Challenges to Recruiting Men on Active Surveillance for Prostate Cancer in Clinical Chemoprevention Trials.

Clinical trials play a critical role in evidence-based medicine, when rigorous scientific methodology is utilized to discover and test the effectiveness and safety of new drugs to prevent or cure diseases, including cancer. Participation in clinical trials thus becomes key to successful completion of these trials. Although it is estimated that >70% of Americans are inclined to participate in clinical trials, less than 5% of adult cancer patients participate in clinical trials. There is thus a large gap between those inclined to participate in clinical trials and actual participation in clinical trials. As with trials targeting men with prostate cancer (PCa) on active surveillance (AS), where the target population is mostly over 50 years of age, others have observed several challenges with recruitment and accrual in clinical trials. The participation rate is currently unavailable for men on primary and secondary chemoprevention trials. Additionally, with unanticipated environmental factors such as a pandemic or other natural emergencies that may severely impact the economy, personal property, travel and person-to person contact for study-related procedures, there is a need to continuously identify these challenges and determine solutions to recruitment barriers in chemoprevention trials to ensure timely completion of early phase trials. Recent studies regarding the impact of the pandemic on clinical trial recruitment have shown that cancer prevention trials were relatively more negatively impacted compared to cancer treatment trials. The goal of this manuscript is to review our experience in continuously evaluating the protocol and patient level challenges to recruiting subjects on AS for PCa in this cancer chemoprevention trial conducted at the Comprehensive Cancer Center (CCC) and report the contemporary strategies that we are utilizing to continue to recruit subjects in this trial. We provide data from our current trial as an example while discussing future strategies to improve overall clinical trial recruitment. These strategies can inform future design of contemporary cancer chemoprevention trials and, additionally, better select, focus and invest in strategies that are the most productive and efficient for recruiting target populations.

Changing incidence of AIDS-related Kaposi sarcoma and non-Hodgkin lymphoma in Ontario, Canada.

OBJECTIVE: To examine the influence of the AIDS epidemic on the incidence of Kaposi sarcoma (KS) and non-Hodgkin lymphoma (NHL) in Ontario. METHODS: Age-standardized incidence rates for KS and NHL from 1981 to 2000 were calculated from the population-based Ontario Cancer Registry. AIDS cases were extracted from Ontario Ministry of Health and Long-Term Care reports. HIV death data were obtained from the Ontario Cancer Registry. RESULTS: KS was a rare cancer before the 1980s; however, incidence increased sharply between 1985 and 1995 by 13.8% per year. Thereafter, incidence rates fell close to those in the early 1980s. NHL incidence in males increased steadily during the 1980s at 3.2% per year and then slowed beyond 1990. In males aged 30-44, NHL incidence rose from 1981 to 1990 (8.8% per year) and then fell (-2.5%) thereafter. NHL and KS cases represented one-third of HIV deaths. CONCLUSIONS: The AIDS epidemic, the introduction of antiretroviral therapies, and the decrease in HIV infection rates explain the rise and decline of KS incidence in Ontario. NHL incidence trends are more complex, although the AIDS epidemic explains the trends observed in younger men (in whom AIDS is more common), and for the AIDS-related subtypes.

Using latent class analysis (LCA) to analyze patterns of drug use in a population of illegal opioid users.

BACKGROUND: The objective of this paper is to empirically determine a categorization of illegal opioid users in Canada in order to describe and analyze drug use patterns within this population. METHODS: Drug use patterns of 679 eligible illegal opioid users outside treatment from the OPICAN study, a pan-Canadian cohort (recruited March to December, 2002) involving the cities of Toronto, Montreal, Vancouver, Edmonton and Quebec City, were empirically examined using latent class analysis. These latent classes were then further analyzed for associations using chi-square and t-test statistics. FINDINGS: The opioid and other drug user sample surveyed were categorized into three latent classes. Class 1 (N=256) was characterized by the use of Tylenol 3 and benzodiazepines along with high levels of depression and self-reported pain. Class 2 (N=68) was described by the non-injection use of both heroin and crack while having a high level of homelessness. Class 3 (N=344) was shown to consist of injection drug users of heroin and cocaine exhibiting the highest levels of HIV and Hepatitis C infections amongst the classes. CONCLUSIONS: Using latent class analysis we found distinct patterns of drug use amongst illegal opioid users differing in terms of type of drugs co-used, social context, and co-morbid pathologies. These data may be useful as the empirical basis for the planning of specific prevention and treatment interventions.

Antidepressant medication use and non-Hodgkin's lymphoma risk: no association.

Animal and human studies have suggested that antidepressant medications may be associated with several cancers. The authors evaluated the association between antidepressant medication use and the risk of non-Hodgkin's lymphoma using a Canadian population-based case-control study, the National Enhanced Cancer Surveillance Study. Non-Hodgkin's lymphoma cases (n=638) diagnosed in 1995-1996 were identified using the Ontario Cancer Registry, and controls (n=1,930) were identified from the Ontario Ministry of Finance Property Assessment Database. Antidepressant medication use was ascertained using a self-administered questionnaire. Multivariate logistic regression was used to estimate odds ratios. "Ever" use of antidepressant medications was not associated with non-Hodgkin's lymphoma risk. The odds ratio for non-Hodgkin's lymphoma with 25 or more months of tricyclic antidepressant medication use was 1.6; however, this was nonsignificant. Duration or history of use or individual types of antidepressant medications were not associated with non-Hodgkin's lymphoma risk. These findings do not support an increased risk of non-Hodgkin's lymphoma with antidepressant medication use.

Hormonal factors and the risk of breast cancer according to estrogen- and progesterone-receptor subgroup.

Evidence suggests hormonal factors may be more strongly associated with estrogen receptor+progesterone receptor+ (ER+PR+) than ER-PR- breast cancer risk. This study evaluated risk factors according to ERPR tumor status among pre- and postmenopausal women participating in two recent population-based case-control studies. Breast cancer cases, ages 25-74 years, and diagnosed 1995-1998 were sampled from the Ontario Cancer Registry. Controls were a random sample of women identified using the Ontario Ministry of Finance rolls and were frequency-matched to cases within 5-year age groups. Epidemiological data were collected from breast cancer cases and controls using two self-administered questionnaires. ERPR data were obtained for 87% of the breast cancer cases (3,276 of 3,748). Multivariate polytomous logistic regression was used to obtain odds ratios estimates and 95% confidence intervals. The following significant differences were observed in the risk factor profiles for ER+PR+ and ER-PR- breast cancer: among premenopausal women, late age at menarche was only associated with a reduction in ER+PR+ breast cancer risk; obesity was associated with an increased ER-PR- and decreased ER+PR+ cancer risk; and the association between alcohol intake and breast cancer risk was heterogeneous across ERPR subgroups, although the direction varied across the levels of alcohol intake. Among postmenopausal women, there were no statistically significant differences observed in the risk factor profiles for ER+PR+ and ER-PR- breast cancer. Some heterogeneity exists in the risk factor profiles of ER+PR+ and ER-PR- premenopausal breast cancer; however, risk factor profiles did not differ markedly for postmenopausal breast cancer.

Use of antidepressant medications and the possible association with breast cancer risk. A review.

BACKGROUND: Antidepressant medication use has dramatically increased over the past decade, particularly for the newer classes such as selective serotonin reuptake inhibitors. While there is no question about the usefulness of these medications, it is important to review animal and epidemiologic studies that have evaluated the association between antidepressant medication use and the risk of breast cancer. METHODS: This paper reviews the scientific literature pertaining to the prevalence of and indications for antidepressant medication use, and the possible association between antidepressant medication use and breast cancer risk. RESULTS: Antidepressant medications are most commonly indicated for depressive disorders, and are also used for other conditions (e.g., anxiety disorders, personality disorders, and pain). In addition, antidepressants may be an effective alternative to estrogen therapy for the alleviation of hot flashes among peri-/postmenopausal women. Several epidemiologic studies have reported that certain antidepressants may be associated with a slightly increased breast cancer risk; however, the literature remains inconsistent. CONCLUSIONS: The possibility of an association between certain antidepressant medications and breast cancer risk has not been excluded, although further studies are needed before the body of scientific evidence can be conclusive. Evidence to date does not support a change in the current use of antidepressant medications.