The association between physical activity and renal cancer: systematic review and meta-analysis

Background:

Physical activity may decrease renal cancer risk by reducing obesity, blood pressure, insulin resistance, and lipid peroxidation. Despite plausible biologic mechanisms linking increased physical activity to decreased risk for renal cancer, few epidemiologic studies have been able to report a clear inverse association between physical activity and renal cancer, and no meta-analysis is available on the topic.

Methods:

We searched the literature using PubMed and Web of Knowledge to identify published non-ecologic epidemiologic studies quantifying the relationship between physical activity and renal cancer risk in individuals without a cancer history. Following the PRISMA guidelines, we conducted a systematic review and meta-analysis, including information from 19 studies based on a total of 2 327 322 subjects and 10 756 cases. The methodologic quality of the studies was examined using a comprehensive scoring system.

Results:

Comparing high vs low levels of physical activity, we observed an inverse association between physical activity and renal cancer risk (summary relative risk (RR) from random-effects meta-analysis=0.88; 95% confidence interval (CI)=0.79–0.97). Summarising risk estimates from high-quality studies strengthened the inverse association between physical activity and renal cancer risk (RR=0.78; 95% CI=0.66–0.92). Effect modification by adiposity, hypertension, type 2 diabetes, smoking, gender, or geographic region was not observed.

Conclusion:

Our comprehensive meta-analysis provides strong support for an inverse relation of physical activity to renal cancer risk. Future high-quality studies are required to discern which specific types, intensities, frequencies, and durations of physical activity are needed for renal cancer risk reduction.     

Leisure-time physical activity and lung cancer: a meta-analysis

Objective: Several studies have evaluated the relationship between physical activity and lung cancer. To summarize and review these studies, we conducted a meta-analysis of all relevant reports published from 1966 through October 2003.Method: Adjusted odds ratios (ORs) from the original studies were pooled by the inverse of their variance, and all pooled estimates were accompanied by an assessment of heterogeneity across investigations. Test for linear trend across activity categories (low, moderate, high) were applied.Results: The combined ORs were 0.87 (95 confidence interval=0.79–0.95) for moderate leisure-time physical activity (LPA) and 0.70 (0.62–0.79) for high activity (ptrend = 0.00). This inverse association occurred for both sexes, although it was somewhat stronger for women. No evidence of publication bias was found. Several studies were able to adjust for smoking, but none adjusted for possible confounding from previous malignant respiratory disease. Our simulations suggest that this condition is unlikely to entirely explain the inverse association.Conclusion: The findings of this meta-analysis indicate that higher levels of LPA protect against lung cancer. The inverse association is possible remains confounded by inadequately controlled smoking patterns. However on the whole, confounding seems an unlikely explanation for the findings of individual studies on non-smokers.     

The association between recreational physical activity and mammographic density

Physical activity has been associated with a reduced risk of breast cancer. However, little is known about the association between recreational physical activity and mammographic density. We examined the association between recreational physical activity and mammographic density using mammograms from 375 white and African American women without breast cancer who served as controls in the Los Angeles component of the Women's Contraceptive and Reproductive Experiences Study. We used data from 5 time periods of activity in the statistical analysis: from menarche to mammogram screening, the first 3 and 10 years after menarche, the most recent 10 years and the 3 years prior to mammogram screening. Lifetime history of recreational physical activity was obtained through interviews using a structured questionnaire. We used multiple linear regression to estimate least-squared mean values of absolute and percent mammographic density within categories of physical activity. Overall, we found no statistically significant evidence that physical activity reduced absolute or percent mammographic density. We observed a modest positive association between lifetime physical activity and percent mammographic density (p for trend = 0.04) among younger women, and between recent physical activity and percent density among both younger (<50 years, p for trend = 0.09) and older (> or =50 years, p for trend = 0.06) women, but these associations diminished after additionally adjusting for body mass index (BMI) (all p > or = 0.10). However, among women younger than 50 years, we found some evidence for a protective effect of "strenuous" physical activity in the first 3 years after menarche, with a nonstatistically significant inverse association with both absolute (p for trend = 0.07) and percent (p for trend = 0.08) mammographic density after adjustment for BMI. Our results suggest that physical activity is not a strong predictor of mammographic density.     

Postdiagnosis recreational physical activity and breast cancer prognosis: Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

It is important to clarify the associations between modifiable lifestyle factors such as physical activity and breast cancer prognosis to enable the development of evidence-based survivorship recommendations. We performed a systematic review and meta-analyses to summarise the evidence on the relationship between postbreast cancer diagnosis physical activity and mortality, recurrence and second primary cancers. We searched PubMed and Embase through 31st October 2021 and included 20 observational studies and three follow-up observational analyses of patients enrolled in clinical trials. In linear dose-response meta-analysis of the observational studies, each 10-unit increase in metabolic equivalent of task (MET)-h/week higher recreational physical activity was associated with 15% and 14% lower risk of all-cause (95% confidence interval [CI]: 8%-22%, studies = 12, deaths = 3670) and breast cancer-specific mortality (95% CI: 4%-23%, studies = 11, deaths = 1632), respectively. Recreational physical activity was not associated with breast cancer recurrence (HR = 0.97, 95% CI: 0.91-1.05, studies = 6, deaths = 1705). Nonlinear dose-response meta-analyses indicated 48% lower all-cause and 38% lower breast cancer-specific mortality with increasing recreational physical activity up to 20 MET-h/week, but little further reduction in risk at higher levels. Predefined subgroup analyses across strata of body mass index, hormone receptors, adjustment for confounders, number of deaths, menopause and physical activity intensities were consistent in direction and magnitude to the main analyses. Considering the methodological limitations of the included studies, the independent Expert Panel concluded ‘limited-suggestive’ likelihood of causality for an association between recreational physical activity and lower risk of all-cause and breast cancer-specific mortality.     

Physical activity and risk of bladder cancer among postmenopausal women

Physical activity is associated with decreased risk for many cancers. Studies on the association between physical activity and risk of bladder cancer are limited, and findings are inconsistent. Postmenopausal women (mean age = 63.3) were recruited into the Women's Health Initiative from 1993 to 1998. Self-reported baseline information on physical activity and other covariates were available in 141 288 participants. Incident bladder cancer cases were collected through 2018 and centrally adjudicated. Hazard ratios (HRs) and 95% confidence intervals (CIs) were determined by Cox proportional hazard regression models. Effect modification due to smoking was assessed. During an average of 18.5 years of follow-up, 817 bladder cancer cases were identified. Compared to physically inactive women, those who engaged in ≥15 MET-hours/week of total physical activity, ≥8.75 MET-hours/week of walking or ≥11.25 MET-hours/week of moderate to vigorous physical activity had lower risk of bladder cancer (HR = 0.74, 95% CI: 0.59-0.94, P for linear trend = .02; HR = 0.79, 95% CI: 0.63-0.98, P for linear trend = .03; and HR = 0.76, 95% CI: 0.61-0.94, P for linear trend = .02, respectively). No effect modification was found by smoking status (P for interaction = .06, 0.91 and 0.27, respectively). We found that total physical activity, walking and moderate to vigorous physical activity were inversely associated with bladder cancer incidence among postmenopausal women in a dose-response manner. Physical activity may play a potential role in the primary prevention of bladder cancer. Further studies with objective measurements of physical activity are needed to confirm these findings.     

A review of physical activity and prostate cancer risk

Objectives: The purpose was to review the etiologic role and the possible biologic mechanisms for physical activity in the primary prevention of prostate cancer and to identify future research priorities. Methods: We conducted literature searches and systematically reviewed all the epidemiologic studies of physical activity and prostate cancer and the literature on the underlying biologic mechanisms. Results: Among 24 previously conducted studies, 14 studies suggested an inverse association of physical activity on prostate cancer; however, no overall association was found in six studies and an increased risk of prostate cancer was observed amongst the most physically active men in four other studies. The methodologic limitations in these studies include variations in detection of latent disease and possible outcome misclassification, crude assessments of physical activity, inadequate control for confounding, and incomplete examination of effect modification. Conclusions: Physical activity may have an inverse association with prostate cancer risk; however, the epidemiologic evidence is currently inconsistent and the magnitude of the risk reduction observed is small. These inconsistent results could be attributable, in part, to methodologic limitations of previous studies. Hence, further investigation of the etiologic role of physical activity is needed before more definitive conclusions can be made. Specifically, research studies should be designed to measure all types and parameters of physical activity throughout lifetimes. Furthermore, a better understanding of the biologic mechanisms and etiologically relevant time periods in prostate carcinogenesis when physical activity may be operative is needed, so that these studies can be properly designed.     

保留膀胱的综合治疗与根治性手术治疗肌层浸润性膀胱癌预后的荟萃分析

目的 比较保留膀胱手术+术后化疗与根治性手术治疗肌层浸润性膀胱癌的预后.方法 检索保留膀胱手术+术后化疗与根治性手术治疗肌层浸润性膀胱癌(muscle-invasive bladder cancer,MIBC)的对照研究,比较两种治疗方案的术后5年生存率,计算合并优势比(OR)和95%CI.结果 共纳入7项研究,累积876例患者.1组研究的OR=1.03,95%CI为1.03(0.52~2.02),4组研究的OR及其95%CI﹤1,2组研究的OR及其95%CI﹥1;7个研究的总OR=1.05,95%CI为1.05(0.53~2.06),跨过"无差异线",故认为根治性膀胱全切术(radical cystectomy,RC)与保留膀胱的综合治疗预后差异无统计学意义(Z=0.13,P=0.89).结论 对于部分肌层浸润性膀胱癌患者,保留膀胱的综合治疗不会降低患者的5年生存率,且能保留患者膀胱的正常功能,提高了患者的生存质量,但适应证需严格把握.     

Prospective study of body mass index, height, physical activity and incidence of bladder cancer in US men and women

We evaluated prospectively the association between body mass index (BMI), height, recreational physical activity and the risk of bladder cancer among US adults. Data were used from 2 ongoing cohorts, the Health Professionals Follow-up Study and the Nurses' Health Study, with 3,542,012 years of follow-up and 866 incident bladder cancer cases (men = 507; women = 359) for the anthropometric analysis and 1,890,476 years of follow-up and 706 incident bladder cancer cases (men = 502; women = 204) for the physical activity analysis. Cox proportional hazard models were used to estimate incidence rate ratios (RR) and 95% confidence intervals (CI) between BMI, height, physical activity and bladder cancer risk adjusting for age, pack-years of cigarette smoking and current smoking. Estimates from each cohort were pooled using a random-effects model. We observed no association between baseline BMI and bladder cancer risk, even when we compared a BMI of > or =30 kg/m(2) to a BMI of 18-22.9 kg/m(2) [pooled multivariate (MV) RR, 1.16; 95% CI: 0.89-1.52]. A weak, but statistically significant, association was observed for the same comparison after excluding bladder cancer cases diagnosed within the first 4 years of follow-up (pooled MV RR, 1.33; 95% CI: 1.01-1.76). Height was not related to bladder cancer risk (pooled MV RR, 0.82; 95% CI: 0.65-1.03, top vs. bottom quintile). Total recreational physical activity also was not associated with the risk of bladder cancer (pooled MV RR, 0.97; 95% CI: 0.77-1.24, top vs. bottom quintile). Our findings do not support a role for BMI, height or physical activity in bladder carcinogenesis.     

Higher dietary folate intake reduces the breast cancer risk: a systematic review and meta-analysis

Background:

Many epidemiological studies have investigated the association between folate intake, circulating folate level and risk of breast cancer; however, the findings were inconsistent between the studies.

Methods:

We searched the PubMed and MEDLINE databases updated to January, 2014 and performed the systematic review and meta-analysis of the published epidemiological studies to assess the associations between folate intake level, circulating folate level and the overall risk of breast cancer.

Results:

In all, 16 eligible prospective studies with a total of 744 068 participants and 26 205 breast cancer patients and 26 case–control studies with a total of 16 826 cases and 21 820 controls that have evaluated the association between folate intake and breast cancer risk were identified. Pooled analysis of the prospective studies and case–control studies suggested a potential nonlinearity relationship for dietary folate intake and breast cancer risk. Prospective studies indicated a U-shaped relationship for the dietary folate intake and breast cancer risk. Women with daily dietary folate intake between 153 and 400 μg showed a significant reduced breast cancer risk compared with those <153 μg, but not for those >400 μg. The case–control studies also suggested a significantly negative correlation between the dietary folate intake level and the breast cancer risk. Increased dietary folate intake reduced breast cancer risk for women with higher alcohol intake level, but not for those with lower alcohol intake. No significant association between circulating folate level and breast cancer risk was found when the results of 8 identified studies with 5924 participants were pooled.

Conclusions:

Our studies suggested that folate may have preventive effects against breast cancer risk, especially for those with higher alcohol consumption level; however, the dose and timing are critical and more studies are warranted to further elucidate the questions.     

Association and mechanism of garlic consumption with gastrointestinal cancer risk: A systematic review and meta-analysis

Gastrointestinal cancer is one of the most commonly diagnosed cancer type worldwide, with millions of cases per year. The aim of this review was to investigate the relationship between garlic intake and the risk reduction of gastrointestinal cancer. We performed saturated data mining on various public domain databases, including PubMed (https://pubmed.ncbi.nlm.nih.gov/), Embase (https://www.embase.com/landing?status=grey), and Cochrane Library (https://www.cochranelibrary.com/), with key terms including: ‘garlic’, ‘allium’, ‘stomach’, ‘gastric’, ‘colon’, ‘neoplasms’, ‘cancer’ and ‘tumor’. Furthermore, we identified additional references through expert manual curation. Finally, a meta-analysis was conducted to determine whether garlic intake reduces the risk of gastric and/or colorectal cancer. The association between garlic intake and reduction in the risk of gastric cancer [odds ratio (OR)=0.65, 95% confidence interval (CI)=0.49-0.87, P<0.001] were clear. Nine studies on garlic intake and colorectal cancer showed that garlic reduced cancer risk with a statistical significance (OR=0.75, 95% CI=0.65-0.87, P<0.001). We summarized that four main organic sulfides in garlic, diallyl disulfide (DADS), diallyl trisulfide (DATS), S-allylmercaptocysteine (SAMC) and allicin, may contribute to the regulation of tumor cell apoptosis, migration and the cell cycle. We identified the association between garlic intake and reduced risk of gastric and colorectal cancers and hypothesized that the active ingredients in garlic may act on multiple pathways to reduce the risk of gastrointestinal tumors according to published papers. Importantly, the potential tumor-preventing effect of these garlic ingredients warrants further investigation in regards to the specific mechanism of the underlying antitumor activities.     

Statin use and breast cancer survival and risk: a systematic review and meta-analysis

The purpose of this study is to determine the associations between statin use and breast cancer survival and risk by performing a systematic review and meta-analysis. We searched PubMed, Embase and Web of Science up to August 2015 for identifying relevant prospective or case-control studies, or randomized clinical trials. Five prospective studies involving 60,911 patients reported the association between statin use and breast cancer mortality. Eleven prospective studies, 12 case-control studies and 9 randomized clinical trials involving 83,919 patients reported the association between statin use and breast cancer risk. After pooling estimates from all available studies, there was a significantly negative association between pre-diagnosis statin use and breast cancer mortality (for overall survival (OS): hazard ratio (HR) = 0.68, 95% confidence interval (CI) 0.54–0.84; for disease specific survival (DSS): HR = 0.72, 95% CI 0.53–0.99). There was also a significant inverse association between post-diagnosis statin use and breast cancer DSS (HR = 0.65, 95% CI 0.43–0.98), although the association with breast cancer OS did not reach statistical significance (HR = 0.71, 95% CI 0.48–1.07). Additionally, there was a non-linear relationship for the duration of post-diagnosis statin use with breast cancer specific mortality. On the other hand, with regards to the relationship between statin use and breast cancer risk, no significant association was detected. Our analyses suggest that although statin use may not influence breast cancer risk, the use of statin may be associated with decrease mortality of breast cancer patients. Further large-scale studies are warranted to validate our findings.     

Anthropometric characteristics,physical activity and risk of hematological malignancies: A systematic review and meta-analysis of cohort studies

Overweight/obesity, adult attained height and physical activity are possible risk factors for hematological malignancies. This meta-analysis aims to evaluate the associations between these factors and hematological cancer risk in adults. Eligible cohort studies were sought in PubMed up to May 31, 2016; overall, 44 studies were included in the present analyses. Pooled relative risk estimates were calculated using random-effects models; separate analyses were conducted for non-Hodgkin lymphoma (NHL) and subtypes (diffuse large B-cell lymphoma, DLBCL; follicular cell lymphoma; small lymphocytic lymphoma/chronic lymphocytic leukemia, SLL/CLL), Hodgkin lymphoma (HL), multiple myeloma (MM), leukemia and subtypes (acute lymphoblastic leukemia, acute myeloid leukemia, AML). Obesity was associated with increased risk of NHL, HL, MM, leukemia overall and AML in both sexes, as well as with higher DLBCL risk in women; the dose–response meta-regression analysis confirmed these associations. Less pronounced effects were observed regarding overweight, as it was associated with increased MM risk in both sexes, NHL risk in males, DLBCL and overall leukemia risk in females. Taller men presented with significantly higher risk of NHL and taller women were affected by higher risk of NHL, DLBCL, FL, CLL/SLL, MM, leukemia and AML. On the other hand, physical activity and abdominal fatness were not associated with the risk of hematological malignancies. In conclusion, this meta-analysis highlights the pivotal role of anthropometric measures in shaping the risk of hematological malignancies in adults. Additional, well-designed studies stemming from all the continents are needed for the further substantiation and generalization of the results.     

Correlation of ulcerative colitis and colorectal cancer: a systematic review and meta-analysis

BackgroundA large number of studies have shown that ulcerative colitis (UC) can increase the risk of colorectal cancer (CRC). The purpose of the present study was to explore the specific mechanism of UC influence on CRC.MethodsWe searched PubMed for articles related to CRC and colitis since the establishment of the database until April 2021. Keywords, such as ulcerative colitis, colorectal cancer, and relevance, were used for the article search. Two investigators read through the full text according to the inclusion and exclusion criteria to screen the articles. Cochrane system review manual (version 5.3) was adopted to evaluate the quality of the selected articles. Then, data was extracted, and the overall risk of UC patients into CRC, the course of the disease, and the region were systematically analyzed.ResultsA total of 11 studies involving 26,765 patients with UC were included. The results showed that UC is one of the risk factors for CRC. we also found that geographical location also had an impact on the transition from UC to CRC, but the impact was not significant. Patients with colitis had a significantly higher rate of conversion to CRC after 10 to 20 years of disease.DiscussionA total of 11 articles were included to analyze the association between UC and CRC. The studies found that the location, duration, and geographical location of patients with UC directly affected the occurrence of CRC and are independent risk factors for the transformation of UC into CRC.     

Treatment of muscle‐invasive bladder cancer: A systematic review

There is uncertainty regarding the use of bladder‐sparing alternatives to standard radical cystectomy, optimal lymph node dissection techniques, and optimal chemotherapeutic regimens. This study was conducted to systematically review the benefits and harms of bladder‐sparing therapies, lymph node dissection, and systemic chemotherapy for patients with clinically localized muscle‐invasive bladder cancer. Systematic literature searches of MEDLINE (from 1990 through October 2014), the Cochrane databases, reference lists, and the ClinicalTrials.gov Web site were performed. A total of 41 articles were selected for review. Bladder‐sparing therapies were found to be associated with worse survival compared with radical cystectomy, although the studies had serious methodological shortcomings, findings were inconsistent, and only a few studies evaluated currently recommended techniques. More extensive lymph node dissection might be more effective than less extensive dissection at improving survival and decreasing local disease recurrence, but there were methodological shortcomings and some inconsistency. Six randomized trials found cisplatin‐based combination neoadjuvant chemotherapy to be associated with a decreased mortality risk versus cystectomy alone. Four randomized trials found adjuvant chemotherapy to be associated with decreased mortality versus cystectomy alone, but none of these trials reported a statistically significant effect. There was insufficient evidence to determine optimal chemotherapeutic regimens. Cancer 2016;122:842–51 . © 2016 American Cancer Society.     

Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis

Background:

The role of tumour-infiltrating inflammation in the prognosis of patients with colorectal cancer (CRC) has not been fully evaluated. The primary objective of our meta-analysis was to determine the impact of tumour-infiltrating inflammation on survival outcomes.

Methods:

Ovid MEDLINE and EMBASE were searched to identify studies reporting the prognostic significance of tumour-infiltrating inflammation for patients with CRC. The primary outcome measures were overall survival (OS), cancer-specific survival (CS) and disease-free survival (DFS).

Results:

A total of 30 studies involving 2988 patients were identified. Studies were subdivided into those considering the associations between CRC survival and generalised tumour inflammatory infiltrate (n=12) and T lymphocyte subsets (n=18). Pooled analyses revealed that high generalised tumour inflammatory infiltrate was associated with good OS (HR, 0.59; 95% CI, 0.48–0.72), CS (HR, 0.40; 95% CI, 0.27–0.61) and DFS (HR, 0.72; 95% CI, 0.57–0.91). Stratification by location and T lymphocyte subset indicated that in the tumour centre, CD3⁺, CD8⁺ and FoxP3⁺ infiltrates were not statistically significant prognostic markers for OS or CS. In the tumour stroma, high CD8⁺, but not CD3⁺ or FoxP3⁺ cell infiltrates indicated increased OS. Furthermore, high CD3⁺ cell infiltrate was detected at the invasive tumour margin in patients with good OS and DFS; and high CCR7⁺ infiltrate was also indicated increased OS.

Conclusion:

Overall, high generalised tumour inflammatory infiltrate could be a good prognostic marker for CRC. However, significant heterogeneity and an insufficient number of studies underscore the need for further prospective studies on subsets of T lymphocytes to increase the robustness of the analyses.