College of American Pathologists Tumor Regression Grading System for Long-Term Outcome in Patients with Locally Advanced Rectal Cancer.

BACKGROUND: The National Comprehensive Cancer Network's Rectal Cancer Guideline Panel recommends American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) system to evaluate pathologic response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer (LARC). Yet, the clinical significance of the AJCC/CAP TRG system has not been fully defined. MATERIALS AND METHODS: This was a multicenter, retrospectively recruited, and prospectively maintained cohort study. Patients with LARC from one institution formed the discovery set, and cases from external independent institutions formed a validation set to verify the findings from discovery set. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were assessed by Kaplan-Meier analysis, log-rank test, and Cox regression model. RESULTS: The discovery set (940 cases) found, and the validation set (2,156 cases) further confirmed, that inferior AJCC/CAP TRG categories were closely /ccorrelated with unfavorable survival (OS, DFS, LRFS, and DMFS) and higher risk of disease progression (death, accumulative relapse, local recurrence, and distant metastasis) (all p < .05). Significantly, pairwise comparison revealed that any two of four TRG categories had the distinguished survival and risk of disease progression. After propensity score matching, AJCC/CAP TRG0 category (pathological complete response) patients treated with or without adjuvant chemotherapy displayed similar survival of OS, DFS, LRFS, and DMFS (all p > .05). For AJCC/CAP TRG1-3 cases, adjuvant chemotherapy treatment significantly improved 3-year OS (90.2% vs. 84.6%, p < .001). Multivariate analysis demonstrated the AJCC/CAP TRG system was an independent prognostic surrogate. CONCLUSION: AJCC/CAP TRG system, an accurate prognostic surrogate, appears ideal for further strategizing adjuvant chemotherapy for LARC. IMPLICATIONS FOR PRACTICE: The National Comprehensive Cancer Network recommends the American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) four-category system to evaluate the pathologic response to neoadjuvant treatment for patients with locally advanced rectal cancer; however, the clinical significance of the AJCC/CAP TRG system has not yet been clearly addressed. This study found, for the first time, that any two of four AJCC/CAP TRG categories had the distinguished long-term survival outcome. Importantly, adjuvant chemotherapy may improve the 3-year overall survival for AJCC/CAP TRG1-3 category patients but not for AJCC/CAP TRG0 category patients. Thus, AJCC/CAP TRG system, an accurate surrogate of long-term survival outcome, is useful in guiding adjuvant chemotherapy management for rectal cancer.

Rapid and sensitive high-performance liquid chromatography-electrospray ionization tandem mass spectrometry for the quantification of potassium dehydroandrographolidi succinas and identification of its degradation products in potassium dehydroandrographolidi succinas injection.

A high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI- MS/MS) method was established for the quantitative and qualitative analysis of potassium dehydroandrographolidi succinas (DAS-K) and its degradation products, respectively, in DAS-K injection, a widely used drug in China. The analytical HPLC was performed on a Waters RP-C18 column using 5 micromol m(-1) ammonium acetate (pH 3.0, adjusted by formic acid) and methanol as the mobile phase. Detection was performed on a Micromass Quattro micro triple quadrupole mass spectrometer with positive electrospray ionization. Three major degradation products were separated, detected and identified simultaneously by HPLC-ESI-MS/MS results. An HPLC method for the assay of DAS-K in its injection was then established. The multiple reaction monitoring function (m/z 550.14-->m/z 297.04 for DAS-K) enabled the quantification of DAS-K down to 0.2 ng m(-1). The calibration graph was linear (r better than 0.999, n = 7) in the concentration range 2.0-100 ng mL(-1). The values for the intra- and inter-day relative standard deviation (RSD) were less than 1.7% and 2.5% for DAS-K. The average recovery rate was over 98%, with an RSD less than 3.0%. This is the first report on the degradation products in DAS-K injection.