Time to treat: A system redesign focusing on decreasing the time from suspicion of lung cancer to diagnosis in a community hospital

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Background: Multiple physician visits, numerous investigations, and serial wait times often result in a lengthy process from the onset of lung cancer-related symptoms until diagnosis. An unpublished retrospective chart review from a Toronto community hospital indicated suboptimal delays for patients from onset of symptoms until the diagnosis of lung cancer. Methods: The Time to Treat Program (TTT), consisting of a streamlined referral system and a clerical facilitator to fast-track patients through a diagnostic pathway algorithm, was designed for patients with clinical or radiological suspicion of lung cancer. Data on patient visits and investigations were collected. Pre- and post-implementation data on median wait times were compared. Results: From April 2005 to December 2006 over 120 physicians referred 188 females and 226 males. For the majority of patients (95.2%), the reason for referral was chest x-ray findings suspicious for lung cancer. After TTT implementation, the median time from suspicion of lung cancer to referral for specialist consultation decreased from 19.9 days to 10 days, and the median time from such referral to the actual consultation date decreased from 16.8 days to 5.3 days. The median time from specialist consultation to CT scan decreased from 52.1 days to 4 days and the median time from CT to diagnosis decreased from 39 days to 12.4 days. Overall, the median time from suspicion of lung cancer to diagnosis decreased from 127.8 days to 30 days. For 25% of the patients in the TTT it took 13 or fewer days from suspicion of lung cancer to diagnosis, while for 5% of the patients it took 90 days or more. Half of the patients in the TTT had a diagnosis by 24 days from the time of suspicion. Of all patients in the TTT, 33% were eventually diagnosed with lung cancer. The time from suspicion to diagnosis took longer for patients who eventually had confirmed lung cancer than those who did not: 36.5 days vs. 28.7 days. Conclusions: By addressing process issues in the work-up of lung cancer, the TTT was effective in shortening the time from suspicion of lung cancer to diagnosis and reduced time intervals at each step in the process. Earlier diagnosis of lung cancer may allow increased treatment options for patients.

No significant financial relationships to disclose.

New York City injection drug users' memories of syringe-sharing patterns and changes during the peak of the HIV/AIDS epidemic

In this oral history, 23 injection drug users (IDUs) were interviewed about the mid-1970s to mid-1980s when they could not legally purchase or possess syringes, and the threat of AIDS began to loom large. Several themes emerged, including: abrupt changes in syringe-sharing patterns; the effects of illnesses or deaths of others on their understanding of AIDS; and, racial/ethnic differences in responses to the threat of AIDS. Settings, such as "shooting galleries," helped HIV spread rapidly in the earliest stages of the city's AIDS epidemic. HIV entered the drug scene in the mid-1970s, just when IDUs were shifting from sharing homemade "works" (consisting of steel needles and syringes devised from rubber baby pacifiers and similar sources) among many IDUs to mass produced and distributed plastic, disposable needle and syringe sets. IDUs remember when they first became aware of AIDS and began to adjust their behaviors and social assumptions.

A 5-year evaluation of a methadone medical maintenance program

Methadone medical maintenance (MMM) is a model for the treatment of opioid dependence in which a monthly supply of methadone is distributed in an office setting, in contrast to more highly regulated settings where daily observed dosing is the norm. We assessed patient characteristics and treatment outcomes of an MMM program initiated in the Bronx, New York, in 1999 by conducting a retrospective chart review. Participant characteristics were compared with those of patients enrolled in affiliated conventional methadone maintenance treatment programs. Patients had diverse ethnicities, occupations, educational backgrounds, and income levels. Urine toxicology testing detected illicit opiate and cocaine use in 0.8% and 0.4% of aggregate samples, respectively. The retention rate was 98%, which compares favorably with the four other MMM programs that have been reported in the medical literature. This study demonstrates that selected patients from a socioeconomically disadvantaged population remained clinically stable and engaged in treatment in a far less intensive setting than traditional methadone maintenance.

Plasma erythropoietin levels in the oldest old

Erythropoietin (EPO) regulates erythrocytes production and is synthesized mainly by the kidney. Its production is reduced during chronic renal failure but is not altered by the senescence process in spite of the morphological changes that occur in the kidney. However, there is no information regarding what happens to erythropoietin synthesis during advanced ageing. Thus, we carried out an investigation to determine whether there was any significant difference in plasma erythropoietin between adults, old and very old people.

MATERIAL AND METHODS

We studied 74 healthy volunteers: 22 adults, 30 old, and 22 very old. None of them were smokers or were suffering from any disease that may intefere with hemoglobin (Hb) levels or with EPO production. Hematocrit, Hb, plasma creatinine and plasma erythropoietin were measured, and creatinine clearance was calculated from serum creatinine using two different formulae. Statistical analysis was performed using ANOVA and Bonferroni tests.

RESULTS AND CONCLUSION

Among the three groups we found a significant difference in creatinine clearance (p < 0.001), but not in plasma erythropoietin levels; we conclude that normal senescence does not alter plasma erythropoietin levels, even during advanced ageing.

Prevalence and characteristics of chronic pain among chemically dependent patients in methadone maintenance and residential treatment facilities

CONTEXT

Little is known about the prevalence and characteristics of chronic pain among patients with different types of chemical dependency.

OBJECTIVES

To estimate the prevalence and to examine the characteristics of chronic severe pain in chemically dependent populations receiving methadone maintenance or inpatient residential treatment.

DESIGN, SETTING, AND PARTICIPANTS

Representative samples of 390 patients from 2 methadone maintenance treatment programs (MMTPs) and 531 patients from 13 short-term residential substance abuse treatment (inpatient) programs, all in New York State, were surveyed in late 2000 and early 2001.

MAIN OUTCOME MEASURE

Prevalence of chronic severe pain, defined as pain that persisted for more than 6 months and was of moderate to severe intensity or that significantly interfered with daily activities.

RESULTS

Chronic severe pain was experienced by 37% of MMTP patients (95% confidence interval [CI], 32%-41%) and 24% of inpatients (95% CI, 20%-28%; P =.03). Pain of any type or duration during the past week was reported by 80% of MMTP patients and 78% of inpatients. Among those with chronic severe pain, 65% of MMTP patients and 48% of inpatients reported high levels of pain-related interference in physical and psychosocial functioning. Among MMTP patients, correlates of chronic pain in a multivariate model were age (odds ratio [OR], 2.08; 95% CI, 1.17-3.70), chronic illness (OR, 1.88; 95% CI, 1.07-3.29), lifetime psychiatric illness (OR, 1.77; 95% CI, 1.06-2.97), psychiatric distress (OR, 1.63; 95% CI, 1.22-2.18), and time in treatment (OR, 2.23; 95% CI, 1.06-4.68). Among inpatients, the correlates of chronic pain were race (blacks vs whites: OR, 0.52; 95% CI, 0.31-0.90; Hispanics vs whites: OR, 0.48; 95% CI, 0.24-0.95), drug craving (OR, 2.78; 95% CI, 1.54-5.02), chronic illness (OR, 2.17; 95% CI, 1.37-3.43), and psychiatric distress (OR, 1.36; 95% CI, 1.03-1.81). Among those with chronic severe pain, inpatients were significantly more likely than MMTP patients to have used illicit drugs, as well as alcohol, to treat their pain complaint (51% vs 34%, P =.005) but were less likely to have been prescribed pain medications (52% vs 67%, P =.01).

CONCLUSIONS

Chronic severe pain is prevalent among patients in substance abuse treatment, especially MMTP patients. Pain is associated with functional impairment and correlates of pain vary with the population. Self-medication for pain with psychoactive drugs appears especially problematic among substance users who enroll in drug-free treatment programs. Substance abuse treatment programs need to develop comprehensive and structured pain management programs.

Homelessness, substance misuse, and access to public entitlements in a soup kitchen population

The study examined the effects of homelessness on access to public entitlements (Medicaid and food stamp programs) in a soup kitchen population. Data were collected between 1997 and 1999 from a sample of 343 adults at two soup kitchen sites in New York City. Five hypotheses, focusing on the effects of housing status (literal homelessness, unstable housing, and domiciled), frequency of drug/heavy alcohol use, drug/alcohol-user treatment history and childcare responsibilities on access to Medicaid and food stamp programs were tested. Multiple logistic regression analysis indicated that both literal homelessness and unstable housing were associated with less access to Medicaid and food stamps. Other significant findings were: current drug/alcohol-user treatment experience was associated with greater access to both Medicaid and food stamps, frequency of drug/heavy alcohol use was associated with less access to Medicaid only, and caring for children was associated with greater access to food stamps only. These findings support the crucial role of housing status in mediating access to entitlements, and the importance of drug/alcohol-user treatment involvement as a cue to seeking entitlements. The need to reduce health disparities through active and sustained outreach programs designed to enhance homeless persons' access to Medicaid and food stamp programs was discussed.

The use of levo-alpha-acetylmethadol (LAAM) in methadone patients who have not achieved heroin abstinence

Levo-alpha-acetylmethadol (LAAM) pharmacotherapy was offered to twelve patients who continued illicit opioid abuse after > or = eleven months in methadone maintenance treatment. After 6-8 weeks on LAAM, plasma concentrations of the norLAAM metabolite varied significantly by LAAM dosing day, plasma adrenocorticotropin (ACTH) concentrations were significantly increased compared to methadone, and two of the seven subjects remaining in LAAM treatment were free of illicit opioids and nonprescribed methadone. After one year, one of five remaining subjects was using illicit opioids, and three were using non-prescribed methadone. While subject acceptance of LAAM was high, subjects were not in a "steady-state," with evidence of ongoing illicit opioid abuse.

Medical outreach to homeless substance users in New York City: preliminary results

An innovative, experimental, medical out-reach initiative, using a fully-equipped mobile medical van with a staff of 2 part-time physicians, a physician assistant, a social worker, and a driver/medical aid serving the needs of 1048, mostly male, minority group, high-level, homeless New York City substance users with infectious diseases is described. The study sample (N = 250) was divided into experimental S's who received Intensive case management and a control group who could choose to refer themselves to the SW. Biological tests revealed high rates of cocaine use and infectious diseases. Preliminary 4-month outcomes (N = 128) showed reductions in drug use, homelessness and health complaints in both groups; experimental subjects compared with controls received more Public Assistance and had fewer emergency room visits.

Hepatitis C and substance use in a sample of homeless people in New York City

This study examined the prevalence of hepatitis C virus (HCV) antibodies and its association with substance use and sexual behavior among a sample of 139 persons visiting a mobile medical clinic in Manhattan. Ninety percent were unstably housed or were living on the street. The prevalence of HCV antibodies was 32%. Prevalence was also high for hepatitis B core antibodies (47%), HIV antibodies (15%), and syphilis exposure (14%); 76% tested positive for cocaine. Among subjects who reported ever injecting (20%), 86% were HCV positive; 19% of non-injectors were HCV positive. In separate multivariate logistic regression models (with injection controlled), HCV was predicted by quantitative hair assays for cocaine and self-reported duration of crack-cocaine use. Alcohol dependence and sexual behavior did not predict HCV. Hepatitis C is a significant public health problem among the urban homeless population, with injection drug use and, to a lesser extent, cocaine use implicated as risk factors.

Integrating the methadone patient in the traditional addiction inpatient rehabilitation program--problems and solutions

Physicians have reported alcoholism and opioid addiction as co-morbid conditions since the 19th century. From the inception of methadone maintenance treatment, heroin addicts with serious alcohol conditions have enrolled in methadone maintenance programs. Programs that treat alcoholism, including the traditional addiction inpatient rehabilitation programs of the Addiction Treatment Centers (ATCs) operated by New York State, have based their treatment regimen on 12-step abstinence models. Methadone maintenance was considered antithetical to this philosophy. It was regarded as simply substituting one drug for another and not a legitimate treatment for opiate dependence. Therefore, methadone patients were often not accepted into alcohol treatment programs, since they were perceived as active addicts taking a mood-altering drug. Alcohol-related conditions among methadone patients are major causes of liver disease and death, and behavior problems associated with excessive drinking are major reasons for discharging patients. To address these issues and the lack of treatment facilities, the administration of the New York State Office of Alcoholism and Substance Abuse Services (OASAS), which licenses both methadone programs and the ATCs in New York State, realized that many of the methadone patients with alcohol problems are in need of the services provided at the ATCs. They instituted, therefore, a rigorous educational effort for the medical and counseling staffs of the ATCs, designed to integrate methadone treatment into the ATC treatment framework. Eighty percent of the 220 methadone patients who entered the ATCs in a demonstration project during the 1997/1998 state fiscal year have been compliant with the treatment regimen. These results have led to acceptance of methadone patients into the ATCs.

[Effect of rheumatoid arthritis associated HLA-DRbeta1 subtypes on protein kinase A signaling]

OBJECTIVE

To investigate the impact of rheumatoid arthritis (RA)-associated HLA-DRbeta(1) (*)0401, (*)0402, (*)0403 and (*)0404 subtypes on protein kinase A (PKA) signaling.

METHODS

To detect the activities of adenylate cyclase (AC), cAMP and PKA in transfectants expressing rheumatoid arthritis-associated HLA-DRbeta(1) subtypes and their mutants.

RESULTS

The levels of AC, cAMP and PKA of HLA-DRbeta(1) (*)0401 and (*)0404 transfectants were significant lower than that of HLA-DRbeta(1) (*)0402 and (*)0403 transfectants (P < 0.01). The mutant HLA-DRbeta(1) (*)0403 transfectants expressing DRRAE or QRRAA secreted lower levels of PKA, cAMP and AC (P < 0.01).

CONCLUSION

RA-associated HLA-DRbeta(1) (*)0401 and (*)0404 expression suppressed intracellular PKA signaling pathway, and may mediate abnormal intracellular signaling in rheumatoid arthritis.

Selected in-treatment outcomes of long-term methadone maintenance treatment patients in New York State

The New York State Office of Alcoholism and Substance Abuse Services (OASAS) licenses the largest system of methadone maintenance clinics nationwide. In 1996, a survey was undertaken to evaluate the functioning of patients continuously active in treatment for ten or more years. Information was obtained on a 10% random sample from the OASAS client data system and the records of the clinics. Data were collected concerning methadone dose, illicit drug and problematic alcohol use, employment, criminal activity, health, living situations, and the primary type of payment for treatment. A contrast group was constructed of discharged patients who had no more than 5 years of continuous treatment. The long-term active patients in the study sample showed superior outcomes on all variables, although some of the differences were small. However, the arrest rate for the discharged contrast group was 20 times as large as the arrest rate for the active study sample. These results are consistent with nationwide evaluations of methadone maintenance treatment. Factors that negatively impacted on the adjustments of the active patients were heavy use of crack/cocaine and disabilities. The long-term active patients in this sample belong to distinct subgroups with different levels of functioning, achievement, and ongoing health and social needs that must be investigated and addressed.

Reduced antibody response to revaccination with meningococcal serogroup A polysaccharide vaccine in adults

Widespread use of meningococcal A and C polysaccharide (MACP) vaccines has raised concerns about induction of hyporesponsiveness to these polysaccharides. Immunological hyporesponsiveness to C polysaccharide has been clearly documented in infants, children and adults but only limited data from Gambian children are available for A polysaccharide. We investigated whether a second dose of MACP, given 6 months after an initial dose affected the immunological response as measured by the serum bactericidal assay (SBA) and enzyme-linked immunosorbent assay (ELISA), to serogroup A meningococci in young adults (university students, n=36). Serogroup A SBA responses 1 month following the second dose of MACP (geometric mean titre (GMT) 103.6, 95% CI 45.6-235.1) were approximately one third of the levels observed 1 month post first dose (GMT 281.9, 95% CI 134.9-581.4). The serogroup A-specific IgG levels post second dose (GMC 21.2, 95% CI 15.3-29.4) were also significantly lower at an average of three-quarters the level post first dose (GMC 28.7, 95% CI 20.8-39.7). This confirms that revaccination with MACP vaccine, 6 months following the initial dose, results in a reduced immunological response to A polysaccharide in adults. Repeated vaccination with MACP vaccine may be ineffective and development and use of meningococcal serogroup A conjugate vaccines should be encouraged.

Methadone maintenance treatment (MMT): a review of historical and clinical issues

Methadone maintenance has been evaluated since its development in 1964 as a medical response to the post-World War II heroin epidemic in New York City. The findings of major early studies have been consistent. Methadone maintenance reduces and/or eliminates the use of heroin, reduces the death rates and criminality associated with heroin use, and allows patients to improve their health and social productivity. In addition, enrollment in methadone maintenance has the potential toreduce the transmission of infectious diseases associated with heroin injection, such as hepatitis and HIV. The principal effects of methadone maintenance are to relieve narcotic craving, suppress the abstinence syndrome, and block the euphoric effects associated with heroin. A majority of patients require 80-120 mg/d of methadone, or more, to achieve these effects and require treatment for an indefinite period of time, since methadone maintenance is a corrective but not a curative treatment for heroin addiction. Lower doses may not be as effective or provide the blockade effect. Methadone maintenance has been found to be medically safe and nonsedating. It is also indicated for pregnant women addicted to heroin. Reviews issued by the Institute of Medicine and the National Institutes of Health have defined narcotic addiction as a chronic medical disorder and have claimed that methadone maintenance coupled with social services is the most effective treatment for this condition. These agencies recommend reducing governmental regulation to facilitate patients access to treatment. In addition, they recommend that the number of programs be expanded, and that new models of treatment be implemented,if the nationwide problem of addiction is to be brought under control. The National Institutes of Health also recommend that methadone maintenance be available to persons under legal supervision, such as probationers, parolees and the incarcerated. However, stigma and bias directed at the programs and the patients have hindered expansion and the effective delivery of services. Professional community leadership is necessary to educate the general public if these impediments are to be overcome.

Causes and rates of death among methadone maintenance patients before and after the onset of the HIV/AIDS epidemic

Causes of death and the mortality rates of active methadone patients and those who had left treatment were compared. Prior to the HIV epidemic, death rates among discharged methadone patients were more than twice that of patients who continued with their methadone treatment. However, the death rate from heroin-related causes in the post-treatment period was 51 times the rate among active patients. Alcohol-related conditions were the leading causes of death in patients more than 30 years old on methadone. During the post-treatment period, alcohol-related deaths were second to those of heroin-related causes. Alcohol-related deaths were particularly pronounced among black patients. Death rates among active male and female patients were identical, but the death rate for discharged female patients was greater than for discharged males. With the onset of the HIV epidemic in the 1980s, AIDS-related causes became the major cause of death in treatment. However, other causes of death, such as alcohol and other medical conditions, identified prior to the AIDS epidemic, persisted. AIDS-related deaths peaked in the mid-1990s and have recently subsided. However, within the past two years, deaths related to HCV have increased to 9% of all patient deaths in a major methadone program. With the emergence of HCV, deaths from this cause are expected to eclipse AIDS-related deaths within the next decade.

Methadone medical maintenance (MMM): treating chronic opioid dependence in private medical practice--a summary report (1983-1998)

BACKGROUND

Methadone Medical Maintenance (MMM) was implemented in 1983 to enable socially rehabilitated methadone patients to be treated in the offices of private physicians rather than in the traditional clinic system. Over a period of 15 years, 158 methadone patients who fulfilled specific criteria within the clinic system entered this program in New York City. Participating patients reported to their physician once a month and received a one-month supply of methadone tablets rather than a one-day liquid dose in a bottle.

METHOD

Of the 158 patients who entered this program, 132 (83.5%) were compliant with the regulations and proved to be treatable within the hospital-based private practices of internists participating in the program. Compliant MMM patients found it easier to improve their employment status and business situations, finish their educations, and normalize their lives in MMM as opposed to the traditional clinic system because they had simplified reporting schedules and fewer clinical restrictions. Twelve (8%) compliant patients were able to successfully withdraw from methadone after an average of 17.7 years of treatment in both the traditional clinics and MMM. Twenty compliant patients (13%) died from a variety of causes, 40% of which were related to cigarette smoking. None of the deaths were attributable to long-term methadone treatment. Other causes of death included hepatitis C, AIDS, cancer, homicide, complications of morbid obesity and meningitis.

RESULTS

The 26 noncompliant patients (16.5%) were referred back to their clinics for continued treatment or were discharged for failure to report as directed. A major cause of failure in MMM was abuse of crack/cocaine.

CONCLUSIONS

Stigma concerning enrollment in methadone treatment was a major social issue that patients faced. Many refused to inform employers, members of their families, friends, and other physicians who treated them for a various of conditions that they were methadone patients. The methadone medical maintenance physician, therefore, functions as a medical ombudsman for the patient, educating other physicians who treat the patient about methadone maintenance and its applicability to the patient. Our results can serve as a model for the expansion of office-based MMM treatment.

The association between cocaine use and HIV/STDs among soup kitchen attendees in New York City

We examined the associations of cocaine use with HIV/sexually transmitted diseases (STDs) in a sample of 184 soup kitchen attendees using a mobile medical van in Manhattan (male = 66%; black or Hispanic = 81%; cocaine use, primarily crack = 75%; ever injected drugs = 22%). In addition to confirming the association between years of cocaine use and HIV antibodies in this sample (odds ratio [OR] = 2.11; p <.05) we examined the pattern of associations of cocaine use and non-HIV STDs under the hypothesis that the strength of an association depends on the efficiency of sexually transmitting a particular STD (high, moderate, and low for syphilis, hepatitis B and hepatitis C, respectively). As predicted, years of cocaine use was strongly associated with syphilis (OR = 2.07; p <.05), moderately associated with hepatitis B core antibodies (OR = 1.50; p <.05), and not significantly associated with hepatitis C antibodies (OR = 1.48; p >.05). A reverse pattern of associations between opiate use (injection drug use) and the three STDs points to the singular significance of cocaine use in the sexual transmission of STDs, and by inference, HIV. This conclusion is further bolstered by correlations of biologic (hair assays) and self-reported measurements of cocaine use (but not opiates) with self-reports of high risk sexual behavior among the women (number of partners and selling sex) and men (number of partners and buying sex). These data underscore the need for effective cocaine treatment and HIV interventions tailored to the large numbers of cocaine users in inner cities.

Substance misuse and related infectious diseases in a soup kitchen population

Representative samples of female (N = 119) and male (N = 100) guests were selected at two inner city soup kitchens. In the preceding month, 75% used cocaine/crack and 25% used heroin/opiates as determined by hair analysis. Relatively few guests (25%) were in substance dependency treatment. Infectious disease rates were: HIV (16%), hepatitis B exposure (21%), hepatitis B carrier (6%), syphilis exposure (15%). Years of injecting drug use and homelessness/marginal housing were associated with HIV infection and hepatitis B exposure. Soup kitchens should be prime locations for outreach to cocaine/crack and heroin users in need of treatment, medical care, and interventions to prevent infectious disease transmission.

Reactivation of latent tuberculosis: variations on the Cornell murine model

Mycobacterium tuberculosis causes active tuberculosis in only a small percentage of infected persons. In most cases, the infection is clinically latent, although immunosuppression can cause reactivation of a latent M. tuberculosis infection. Surprisingly little is known about the biology of the bacterium or the host during latency, and experimental studies on latent tuberculosis suffer from a lack of appropriate animal models. The Cornell model is a historical murine model of latent tuberculosis, in which mice infected with M. tuberculosis are treated with antibiotics (isoniazid and pyrazinamide), resulting in no detectable bacilli by organ culture. Reactivation of infection during this culture-negative state occurred spontaneously and following immunosuppression. In the present study, three variants of the Cornell model were evaluated for their utility in studies of latent and reactivated tuberculosis. The antibiotic regimen, inoculating dose, and antibiotic-free rest period prior to immunosuppression were varied. A variety of immunosuppressive agents, based on immunologic factors known to be important to control of acute infection, were used in attempts to reactivate the infection. Although reactivation of latent infection was observed in all three variants, these models were associated with characteristics that limit their experimental utility, including spontaneous reactivation, difficulties in inducing reactivation, and the generation of altered bacilli. The results from these studies demonstrate that the outcome of Cornell model-based studies depends critically upon the parameters used to establish the model.

Overexpression of a kinase-deficient transforming growth factor-beta type II receptor in mouse mammary stroma results in increased epithelial branching

Members of the transforming growth factor-beta (TGF-beta) superfamily signal through heteromeric type I and type II serine/threonine kinase receptors. Transgenic mice that overexpress a dominant-negative mutation of the TGF-beta type II receptor (DNIIR) under the control of a metallothionein-derived promoter (MT-DNIIR) were used to determine the role of endogenous TGF-betas in the developing mammary gland. The expression of the dominant-negative receptor was induced with zinc and was primarily localized to the stroma underlying the ductal epithelium in the mammary glands of virgin transgenic mice from two separate mouse lines. In MT-DNIIR virgin females treated with zinc, there was an increase in lateral branching of the ductal epithelium. We tested the hypothesis that expression of the dominant-negative receptor may alter expression of genes that are expressed in the stroma and regulated by TGF-betas, potentially resulting in the increased lateral branching seen in the MT-DNIIR mammary glands. The expression of hepatocyte growth factor mRNA was increased in mammary glands from transgenic animals relative to the wild-type controls, suggesting that this factor may play a role in TGF-beta-mediated regulation of lateral branching. Loss of responsiveness to TGF-betas in the mammary stroma resulted in increased branching in mammary epithelium, suggesting that TGF-betas play an important role in the stromal-epithelial interactions required for branching morphogenesis.

Treatment with farnesyl-protein transferase inhibitor induces regression of mammary tumors in transforming growth factor (TGF) alpha and TGF alpha/neu transgenic mice by inhibition of mitogenic activity and induction of apoptosis

Mouse mammary tumor virus-transforming growth factor alpha (MMTV-TGF alpha) and MMTV-TGF alpha/neu transgenic mice develop mammary tumors after a long latency and therefore provide useful model systems for breast cancer with its recognized activation of receptor tyrosine kinase signaling. We used these mice to study the antitumor effect of L-744,832 (FTI), a potent and selective inhibitor of farnesyl-protein transferase, and hence of Ras function. A total of 55 mice were assigned randomly to treatment with FTI or vehicle, and one-half of the mice were crossed over after initial treatment to the opposite group. L-744,832 induced reversible regression of mammary tumors that was paralleled by a decrease in serum levels of TGF alpha secreted by the tumor cells. There was no difference in response to treatment with FTI between MMTV-TGF alpha mice, in which tumorigenesis was accelerated by multiparity or the chemical carcinogen 7,12-dimethylbenzanthracene, and MMTV-TGF alpha/neu mice. The tumor histological type had no impact on FTI sensitivity. For mechanistic analyses, tumor excision biopsies were obtained from 12 mice before and after treatment with L-744,832. In these samples, tumor regression was paralleled biochemically by inhibition of mitogen-activated protein kinase activity and biologically by an increase in G1-phase and decrease in S-phase fractions, as well as induction of apoptosis. These results suggest that the potential clinical use of FTI could be expanded to include cancers harboring activated receptor tyrosine kinases as well as those containing activated Ras.