Choice of Survival Metric and Its Impacts on Cancer Survival Estimates for American Indian and Alaska Native People

BACKGROUND

Different survival metrics have different applicability to clinical practice and research. We evaluated how choice of survival metric influences assessment of cancer survival among American Indian and Alaska Native (AIAN) people relative to non-Hispanic Whites (NHW). A secondary objective was to present variations in survival among AIAN people by age, sex, stage, and Indian Health Service (IHS) region.

METHODS

Five-year survival was calculated using the North American Association of Central Cancer Registries Cancer in North America dataset. We calculated survival among AIAN people, compared with NHW using four approaches: (i) observed (crude) survival, (ii) cause-specific survival, (iii) relative survival using age- and sex-adjusted lifetables, and (iv) relative survival using lifetables additionally adjusted for race, geography, and socioeconomic status. For AIAN people, we evaluated how survival varied by age, stage at diagnosis, and IHS region.

RESULTS

Observed survival methods produced the lowest estimates, and-excepting prostate cancer-cause-specific methods produced the highest survival estimates. Survival was lower among AIAN people than NHW for all methods. Among AIAN people, survival was higher among those 20-64 years, females, and tumors diagnosed at local stage. Survival varied by IHS region and cancer sites.

CONCLUSIONS

These results support the assertion that using the same methodology to compare survival estimates between racial and ethnic groups is of paramount importance, but that the choice of metric requires careful consideration of study objectives.

IMPACT

These findings have the potential to impact choice of survival metric to explore disparities among AIAN people.

Cancer survival in Qidong between 1972 and 2011: A population-based analysis

Population-based cancer survival is an improved index for evaluating the overall efficiency of cancer health services in a given region. The current study analysed the observed survival and relative survival of leading cancer sites from a population-based cancer registry between 1972 and 2011 in Qidong, China. A total of 92,780 incident cases with cancer were registered and followed-up for survival status. The main sites of the cancer types, based on the rank order of incidence, were the liver, stomach, lung, colon and rectum, oesophagus, breast, pancreas, leukaemia, brain and central nervous system (B and CNS), bladder, blood [non-Hodgkin's lymphoma (NHL)] and cervix. For all malignancies combined, the 5-year observed survival was 13.18% and the relative survival was 15.80%. Females had higher observed survival and relative survival (19.32 and 22.71%, respectively) compared with males (9.63 and 11.68%, respectively). The cancer sites with the highest five-year relative survival rates were the female breast, bladder, cervix and colon and rectum; followed by NHL, stomach, B and CNS cancer and leukaemia. The poorest survival rates were cancers of oesophagus, lung, pancreas and liver. Higher survival rates were observed in younger patients compared with older patients. Cancers of the oesophagus, female breast and bladder were associated with higher survival in middle-aged groups. Improved survival rates in the most recent two 5-year calendar periods were identified for stomach, lung, colon and rectum, oesophagus, female breast and bladder cancer, as well as leukaemia and NHL. The observations of the current study provide the opportunity for evaluation of the survival outcomes of frequent cancer sites that reflects the changes and improvement in a rural area in China.

Incidence, mortality and survival of female breast cancer during 2003-2011 in Jiangsu province, China

OBJECTIVE

To assess the incidence, mortality and survival status of female breast cancer in Jiangsu province of China.

METHODS

Population-based cancer registry data in Jiangsu province were collected during 2003-2011. Crude rates, age-specific rates, age-standardized rates and annual percent changes of incidence and mortality were calculated to describe the epidemiologic characteristics and time trends. Patients diagnosed from 2003 to 2005 were chosen for analyzing the survival status of breast cancer.

RESULTS

From 2003 to 2011, 17,605 females were diagnosed with breast cancer and 4,883 died in selected registry areas in Jiangsu province. The crude incidence rate was 25.18/100,000, and the age-standardized rates by Chinese population (ASRC) and by world population (ASRW) were 19.03/100,000 and 17.92/100,000, respectively. During the same period, the crude mortality rate was 6.98/100,000 and the ASRC and ASRW were 4.93/100,000 and 4.80/100,000, respectively. From 2003 to 2011, the incidence and mortality increased with annual percent change of 11.37% and 5.78%, respectively. For survival analysis, 1,392 patients in 7 areas were identified in 2003-2005 and finished 5 years of follow-up. Survival rates were found to decrease with survival years, the 5-year observed survival rate was 45.9% and the relative survival rate was 52.0%. We also found that the survival rate varied across the province, which was lower in the north and higher in the south of Jiangsu province.

CONCLUSIONS

Breast cancer has become a significant public health problem in Jiangsu province and China. More resources should be invested in primary prevention, earlier diagnosis and better health services in order to increase survival rates among Chinese females.