Five-Year Survival is Not a Useful Measure for Cancer Control in the Population: an Analysis Based on UK Data

Background: Five-year survival is an important metric for progress in cancer control broadly used both in the cancer literature and by the public. In order to assess its validity and relation to other common metrics, we analyzed the relationship between 5-year survival, incidence and mortality using publicly available cancer registry data from England and Wales. Methods: Five-year survival, incidence and mortality data were obtained from the online database of a registered charity, Cancer Research UK. We extracted sex-specific age-standardized mortality, incidence, and 5-year survivalfor16 types of cancer over the period from 1976 to 1995. The relationships between 5-year survival, incidence and mortality were estimated using both Pearson and Spearman correlation coefficients. Results: All 16cancer types showed an increase in 5-year survival for both genders from 1976 to 1995, ranging from 0.2% (pancreas and lung cancer) to 16.6% (prostate cancer) for males and 0.2% (pancreas cancer) to 16.6% (leukemia) for females. From 1976 to 1995, there was no significant correlation between changes in 5-year survival and cancer mortality for either sex (males, Pearson r=0.16, Spearman r=-0.06; females, Pearson r=-0.33, Spearman r=-0.43). A positive relationship between 5-year survival and incidence was noted among males, but not among females (males, Pearson r=0.61, Spearman r=0.53; females, Pearson r=0.03, Spearman r=0.11). However, after excluding breast and prostate cancer, the positive association became weaker and became statistically non-significant for males (Pearson r=0.47; Spearman r=0.41). Conclusions: Our findings suggest that there are no reliable relationships between changes in 5-year survival and cancer incidence or mortality. Increases in 5-year survival might therefore represent poor indicators of progress in cancer control at the population level. In the absence of over-diagnosis, 5-year survival might only indicate improved diagnosis and treatment in clinical practice.

Prevalence of depressive symptoms and its correlates among medical students in China: a national survey in 33 universities.

We conducted a national survey among medical students in China to estimate the prevalence of depressive symptoms and explore associated risk factors based on an established questionnaire composed of demographic information, life events in the past four weeks before survey, and the validated Chinese version of the 21-item Beck's Depression Inventory (BDI). The mean age of enrolled 9010 students was 20.7 (standard deviation: 1.6) years. BDI scores indicated that 19.9% had depressive symptoms based on the cut-off score of 14. Socioeconomic factors and student characteristics such as male sex, low monthly income per capita, father's poor education background, and higher year of study were associated with higher prevalence of depressive symptoms among medical students. Students who studied in comprehensive universities were more likely to have depressive symptoms compared with those from medical universities. Habitual smoking and alcohol drinking, sleep deprivation, and hospitalization or medication for one week or more in the last four weeks also predisposed students to higher risk of depressive symptoms. Our results indicate that depressive symptoms are becoming a highly prevalent health problem among Chinese medical students. Primary and secondary prevention should be prioritized to tackle this issue based on potential risk factors.

Knowledge of human papillomavirus (HPV) infection, cervical cancer, and HPV vaccine and its correlates among medical students in Southwest China: a multi-center cross-sectional survey.

BACKGROUND: Since cervical cancer can be prevented and controlled through human papillomavirus (HPV) vaccination, it is important to train health care providers and provide them with appropriate knowledge. This study aimed to understand the level of HPV related knowledge among medical students and correlates in Southwest China in order to address any potential gap in their knowledge base. METHODS: We conducted a cross-sectional survey among medical students in six selected universities across Southwest China based on a pretested questionnaire regarding HPV infection, cervical cancer, and HPV vaccines. RESULTS: We successfully surveyed 1, 878 medical students, of whom 32.1% were males and 67.9% were females. Their mean age was 20.8 (standard deviation: 1.3) years. 91.8% of them were ethnic Han Chinese, and 43.8% were students in clinical medicine. While 76.5% had heard of HPV only 48.8% knew that the prevention of cervical cancer was possible through HPV vaccination. Only 42.9% of the male and 49.2% of the female students correctly answered over 10 out of 22 questions on HPV related knowledge. Female students appeared to know more about HPV and HPV vaccination (OR: 1.39; 95% CI: 1.11-1.75). In addition, the student knowledge improved with the grade (p<0.001). University courses were the most selected source of knowledge about HPV vaccination (66.4%). 83.6% of males and 91.4% of females were willing to have more HPV related education by experts (p<0.001). Only 10.1% of the students acknowledged that people had asked for their advice regarding HPV vaccination. CONCLUSIONS: Our survey indicates that medical students from Southwest China have poor knowledge of HPV and HPV vaccination, but are willing to receive more relevant information. Targeted education should be incorporated into school courses to inform these future health care providers and ensure success of programs for cervical cancer control and prevention.