Treatment guidelines for colon cancer recommend colectomy with lymphadenectomy of at least 12 lymph nodes for patients with stage I to stage III disease as surgery adherence (SA) and adjuvant chemotherapy for individuals with stage III disease. Herein, the authors evaluated adherence to these guidelines among older patients in Texas with colon cancer and the associated survival outcomes.
Using Texas Cancer Registry data linked with Medicare data, the authors included patients with AJCC stage II and III colon cancer who were aged ≥66 years and diagnosed between 2001 and 2011. SA and adjuvant chemotherapy adherence rates to treatment guidelines were estimated. The chi-square test, general linear regression, survival probability, and Cox regression were used to identify factors associated with adherence and survival.
The rate of SA increased from 47.2% to 84% among 6029 patients with stage II or stage III disease from 2001 to 2011, and the rate of adjuvant chemotherapy increased from 48.9% to 53.1% for patients with stage III disease during the same time period. SA was associated with marital status, tumor size, surgeon specialty, and year of diagnosis. Patient age, sex, marital status, Medicare state buy-in status, comorbidity status, and year of diagnosis were found to be associated with adjuvant chemotherapy. The 5-year survival probability for patients receiving guideline-concordant treatment was the highest at 87% for patients with stage II disease and was 73% for those with stage III disease. After adjusting for demographic and tumor characteristics, improved cancer cause-specific survival was associated with the receipt of stage-specific, guideline-concordant treatment for patients with stage II or stage III disease.
The adherence to guideline-concordant treatment among older patients with colon cancer residing in Texas improved over time, and was associated with better survival outcomes. Future studies should be focused on identifying interventions to improve guideline-concordant treatment adherence. Cancer 2018;124:679-87. © 2017 American Cancer Society.

To examine usage trends, guideline adherence, and survival data for patients undergoing lymphadenectomy (LND) at the time of radical prostatectomy (RP) for Gleason 7 prostate cancer (PCa).
The SEER database was queried for all patients with nonmetastatic biopsy Gleason 7 PCa from 2004 to 2013. Distribution and trends of LND were analyzed. The Memorial-Sloan Kettering Cancer Center nomogram was applied to stratify patients based on risk of nodal disease at time of RP (<5% risk or ≥5% risk). Analyses were performed to determine covariates associated with LND receipt at time of RP and cancer-specific mortality (CSM).
A total of 78,641 patients with either G34 or G43 PCa underwent RP (59,194 and 19,447, respectively). Of these patients, 61.2% of G34 and 73.5% of G43 patients underwent LND. During this 10-year period, the proportion of G43 patients undergoing LND remained relatively stable, whereas the proportion of G34 patients undergoing LND ranged between 55.9% and 67.9%. Regional differences were a predictor of LND receipt regardless of risk stratification, but did not translate to higher risk of CSM. Receipt of LND was not predictive of improved CSM in any of the cohorts analyzed.
The role of LND for Gleason 7 prostate adenocarcinoma is not yet standardized, as indicated by the variability of LND dissection rates. Receipt of LND did not improve CSM, and in G43 patients, it predicted higher CSM. As the effect of LND on CSM is uncertain, further evaluation of oncologic benefit in this patient population is warranted.