Sound Surveillance, Epidemiology, And End Results Research Articles

Cannabis use after a cancer diagnosis in a population-based sample of cancer survivors.

This study aimed to characterize the prevalence and correlates of cannabis use and the methods and reasons for use among recently diagnosed cancer survivors in a population sample within Washington state. We identified individuals diagnosed with invasive cancers in the prior 6 to 17months from April 2020 to December 2020 using the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. Participants (n = 1,515) completed a questionnaire, including demographics, medical history, cannabis use, and other substance use. Cancer characteristics and date of diagnosis were obtained from SEER registry data. We calculated weighted prevalence estimates and logistic regression models to evaluate correlates of cannabis use. Overall, 41.3% of survivors reported cannabis use at any time after diagnosis, most commonly via edibles (60.5%) and smoking (43.8%). The most frequently reported reasons for use were sleep (54.5%), mood, stress, anxiety, and depression (44.3%), pain (42.3%), and recreation (42.3%). Cannabis use was associated with younger age, race (White vs. Asian), less education, former or current smoking, consuming more than 2 alcohol-containing drinks per day, having late-stage cancer, and cancer site. In this first evaluation of cannabis use in a registry-linked, population-based sample of survivors of all cancer types, based in a state where recreational and medical cannabis have been legal for a decade, approximately 2 in 5 survivors reported post-diagnosis use. Given how common cannabis use is among cancer survivors, there is a great need to understand its impact on cancer treatment outcomes and the overall health of cancer survivors.

Prevalence and Correlates of Post-Diagnosis Alcohol Use among Cancer Survivors.

Alcohol is a risk factor for cancer and may pose unique risks for cancer survivors. Population-based studies of confirmed cancer cases are needed to estimate the extent of drinking among cancer survivors and to understand which survivors are most at risk of alcohol-related health problems. Cancer survivors who resided in the Puget Sound Surveillance, Epidemiology, and End Results (SEER) region, were ages 21 to 74 years at diagnosis, and were 6 to 17 months post-diagnosis at the start of the recruitment period (April 2020-December 2020) were sent a survey that included demographics, substance use, mental health, and cancer-related items. Data from returned surveys (n = 1,488) were weighted to represent the characteristics of the Puget Sound SEER region. We estimated the prevalence of post-diagnosis alcohol use as well as demographic, behavioral, and clinical correlates of three levels of drinking: any drinking, drinking exceeding cancer prevention guidelines, and hazardous drinking. The weighted prevalence of any drinking, drinking exceeding cancer prevention guidelines, and hazardous drinking was 71%, 46.2%, and 31.6%, respectively. Higher income and cannabis use were associated with increased odds of all three drinking levels. Lower physical health quality of life, having non-colorectal gastrointestinal cancer, and receiving chemotherapy within the last month were associated with decreased odds of all three drinking levels. The prevalence of any drinking and at-risk drinking was higher than in previous studies and differed based on sociodemographic, substance use, and cancer-related factors. Findings highlight the importance of identifying and addressing risky alcohol use in cancer care settings.

Cannabis use is associated with patient and clinical factors in a population-based sample of colorectal cancer survivors.

This study aimed to characterize patient and clinical factors associated with cannabis (marijuana) use among patients diagnosed with colorectal cancer (CRC). We identified CRC patients, diagnosed from 2016 to 2018, using the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. CRC patients were recruited via mail and telephone, and participants completed a questionnaire eliciting information on medical history, demographics, and lifestyle factors, including cannabis use. Cancer stage was obtained from SEER registry data. Of 1,433 survey respondents, 339 (24%) were current cannabis users. Current cannabis use was associated with younger age at diagnosis, lower BMI, and a higher prevalence of cigarette smoking and alcohol consumption (p-value < 0.05). Cannabis use was also associated with lower quality of life scores (FACT-C) and advanced-stage cancer (p-value < 0.05). Cannabis use among CRC patients was common. Patients with more advanced disease were more likely to report cannabis use. Use also varied by some personal factors, consistent with patterns in the general population. Given the high prevalence of cannabis use among CRC patients, research is needed to determine the benefits and harms of cannabis use for symptom management in cancer patients.

The association between colorectal sessile serrated adenomas/polyps and subsequent advanced colorectal neoplasia.

Colorectal cancer (CRC) screening guidelines recommend increased surveillance of individuals with sessile serrated adenomas/polyps (SSA/Ps), but there is uncertainty about the risk associated with SSA/Ps. We aimed to determine the association between SSA/Ps and subsequent advanced colorectal neoplasia. This case-control study included Kaiser Permanente Washington (KPWA) members who received an index colonoscopy between 1/1/1998 and 12/31/2007, and had hyperplastic polyps (HPs) or SSA/Ps but no conventional adenomas according to study pathologist histologic review. Subsequent pathology reports and biopsies through 1/1/2013 were reviewed for advanced colorectal neoplasia. We linked to the Seattle-Puget Sound Surveillance Epidemiology and End Results (SEER) registry to identify additional CRC cases. We used generalized estimating equations with a logit link to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for advanced colorectal neoplasia, comparing those with SSA/Ps to those with HPs. There were 161 individuals with index SSA/Ps, 548 with HPs, and 918 subsequent endoscopies included in analyses. Of those with index SSA/Ps, 19 had subsequent advanced colorectal neoplasia; 39 with HPs had subsequent advanced colorectal neoplasia. Compared to those with HPs, those with SSA/Ps were not statistically significantly more likely to have subsequent advanced colorectal neoplasia (adjusted OR 1.79; CI 0.98-3.28). Polyp size ≥ 10mm, right colon location, and the presence of multiple serrated polyps were also not associated with advanced colorectal neoplasia. Our results suggest that there is not a strong association between SSA/Ps and subsequent advanced colorectal neoplasia during the 5years following SSA/P removal.

Stage IV colorectal cancer primary site and patterns of distant metastasis

BackgroundAlthough colorectal cancer (CRC) usually metastasizes to the liver and/or lungs, factors influencing the anatomic pattern of metastases remain poorly understood. MethodsWe assessed the relationship between primary CRC site and pattern of synchronous metastasis among 1202 individuals diagnosed with incident metastatic CRC between 2010 and 2014 and identified through the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) registry. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between primary tumor site and synchronous metastatic pattern. ResultsCompared to patients with proximal colon primaries, patients with rectal primaries were more likely to present with lungs-only or liver and lungs metastases versus liver-only metastases (ORlungs–onlyvs.liver-only: 2.39, 95% CI: 1.35–4.24, ORliver+lungsvs.liver-only: 2.20, 95% CI: 1.46–3.32). ConclusionThese findings suggest that patients with rectal primaries are more likely than patients with colon primaries to present with synchronous lung metastases.

Abstract LB-360: Association between weight change after colorectal cancer diagnosis and long-term mortality differs by age

Abstract Previous studies evaluating the association of weight gain following colorectal cancer (CRC) diagnosis with mortality have been inconsistent. In this study, we evaluate whether this association differs by age at diagnosis. Incident, invasive CRC cases were identified from the Puget Sound Surveillance, Epidemiology and End Results (SEER) Registry from 1997-2008 and enrolled in the Seattle Colon Cancer Family Registry. A standardized interview (at mean 8 months after diagnosis) ascertained self-reported height and weight two years prior. A follow-up questionnaire was administered approximately 5 years after baseline, with 1,087 participants providing height and weight at both time points. Survival outcomes were assessed through linkage to the National Death Index. Delayed-entry Cox regression was used to estimate the association between change in weight (kg) and all-cause or CRC-specific mortality (Hazard Ratio (HR) and 95% Confidence Interval (95% CI)), with survival time beginning at the 5-year follow-up survey. Models adjusted for age at diagnosis, sex, smoking history (ever/never), cancer stage at diagnosis (I-IV, missing), days from diagnosis and baseline survey, and body mass index (kg/m2) at baseline. Analyses were stratified by age at diagnosis (&amp;lt;50 or ?50 years). We also evaluated an interaction term between age at diagnosis (continuous) and per-kg weight change. Over a median 4.7 years (range 0-9.0) of follow-up after the 5-year survey, 234 participants died (69 from CRC). At the 5-year follow-up, 579 (54%) participants had lost weight (median -5 kg), 114 (11%) reported the same weight, and 385 (36%) had gained weight (median 4 kg). Among those aged &amp;lt;50 at CRC diagnosis, weight gain at follow-up was significantly associated with higher subsequent all-cause mortality (HR = 1.19 per 5kg, 95% CI: 1.02-1.39), but not CRC-specific mortality. Among those aged ?50 at CRC diagnosis, weight gain at the follow-up time point was significantly associated with higher CRC-specific mortality (HR = 1.34 per 5kg, 95% CI: 1.11-1.61), but not all-cause. The association between weight change and survival differed by age for CRC-specific mortality (P-interaction = 0.01) but not all-cause mortality (P-interaction = 0.82). These findings support the importance of maintaining a healthy body weight after CRC diagnosis, and may suggest the association of weight change with risk of cause-specific death differs in individuals younger versus older than age 50 at diagnosis. Citation Format: Jonathan M. Kocarnik, Xinwei Hua, Jamaica Robinson, Amanda I. Phipps, Stacey Cohen, Polly A. Newcomb. Association between weight change after colorectal cancer diagnosis and long-term mortality differs by age. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-360.

Pre- and Post-Diagnostic Non-Steroidal Anti-Inflammatory Drug Use and Colorectal Cancer Survival in Seattle Colon Cancer Family Registry

Abstract Purpose: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in the general population, and regular NSAID use is associated with improved survival among colorectal cancer (CRC) patients. We examined the association of NSAID use prior to, and after, diagnosis in relation to CRC-specific and overall survival. Methods: Study subjects were incident, invasive CRC cases from the population-based Seattle Colon Cancer Family Registry. Eligible cases were 20–74 years of age, diagnosed from 1997 to 2008, and identified from the Puget Sound Surveillance, Epidemiology and End Results (SEER) Registry. NSAID use two years prior to the interview date (“pre-diagnosis period”) was collected by telephone interview at study enrollment an average of eight months after diagnosis. A follow-up questionnaire was administered approximately five years after the cases' CRC diagnosis (“post-diagnosis period”). Regular NSAID use was defined as having taken aspirin or ibuprofen at least twice per week for more than a month. Follow-up for survival and cause of death was completed through linkage to the National Death Index. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations of pre- and post-diagnostic NSAID use, and initiation, continuation and discontinuation of NSAIDs between pre- and post-diagnostic periods with survival after CRC diagnosis. Results: Compared to never users, regular NSAID use after diagnosis was associated with better overall survival (HR = 0.69, 95% CI, 0.54–0.89) and CRC-specific survival (HR = 0.48, 95% CI, 0.29–0.80). Among people who survived five years after diagnosis, both overall and CRC-specific survival were better for patients who initiated NSAID use post-diagnosis compared to never users, with HRs (95% CI) of 0.70 (0.51–0.95) and 0.43 (0.23–0.82), respectively. HR estimates were stronger for CRC-specific survival among those with non-advanced (local and regional) CRC (HR = 0.38, 95% CI, 0.18–0.77). Conclusion: Our results suggest that among long-term CRC survivors, regular use of NSAID after CRC diagnosis, including when initiated after diagnosis, is significantly associated with longer CRC-specific survival. This association is more pronounced for patients with non-advanced CRC.

Common colorectal cancer risk variants in SMAD7 are associated with survival among prediagnostic nonsteroidal anti‐inflammatory drug users: A population‐based study of postmenopausal women

Common single nucleotide polymorphisms (SNPs) in SMAD7 (18q21) have been linked to colorectal cancer (CRC) risk in genome-wide association studies, but little is known about their effects on survival. SMAD7 regulates gastrointestinal inflammation by inhibiting transforming growth factor-β (TGFB), which can act as both a tumor suppressor and a promoter of metastasis. Regular use of cyclooxygenase-2 (COX2) inhibitors, such as nonsteroidal anti-inflammatory drugs (NSAIDs), reduces the risk of developing CRC. Because COX2 overexpression reduces the growth suppressing effects of TGFB, we hypothesized that survival may depend on both SMAD7 genotype and prediagnostic NSAID use. Postmenopausal women, ages 50-74, diagnosed with incident invasive CRC from 1997 to 2002 were identified using the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. Information on prediagnostic NSAID use and other risk factors was ascertained by interview, and women were followed-up for survival through December 31, 2009. Seven hundred and twenty-seven cases were genotyped for two GWAS hits in SMAD7 with minor allele frequency > 30%, one with minor allele associated with decreased risk (rs4939827) and one with minor allele associated with increased risk (rs4464148). Two hundred and forty-two deaths occurred, 160 attributable to CRC. Among those without distant disease at diagnosis, CRC-specific survival differed by genotype only for NSAID users: each minor allele of rs4939827 was associated with worse survival [hazard ratio (HR) = 2.67, 95% confidence interval (CI): 1.33-5.37] and each minor allele of rs4464148 was associated with better survival (HR = 0.41, CI 0.18-0.94). SMAD7 variants known to be important for CRC risk were associated with disease-specific survival among prediagnostic NSAID users.

Long-Term Use of Acetaminophen, Aspirin, and Other Non-Steroidal Anti-Inflammatory Drugs and Risk of Hematologic Malignancies: Results From the Large, Prospective VITamins and Lifestyle (VITAL) Cohort Study

AbstractAbstract 2153 Background:Several epidemiological studies have examined the association of aspirin use and other over-the-counter analgesics or anti-inflammatory drugs and the incidence of hematologic malignancies. Although previous results have been inconsistent, some studies have suggested a reduced risk of leukemia or lymphoma with regular use of aspirin or non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs). On the other hand, some but not all studies have reported an increased risk of leukemia or lymphoma with regular use of acetaminophen. Methods:We evaluated the association of analgesic use to hematologic malignancies in a prospective cohort of 64,839 men and women aged 50 to 76 years from Washington State recruited in 2000 to 2002 to the VITamins And Lifestyle (VITAL) study. Eligible participants completed a 24-page baseline questionnaire, including detailed questions about medication use during the previous 10 years. Incident cases of hematologic malignancies (n=577, including MDS [n=54], AML [n=36], myeloproliferative disorders [n=46], CLL/SLL [n=88] and other non-Hodgkin lymphomas [n=235], Hodgkin lymphomas [n=22], plasma cell disorders [n=66], mature NK/T cell neoplasms [n=17], and other entities [n=13]) were identified through December 2008 by linkage to the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. The censored date was the date of withdrawal from the study, death, move out of the SEER catchment area, or last date of linkage to SEER for diagnosis of hematologic malignancy. In addition, participants were excluded if they had any cancer prior to baseline other than non-melanoma skin cancer and were censored at the time of diagnosis of a non-hematologic malignancy during follow-up to remove treatment for a prior cancer as a cause of any subsequent hematologic cancer. Medication use was categorized as “no use”, “low use” (use for either less than 4 days/week or less than 4 years), and “high use” (use for at least 4 days/week and at least 4 years). Hazards ratios (HRs) and 95% confidence intervals (95% CI) associated with use of acetaminophen, aspirin, and non-aspirin NSAIDs for total incident hematologic malignancies and cancer subcategories were estimated by Cox proportional hazards models. Multivariable-adjusted models were fit by adjusting for age, sex, race/ethnicity, education, smoking, self-rated health, history of fatigue/lack of energy, and family history of leukemia or lymphoma. All models except low-dose aspirin were further adjusted for history of rheumatoid arthritis, history or non-rheumatoid arthritis or chronic neck/back/joint pain, and history of migraines or frequent headaches. The model for low-dose aspirin was further adjusted for history of coronary artery disease, stroke, diabetes, or use of antihypertensive or lipid-lowering medications. Results:After adjustment, there was an increased risk of incident hematologic malignancies associated with increasing use of acetaminophen (HR=1.81 [95% CI: 1.33–2.46] for high use; p=0.009 for trend). The association with high use of acetaminophen was seen for MDS/AML (HR=2.23 [1.09-4.56]), non-Hodgkin lymphomas (HR=1.82 [1.14-2.92]), and plasma cell disorders (HR=2.32 [0.98-5.50]) but not CLL/SLL (HR=0.83 [0.30-2.35]). By comparison, there was no association with risk of incident hematologic malignancies for increasing use of low-dose aspirin (HR=1.04 [0.81-1.33] for high use; p=0.856 for trend), regular-dose aspirin (HR=0.86 [0.67-1.11] for high use; p=0.329 for trend), non-aspirin NSAIDs (HR=1.04 [0.75-1.43] for high use; p=0.820 for trend), or ibuprofen (HR=0.98 [0.67-1.44] for high use; p=0.956 for trend). Conclusion:Use of acetaminophen increased the risk of incident hematologic malignancies other than CLL/SLL in a usage-dependent manner, with an almost 100% increased risk for use least 4 days/week for of at least 4 years. Neither aspirin nor non-aspirin NSAIDs decreased risk and are unlikely to be useful for chemoprevention. Disclosures:No relevant conflicts of interest to declare.

Comparison of the Veterans Affairs Oncology Registry and the SEER Cancer Registry among patients with lung cancer.

6056 Background: The recently established VA Oncology Registry (VAOR) offers the ability to identify newly diagnosed patients with cancer treated at VA Medical Centers, for whom detailed clinical information can be linked to VA electronic medical data to evaluate treatment and outcomes of care. Methods: We compared male Veterans in the Pacific Northwest VAOR to male subjects in the Puget Sound Surveillance, Epidemiology, and End Results (SEER) Registry for the period 2000 through 2006. Women were excluded as they comprised 47% of SEER data but only 3% of VA patients with lung cancer. Results: We identified 1,715 Veterans and 7,864 men diagnosed with lung cancer in the Puget Sound SEER region between 2000 and 2006. Stage IV disease was common among Veterans and the SEER population (37% VAOR; 39% SEER) although stage information was missing for more subjects from SEER. Veterans were more likely to be diagnosed at an earlier age than the SEER population. Over 97% of Veterans were current or former smokers. The frequency of surgery was similar among stage I and II subjects from both data sources. Overall survival did not differ between VAOR and SEER. Within stage comparisons showed similar survival for stage III patients, and higher survival rates for individuals in SEER for all other stages. Conclusions: Demographic and survival data from the VAOR are comparable to the SEER Cancer Registry for men within the same geographic region. The VAOR incorporates detailed patient records on diagnosis, comorbidities, treatments, adverse events, and laboratory values from the VA Computerized Patient Record System (CPRS), making it a rich resource for assessing risk factors and determinants of clinical outcomes for patients with lung cancer and perhaps other types of cancer. Pacific Northwest VAOR N = 1,715 (%) Puget Sound SEER Registry N = 7,864 (%) Stage at diagnosis I 25 17 II 8 4 III 25 27 IV 37 39 Unknown 5 12 Histology Adenocarcinoma 21 28 Squamous 27 22 NSCLC (other than squamous or adenocarcinoma) 7 12 NSCLC–NOS 46 38 % White 88 89 % Smoking history 97 n/a Age <65 38 32 65-74 35 32 75+ 27 36 % Surgery stage I and II 75 77 5-yr survival (Age 55-74) Overall 16.0 16.2 Stage I 42.5 50.3 Stage II 31.4 38.8 Stage III 8.1 11.4 Stage IV 0.4 2.6 Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Genentech

Identification of ovarian cancer symptoms in health insurance claims data.

Women with ovarian cancer have reported abdominal/pelvic pain, bloating, difficulty eating or feeling full quickly, and urinary frequency/urgency prior to diagnosis. We explored these findings in a general population using a dataset of insured women aged 40-64 and investigated the potential effectiveness of a routine review of claims data as a prescreen to identify women at high risk for ovarian cancer. Data from a large Washington State health insurer were merged with the Seattle-Puget Sound Surveillance, Epidemiology and End Results (SEER) cancer registry for 2000-2004. We estimated the prevalence of symptoms in the 36 months prior to diagnosis for early and late-stage ovarian cancer cases and for two comparison groups. The potential performance of a passive screener that would flag women with two or more visits for any of the symptoms in the previous 2-month period was examined. Of the 223,903 insured women, 161 had incident cases of ovarian cancer. Both early and late-stage patients had a higher prevalence of abdominal/pelvic pain and bloating than the comparison groups, primarily in the 3 months before diagnosis. The passive screener had a sensitivity of 0.31 and specificity of 0.83 and usually identified women right before diagnosis. Assuming an average cost of $500 per false positive, the screener would be considered cost-effective if the true positives had an average increase of 8.5 years of life expectancy. These results support previous findings that ovarian cancer symptoms were reported in health insurance claims and were more prevalent before diagnosis, but the symptoms may occur too close to the diagnosis date to provide useful diagnostic information. The passive screening approach should be reevaluated in the future using electronic medical records; if found to be effective, the method may be potentially useful for other incident diseases.

Colorectal Cancer Cases and Relatives of Cases Indicate Similar Willingness to Receive and Disclose Genetic Information

Recent developments in genetic testing allow us to detect individuals with inherited susceptibility to some cancers. Genetic testing to identify carriers of cancer-related mutations may help lower risk by encouraging preventive behaviors and surveillance. This study assessed willingness of colon cancer cases and relatives to receive genetic information that may indicate an increased risk for cancer, to whom they would disclose genetic information, and whether receiving genetic test results may influence future prevention behaviors among individuals enrolled in the Seattle Colorectal Cancer Family Registry. Incident invasive colorectal cancer cases were identified from the Puget Sound Surveillance Epidemiology and End Results (SEER) registry. In 2007, a sequential sample of cases and relatives (n = 147) were asked to respond to a questionnaire addressing study aims. The questionnaire was administered during a baseline or 5-year follow-up interview. Patterns of response to each statement were similar between colorectal cancer cases and relatives. Both colorectal cases (95%) and relatives (95%) reported willingness to receive genetic information. Nearly all participants would tell their doctor the results of a genetic test (99% of cases; 98% of relatives), and all married participants would tell their spouses. Cases (96%) anticipated being slightly more likely than relatives (90%) to change their cancer screening behavior, but this difference was not statistically significant (p = 0.33). A high percentage of both colorectal cancer cases and relatives sampled from the Seattle Colorectal Cancer Family Registry are interested in identifying their genetic status, discussing their genetic status with their family and doctor, and adopting behavioral changes that may reduce cancer risk.

Long-term use of supplemental multivitamins, vitamin C, vitamin E, and folate does not reduce the risk of lung cancer.

Lung cancer is the leading cause of cancer-related mortality in the United States. Although supplements are used by half the population, limited information is available about their specific effect on lung cancer risk. To explore the association of supplemental multivitamins, vitamin C, vitamin E, and folate with incident lung cancer. Prospective cohort of 77,721 men and women aged 50-76 years from Washington State in the VITAL (VITamins And Lifestyle) study. Cases were identified through the Seattle-Puget Sound SEER (Surveillance, Epidemiology, and End Results) cancer registry. Hazard ratios (HRs) for incident lung cancer according to 10-year average daily use of supplemental multivitamins, vitamin C, vitamin E, and folate. A total of 521 cases of lung cancer were identified. Adjusting for smoking, age, and sex, there was no inverse association with any supplement. Supplemental vitamin E was associated with a small increased risk of lung cancer (HR, 1.05 for every 100-mg/d increase in dose; 95% confidence interval [CI], 1.00-1.09; P = 0.033). This risk of supplemental vitamin E was largely confined to current smokers (HR, 1.11 for every 100-mg/d increase; 95% CI, 1.03-1.19; P < 0.01) and was greatest for non-small cell lung cancer (HR, 1.07 for every 100-mg/d increase; 95% CI, 1.02-1.12; P = 0.004). Supplemental multivitamins, vitamin C, vitamin E, and folate were not associated with a decreased risk of lung cancer. Supplemental vitamin E was associated with a small increased risk. Patients should be counseled against using these supplements to prevent lung cancer.

Sexual factors and the risk of prostate cancer.

A population-based case-control study of prostate cancer was performed in King County, Washington, in White men and Black men aged 40-64 years, between 1993 and 1996. Incident prostate cancer cases (n = 753) were identified from the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. Controls (n = 703) were identified through random digit dialing and were frequency matched to cases on age. Sexual behavior, medical history, and other potential prostate cancer risk factors were ascertained through an in-person interview. There was no relation between sexual orientation and prostate cancer, although the number of men who had sex with men was small. Risk estimates increased directly with the lifetime number of female sexual partners (trend p < 0.001) but not with male partners (trend p = 0.62). Risk also increased with decreasing age at first intercourse, but this effect disappeared after adjusting for the number of female partners. Prior infection with gonorrhea was positively associated with risk (odds ratio = 1.50; 95% confidence interval: 1.0, 2.2), but no effect was seen among men with other sexually transmitted diseases. No relation between lifetime frequency of sexual intercourse and risk of prostate cancer was apparent. These findings are consistent with previous studies that support an infectious etiology for prostate cancer.

Leisure-time physical activity in relation to breast cancer among young women (Washington, United States).

It has been hypothesized that women who participate in vigorous physical activity may have lower risk of breast cancer due to lower lifetime exposure to ovarian hormones. A population-based case-control study was conducted to investigate the association between leisure-time physical activity and risk of breast cancer among women aged 21 to 45 years. Cases were 747 women diagnosed with invasive breast cancer between 1983 and 1990 in three counties of western Washington state (United States), and were identified through the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) registry. Controls were 961 women selected from the same area by random-digit telephone dialing. Physical activity was assessed through personal interview, with questions on frequency and duration of each type of recreational activity during the two-year period immediately prior to reference data (date of diagnosis for cases and a comparable assigned date for controls) and between ages 12 and 21. For the two-year time period before diagnosis, there was no association with frequency of activity (age-adjusted odds ratio [OR] = 0.93, 95 percent confidence interval [CI] = 0.71-1.22 for four or more episodes per week cf none), total hours spent in physical activity (age-adjusted OR = 0.92, CI = 0.71-1.22 for four or more hours per week cf none) or MET (metabolic equivalent energy expenditure unit) (age-adjusted OR = 0.95, CI = 0.73-1.23 for 18 or more METs per week of none), nor any trend is risk with increasing activity levels. Similarly, there was no association between leisure activity during adolescence and breast cancer risk. These results were not confounded further by body mass index (wt/ht2), age at menarche, age at first full-term pregnancy, parity, family history of breast cancer, or other measured health behaviors. Our findings do not support a protective effect of leisure-time physical activity either in the adolescent years or in adulthood on breast cancer in young women.

Racial Misclassification of Native Americans in a Surveillance, Epidemiology, and End Results Cancer Registry

The cancer incidence for all sites has been reported to be lower in Native Americans than in White Americans. Concerns have been expressed, however, that the observed low incidence may be a result of inaccurate reporting of race. The objective of this study was to investigate the extent to which racial misclassification may contribute to the observed low cancer incidence among Native Americans. A registry of individuals eligible to receive medical services funded by the Indian Health Service was linked by computer to the Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. Only 137 (60%) of the patients with invasive cancer registered with the Indian Health Service and for whom race was recorded were identified as Native Americans in the SEER registry. Similarly, 55 (69%) of 80 in situ cervical cancer case patients were classified as Native American. A strong association was observed between Native-American blood quantum level and racial misclassification. The results of this study indicate that the observed low cancer incidence in Native Americans relative to Whites in the northwest United States is at least partially attributable to racial misclassification in the SEER cancer registry.

Evaluation of the Increase in Breast Cancer Incidence in Relation to Mammography Use

The breast cancer incidence rate (i.e., the detected number of new cases per 100,000 women) increased by 31% in western Washington State between the time periods 1974-1978 and 1986-1987. If this increase is largely due to earlier detection of cases through mammography, it is encouraging; otherwise (if it cannot be attributed to mammography alone), investigation of other factors may be needed. The observed increase, based on 18,559 documented breast cancer cases from the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) registry, was compared with the predicted increase based on mammography utilization by year from a survey of 1,212 women in western Washington and on data from published studies regarding the impact of mammography on the detection rate for new breast cancer cases. Among women aged 45-64, all of the increase was associated with local stage disease and with tumors detected at a smaller size. Further, the 15% observed increase in incidence in this age group was less than the 20% increase predicted due to the utilization of mammography. However, the observed increase was approximately twice the predicted increase for women aged 65-74 (observed 57%, predicted 26%) and for women aged 25-44 (observed 29%, predicted 12%). Thus, all of the increase in detected breast cancer among 45-64 year old women appears to be explained by the increased use of mammography, while among older women and younger women there may be other contributing factors. The limitations and implications of this analysis are discussed.