Increased stomach cancer risk following radiotherapy for testicular cancer.

BACKGROUND: Abdominal radiotherapy for testicular cancer (TC) increases risk for second stomach cancer, although data on the radiation dose-response relationship are sparse. METHODS: In a cohort of 22,269 5-year TC survivors diagnosed during 1959-1987, doses to stomach subsites were estimated for 92 patients who developed stomach cancer and 180 matched controls. Chemotherapy details were recorded. Odds ratios (ORs) were estimated using logistic regression. RESULTS: Cumulative incidence of second primary stomach cancer was 1.45% at 30 years after TC diagnosis. The TC survivors who received radiotherapy (87 (95%) cases, 151 (84%) controls) had a 5.9-fold (95% confidence interval (CI) 1.7-20.7) increased risk of stomach cancer. Risk increased with increasing stomach dose (P-trend<0.001), with an OR of 20.5 (3.7-114.3) for ⩾50.0 Gy compared with <10 Gy. Radiation-related risks remained elevated ⩾20 years after exposure (P<0.001). Risk after any chemotherapy was not elevated (OR=1.1; 95% CI 0.5-2.5; 14 cases and 23 controls). CONCLUSIONS: Radiotherapy for TC involving parts of the stomach increased gastric cancer risk for several decades, with the highest risks after stomach doses of ⩾30 Gy. Clinicians should be aware of these excesses when previously irradiated TC survivors present with gastrointestinal symptoms and when any radiotherapy is considered in newly diagnosed TC patients.

Pancreatic cancer risk after treatment of Hodgkin lymphoma.

BACKGROUND: Although elevated risks of pancreatic cancer have been observed in long-term survivors of Hodgkin lymphoma (HL), no prior study has assessed the risk of second pancreatic cancer in relation to radiation dose and specific chemotherapeutic agents. PATIENTS AND METHODS: We conducted an international case-control study within a cohort of 19 882 HL survivors diagnosed from 1953 to 2003 including 36 cases and 70 matched controls. RESULTS: Median ages at HL and pancreatic cancer diagnoses were 47 and 60.5 years, respectively; median time to pancreatic cancer was 19 years. Pancreatic cancer risk increased with increasing radiation dose to the pancreatic tumor location (Ptrend = 0.005) and increasing number of alkylating agent (AA)-containing cycles of chemotherapy (Ptrend = 0.008). The odds ratio (OR) for patients treated with both subdiaphragmatic radiation (≥10 Gy) and ≥6 AA-containing chemotherapy cycles (13 cases, 6 controls) compared with patients with neither treatment was 17.9 (95% confidence interval 3.5-158). The joint effect of these two treatments was significantly greater than additive (P = 0.041) and nonsignificantly greater than multiplicative (P = 0.29). Especially high risks were observed among patients receiving ≥8400 mg/m(2) of procarbazine with nitrogen mustard or ≥3900 mg/m(2) of cyclophosphamide. CONCLUSION: Our study demonstrates for the first time that both radiotherapy and chemotherapy substantially increase pancreatic cancer risks among HL survivors treated in the past. These findings extend the range of nonhematologic cancers associated with chemotherapy and add to the evidence that the combination of radiotherapy and chemotherapy can lead to especially large risks.

Risk of treatment-related esophageal cancer among breast cancer survivors.

BACKGROUND: Radiotherapy for breast cancer may expose the esophagus to ionizing radiation, but no study has evaluated esophageal cancer risk after breast cancer associated with radiation dose or systemic therapy use. DESIGN: Nested case-control study of esophageal cancer among 289 748 ≥5-year survivors of female breast cancer from five population-based cancer registries (252 cases, 488 individually matched controls), with individualized radiation dosimetry and information abstracted from medical records. RESULTS: The largest contributors to esophageal radiation exposure were supraclavicular and internal mammary chain treatments. Esophageal cancer risk increased with increasing radiation dose to the esophageal tumor location (P(trend )< 0.001), with doses of ≥35 Gy associated with an odds ratio (OR) of 8.3 [95% confidence interval (CI) 2.7-28]. Patients with hormonal therapy ≤5 years preceding esophageal cancer diagnosis had lower risk (OR = 0.4, 95% CI 0.2-0.8). Based on few cases, alkylating agent chemotherapy did not appear to affect risk. Our data were consistent with a multiplicative effect of radiation and other esophageal cancer risk factors (e.g. smoking). CONCLUSIONS: Esophageal cancer is a radiation dose-related complication of radiotherapy for breast cancer, but absolute risk is low. At higher esophageal doses, the risk warrants consideration in radiotherapy risk assessment and long-term follow-up.

Prevalence of Norwegian patients diagnosed with childhood cancer, their working ability and need of health insurance benefits.

The object of this study was in a population-based material to investigate the prevalence of patients diagnosed with childhood cancer, and compared to the general population to assess working ability, yearly income and need for health insurance benefits in patients surviving at least five years after treatment for childhood CNS tumours or hematological malignancies. During the period January 1, 1970 to December 31, 2002 the prevalence in the Norwegian population of patients diagnosed with any childhood cancer increased from 12.2 (473/3 888 305) to 65.1 (2944/4 524 066) per 100 000 population. The proportion of survivors in need of any health insurance benefit was for CNS tumours 47.1% and for hematological malignancies 21.0%. The proportion in the age group 16-67 receiving disability pension for CNS tumours was 94/454 (20.7%) compared to 21/575 (3.7%) for patients treated for hematological malignancies (p < 0.001). Of patients given radiotherapy 25/70 (35.7%) received disability pension, compared to 90/959 (9.4%) in unirradiated patients, p < 0.001. Yearly income and working ability was particularly low for CNS tumour survivors. This study illustrates loss of working capability associated with pediatric cancer and treatment and long-term requirement of health insurance benefits.

Early life events and later risk of colorectal cancer: age-period-cohort modelling in the Nordic countries and Estonia.

BACKGROUND: A lowering of colorectal cancer risk for the birth cohorts born around World War II (WWII) has previously been observed in Norway, a country which suffered some 20% caloric restriction during the war. The purpose of the study was to conduct a similar kind of analysis in the other Nordic countries and Estonia, which were also subjected to various degrees of energy restriction during WWII. METHODS: All new cases of colorectal cancer in the Nordic countries and Estonia diagnosed between 40 and 84 years of age and born between 1874 and 1953, were collected from the national cancer registries. The incidence data were fitted to an age-period-cohort model. RESULTS: A transient drop in the estimated colorectal cancer incidence rate was observed for the birth cohorts born around WWII in Estonia, together with a tendency of decreased risk in Sweden and Denmark. CONCLUSION: The previously observed lowering of colorectal cancer risk for persons born during WWII in Norway also prevails in Estonia. Energy restriction is a possible explanation for these findings, since the countries suffered from varying nutritional conditions during the war. Exogenous factors acting during periods early in life may have an impact on later colorectal cancer risk.

Trends in incidence of brain and central nervous system tumors in Norway, 1970-1999.

The aim of this study was to investigate trends in the incidence of childhood and adult brain and central nervous system (CNS) tumors in Norway from 1970 through 1999. In this period, a total of 14,641 patients were diagnosed with a primary benign or malignant neoplasm of the brain and CNS. Age-adjusted incidence rates were reported together with results of loglinear regression and an age-period-cohort model based on the Poisson regression model. In children (<15 years), the proportion of brain and CNS tumors was 28.2% (1,042/3,697) of all new cancer cases compared with 2.8% in adults (13,599/492,237). The overall rate of brain and CNS tumors increased during the study period from 6.49 to 12.02 cases per 100,000 person-years. A trend of leveling off in incidence of most tumor categories during the study period was indicated with a possible continuing increase in the period 1995-1999, especially in the age group 0-4 years and in patients aged 60 years or more. Age and period together provided a satisfactory model in patients being <60 years of age and less completeness of diagnosis was found in males compared with females, possibly due to the distribution in males of more aggressive tumors.

Colorectal cancer survival trends in Norway 1958-1997.

The purpose of this study was to examine the pattern of survival for colorectal adenocarcinoma (CRC), and to investigate the prognostic factors for the disease. In the analysis, 50993 cases of CRC aged 40-84 years, diagnosed between 1958 and 1997 in Norway, were included. Esteve's relative survival method was used, together with a time trend analysis, conducted by least-squares linear regression. Cox proportional hazards regression analysis was used to examine cause-specific mortality. Five-year relative CRC survival has increased by an estimated 3% per 5-year diagnostic period. In 1958-1962, relative survival was about 40% for both males and females, and increased to 56 and 60%, respectively, in 1993-1997. Rectal cancer had a higher cause-specific mortality (RR 1.26, 95% CI 1.22-1.30) than proximal colon (reference) and distal colon (RR 0.97, 95% CI 0.93-1.00 cancers), while females had a lower cause-specific mortality than males (RR 0.88, 95% CI 0.86-0.90). The increase in the relative survival rate in Norway is probably due to improved treatments and advanced diagnostics. Norway has a higher CRC survival rate than the EUROCARE average.

European health systems and cancer care.

INTRODUCTION: Data on the survival of all incident cases collected by population-based cancer registries make it possible to evaluate the overall performance of diagnostic and therapeutic actions on cancer in those populations. EUROCARE-3 is the third round of the EUROCARE project, the largest cancer registry population based collaborative study on survival in European cancer patients. The EUROCARE-3 study analysed the survival of cancer patients diagnosed from 1990 to 1994 and followed-up to 1999. Sixty-seven cancer registries of 22 European countries characterised by differing health systems participated in the study. This paper includes essays providing brief overviews of the state and evolution of the health systems of the considered countries and comments on the relation between cancer survival in Europe and some European macro-economic and health system indicators, in the 1990s. OVERVIEW OF THE EUROPEAN HEALTH SYSTEMS: The European health systems underwent a great deal of reorganisation in the last decade; a general tendency being to facilitate expanding involvement of the private sector in health care, a process which occurred mainly in the eastern countries (i.e. the Czech Republic, Estonia, Poland, Slovakia and Slovenia). In contrast, organisational changes in the northern European countries (i.e. Denmark, Iceland, Finland and Sweden) tended to confirm the established public sector systems. Other countries, including the UK and some southern European countries (i.e. England, Scotland, Wales, Malta and Italy) have reduced the public role while the systems remain basically public, at least at present. Our findings clearly suggest that cancer survival (all cancer combined) is related to macro-economic variables such as the gross domestic product (GDP), the total national (public and private) expenditure on health (TNEH) and the total public expenditure on health (TPEH). We found, however, that survival is related to wealth (GDP), but only up to a certain level, after which survival continues to be related to the level of health investment (both TNEH and TPEH). According to the Organisation for Economic Co-operation and Development (OECD), the TNEH increased during the 1990s in all EUROCARE-3 countries, while the ratio of TPEH to TNEH reduced in all countries except Portugal. CONCLUSIONS: Cancer survival depends on the widespread application of effective diagnosis and treatment modalities, but our enquiry suggests that the availability of these depends on macro-economic determinants, including health and public health investment. Analysis of the relationship between health system organisation and cancer outcome is complicated and requires more information than is at present available. To describe cancer and cancer management in Europe, the European Cancer Health Indicator Project (EUROCHIP) has proposed a list of indicators that have to be adopted to evaluate the effects on outcome of proposed health system modifications.

Cause of death and long-term survival in patients with neuro-epithelial brain tumours: a population-based study.

Long-term survivors of neuro-epithelial brain tumours have a higher death rate compared with the general population and the aims of this study were to investigate the causes of death and analyse long-term survival using population-based material. A total of 6209 patients were registered in the period of 1970-1993 with a primary intracranial neuro-epithelial tumour in the The Norwegian Cancer Registry. In a pilot study, a high level of agreement with regard to the cause of death was found between clinical data and the registered cause of death. Underlying causes of death in the whole population were therefore analysed. Most deaths were caused by the primary neuro-epithelial brain tumour within 10 years of diagnosis. Although the numbers were small, the proportion of patients dying from other cancers, vascular disease, infections and accidents continued to rise with time. Survival was computed using the Kaplan-Meier method. For children, survival at 5, 10 and 15 years significantly improved from the time period of 1970-1981 to 1982-1993 (47.9, 43.6 and 43.3% versus 63.8, 59.8 and 59.8%, respectively, P <0.0001). Similar improvements in survival at 5, 10 and 15 years were observed for young adults aged 15-49 years (32.7, 21.3 and 16.5% versus 50.1, 37.5 and 33.1%, for the same time periods, P<0.0001). No such improvement for those aged 50 years and over was observed (corresponding figures of 6.6, 3.8 and 2.8% versus 7.7, 4.8 and 3.4%). Prognosis for those with childhood medulloblastomas improved significantly, as did the prognosis of younger adults with low-grade gliomas and unbiopsied/ unclassifiable grade gliomas.

Trends in colorectal cancer incidence in Norway by gender and anatomic site: an age-period-cohort analysis.

The purpose of this study was to examine the secular trend of colorectal cancer in Norway by gender and subsite. All new cases of cancer in proximal colon, distal colon and rectum diagnosed between 1958 and 1997 in Norway were included in the study, altogether 34 202 and 34 097 cases for men and women, respectively. The incidence data were fitted separately for each gender and subsite to an age-period-cohort model. An increase in incidence of colorectal cancer was seen from 1958 to 1997 for both men and women, although a moderate attenuation of the increase has taken place in the last 15-20 years. This observation is most pronounced for cancer of the distal colon, but is also evident for proximal colonic and rectal cancers. For the distal colon and rectum, the period effect is more important than the cohort effect for both genders, whilst opposite for the proximal colon. The main estimated trend for cohort effects is a steady increase for both men and women, apart from an unexpected drop in incidence among the cohorts born during or shortly after World War II. These findings indicate that different aetiological risk factors may act on cancers of the proximal and distal part of the large bowel and further suggest that exogenous risk factors acting very early in life may play a more important role for colorectal cancer than previously recognized.

Cancer in siblings of children with cancer in the Nordic countries: a population-based cohort study.

BACKGROUND: In some rare inherited disorders such as Li-Fraumeni syndrome, relatives of children with cancer are at increased risk of cancer. We aimed to assess relations between childhood cancer and sibling risk, and evaluate the influence of recessive conditions in cancer causation. METHODS: We did a population-based cohort study in the Nordic countries of 42277 siblings of 25605 children with cancer. Children with cancer were identified from records in the five Nordic cancer registries, and their siblings from nationwide population registries. Cancers in siblings were documented through record linkage with cancer registries and compared with national incidence rates. We also assessed cancer incidence in parents to identify familial cancer syndromes. FINDINGS: 284.2 cancers were expected in siblings, whereas 353 were diagnosed (standardised incidence ratio 1.24 95% CI 1.12-1.38). Risk ratios for siblings were highest in the first decade of life (2.59, 1.89-3.46). We excluded 56 families with genetic syndromes linked to cancer, which reduced this ratio from 1.7 to 1.0 (0.7-1.3) for siblings younger than 20 years, and from 1.3 to 1.0 (0.8-1.3) for those aged 20-29 years. We found no new patterns of familial cancer that indicated inherited susceptibility, or evidence that recessive conditions might contribute to cancers not explained by syndromes. 40% of cancers in siblings that occurred before age 20 years could be attributed to known genetic factors, whereas 60% remained unexplained. INTERPRETATION: Apart from rare cancer syndromes, paediatric cancer is not an indicator of increased cancer risk in siblings.

[Psychological, social and economic situation of women surgically treated for cancer]. / Kreftopererte kvinners psykiske, sosiale og økonomiske forhold.

INTRODUCTION: As part of an international effort, a study of the psychosocial condition of women with cancer in Norway was performed in 1997. MATERIAL AND METHODS: 851 women with breast or gynaecological cancer in 27 Norwegian hospitals were asked to fill in a multi-choice questionnaire. RESULTS: 76% of the breast cancers were detected by the women themselves, 19% by mammography and 11% by clinical examination. Similar numbers for gynaecological cancer were 59% by the women and 41% by the doctors (13% screening smear). 25% of the women were informed about the cancer diagnosis by telephone and 9% by letter. 87% were satisfied with treatment and care, 7% dissatisfied. 62% were satisfied with the availability of doctors, 20% not. In 47% of the breast cases, therapy alternatives were discussed with the patients. In 23% of gynaecological, 50% of breast, and 72% of gynaecological cancer, patients had no wish to participate in the decision. 94 of a total of 850 patients (11%) experienced financial problems after the diagnosis had been established. More than 90% of the women had a better or unchanged relation to their partner, family and friends after treatment. However, 30% of the breast and 14% of the gynaecological cancer patients had problems with their body image, and 16% and 15% felt they were less sexually attractive. 89% felt their partner coped well with the situation, 9% had problems and only 2% lost their partner. 32% of the patients had used alternative medicine, 44% of those with recurrence and 28% under primary treatment. INTERPRETATION: Women operated for breast and gynaecological cancer face a variety of psychosocial and financial problems.

Second malignant neoplasms after cancer in childhood and adolescence: a population-based case-control study in the 5 Nordic countries. The Nordic Society for Pediatric Hematology and Oncology. The Association of the Nordic Cancer Registries.

Our purpose was to assess the risk of developing a second malignant neoplasm (SMN) after cancer in childhood and adolescence associated with different treatment modalities. Our investigation was performed as a nested case-control study within a Nordic cohort of 25,120 patients younger than 20 years old at first malignant neoplasm (FMN) diagnosed in 1960 through 1987. SMNs were diagnosed in 1960 through 1991. For each case of SMN, 3 controls were sampled, matched by sex, age, calendar year of diagnosis and length of follow-up. For the final analysis, there were 234 cases and 678 controls. Relative risks (RRs) of various exposures were estimated by means of conditional logistic regression, with non-exposed as the reference. The RR of developing SMN in the radiated volume was 4.3 (95% confidence interval 3.0-6.2). The risk was highest in children diagnosed before the age of 5 years; it increased with the dose of radiation and with increasing follow-up time after FMN. Chemotherapy alone was not associated with an increased RR, but it significantly potentiated the effect of radiotherapy. RRs were unchanged between the periods 1960-1973 and 1974-1987, and since the use of chemotherapy increased in the latter period, the number of SMNs may increase. Hereditary factors were important for the occurrence of SMN independently of therapy. We conclude that radiation was the most important treatment-related risk factor for the development of SMN. Chemotherapy appeared to play only an accessory role during the study period, potentiating the carcinogenic effect of radiotherapy.

[Diagnostic delay in malignant melanoma]. / Diagnostisk forsinkelse ved malignt melanom.

BACKGROUND: Malignant melanoma accounts for 1 to 3% of all cancers and has been the most rapidly increasing type of cancer during the last decades. Early diagnosis and treatment favours a good prognosis. We wanted to investigate delays in the diagnostic process and patients' knowledge concerning malignant melanoma. MATERIAL AND METHODS: 457 patients with primary cutaneous malignant melanoma received a questionnaire through their physician; 352 (77%) returned the questionnaire. RESULTS: Median patient delay, defined as time between the patient's first observation of changes in a naevus and the first medical consultation, was eight weeks. Younger men had the longest patient delays. Median professional delay, defined as time from the first medical consultation to the time of diagnosis, was one week. 60% of the patients observing changes in a naevus did not initially seek medical advice, as they did not believe the changes were significant. In 65% of the cases, the patients themselves initiated the consultation. Television and other media were principal sources of information. INTERPRETATION: Public campaigns should be designed to reach younger men in particular and focus on self-examination of naevi and immediate contact with a physician when a suspicious lesion is discovered.

Population-based surveillance by colonoscopy: effect on the incidence of colorectal cancer. Telemark Polyp Study I.

BACKGROUND: Most cases of colorectal cancer (CRC) develop from adenomas. Polypectomy is believed to reduce the incidence of CRC, but this effect has never been explored in prospective controlled studies. The aim of the present study was to evaluate the effect of polypectomy on colorectal cancer incidence in a population-based screening program. METHODS: In 1983, 400 men and women aged 50-59 years were randomly drawn from the population registry of Telemark, Norway. They were offered a flexible sigmoidoscopy and, if polyps were found, a full colonoscopy with polypectomy and follow-up colonoscopies in 1985 and 1989. A control group of 399 individuals was drawn from the same registry. In 1996 both groups (age, 63-72 years) were invited to have a colonoscopic examination. Hospital files and the files of The Norwegian Cancer Registry were searched to register any cases of CRC in the period 1983-96. RESULTS: At screening endoscopy 324 (81%) individuals attended in 1983 and 451 (71%) in 1996. From 1983 to 1996, altogether 10 individuals in the control group and 2 in the screening group were registered to have developed CRC (relative risk, 0.2; 95% confidence interval (CI), 0.03-0.95; P = 0.02). A higher overall mortality was observed in the screening group, with 55 (14%) deaths, compared with 35 (9%) in the control group (relative risk, 1.57; 95% CI, 1.03-2.4; P = 0.03). CONCLUSION: Endoscopic screening examination with polypectomy and follow-up was shown to reduce the incidence of CRC in a Norwegian normal population. The possible effect of screening on overall mortality should be addressed in larger studies.

Risk of cancer among offspring of childhood-cancer survivors. Association of the Nordic Cancer Registries and the Nordic Society of Paediatric Haematology and Oncology.

BACKGROUND: Increasing numbers of children with cancer survive and reach reproductive age. However, the risk of cancer (other than retinoblastoma) in the offspring of survivors of childhood and adolescent cancer is uncertain. METHODS: Using data from national cancer and birth registries, we assessed the risk of cancer among 5847 offspring of 14,652 survivors of cancer in childhood or adolescence diagnosed since the 1940s and 1950s in Denmark, Finland, Iceland, Norway, and Sweden. The offspring were followed up for a diagnosis of cancer for 86,780 person-years, and standardized incidence ratios were calculated. RESULTS: Among the 5847 offspring, 44 malignant neoplasms were diagnosed (standardized incidence ratio, 2.6; 95 percent confidence interval, 1.9 to 3.5). There were 17 retinoblastomas, yielding a standardized incidence ratio of 37. There were 27 neoplasms other than retinoblastoma (standardized incidence ratio, 1.6; 95 percent confidence interval, 1.1 to 2.4). The second most common primary site of cancer among the offspring was the brain and nervous system, in which eight tumors were observed (standardized incidence ratio, 2.0; 95 percent confidence interval, 0.9 to 3.9.) There were between zero and four apparently sporadic cases of cancer in other primary sites among the offspring. Excluding 4 likely cases of hereditary cancer and 2 subsequent cancers among the offspring with hereditary retinoblastoma, there were 22 sporadic cancers, for a standardized incidence ratio of 1.3 (95 percent confidence interval, 0.8 to 2.0). CONCLUSIONS: There is no evidence of a significantly increased risk of nonhereditary cancer among the offspring of survivors of cancer in childhood.

A lack of neuroblastoma in Down syndrome: a study from 11 European countries.

An epidemiological investigation in 11 European countries comprising a total childhood population of 54.1 million children and using 8 separate data sources was conducted to evaluate the occurrence of neuroblastoma in Down syndrome (DS). No cases of DS were detected among 6724 infants and children with neuroblastoma, although more than five were expected. This highly significant result (P = 0.0045 according to the Poisson test) is consistent with data in the literature, which contains only two poorly detailed cases in epidemiological studies and one ganglioneuroma in a DS mosaic patient. Like other tumors, such as leukemias, testicular germ cell tumors and lymphomas are in excess in DS patients; the lack of neuroblastomas does not reflect a general decreased incidence of cancer but rather a specific underrepresentation of this precise tumor. S-100 b protein, the gene for which maps to the long arm of chromosome 21, (a) is overproduced in DS patients, (b) produces growth inhibition and differentiation of neural cells in vitro, (c) is abundant in good-prognosis neuroblastomas, and (d) has been shown to induce growth inhibition and differentiation and cell death in several human and murine neuroblastoma cell lines and could be responsible for this variation. Additional epidemiological and experimental studies are warranted to confirm our interpretation of these data.

Risk of second cancers in classical Kaposi's sarcoma.

An association between Kaposi's sarcoma (KS) and malignant lymphoma has been suspected for many years. Both cancers belong to the group of malignancies associated with immune suppression and have been known to occur in the same individual. Accordingly, a common etiology has been suspected. Through linkage within the Nordic cancer registries, we studied the occurrence of cancers in a population-based cohort of 741 patients with classical KS. The relative risk of subsequent malignancies was expressed as the ratio of the observed numbers of cancer to the numbers expected based on age-, sex-, period- and country-specific incidence rates, i.e., the standardized incidence ratio (SIR). A total of 104 cancers was observed during 5,802 person-years of follow-up, which was close to the expected 98.8 cases (SIR, 1.05). During the first year of follow-up, 3 lymphomas were observed, which is in significant excess of the 0.2 lymphomas expected (SIR, 13.0). In contrast, no lymphomas occurred in the period beyond the first year of follow-up vs. 2.3 expected. Cancers of the buccal cavity and pharynx (SIR, 10.6; n = 4) and of the colon (SIR, 2.7; n = 7) occurred in excess among women but not among men. Accordingly, our results indicate that patients with classical KS are not at increased risk of cancer in general. In particular, the overall risk of lymphomas was not significantly increased. The high relative risk of malignant lymphoma immediately after KS was based on a limited number of cases, and this observation is unlikely to indicate a common etiology.