Co(III)-Catalyzed C6-Selective C-H Activation/Pyridine Migration of 2-Pyridones with Propiolates.

A versatile Co(III)-catalyzed C6-selective C-H activation/pyridine migration of 2-pyridones with available propiolates as coupling partners was demonstrated. This method features high atom economy, excellent regioselectivity, and good functional group tolerance by employing an inexpensive Co(III) catalyst under mild reaction conditions. Moreover, gram-scale synthesis and late-stage modifications of pharmaceuticals were performed to prove the effectiveness of these synthetic approaches.

Palladium(II)-Catalyzed Remote meta-C-H Functionalization of Arenes Enabled by Multitasking Oxyamides as the Linker.

A palladium-catalyzed olefination of meta-C-H bonds in arenes containing oxyamides using a nitrile template as the directing group has been established. The methodology exhibited high meta-selectivity and tolerated different functional groups such as benzyloxyamides and olefin substrates. The desired products were obtained in good yields. This approach enabled the modification of natural products and drugs and was also applicable on the gram-scale. Furthermore, the directing template was readily removed by selective cleavage of the amide bond or the O-N bond to obtain meta-functionalized hydroxylamines and benzyl alcohols. The proposed method holds great potential for the design of novel drugs.

Mild Three-Step Consecutive C-H Activations.

Herein, the Rh-catalyzed consecutive C-H bond olefination/annulation/olefination cascade, tandemly directed by sulfonamide and ester groups, has been developed under mild conditions with the assistance of 1-adamantane carboxylic acid. A seven-membered metallacycle including an ester group was preferred to the five-membered one including a sulfonamide group for the third C-H activation. In this transformation, the Rh catalyst exhibits its high reactivity by catalyzing a triple C-H activation process with a low catalyst loading at 50 °C. This method can be applied in the construction of various pharmaceutical derivatives.

Impact of neoadjuvant chemoradiotherapy on the local recurrence and distant metastasis pattern of locally advanced rectal cancer: a propensity score-matched analysis.

BACKGROUND: Previous studies have demonstrated different predominant sites of distant metastasis between patients with and without neoadjuvant chemoradiotherapy (NCRT). This study aimed to explore whether NCRT could influence the metastasis pattern of rectal cancer through a propensity score-matched analysis. METHODS: In total, 1296 patients with NCRT or post-operative chemoradiotherapy (PCRT) were enrolled in this study between January 2008 and December 2015. Propensity score matching was used to correct for differences in baseline characteristics between the two groups. After propensity score matching, the metastasis pattern, including metastasis sites and timing, was compared and analyzed. RESULTS: After propensity score matching, there were 408 patients in the PCRT group and 245 patients in the NCRT group. NCRT significantly reduced local recurrence (4.1% vs. 10.3%, P = 0.004), but not distant metastases (28.2% vs. 27.9%, P = 0.924) compared with PCRT. In both the NCRT and PCRT groups, the most common metastasis site was the lung, followed by the liver. The NCRT group developed local recurrence and distant metastases later than the PCRT group (median time: 29.2 [18.8, 52.0] months vs. 18.7 [13.3, 30.0] months, Z = -2.342, P = 0.019; and 21.2 [12.2, 33.8] vs. 16.4 [9.3, 27.9] months, Z = -1.765, P = 0.035, respectively). The distant metastases occurred mainly in the 2nd year after surgery in both the PCRT group (39/114, 34.2%) and NCRT group (21/69, 30.4%). However, 20.3% (14/69) of the distant metastases appeared in the 3rd year in the NCRT group, while this number was only 13.2% (15/114) in the PCRT group. CONCLUSIONS: The predominant site of distant metastases was the lung, followed by the liver, for both the NCRT group and PCRT group. NCRT did not influence the predominant site of distant metastases, but the NCRT group developed local recurrence and distant metastases later than the PCRT group. The follow-up strategy for patients with NCRT should be adjusted and a longer intensive follow-up is needed.

The prognostic significance of the treatment response of regional lymph nodes and the refinement of the current TNM staging system in locally advanced rectal cancer after neoadjuvant chemoradiotherapy.

The current TNM staging system uses the same category definitions for both rectal cancer patients with and without neoadjuvant chemoradiotherapy (NCRT). However, ypTNM stage, especially ypN stage does not predict patient survival after NCRT well. Whether tumor regression in lymph nodes (LRG) may improve the prediction has not been well studied. In total, 358 patients with rectal cancer who received NCRT followed by radical resection were recruited from 2004 to 2015, and the median follow-up time was 57.5 months. The main outcome measure was disease-free survival (DFS). In univariate analysis, factors associated with DFS were ypT stage, ypN stage, number of negative lymph nodes (NLN), lymph node ratio (LNR), tumor regression grade (TRG), M-TTRG (modified ypT stage by combining ypT stage and TRG), maximum LRG (LRGmax), sum score of LRG (LRGsum), LRG ratio (average value of LRGsum), and M-NLRG (modified ypN stage by combining LRGmax and LNR). In the multivariate Cox regression analysis, M-TTRG and M-NLRG (p < 0.001 and p = 0.030, respectively) were significantly associated with DFS. The estimated 5-year DFS rates were 86.6%, 60.3%, and 36.4% for patients with M-NLRG-0, M-NLRG-1, and M-NLRG-2, respectively (p < 0.001). A significant difference in survival was observed among patients with NCRT after incorporating TRG and LRG simultaneously into the current ypTNM staging system (p < 0.001). LRG was an important prognostic factor in rectal cancer patients treated with NCRT and could refine the ypTNM staging system. The modified ypTNM staging system in combination with LRGmax, LNR, and TRG could improve the DFS prediction in each subset of patients.

Unnecessity of lymph node regression evaluation for predicting gastric adenocarcinoma outcome after neoadjuvant chemotherapy.

BACKGROUND: Neoadjuvant chemotherapy has been applied worldwide to improve the survival of patients with gastric adenocarcinoma (GAC). The evaluation of histological regression in primary tumors is valuable for predicting prognosis. However, the prognostic effect of regression change in lymph nodes (LNs) remains unclear. AIM: To confirm whether the evaluation of regression change in LNs could predict the prognosis of GAC patients who received neoadjuvant chemotherapy followed by surgery. METHODS: In this study, we evaluated the histological regression of resected LNs from 192 GAC patients (including those with esophagogastric junction adenocarcinoma) treated with neoadjuvant chemotherapy. We classified regression change and residual tumor in LNs into four groups: (A) true negative LNs with no evidence of a preoperative therapy effect, (B) no residual metastasis but the presence of regression change in LNs, (C) residual metastasis with regression change in LNs, and (D) metastasis with minimal or no regression change in LNs. Correlations between regression change and residual tumor groups in LNs and regression change in the primary tumor, as well as correlations between regression change in LNs and clinicopathological characteristics, were analyzed. The prognostic effect of regression change and residual tumor groups in LNs was also analyzed. RESULTS: We found that regression change and residual tumor groups in LNs were significantly correlated with regression change in the primary tumor, tumor differentiation, ypT stage, ypN stage, ypTNM stage, lymph-vascular invasion, perineural invasion and R0 resection status. Regression change and residual tumor groups in LNs were statistically significant using univariate Cox proportional hazards analysis, but were not independent predictors. For patients who had no residual tumor in LNs, the 5-year overall survival (OS) rates were 67.5% in Group A and 67.4% in Group B. For the patients who had residual tumors in LNs, the 5-year OS rates were 28.2% in Group C and 39.5% in Group D. The patients in Groups A+B had a significantly better outcome than the patients in Groups C+D (P < 0.01). No significant differences in survival were found between Groups A and B, or between Groups C and D. CONCLUSION: The existence of residual tumor in LNs, rather than regression change in LNs, is useful for predicting the prognosis after neoadjuvant chemotherapy in GAC patients. In practice, it may not be necessary to report regression change in LNs.