High-Risk Features Are Prognostic in dMMR/MSI-H Stage II Colon Cancer.

BACKGROUND: High-risk features, such as T4 disease, bowel obstruction, poorly/undifferentiated histology, lymphovascular, perineural invasion, and <12 lymph nodes sampled, indicate poor prognosis and define high-risk stage II disease in proficient mismatch repair stage II colon cancer (CC). The prognostic role of high-risk features in dMMR/MSI-H stage II CC is unknown. Similarly, the role of adjuvant therapy in high-risk stage II CC with dMMR/MSI-H (≥1 high-risk feature) has not been studied in prospective trials. The aim of this analysis of the National Cancer Database is to evaluate the prognostic value of high-risk features in stage II dMMR/MSI-H CC. METHODS: Univariate (UVA) and multivariate (MVA) Cox proportional hazards (Cox-PH) models were built to assess the association between clinical and demographic characteristics and overall survival. Kaplan-Meier survival curves were generated with log-rank tests to evaluate the association between adjuvant chemotherapy in high-risk and low-risk cohorts separately. RESULTS: A total of 2,293 stage II CC patients have dMMR/MSI-H; of those, 29.5% (n = 676) had high-risk features. The high-risk dMMR/MSI-H patients had worse overall survival [5-year survival and 95%CI, 73.2% (67.3-78.1%) vs. 80.3% (76.7-83.5%), p = 0.0001]. In patients with stage II dMMR/MSI-H CC, the high-risk features were associated with shorter overall survival (OS) along with male sex, positive carcinoembryonic antigen, Charlson-Deyo score >1, and older age. Adjuvant chemotherapy administration was associated with better OS, regardless of the high-risk features in dMMR/MSI-H (log-rank test, p = 0.001) or not (p = 0.0006). When stratified by age, the benefit of chemotherapy was evident only in patients age ≥65 with high-risk features. CONCLUSION: High-risk features are prognostic in the setting of dMMR/MSI-H stage II CC. Adjuvant chemotherapy may improve survival specifically in patients ≥65 years and with high-risk features.

Elderly Patients Benefit From Enhanced Recovery Protocols After Colorectal Surgery.

BACKGROUND: Enhanced recovery protocols (ERAS) aim to decrease physiological stress response to surgery and maintain postoperative physiological function. Proponents of ERAS state these protocols decrease lengths of stay (LOS) and complication rates. Our aim was to assess whether elderly patients receive the same benefit as younger patients using ERAS protocols. METHODS: We queried patients from 2015 to 2017 at our institution with Enhanced Recovery in Surgery (ERIN) variables from the targeted colectomy NSQIP database. The patients were divided into sextiles and analyzed for readmission, LOS, return of bowel function, tolerating diet, mobilization, and multimodal pain management comparing the youngest sextile to the oldest sextile. RESULTS: Two hundred sixty-two patients (73% colectomies) were enrolled in ERAS. When compared with the youngest sextile (age 19-43.8), the oldest sextile (age 71.4-92.5) had similar readmission rates at 9.8% versus 9.5% (P-value = 0.87), quicker return of bowel function, average 1.9 d versus 3.7 d (P-value < 0.01), and tolerated diet quicker, average POD 2.4 d versus 5.1 d (P-value < 0.01). There was a slight decrease in the use of multimodal pain management 88% versus 100% (P-value = 0.07), but mobilization on POD1 was slightly better in the elderly at 80% versus 78% (P-value = 0.76). Elderly patients enrolled in ERAS had an average LOS of 4.9 days versus 7.8 in the younger patients (P-value = 0.08). Among elderly non-ERAS patients average LOS was 14.6 days. CONCLUSION: Overall, elderly patients fared better or the same on the ERIN variables analyzed than the younger cohort. ERAS protocols are beneficial and applicable to elderly patients undergoing colorectal surgery.

Receipt of Adjuvant Chemotherapy in Stage II Colon Cancer and Overall Survival: A National Cancer Database Study.

BACKGROUND: There are variations in the use of adjuvant chemotherapy (AC) in stage II colon cancer (CRC). We sought to determine which patients received chemotherapy, what factors were associated with receipt of AC, and how this impacted overall survival. METHODS: Using the National Cancer Database, patients with stage II CRC who underwent surgical resection were selected; patients who received radiation or neoadjuvant chemotherapy were excluded. High-risk features (HRFs) were defined as pathological tumor stage IV, positive surgical margins, and perineural or lymphovascular invasion. Multivariable and subgroup analysis with eight subgroups stratified in the presence of HRFs, age, and the Charlson-Deyo score was performed. RESULTS: Of 77,739 patients identified with stage II CRC, 18.3% received AC. Younger, healthier patients with HRFs had the highest chemotherapy receipt rate (46.7%), whereas patients without HRFs, ≥ 75 y, and with the Charlson-Deyo score of 2+ had the lowest rate (2.1%). Community cancer centers were more likely to initiate AC (odds ratio = 1.24 P < 0.01) especially among healthy HRF-negative patients and younger patients. No significant racial differences in AC use were observed. AC was associated with improved overall survival in subgroups with HRFs (hazard ratio [HR]: 0.81 P < 0.001; HR: 0.75 P < 0.001; HR: 0.65 P = 0.03; HR: 0.55, P < 0.001) but not in patients without HRFs. CONCLUSIONS: AC receipt rates differed depending on patient age and type of institution delivering care. AC was associated with survival benefits only in patients with HRFs regardless of age. These findings are clinically relevant to inform appropriate use of AC in stage II CRC.