Application of the Eighth Edition of the American Joint Committee on Cancer Staging for Pancreatic Adenocarcinoma.

OBJECTIVES: Notable modifications have been made in the American Joint Committee on Cancer (AJCC) Staging eighth edition staging for pancreatic cancer for the consideration of the irreproducible and inapplicable of the AJCC seventh edition staging. However, the new staging classification has not been systemically verified. METHODS: A comparison was performed to evaluate the application of the AJCC seventh and eighth staging classifications using the Surveillance, Epidemiology, and End Results registry (18,450 patients) and an institutional series (2040 patients). RESULTS: For the eighth staging classification, patients with tumor diameter of greater than 4 cm (T3N0M0, IIA) had similar prognosis to patients with 1 to 3 positive nodes (T1-3N1M0, IIB). For patients who underwent tumor resection and without lymph node involvement, survival curves of T1 (≤2 cm), T2 (2-4 cm), and T3 (>4 cm) were well separated. Statistical difference in survival analyses was demonstrated in N0 (0 positive node), N1 (1-3 positive nodes), and N2 (≥4 positive nodes) patients underwent tumor resection. The AJCC eighth edition had better stage distribution than the AJCC seventh edition for pancreatic cancer. CONCLUSIONS: The eighth edition of AJCC staging is more applicable and accurate than the seventh edition for pancreatic adenocarcinoma.

Improved estimates of cancer-specific survival rates from population-based data.

BACKGROUND: Accurate estimates of cancer survival are important for assessing optimal patient care and prognosis. Evaluation of these estimates via relative survival (a ratio of observed and expected survival rates) requires a population life table that is matched to the cancer population by age, sex, race and/or ethnicity, socioeconomic status, and ideally risk factors for the cancer under examination. Because life tables for all subgroups in a study may be unavailable, we investigated whether cause-specific survival could be used as an alternative for relative survival. METHODS: We used data from the Surveillance, Epidemiology, and End Results Program for 2,330,905 cancer patients from January 1, 1992, through December 31, 2004. We defined cancer-specific deaths according to the following variables: cause of death, only one tumor or the first of multiple tumors, site of the original cancer diagnosis, and comorbidities. Estimates of relative survival and cause-specific survival that were derived by use of an actuarial method were compared. RESULTS: Among breast cancer patients who were white, black, or of Asian or Pacific Islander descent and who were older than 65 years, estimates of 5-year relative survival (107.5%, 106.6%, and 103.0%, respectively) were higher than estimates of 5-year cause-specific survival (98.6%, 95% confidence interval [CI] = 98.4% to 98.8%; 97.4%, 95% CI = 96.2% to 98.2%; and 99.2%, 95% CI = 98.4%, 99.6%, respectively). Relative survival methods likely underestimated rates for cancers of the oral cavity and pharynx (eg, for white cancer patients aged ≥65 years, relative survival = 54.2%, 95% CI = 53.1% to 55.3%, and cause-specific survival = 60.1%, 95% CI = 59.1% to 60.9%) and the lung and bronchus (eg, for black cancer patients aged ≥65 years, relative survival = 10.5%, 95% CI = 9.9% to 11.2%, and cause-specific survival = 11.9%, 95% CI = 11.2 % to 12.6%), largely because of mismatches between the population with these diseases and the population used to derive the life table. Socioeconomic differences between groups with low and high status in relative survival estimates appeared to be inflated (eg, corpus and uterus socioeconomic status gradient was 13.3% by relative survival methods and 8.8% by cause-specific survival methods). CONCLUSION: Although accuracy of the cause of death on a death certificate can be problematic for cause-specific survival estimates, cause-specific survival methods may be an alternative to relative survival methods when suitable life tables are not available.

Quality of race, Hispanic ethnicity, and immigrant status in population-based cancer registry data: implications for health disparity studies.

Population-based cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) Program at the National Cancer Institute are based on medical records and administrative information. Although SEER data have been used extensively in health disparities research, the quality of information concerning race, Hispanic ethnicity, and immigrant status has not been systematically evaluated. The quality of this information was determined by comparing SEER data with self-reported data among 13,538 cancer patients diagnosed between 1973-2001 in the SEER--National Longitudinal Mortality Study linked database. The overall agreement was excellent on race (kappa = 0.90, 95% CI = 0.88-0.91), moderate to substantial on Hispanic ethnicity (kappa = 0.61, 95% CI = 0.58-0.64), and low on immigrant status (kappa = 0.21. 95% CI = 0.10, 0.23). The effect of these disagreements was that SEER data tended to under-classify patient numbers when compared to self-identifications, except for the non-Hispanic group which was slightly over-classified. These disagreements translated into varying racial-, ethnic-, and immigrant status-specific cancer statistics, depending on whether self-reported or SEER data were used. In particular, the 5-year Kaplan-Meier survival and the median survival time from all causes for American Indians/Alaska Natives were substantially higher when based on self-classification (59% and 140 months, respectively) than when based on SEER classification (44% and 53 months, respectively), although the number of patients is small. These results can serve as a useful guide to researchers contemplating the use of population-based registry data to ascertain disparities in cancer burden. In particular, the study results caution against evaluating health disparities by using birthplace as a measure of immigrant status and race information for American Indians/Alaska Natives.