The association between smoking marijuana and the occurrence of lung cancer

It is still unclear if an association exists between the smoking of marijuana and the occurrence of lung cancer although one clearly exists between cigarette smoking and lung cancer. The objective of this study was to systematically review the literature in order to assess the impact of marijuana smoking, which is increasingly becoming a significant public health issue, on the occurrence of the number one killing cancer, lung cancer. ^ Method. Selected studies in the English language conducted on humans that assess the impact of marijuana smoking on lung cancer were identified from EBSCO MEDLINE, PUBMED, and GOOGLE databases. The search keywords were marijuana, cannabis, hashish, kif, and lung cancer with selection criteria including studies in the English language identified from 1950 to April 2008. Excluded were non-research studies such as editorials, letters, and reviews. Also excluded were studies that did not involve humans with direct intentional marijuana smoking or in vivo studies with mice. Case report studies or case series studies involving less than 10 patients were also excluded as well as studies that did not examine lung conditions related to premalignant or cancerous changes. ^ Results. Ten studies met the selection criteria and were analyzed. The ten studies in this review overall offer biological evidence of the potential association between marijuana smoking and premalignant lung findings but no overwhelming conclusive evidence for the association between marijuana smoking and the occurrence of lung cancer. Two of the observational studies [1, 2] failed to demonstrate an association between marijuana and lung cancer, but the remaining studies supported an association between marijuana smoking and premalignant or malignant lung findings. ^ Conclusion. It must, therefore, be concluded that no convincing evidence exists, based on the existing data, for an association between marijuana smoking and the occurrence of lung cancer even though the few observational studies failing to report such an association may be due to certain limitations particularly the relative young age of the participants precluding sufficient lag time for the identification of lung cancer outcome as explained in other sections of this paper. ^ Further research is, therefore, necessary to better evaluate this critical issue, while recommendations against smoking marijuana because of its potential harmful effects, including the potential for premalignant lung changes as noted in this review, should continue to be made. ^ In the future, large prospective studies with study participants representing a much wider spectrum of ages, and longer follow-up periods, with detailed assessment of marijuana exposure and definitive pathologic diagnosis of lung cancer are necessary^

Hormonal risk factors and testicular cancer

The cause of testicular cancer is not known and recent hypotheses have suggested an altered hormonal milieu may increase the risk of testis cancer. This study examined modulation of testicular cancer risk by hormonal factors, specifically: environmental xenoestrogens (e.g. organochlorines), prenatal maternal estrogens, testosterone indices (age at puberty, severe adolescent acne, self-reported balding), sedentary lifestyle and dietary consumption of fats and phytoestrogens.^ A hospital based friend matched case-control study was conducted at the University of Texas M. D. Anderson Cancer Center in Houston, Texas, between January 1990 and October 1996. Cases had a first primary testis tumor diagnosed between age 18 to 50 years and resided in Texas, Louisiana, Oklahoma or Arkansas.^ Cases and friend controls completed a mail questionnaire and case/control mothers were contacted by phone regarding pregnancy related variables. The study population comprised 187 cases, 148 controls, 147 case mothers and 86 control mothers. Odds ratios were virtually identical whether the match was retained or dissolved, thus the analyses were conducted using unconditional logistic regression.^ Cryptorchidism was a strong risk factor for testis cancer with an age-adjusted odds ratio (OR) of 7.7 (95% confidence interval (CI): 2.3-26.3). In a final model (adjusted for age, education, and cryptorchidism), history of severe adolescent acne and self-reported balding were both significantly protective, as hypothesized. For acne (yes vs. no) the OR was 0.5 (CI: 0.3-1.0) and for balding (yes vs. no) the OR was 0.6 (CI: 0.3-1.0). Marijuana smoking was a risk factor among heavy, regular users (17 times/week, OR = 2.4; CI: 0.9-6.4) and higher saturated fat intake increased testis cancer risk (saturated fat intake $>$ 15.2 grams/day vs. $<$ 11.8 grams/day, OR = 3.3; CI: 1.5-7.1). Early puberty, xenoestrogen exposure, elevated maternal estrogen levels, sedentary lifestyle and dietary phytoestrogen intake were not associated with risk of testicular cancer.^ In conclusion, testicular cancer may be associated with endogenous androgen metabolism although environmental estrogen exposure can not be ruled out. Further research is needed to understand the underlying hormonal mechanisms and possible dietary influences. ^

Childhood sexual victimization: Risk factor for drug use and sexual risk behaviors

The purpose of this dissertation was to survey men in the Harris County Jail (HCJ) to establish a more valid estimate of childhood sexual abuse (CSA) prevalence in a jailed-based population; to assess whether inmates with a history of CSA were at greater risk for use of drugs and alcohol and engaging in high-risk sexual behaviors than those without histories of childhood sexual abuse. ^ The first study determined the prevalence of childhood sexual abuse among incarcerated males in a county jail. In this study, sixty-three percent of the subjects reported having been sexually abused. Sixty-one percent reported abuse pre-puberty and 10% reported abuse post puberty. In pre-puberty abuse the initiation of first abuse occurred at a mean age of 5.6 years (SD 5.096, range: 2–13 years). ^ The second study explored the association between inmates with histories of CSA as a risk factor for sexual risk behaviors. A history of sexual abuse did not appear to be associated with an elevated risk of sexual risk behaviors. ^ The third study explored a history of drug use and a history of CSA among the inmates. A chi-square test showed that the inmates who reported a history of CSA, was significantly greater for the following drugs: Marijuana (02), Crack (03), Heroin/Morphine (.03), Amphetamines/Speed (01), Downers/Barbiturates (.001), Methamphetamine/Crystal Meth (.001), Valium .02), LSD/Acid (.001), and Inhalants (.001), p < .05). Significance was not found in alcohol, tobacco, cocaine, Quaaludes and methadone. ^ The research from this study provides empirical data supporting previous research. The current data shows that incarcerated inmates have a high prevalence of childhood sexual abuse and drug use. Sexual victimization as a child does not appear to be associated with an elevated risk of unsafe sexual behaviors. However, men who used drugs were twice as likely to have engaged in unprotected sex with casual and regular partners, and rarely used condoms with paid sex. Although our study methods do not permit a causal explanation for this association, we believe it is of concern. Finally, data in this study shows that sexually abused children are likely candidates for adult criminal behavior. ^

Depressive symptoms and sexual risk behaviors in adolescents

The purpose of this study was to determine whether depression is a factor in explaining the difference in sex behaviors among adolescents with different ethnic backgrounds, family and school contexts. We hypothesize that adolescents with a higher number of depressive symptoms are more likely to engage in sexual risk behaviors than adolescents with fewer depressive symptoms. Further, adolescent depression and sexual behaviors are mediated or moderated by individual characteristics, family and school contexts. ^ Background. large ethnic disparities exist in adolescent engagement in risky sexual behaviors, yet, there is little in the literature that explains these disparities. Studies of sexual behavior of youths abound; yet, there is little literature on the prevalence and correlates of depression or the association between depression and sexual behaviors among different ethnic groups. Objectives. (1) To determine ethnic differences in the prevalence of depressive symptoms using data collected through the National Longitudinal Study of Adolescent Health (Add Health). (2) To determine predictors of sex risk behaviors among adolescents, including the role of depression. (3) To identify predictors of depression among these adolescents. Methods. Add Health data from wave 1 and wave 2 interviews of 7th–12th graders were analyzed using multivariate models constructed with both depression and sexual behavior as outcome variables. Logistic regression models determined whether and to what extent the independent variables, including depression, sex behaviors, demographic factors, individual and family characteristics, and school context were related to the probability of engaging in risky sexual behaviors. Results. Ethnic differences in depressive symptoms did not persist after demographic and contextual variables were included in the model. Sex behaviors all shared the hypothesized relationship with depressive symptoms. The odds of risky sex behaviors increased as number of depressive symptoms increased. Depression was predicted by marijuana use and having a serious argument with father for males at Wave 1 and by age and future orientation for females. Wave 2 depression was predicted by Wave 1 depression. ^

Sleep quality and quantity and associated factors among high school students from south Texas

Background. Insufficient and poor quality sleep among adolescents affects not only the cognitive functioning, but overall health of the individual. Existing research suggests that adolescents from varying ethnic groups exhibit differing sleep patterns. However, little research focuses on sleep patterns and associated factors (i.e. tobacco use, mental health indicators) among Hispanic youth. ^ Methods. The study population (n=2,536) included students in grades 9-12 who attended one of the three public high schools along the Texas-Mexico border in 2003. This was a cross sectional study using secondary data collected via a web-based, confidential, self-administered survey. Separate logistic regression models were estimated to identify factors associated with reduced (<9 hours/night) and poor quality sleep on average during weeknights. ^ Results. Of participants, 49.5% reported reduced sleep while 12.8% reported poor quality sleep. Factors significantly (p<0.05) associated with poor quality sleep were: often feeling stressed or anxious (OR=5.49), being born in Mexico (OR=0.65), using a computer/playing video games 15+ hours per week (OR=2.29), working (OR=1.37), being a current smoker (OR=2.16), and being a current alcohol user (OR=1.64). Factors significantly associated with reduced quantity of sleep were: often feeling stressed or anxious (OR=2.74), often having headaches/stomachaches (OR=1.77), being a current marijuana user (OR=1.70), being a current methamphetamine user (OR=4.92), and being a current alcohol user (OR=1.27). ^ Discussion. Previous research suggests that there are several factors that can influence sleep quality and quantity in adolescents. This paper discusses these factors (i.e. work, smoking, alcohol, etc.) found to be associated with poor sleep quality and reduced sleep quantity in the Hispanic adolescent population. A reduced quantity of sleep (81.20% of the participants) and a poor quality of sleep (12.80% of the participants) were also found in high school students from South Texas. ^

Prevalence and trends of substance abuse in Harris County, Texas, 1989 to 1991

In the late 1980s, Harris County, Texas began experiencing an escalation of drug-related activities. Various indicators used in this analysis tracked drug-related trends from 1989 to 1991 to determine patterns for comparison of local (Houston/Harris County, Texas) to national levels.^ An important indicator of the drug scenario was drug-related activities among youths, which increased during the period of this study. The Harris County Juvenile Probation Department showed that among arrests for drug-related activities, felonies increased from 25% in 1988 to 53% in 1991. With the rise in drug-related crimes, and substance abuse among the student body, school districts were forced to institute drug education programs in an effort to curtail such activities.^ Law enforcement agencies in the county saw increased demands for their services as a result of drug activities. Harris County Sheriffs Department reported a 32% plus increase in drug-related charges between 1986 and 1991. Houston Police Department reported an increase of 109% for the same period.^ Data from the Harris County Medical Examiner, the National Institute of Justice's Drug Use Forecasting System (Houston), and drug treatment facilities around Houston/Harris County, Texas indicated similar drug usage trends. Over a four-year period (1988-91), the drugs most frequently detected during blood and urine analyses were cocaine, followed by marijuana, heroin, LSD, and methamphetamines.^ From 1988 to 1991, most drug rehabilitation organizations experienced increased demands for their services by approximately 35%. Several other organizations experienced as much as a 70 percent increase. Males accounted for roughly 70% and females about 30% of persons seeking treatment. However, the number of females pursuing treatment increased, thereby reducing the gender gap.^ Blacks in Houston/Harris County were at higher risk for drug usage among the general population, but sought treatment more readily than other ethnic groups. Whites sought treatment in similar numbers as Blacks, but overall the risk appeared smaller because they made up a larger portion of the Houston/Harris County population.^ This analysis concluded that drug trends for the Houston/Harris County, Texas did not follow national trends, but showed patterns of its own. It was recommended that other communities carry out similar studies to determine drug use trends particular to their local. ^

Association of coping styles & adolescent substance use

Adolescent substance use is a serious public health concern with long-lasting consequences. Although specific coping behaviors have been associated with adolescent substance use, less is known about the role of multidimensional coping styles that account for both positive and negative coping behaviors. This study examined the association of coping styles and substance use (alcohol, marijuana, and other illicit drugs) of 1,019 ethnically diverse high school students. Coping styles were categorized by high or low negative coping behaviors (e.g. distraction, social withdrawal, self-criticism, blame others, wishful thinking, resignation, and negative emotional regulation) and high or low positive coping behaviors (e.g. cognitive restructuring, problem-solving, social support, and positive emotional regulation). My hypothesis that high positive coping, regardless of the use of negative coping behaviors, would be protective against substance use was rejected. Logistic regression analyses controlling for age, gender, race, and parent education indicated that adolescents who relied primarily on adaptive coping were 45-67% less likely to report lifetime or past year substance use than any other coping style. However, mixed copers (i.e. high in both positive and negative coping behaviors) were 2 to 3 times as likely to report substance use than their adaptive coping counterparts.^