Progress in the war on cancer

Evidence-based medicine: A cornerstone for clinical care but not for quality improvement

Quality improvement (QI) as a clinical improvement science has been criticized for failing to deliver broad patient outcome improvement and for being a top-down regulatory and compliance construct. These critics have argued that the focus of QI should be on increasing adherence to clinical practice guidelines (CPGs) and, as a result, should be consolidated into research structures with the science of evidence-based medicine (EBM) at the helm. We argue that EBM often overestimates the role of knowledge as the root cause of quality problems and focuses almost exclusively on the effectiveness of care while often neglecting the domains of safety, efficiency, patient-centredness, and equity. Successfully addressing quality problems requires a much broader, systems-based view of health-care delivery. Although essential to clinical decision-making and practice, EBM cannot act as the cornerstone of health system improvement.

Autophagy inducers in cancer

Autophagy is a complex, physiological process devoted to degrade and recycle cellular components. Proteins and organelles are first phagocytized by autophagosomes, then digested in lysosomes, and finally recycled to be utilized again during cellular metabolism. Moreover, autophagy holds an important role in the physiopathology of several diseases. In cancer, excellent works demonstrated the dual functions of autophagy in tumour biology: autophagy activation can promote cancer cells survival (protective autophagy), or contribute to cancer cell death (cytotoxic/nonprotective autophagy). A better understanding of the dichotomy roles of autophagy in cancer biology can help to identify or design new drugs able to induce/enhance (or block) autophagic flux. These features will necessary be tissue-dependent and confined to a specific time of treatment. The intent of this review is to focus on the different potentialities of autophagy inducers in cancer prevention versus therapy in order to elicit a desirable clinical response. Few promising synthetic and natural compounds have been identified and the pros and cons of their role in autophagy regulation is reviewed here. In the complex framework of autophagy modulation, "connecting the dots" is not a simple work and the lack of clinical studies further complicates the scenario, but the final goal to obtain clinically relevant autophagy inducers can reveal an unexpected landscape.

Assessing progress in reducing the burden of cancer mortality, 1985-2005

PURPOSE

Measuring the effect of cancer interventions must take into account rising cancer incidence now that people live longer because of declines in mortality from cardiovascular disease (CVD). Cancer mortality rates in the population do not accomplish this objective. We sought a measure that would reveal the effects of changing mortality rates from other diseases.

METHODS

We obtained annual breast, colorectal, lung, and prostate cancer mortality rates from the Surveillance, Epidemiology, and End Results registries; we obtained noncancer mortality rates from national death certificates, 1975 to 2005. We used life-table methods to calculate the burden of cancer mortality as the average person-years of life lost (PYLL) as a result of cancer (cancer-specific PYLL) and quantify individual-and perhaps offsetting-contributions of the two factors that affect cancer-specific PYLL: mortality rates as a result of cancer and other-cause mortality.

RESULTS

Falling cancer mortality rates reduced the burden of mortality from leading cancers, but increasing cancer incidence as a result of decreasing other-cause mortality rates partially offset this progress. Between 1985 and 1989 and between 2000 and 2004, the burden of lung cancer in males declined by 0.1 year of life lost. This decline reflects the sum of two effects: decreasing lung cancer mortality rates that reduced the average burden of lung cancer mortality by 0.33 years of life lost and declining other-cause mortality rates that raised it by 0.23 years. Other common cancers showed similar patterns.

CONCLUSION

By using a measure that accounts for increased cancer incidence as a result of improvements in CVD mortality, we find that prior assessments have underestimated the impact of cancer interventions.

Cancer prevention for the next generation

Given the continued growth in the number of persons with cancer in the United States, the primary prevention of cancer remains an urgent public health priority. As the field of cancer prevention continues to mature and scientific knowledge evolves, it is imperative to challenge the status quo and embrace new approaches to cancer prevention. In this commentary, we summarize recent trends and some of the scientific advances that have been made over the past few decades regarding the complex process of cancer development and the interaction of individual and social risk factors. We examine some of the assumptions and terminology that have characterized cancer prevention approaches for more than a quarter century and the impact of these assumptions and our use of terminology. We propose that it is possible for today's youth to experience lower cancer incidence rates as adults compared with previous generations. To accomplish this goal, a more transdisciplinary and multifaceted approach is needed, adapted as appropriate for different populations and stages of life. The greatest improvements in cancer prevention may occur as a result of innovative, multilevel interventions that build on the expanding scientific evidence base.

Long-term outcomes of the FRESH START trial: exploring the role of self-efficacy in cancer survivors' maintenance of dietary practices and physical activity

BACKGROUND

This study examined whether changes in self-efficacy explain the effects of a mailed print intervention on long-term dietary practices of breast and prostate cancer survivors. The relationship between change in self-efficacy and long-term physical activity (PA) also was examined.

METHODS

Breast and prostate cancer survivors (N = 543) from 39 US states and two Canadian provinces participated in the FRESH START intervention trial. Participants were randomly assigned to receive a 10-month program of mailed print materials on diet and PA available in the public domain or a 10-month program of tailored materials designed to increase fruit and vegetable (F&V) intake, decrease fat intake, and/or increase PA. Changes in self-efficacy for F&V intake and fat restriction were analyzed as potential mediators of the intervention's effects on diet at 2-year follow-up. Because we previously found that change in self-efficacy for PA did not vary by group assignment, the relationship between change in self-efficacy and PA at 2-year follow-up was examined across study conditions.

RESULTS

Results suggest that change in self-efficacy for fat restriction partially explained the intervention's effect on fat intake (mean indirect effect = -0.28), and change in self-efficacy for F&V consumption partially explained the intervention's effect on daily F&V intake (mean indirect effect = .11). Change in self-efficacy for fat restriction partially accounted for the intervention's impact on overall diet quality among men only (mean indirect effect = 0.60). Finally, change in self-efficacy for PA predicted PA at 2-year follow-up.

CONCLUSIONS

Findings suggest that self-efficacy may influence long-term maintenance of healthy lifestyle practices among cancer survivors.

Long-term dietary outcomes of the FRESH START intervention for breast and prostate cancer survivors

BACKGROUND

Cancer survivors are at increased risk for secondary cancers and other diseases. Healthy dietary practices may improve cancer survivors' health and well-being.

OBJECTIVE

The durability of the effects of the FRESH START intervention, a program of sequentially tailored mailed materials, and standardized mailed materials (for controls) on cancer survivors' dietary outcomes was assessed over a 2-year period. Greater dietary gains were expected for FRESH START participants relative to controls.

DESIGN

Participants were randomized to receive tailored vs standardized 10-month mailed print interventions promoting diet and exercise behaviors. Data were collected at baseline and 1- and 2-year follow-ups.

PARTICIPANTS/SETTING

Breast and prostate cancer survivors (n=543) were recruited from 39 states and two provinces within North America. A total of 489 participants completed the 2-year follow-up assessment (10% attrition).

INTERVENTION

Participants were randomly assigned to either a 10-month program of tailored mailed print materials promoting fruit and vegetable consumption, reduced total and saturated fat intake, and/or increased exercise or to a 10-month program of publicly available mailed materials on diet and exercise.

MAIN OUTCOME MEASURES

Telephone surveys (supported with blood biomarkers) assessed dietary habits at baseline and 1- and 2-year follow-ups.

STATISTICAL ANALYSES PERFORMED

Paired-samples t tests were conducted to examine the durability of the intervention's effects on dietary outcomes within each study arm. Arm differences in follow-up outcomes were then tested with the general linear model, controlling for the baseline value of the outcomes.

RESULTS

Both arms reported decreased saturated fat intake, increased servings of fruits and vegetables, and better overall diet quality at year 2 relative to baseline. However, FRESH START participants reported better overall diet quality and lower total and saturated fat intake compared to controls at the 2-year follow-up.

CONCLUSIONS

Results suggest that mailed material interventions, especially those that are tailored, can produce long-term dietary improvement among cancer survivors.

Parkinson's disease and cancer: two wars, one front

Parkinson's disease is caused by the premature death of neurons in the midbrain. By contrast, cancer spawns from cells that refuse to die. We would therefore expect their pathogenic mechanisms to be very different. However, recent genetic studies and emerging functional work show that strikingly similar and overlapping pathways are involved in both diseases. We consider these areas of convergence and discuss how insights from one disease can inform us about, and possibly help us to treat, the other.

Following cancer prevention guidelines reduces risk of cancer, cardiovascular disease, and all-cause mortality

BACKGROUND

Few studies have evaluated the combined impact of following recommended lifestyle behaviors on cancer, cardiovascular disease (CVD) and all-cause mortality, and most included tobacco avoidance. Because 80% of Americans are never or former smokers, it is important to consider the impact of other recommended behaviors.

METHODS

In 1992 and 1993, 111,966 nonsmoking men and women in the Cancer Prevention Study-II Nutrition Cohort completed diet and lifestyle questionnaires. A score ranging from 0 to 8 points was computed to reflect adherence to the American Cancer Society cancer prevention guidelines on body mass index, physical activity, diet, and alcohol consumption, with 8 points representing optimal adherence. Multivariable-adjusted relative risks (RR) of death and 95% CI were computed by Cox proportional hazard regression.

RESULTS

During 14 years of follow-up, 10,369 men and 6,613 women died. The RR of all-cause mortality was lower for participants with high (7, 8) versus low (0-2) scores (men, RR = 0.58, 95% CI: 0.53-0.62; women, RR = 0.58, 95% CI: 0.52-0.64). Inverse associations were found with CVD mortality (men, RR = 0.52, 95% CI: 0.45-0.59; women, RR = 0.42, 95% CI: 0.35-0.51) and cancer mortality (men, RR = 0.70, 95% CI: 0.61-0.80; women, RR = 0.76, 95% CI: 0.65-0.89). Similar associations, albeit not all statistically significant, were observed for never and former smokers.

CONCLUSION

Adherence to cancer prevention guidelines for obesity, diet, physical activity, and alcohol consumption is associated with lower risk of death from cancer, CVD, and all causes in nonsmokers.

IMPACT

Beyond tobacco avoidance, following other cancer prevention guidelines may substantially lower risk of premature mortality in older adults.

No stone unturned

Gregory Petsko proposes a new motto for the National Institutes of Health.