Xue Qin Yu

Cancer statistics in China, 2015

With increasing incidence and mortality, cancer is the leading cause of death in China and is a major public health problem. Because of Chinas massive population (1.37 billion), previous national incidence and mortality estimates have been limited to small samples of the population using data from the 1990s or based on a specific year. With high‐quality data from an additional number of population‐based registries now available through the National Central Cancer Registry of China, the authors analyzed data from 72 local, population‐based cancer registries (2009‐2011), representing 6.5% of the population, to estimate the number of new cases and cancer deaths for 2015. Data from 22 registries were used for trend analyses (2000‐2011). The results indicated that an estimated 4292,000 new cancer cases and 2814,000 cancer deaths would occur in China in 2015, with lung cancer being the most common incident cancer and the leading cause of cancer death. Stomach, esophageal, and liver cancers were also commonly diagnosed and were identified as leading causes of cancer death. Residents of rural areas had significantly higher age‐standardized (Segi population) incidence and mortality rates for all cancers combined than urban residents (213.6 per 100,000 vs 191.5 per 100,000 for incidence; 149.0 per 100,000 vs 109.5 per 100,000 for mortality, respectively). For all cancers combined, the incidence rates were stable during 2000 through 2011 for males (+0.2% per year; P = .1), whereas they increased significantly (+2.2% per year; P < .05) among females. In contrast, the mortality rates since 2006 have decreased significantly for both males (−1.4% per year; P < .05) and females (−1.1% per year; P < .05). Many of the estimated cancer cases and deaths can be prevented through reducing the prevalence of risk factors, while increasing the effectiveness of clinical care delivery, particularly for those living in rural areas and in disadvantaged populations. CA Cancer J Clin 2016;66:115–132.

Cancer survival in China, 2003-2005: A population-based study

Limited population‐based cancer registry data available in China until now has hampered efforts to inform cancer control policy. Following extensive efforts to improve the systematic cancer surveillance in this country, we report on the largest pooled analysis of cancer survival data in China to date. Of 21 population‐based cancer registries, data from 17 registries (n = 138,852 cancer records) were included in the final analysis. Cases were diagnosed in 2003–2005 and followed until the end of 2010. Age‐standardized relative survival was calculated using region‐specific life tables for all cancers combined and 26 individual cancers. Estimates were further stratified by sex and geographical area. The age‐standardized 5‐year relative survival for all cancers was 30.9% (95% confidence intervals: 30.6%‐31.2%). Female breast cancer had high survival (73.0%) followed by cancers of the colorectum (47.2%), stomach (27.4%), esophagus (20.9%), with lung and liver cancer having poor survival (16.1% and 10.1%), respectively. Survival for women was generally higher than for men. Survival for rural patients was about half that of their urban counterparts for all cancers combined (21.8% vs. 39.5%); the pattern was similar for individual major cancers except esophageal cancer. The poor population survival rates in China emphasize the urgent need for government policy changes and investment to improve health services. While the causes for the striking urban‐rural disparities observed are not fully understood, increasing access of health service in rural areas and providing basic health‐care to the disadvantaged populations will be essential for reducing this disparity in the future.

The spectrum of human immunodeficiency virus-associated cancers in a South African black population: results from a case-control study, 1995-2004

The effect of the evolving HIV epidemic on cancer has been sparsely documented in Africa. We report results on the risk of cancer associated with HIV‐1 infection using data from an ongoing study. A case–control analysis was used to estimate the relative risk (odds ratio, OR) of cancer types known to be AIDS defining: Kaposis sarcoma (n = 333), non‐Hodgkin lymphoma (NHL, n = 223) and cancers of the cervix (n = 1,586), and 11 cancer types possibly associated with HIV infection: Hodgkin lymphoma (n = 154), cancers of other anogenital organs (n = 157), squamous cell cancer of the skin (SCC, n = 70), oral cavity and pharynx (n = 319), liver (n = 83), stomach (n = 142), leukemia (n = 323), melanoma (n = 53), sarcomas other than Kaposis (n = 93), myeloma (n = 189) and lung cancer (n = 363). The comparison group comprised 3,717 subjects with all other cancer types and 682 subjects with vascular disease. ORs were adjusted for age, sex (except cervical cancer), year of diagnosis, education and number of sexual partners. Significantly increased risks associated with HIV‐1 infection were found for HIV/AIDS associated Kaposis sarcoma (OR = 47.1, 95% CI = 31.9–69.8), NHL (OR = 5.9, 95% CI = 4.3–8.1) and cancer of the cervix (OR = 1.6, 95% CI = 1.3–2.0); Hodgkins disease (OR = 1.6, 95% CI = 1.0–2.7), cancers of anogenital organs other than the cervix (OR = 2.2; 95% CI = 1.4–3.3) and SCC (OR = 2.6, 95% CI = 1.4–4.9) were also significantly increased. No significant associations were found between HIV and any of the other cancers examined. Risks for HIV‐related cancers are consistent with previous studies in Africa, and are lower when compared to those observed in developed countries.

Socioeconomic disparities in breast cancer survival: relation to stage at diagnosis, treatment and race

BackgroundPrevious studies have documented lower breast cancer survival among women with lower socioeconomic status (SES) in the United States. In this study, I examined the extent to which socioeconomic disparity in breast cancer survival was explained by stage at diagnosis, treatment, race and rural/urban residence using the Surveillance, Epidemiology, and End Results (SEER) data.MethodsWomen diagnosed with breast cancer during 1998-2002 in the 13 SEER cancer registry areas were followed-up to the end of 2005. The association between an area-based measure of SES and cause-specific five-year survival was estimated using Cox regression models. Six models were used to assess the extent to which SES differences in survival were explained by clinical and demographical factors. The base model estimated the hazard ratio (HR) by SES only and then additional adjustments were made sequentially for: 1) age and year of diagnosis; 2) stage at diagnosis; 3) first course treatment; 4) race; and 5) rural/urban residence.ResultsAn inverse association was found between SES and risk of dying from breast cancer (p < 0.0001). As area-level SES falls, HR rises (1.00 → 1.05 → 1.23 → 1.31) with the two lowest SES groups having statistically higher HRs. This SES differential completely disappeared after full adjustment for clinical and demographical factors (p = 0.20).ConclusionStage at diagnosis, first course treatment and race explained most of the socioeconomic disparity in breast cancer survival. Targeted interventions to increase breast cancer screening and treatment coverage in patients with lower SES could reduce much of socioeconomic disparity.

Changes in smoking prevalence among U.S. adults by state and region: Estimates from the Tobacco Use Supplement to the Current Population Survey, 1992-2007

BackgroundTobacco control policies at the state level have been a critical impetus for reduction in smoking prevalence. We examine the association between recent changes in smoking prevalence and state-specific tobacco control policies and activities in the entire U.S.MethodsWe analyzed the 1992-93, 1998-99, and 2006-07 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) by state and two indices of state tobacco control policies or activities [initial outcome index (IOI) and the strength of tobacco control (SOTC) index] measured in 1998-1999. The IOI reflects cigarette excise taxes and indoor air legislation, whereas the SOTC reflects tobacco control program resources and capacity. Pearson Correlation coefficient between the proportionate change in smoking prevalence from 1992-93 to 2006-07 and indices of tobacco control activities or programs was the main outcome measure.ResultsSmoking prevalence decreased from 1992-93 to 2006-07 in both men and women in all states except Wyoming, where no reduction was observed among men, and only a 6.9% relative reduction among women. The percentage reductions in smoking in men and women respectively were the largest in the West (average decrease of 28.5% and 33.3%) and the smallest in the Midwest (18.6% and 20.3%), although there were notable exceptions to this pattern. The decline in smoking prevalence by state was correlated with the states IOI in both women and men (r = -0.49, p < 0.001; r = -0.31, p = 0.03; respectively) and with states SOTC index in women(r = -0.30, p = 0.03 0), but not men (r = -0.21, p = 0.14).ConclusionState level policies on cigarette excise taxes and indoor air legislation correlate strongly with reductions in smoking prevalence since 1992. Strengthening and systematically implementing these policies could greatly accelerate further reductions in smoking.

Trends in prognostic factors and survival from cutaneous melanoma in Yorkshire, UK and New South Wales, Australia between 1993 and 2003.

The aim of this study was to compare trends in prognostic factors and survival from cutaneous melanoma between 1993 and 2003 in 2 populations with dramatically different underlying incidence rates [Yorkshire, UK, and New South Wales (NSW), Australia] and to look at whether the greater investment in melanoma prevention and early detection in Australia has resulted in any relative differences in survival. Patients diagnosed with invasive melanoma between 1993 and 2003 in Yorkshire (n = 4,170) and NSW (n = 30,520) were identified from cancer registry databases and prognostic information (age, sex, socioeconomic background, tumour site and Breslow thickness) was extracted. Age‐standardised incidence rates, 5‐year relative survival and relative excess risk of death were calculated. Between 1993–1995 and 2001–2003, the incidence of melanoma increased in both areas. These increases were mainly seen in tumours with thickness ≤1 mm. Five‐year relative survival was 86.9% (95% CI 85.2–88.5) in Yorkshire and 88.6% (95% CI 88.1–89.1) in NSW. Compared with that in NSW, survival in Yorkshire was lower for males and for those living in the most deprived areas. Despite the increase in good prognosis of thin tumours, there was no significant change in survival over the time period in either area. After adjustment for differences in prognostic factors, the relative excess risk of death in Yorkshire compared to that in NSW reduced from 1.36 (95% CI 1.20–1.53) to 1.11 (95% CI 0.99–1.23). Differences in tumour thickness appeared to be the most important factor.

Trends in survival and excess risk of death after diagnosis of cancer in 1980-1996 in New South Wales, Australia.

Survival from almost all cancers has improved during the last 30 years. There is debate over the reasons for the improvement. We examined trends in survival for 28 cancers from 1980 to 1996 in New South Wales (NSW), Australia, with adjustment for disease spread at diagnosis. NSW Central Cancer Registry data were used to estimate 5‐year relative survival and relative excess risk of death for patients diagnosed in 1980–84, 1985–88, 1989–92 and 1993–96. Statistical significance of variation in excess deaths between periods of diagnosis was assessed using Poisson regression, with adjustment for age, sex, duration of follow‐up, histology and spread of disease at diagnosis. There were statistically significant falls in excess deaths for 20 of the cancers with a 25% fall for all cancers combined. Cancers of the prostate, liver, thyroid, breast, gallbladder, body of uterus, rectum, cervix and ovary had falls of >30%. The falls varied by spread of disease; the largest being in localised and regionally spread tumours. Overall survival, when unadjusted for spread of cancer, generally fell in parallel with that in the specific categories of spread, which implies that stage migration did not contribute importantly to survival trends. While acknowledging the limitations of incomplete data on stage of cancer at diagnosis, we conclude that falls in excess deaths in NSW from 1980 to 1996 are unlikely, for many cancers, to be attributed to earlier diagnosis or stage migration; thus advances in cancer treatment have almost certainly contributed to them.

Estimating regional variation in cancer survival: a tool for improving cancer care.

AbstractObjective: To improve estimation of regional variation in cancer survival and identify cancers to which priority might be given to increase survival. Methods: Survival measures were calculated for 25 major cancer types diagnosed in each of 17 health service regions in New South Wales, Australia, from 1991 to 1998. Region-specific risks of excess death due to cancer were estimated adjusting for age, sex, and extent of disease at, and years since, diagnosis. Empirical Bayes (EB) methods were used to shrink the estimates. The additional numbers of patients who would survive beyond five years were estimated by shifting the State average risk to the 20th centile. Results: Statistically significant regional variation in the shrunken estimates of risk of excess death was found for nine of the 25 cancer types. The lives of 2903 people (6.4%) out of the 45,047 whose deaths within 5 years were attributable to cancer could be extended with the highest number being for lung cancer (791). Conclusions: The EB approach gives more precise estimates of region-specific risk of excess death and is preferable to standard methods for identifying cancer sites where gains in survival might be made. The estimated number of lives that could be extended can assist health authorities in prioritising investigation of and attention to causes of regional variation in survival.

Geographic variation in prostate cancer survival in New South Wales

Objectives: To determine whether the previously reported urban–rural differential in prostate cancer survival remains after adjusting for demographic and clinical factors, and to investigate temporal trends in this differential.

Estimating the proportion cured of cancer: Some practical advice for users

BACKGROUND Cure models can provide improved possibilities for inference if used appropriately, but there is potential for misleading results if care is not taken. In this study, we compared five commonly used approaches for modelling cure in a relative survival framework and provide some practical advice on the use of these approaches. PATIENTS AND METHODS Data for colon, female breast, and ovarian cancers were used to illustrate these approaches. The proportion cured was estimated for each of these three cancers within each of three age groups. We then graphically assessed the assumption of cure and the model fit, by comparing the predicted relative survival from the cure models to empirical life table estimates. RESULTS Where both cure and distributional assumptions are appropriate (e.g., for colon or ovarian cancer patients aged <75 years), all five approaches led to similar estimates of the proportion cured. The estimates varied slightly when cure was a reasonable assumption but the distributional assumption was not (e.g., for colon cancer patients ≥75 years). Greater variability in the estimates was observed when the cure assumption was not supported by the data (breast cancer). CONCLUSIONS If the data suggest cure is not a reasonable assumption then we advise against fitting cure models. In the scenarios where cure was reasonable, we found that flexible parametric cure models performed at least as well, or better, than the other modelling approaches. We recommend that, regardless of the model used, the underlying assumptions for cure and model fit should always be graphically assessed.