Screening Program. MATERIALS AND METHODS: In this program, 78,224 (72.98%) of the 107,178 women invited (aged 45-65 years) underwent screening. Complementary views were obtained in 5,771 women (7.38%). Among the total population studied, 3,502 (4.48%) underwent short-term mammographic follow-up studies; 3,898 (4.98%) underwent additional studies and treatment at hospitals. Five hundred eighty-seven women (0.75%) underwent biopsy. RESULTS: Cancer was detected in 334 patients (4.27 cancers per 1,000 women [3.24 per 1,000 women aged 45-49 years, 6.30 per 1,000 women aged 60-65 years]; six patients with lobular carcinoma in situ excluded). The estimated sensitivity was 89%; specificity, 99%. The positive predictive value of mammography was 8.56%; of mammography with additional examinations, 26.82%; and of biopsy, 56.89%. Forty-one patients (12.28%) had ductal carcinoma in situ; 284 (85.03%) had infiltrating carcinoma. In 73 (25.70%) of the 284 patients, infiltrating carcinomas were smaller than 1 cm. Two hundred twenty-five patients (76.27%) had no lymph node involvement. One hundred seventy-nine (61.09%) had stage 0 or 1 cancer. CONCLUSION: Results are consistent with other published results; differences are due to methods and patient population characteristics.     

Cutaneous malignant melanoma in Scotland: incidence, survival, and mortality, 1979-94. The Scottish Melanoma Group

OBJECTIVE: To determine the changing incidence of and mortality from cutaneous malignant melanoma in Scotland from 1979 to 1994. DESIGN: Detailed registration of clinical and pathological features, surgical and other treatment, and follow up of all cases of cutaneous malignant melanoma diagnosed from 1979 to 1994 and registered with specialist database for Scotland. SETTING: Scotland. SUBJECTS: 6288 patients with invasive primary cutaneous malignant melanoma diagnosed between 1 January 1979 and 31 December 1994. RESULTS: The annual age standardised incidence of cutaneous malignant melanoma rose significantly from 3.5 to 7.8 per 100,000 per year in men and from 6.8 to 12.3 per 100,000 per year in women (P < 0.001 for both). World standardised rates increased from 2.7 to 6.0 per 100,000 per year in men and 4.6 to 8.50 per 100,000 in women. The incidence of melanoma continued to increase significantly in men of all ages during the study, but the rate stabilised in women after 1986. Mortality from cutaneous malignant melanoma was 1.3 per million per annum in men in 1979, rising to 2.3 per million per annum in 1994 (P < 0.01); it was 2.4 per million per annum in women in 1979, falling to 1.9 per million per annum in 1994 (P = 0.09). The underlying mortality trends showed a continuing rise for men but a downward trend for women that was not significant (P = 0.09). In men, melanoma free survival was 69% at 5 years and 61% at 10 years; in women the corresponding rates were 82% and 75%. Younger patients had higher survival rates, which were not entirely explained by thinner tumours. Over the 15 year period, survival rates improved by 12% overall, only partly owing to thinner tumours. CONCLUSIONS: In Scotland the incidence of melanoma in women has stabilised, while mortality associated with melanoma in women shows a downward trend.     

Internal jugular to axillary vein bypass for subclavian vein thrombosis in the setting of brachial arteriovenous fistula

Relatively little is known about the epidemiology of carcinoid tumours in contrast to the extensive information available on their biochemical effects and natural history. Accordingly, we have used cancer registrations in England from 1979 to 1987, and in Scotland from 1980 to 1989, to estimate the incidence of carcinoid tumours in Britain. Age-standardised incidence rates for England, based on 3,382 registrations, were 0.71 (0.68-0.75) for men and 0.87 (0.83-0.91) for women, per 100,000 per year. The equivalent rates for Scotland, based on 639 registrations, were 1.17 (0.91-1.44) for men and 1.36 (1.09-1.63) for women. There was a consistent female excess of carcinoid tumours in the reproductive years, which was reversed after the age of 50. The female excess was most striking for gastrointestinal carcinoid tumours in women aged 15-19 years (F:M ratio = 2.14). The sex differences are probably due in part to incidental diagnosis of carcinoid tumours during abdominal procedures, which are more common in women than men at ages 15-49 years. However, there is some evidence to suggest a true sex difference in incidence, particularly the fact that the sex ratio for thoracic tumours varies with age in a similar way to that for gastrointestinal tumours. Hormonal factors may, therefore, be important in the aetiology of carcinoid tumours.     

Immunoelectron microscopic localization of gelatinase A in human gastrointestinal and skin carcinomas: difference between cancer cells and fibroblasts

Previous reports revealed a discrepancy in gelatinase A localization in human cancers; i.e., protein localization in cancer cells and mRNA localization in stromal fibroblastic cells. To clarify this, we conducted immunoelectron microscopic study of gelatinase A in cancer and stromal cells in human gastrointestinal and skin carcinomas. Although both carcinoma cells and fibroblasts were positive for gelatinase A, the subcellular localizations were different. On immunoelectron microscopy, fibroblasts showed immunoreactivity in the lumen of the rough endoplasmic reticulum (rER) or in the cytosol on the surface of rER, demonstrating synthesis of the protein. Carcinoma cells showed diffuse deposition of gelatinase A in the cytosol, suggesting the accumulation of the antigen both in adenocarcinoma and squamous cell carcinoma. Immunoreactivity along the cell membrane was demonstrated in one case of skin carcinoma. Macrophages showed also diffuse deposition of gelatinase A in the cytosol. In conclusion, we found a qualitative difference of gelatinase A localization between carcinoma cells and fibroblasts, and concluded that carcinoma cells may not be important in the secretion of gelatinase A.     

Aggressive cutaneous squamous cell carcinoma of the head and neck in patients with chronic lymphocytic leukaemia

We describe multiple cutaneous squamous cell carcinomas of the head and neck in five patients with chronic lymphocytic leukaemia (CLL). When associated with CLL, cutaneous squamous cell carcinomata behave in a much more aggressive manner than otherwise expected. Four patients developed local recurrence after primary treatment. All five patients developed lymph node metastases containing squamous cell carcinoma. Three of five patients (60 per cent) had multiple primary lesions. Whereas the increased incidence of second cancers in CLL and notably of skin cancers is documented, little has been written to describe the aggressive behaviour of these tumours. It is important, when treating these patients, to be aware of the high tendency towards local recurrence and lymph node metastasis and to consider an aggressive management plan and careful follow-up.     

FPSUND: a pan-Canadian evaluation of a clinical classification of urinary incontinence

To obtain quantitative information on the risk of invasive cancers following a diagnosis of basal cell carcinoma (BCC) of the skin, patients with incident BCC cases listed in the cancer registries of the Swiss cantons of Vaud and Neuchatel between 1974 and 1994 were actively followed up through December 31, 1994, for the occurrence of subsequent invasive neoplasms. Among 11,878 persons with incident BCC who were followed for a total of 76,510 person-years at risk, 1,543 metachronous cancers were observed versus 1,397.9 expected, corresponding to a standardized incidence ratio (SIR) of 1.1 (95% confidence interval (CI) 1.0-1.2). However, after exclusion of skin cancers (mostly squamous cell carcinoma and melanoma), 975 second primary cancers were observed versus 1,059 expected (SIR = 0.9, 95% CI 0.8-1.0). Significant excesses were registered for cancer of the lip (SIR = 2.2), for squamous cell skin cancer (SIR = 4.5) and melanoma of the skin (SIR = 2.5), and for non-Hodgkin's lymphoma (SIR = 1.9). The SIRs were also above unity, though not significantly, for cancers of the salivary glands (SIR = 2.8) and the small intestine (SIR = 2.1) and for soft-tissue sarcomas (SIR = 1.7). The SIR for lung cancer was 0.9. The SIRs for salivary gland and skin cancer were appreciably greater below age 70 years. For most sites, particularly for squamous cell cancer and melanoma of the skin, the SIRs remained elevated 5 or more years after BCC diagnosis. The cumulative incidence of squamous cell skin cancer was 13% at 19 years; this stresses the importance of carefully monitoring skin lesions among persons previously diagnosed with BCC.     

Time of appearance and histology of tumors induced in the dorsal skin of C3Hf mice by ultraviolet radiation from a mercury arc lamp

The time course of skin tumor induction was determined in hair-clipped inbred agouti C3Hf mice irradiated three times per week with a medium-pressure quartz-mercury lamp; 4 different UV doses were used. Although the ears were also exposed to the radiation, in the 3 groups given the highest doses no ear tumors were observed by the time each animal had developed at least 1 tumor on its back. No tumors were found in the animals receiving the lowest UV dose. In the group receiving the highest dose, males developed tumors earlier than did females; this trend continued in the lower dose groups. Many tumors that developed in the back skin were well-differentiated squamous cell carcinomas. Others were less well-differentiated squamous cell carcinomas. Others were less well defined so that the cell of origin was difficult to determine. In the group receiving the highest UV dose, the squamous cell carcinomas were few, whereas at the lower doses they predominated.