Pairwise association of key lifestyle factors and risk of solid cancers - A prospective pooled multi-cohort register study.

Smoking, alcohol consumption, obesity, and physical inactivity are key lifestyle risk factors for cancer. Previously these have been mostly examined singly or combined as an index, assuming independent and equivalent effects to cancer risk. The aim of our study was to systematically examine the joint pairwise and interactive effects of these lifestyle factors on the risk of a first solid primary cancer in a multi-cohort prospective setting. We used pooled data from seven Finnish health survey studies during 1972-2015, with 197,551 participants diagnosed with 16,373 solid malignant primary tumors during follow-up. Incidence of any cancer was analyzed separately without and with lung cancers using Poisson regression with main and interaction effects of key lifestyle factors. When excluding lung cancer, the highest risk of any cancer in men was observed for smokers with a BMI of ≥25 kg/m2 (HR 1.36, 95 % CI 1.25-1.48) and in women for smokers consuming alcohol (HR 1.22, 1.14-1.30). No statistically significant interactions between any studied risk factor pairs were observed. When including lung cancer, the highest HRs among men were observed for smokers who consume alcohol (HR 1.72, 1.57-1.89) and among women for smokers who were physically inactive (HR 1.38, 1.27-1.49). Smoking combined with other lifestyle factors at any exposure level resulted in highest pairwise risks, both in men and women. These results highlight the importance of smoking prevention, but also the importance of preventing obesity and reducing alcohol consumption.

Every tenth malignant solid tumor attributed to overweight and alcohol consumption: A population-based cohort study.

BACKGROUND: Recent studies have shown that some four in ten cancers are attributable to a few key risk factors. The aim of this study was to estimate cohort-based population attributable fractions (PAFs) in Finland for potentially modifiable cancer risk factors. METHODS: Data from eight health studies including 253,953 subjects with 29,802 incident malignant solid tumors were analysed using Bayesian multivariate regression model with multiplicative risk factor effects. We estimated the effects of smoking, excess body weight, alcohol consumption, physical activity, parity and education on cancer incidence and related PAFs by cancer site, accounting for competing mortality. RESULTS: PAF for all cancer sites and exposures combined was 34% (95% credible interval 29%-39%) in men and 24% (19%-28%) in women. In men, 23% (21%-27%) and in women 8% (6%-9%) of all cancers were attributed to smoking. PAF related to excess body weight was 4% (2%-6%) in men and 5% (2%-7%) in women, to alcohol 7% (3%-10%) in men and 4% (0%-7%) in women, and to excess body weight and alcohol combined 10% (6%-15%) in men and 9% (4%-13%) in women. CONCLUSION: Smoking was the most important factor contributing to cancer burden in Finnish men and women over the last 40 years. The contribution of excess body weight and alcohol consumption together outweighed the role of smoking in women. As the prevalence of overweight is expected to increase, more efficient public health measures supporting adherence to healthy weight are essential to reduce cancer burden.

Use of health services one year before primary colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) patient pathways focus typically on periods after confirmed diagnosis and only limited data are available on pathways prior to cancer diagnosis. The aim of the study was to describe the use of health services (HS) one year before diagnosis among CRC patients in Finland. We also studied the role of sex, age, stage, and university hospital district in relation to the use of HS during the pre-diagnostic phase. This information is expected to bring light on the question why CRC is often not found in its early stages. METHODS: Incident CRC cases (N = 3115) concerning year 2015 were retrieved from the Finnish Cancer Registry and linked with data from the Finnish Institute for Health and Welfare on primary or specialised care outpatient visits or inpatient episodes over one year prior to CRC diagnosis. We modelled the average number of HS events per patient using Poisson regression model with log-link. Change points for monthly HS event rates and 95% CIs one year before diagnosis were evaluated using Poisson broken line regression models. RESULTS: Around 10% of patients diagnosed in 2015 had no events prior to cancer leaving 2816 CRCs in the study. Of all pre-diagnostic events (N = 23268), 86% were outpatient events and 14% inpatient episodes. More than half of the inpatient episodes (65%) started as urgent admissions. The use of HS started to increase 3-4 months before diagnosis. The average number of pre-diagnostic HS events per patient varied by sex, age, stage and university hospital district. Overall, men had more events per patient than women and older patients had more events than younger patients. CONCLUSIONS: The amount of inpatient episodes starting as urgent admissions indicate potential bottlenecks in the access to health services. An increase in service use only 3-4 months prior to diagnosis reflects a need for advice both for health care professionals and the general population in recognising symptoms of CRC.

Pairwise association of key lifestyle factors and risk of colorectal cancer: a prospective pooled multicohort study.

BACKGROUND: Several lifestyle factors are associated with an increased risk of colorectal cancer (CRC). Although lifestyle factors co-occur, in most previous studies these factors have been studied focusing upon a single risk factor or assuming independent effects between risk factors. AIM: To examine the pairwise effects and interactions of smoking, alcohol consumption, physical inactivity, and body mass index (BMI) with risk of subsequent colorectal cancer (CRC). METHODS AND RESULTS: We used METCA cohort data (pooled data from seven population-based Finnish health behavior survey studies during years 1972-2015) consisting of 171 063 women and men. Participants' smoking, alcohol consumption, physical inactivity and BMI measures were gathered, and participants were categorized into those exposed and those not exposed. The incidence of CRC was modeled by Poisson regression with main and interaction effects of key lifestyle factors. The cohort members were followed-up through register linkage to the Finnish Cancer Registry for first primary CRC case until the end of 2015. Follow-up time was 1715, 690 person years. The highest pairwise CRC risk was among male smokers who had overweight (BMI ≥ 25 kg/m2 ) (HR 1.75, 95% CI 1.36-2.26) and women who had overweight and consumed alcohol (HR 1.45, 95% CI 1.14-1.85). Overall, among men the association of lifestyle factors and CRC risk was stronger than among women. In men, both having overweight and being a smoker combined with any other adverse lifestyle factor increased CRC risk. Among women, elevated CRC risks were observed for those who were physically inactive and who consumed alcohol or had overweight. No statistically significant interactions were detected between pairs of lifestyle factors. CONCLUSIONS: This study strengthens the evidence of overweight, smoking, and alcohol consumption as CRC risk factors. Substantial protective benefits in CRC risk can be achieved by preventing smoking, maintaining BMI to <25 kg/m2 and not consuming alcohol.

Incidence trends and risk factors of lung cancer in never smokers: Pooled analyses of seven cohorts.

The trends in incidence of lung cancer in never smokers are unclear as well as the significance of risk factors. We studied time trends in the incidence and risk factors of lung cancer in never smokers in Finland in a large, pooled cohort. We pooled data from seven Finnish health cohorts from the period between 1972 and 2015 with 106 193 never smokers. The harmonised risk factors included education, alcohol consumption, physical activity, height and BMI. We retrieved incident lung cancers from the nation-wide Finnish Cancer Registry. We estimated average annual percent change (AAPC) and the effects of risk factors on cause-specific hazard ratios (HRs) of lung cancer using Poisson regression. We detected 47 lung cancers in never smoking men (n = 31 859) and 155 in never smoking women (n = 74 334). The AAPC of lung cancer incidence was -3.30% (95% confidence interval [CI]: -5.68% to -0.88%, P = .009) in never smoking men and 0.00% (95% CI: -1.57% to 1.60%, P = .996) in never smoking women. Of the five studied risk factors only greater height in women had a statistically significant increased risk of lung cancer (multivariate HR = 1.84, 95%CI: 1.08 to 3.12). It is plausible that tobacco control measures focused on working places have reduced passive smoking among men more than among women, which could explain the declining trend in lung cancer incidence in never smoker men but not in never smoker women. As tobacco control measures have not been targeted to domestic environments, it is likely that women's exposure to passive smoking has continued longer.

Accuracy of Finnish Cancer Registry colorectal cancer data: a comparison between registry data and clinical records.

BACKGROUND: The population-based Finnish Cancer Registry (FCR) is an important resource for research and healthcare politics in Finland. The aim of this study was to validate the accuracy of the colorectal cancer (CRC) data within the FCR. MATERIAL AND METHODS: FCR data are based on independent cancer report forms (CRFs) from both clinicians and pathologists. Data from patients diagnosed with CRC during a randomized, population-based CRC screening program between 2004 and 2012 were extracted from the FCR and compared to data extracted from the original clinical patient records of these individuals by two gastrointestinal surgeons. The study focused on tumour characteristics and primary treatment. Accuracy was measured by calculating Cohen's kappa coefficient (κ), which considers the possibility of agreement by chance. RESULTS: Altogether, 1475 patients were studied. κ was 0.74 for stage, 0.87 for tumour location (right/left), 0.78 for a more detailed location, 0.72 for tumour histology, 0.46 for surgical removal of the primary tumour, and 0.43 for chemotherapy. Among those who underwent surgery, the radicality of surgical treatment had a κ of 0.24. In total, 173 (12%) patients were lacking a CRF from a clinician. CONCLUSION: The FCR data had good accuracy regarding tumour characteristics, but poor accuracy in treatment information. The main reason for this suboptimal accuracy was missing CRFs from treating clinicians. Awareness of these findings is crucial when research and decision making is based on FCR data. Measures have since been taken to improve the completeness of FCR recording.

Suicides and deaths linked to risky health behavior in childhood cancer patients: A Nordic population-based register study.

BACKGROUND: Childhood cancer survivors have been reported to be vulnerable to psychiatric morbidities and risky health behavior. Suicides, substance abuse, accidents, and violence as causes of death can be regarded as an extreme manifestation of risky health behavior. In the current study, the authors studied the risk of suicide and other risky health behavior-related deaths among childhood cancer patients in Denmark, Finland, and Sweden. METHODS: Using linkage between national cancer, population, and cause-of-death registries, the authors investigated the causes of death in 29,285 patients diagnosed with cancer before age 20 years between 1971 and 2009 compared with a cohort of 146,282 age-matched, sex-matched, and country-matched population comparisons. Rate ratios (RRs) with 95% CIs were estimated using Poisson regression models, adjusting for demographic factors. RESULTS: The overall risk of dying of a risky health behavior was found to be increased among childhood cancer patients (RR, 1.25; 95% CI, 1.06-1.47) when compared with population comparisons. The elevated risk was statistically significant among patients with central nervous system tumors (RR, 1.49; 95% CI, 1.08-2.05) and patients diagnosed at ages 5 to 9 years and 15 to 19 years (RR, 1.50 [95% CI, 1.01-2.24] and RR, 1.31 [95% CI, 1.03-1.67], respectively). The overall risk of suicide was found to be increased (RR, 1.37; 95% CI, 1.02-1.83), and statistically significantly so when patients were diagnosed between ages 15 and 19 years (RR, 1.61; 95% CI, 1.09-2.39). CONCLUSIONS: Childhood cancer patients appear to have an increased risk of risky health behavior-related causes of death compared with the general population. The results of the current study suggest the importance of integrating psychosocial support into the follow-up care of these individuals.

The impact of socioeconomic status on stage specific prostate cancer survival and mortality before and after introduction of PSA test in Finland.

Socioeconomic status (SES) has an impact on prostate cancer (PCa) outcomes. Men with high SES have higher incidence and lower mortality of PCa versus lower SES males. PCa cases diagnosed in Finland in 1985-2014 (N = 95,076) were identified from the Finnish Cancer Registry. Information on education level (EL) was obtained from Statistics Finland. EL was assessed with three-tiered scale: basic, upper secondary and higher education. PCa stage at diagnosis was defined as localized, metastatic or unknown. Years of diagnosis 1985-1994 were defined as pre-PSA period and thereafter as post-PSA period. We report PCa-specific survival (PCSS) and relative risks (RR) for PCa specific mortality (PCSM) among cancer cases in Finland, where healthcare is 100% publicly reimbursed and inequality in healthcare services low. Men with higher EL had markedly better 10-year PCSS: 68 versus 63% in 1985-1994 and 90 versus 85% in 1995-2004 compared to basic EL in localized PCa. The RR for PCSM among men with localized PCa and higher EL compared to basic EL was 0.76(95%confidence interval (CI) 0.66-0.88) in 1985-1994 and 0.61(95%CI 0.53-0.70) in 1995-2004. Variation in PCSS and PCSM between EL categories was evident in metastatic PCa, too. The difference in PCSM between EL categories was larger in the first 10-year post-PSA period than before that but decreased thereafter in localized PCa, suggesting PSA testing became earlier popular among men with high EL. In summary, higher SES/EL benefit PCa survival both in local and disseminated disease and the effect of EL was more pronounced in early post-PSA period.