CT-based radiomics scores predict response to neoadjuvant chemotherapy and survival in patients with gastric cancer.

BACKGROUND: Neoadjuvant chemotherapy is a promising treatment option for potential resectable gastric cancer, but patients' responses vary. We aimed to develop and validate a radiomics score (rad_score) to predict treatment response to neoadjuvant chemotherapy and to investigate its efficacy in survival stratification. METHODS: A total of 106 patients with neoadjuvant chemotherapy before gastrectomy were included (training cohort: n = 74; validation cohort: n = 32). Radiomics features were extracted from the pre-treatment portal venous-phase CT. After feature reduction, a rad_score was established by Randomised Tree algorithm. A rad_clinical_score was constructed by integrating the rad_score with clinical variables, so was a clinical score by clinical variables only. The three scores were validated regarding their discrimination and clinical usefulness. The patients were stratified into two groups according to the score thresholds (updated with post-operative clinical variables), and their survivals were compared. RESULTS: In the validation cohort, the rad_score demonstrated a good predicting performance in treatment response to the neoadjuvant chemotherapy (AUC [95% CI] =0.82 [0.67, 0.98]), which was better than the clinical score (based on pre-operative clinical variables) without significant difference (0.62 [0.42, 0.83], P = 0.09). The rad_clinical_score could not further improve the performance of the rad_score (0.70 [0.51, 0.88], P = 0.16). Based on the thresholds of these scores, the high-score groups all achieved better survivals than the low-score groups in the whole cohort (all P < 0.001). CONCLUSION: The rad_score that we developed was effective in predicting treatment response to neoadjuvant chemotherapy and in stratifying patients with gastric cancer into different survival groups. Our proposed strategy is useful for individualised treatment planning.

Assessment of Rectal Tumors with Shear-Wave Elastography before Surgery: Comparison with Endorectal US.

Purpose To compare the value of endorectal ultrasonography (US) with shear-wave elastography (SWE) in staging rectal tumors before surgery. Materials and Methods This prospective study was approved by the institutional review board and written informed consent was obtained. In a pilot cohort from April 2015 to January 2016, 70 patients with rectal adenocarcinomas and/or adenomas confirmed with histopathologic examination underwent both endorectal US and SWE. Tumor stiffness and three regions of reference backgrounds, as well as tumor stiffness ratios (SRs) versus these backgrounds, were analyzed. The optimal staging feature was selected by using receiver operating characteristic analysis, and the concordance rate with pathologic stage was analyzed and compared with endorectal US. The results were validated in an independent cohort of 30 patients from February 2016 to July 2016. Results In the pilot study, from rectal adenoma to stage T3 cancers, the tumor stiffness, stiffness of peritumoral fat, tumor SR versus distant perirectal fat, and tumor SR versus normal rectal wall were significantly increased (all P < .05, correlation coefficients between SWE features and pathologic T stages were 0.589-0.853). Receiver operating characteristic analysis of tumor staging demonstrated that tumor stiffness was the optimal feature with the highest area under the receiver operating characteristic curve (AUC = 0.991-1.000). The cutoff values of stage T1, T2, and T3 cancers were 26.9 kPa, 70.3 kPa, and 112.0 kPa, respectively. For SWE, the diagnostic concordance rate with pathologic stage (95.7%, weighted κ = 0.962) was higher than that of endorectal US (75.7%, weighted κ = 0.756). In the validation cohort, similar findings were revealed for diagnostic concordance rate (93.3% vs 76.7%; weighted κ = 0.927 vs 0.651) and diagnostic performance of tumor staging (AUC = 0.950-1.000 vs 0.700-0.833). Conclusion By using the feature of tumor stiffness at SWE, the accuracy of preoperative staging for rectal tumors was improved compared with endorectal US in the pilot study, but was not significantly different in the validation cohort, potentially due to small sample size. © RSNA, 2017 Online supplemental material is available for this article.

A Substage Increase in The AJCC Classification System Improves Prognostic Prediction in Stage III Gastric Cancer With Insufficient Lymph Nodes Removed.

BACKGROUND: The impact of lymph nodes (LNs) removed on the survivals of patients with stage III gastric cancer, especially on that of those who undergo the adjuvant chemotherapy as a compensation for a possibly insufficient lymphadenectomy, is still unclear. METHODS: Consecutive patients (n = 488) with stage III gastric cancer under R0 curative resection followed by adjuvant chemotherapy were analyzed. The overall survival (OS) was compared between patients with insufficient LNs removed (ILNr, <16 LNs) and sufficient LNs removed (SLNr, ≥16 LNs). Performance of the prediction systems was evaluated using the Likelihood ratio χ2 test, Akaike information criterion (AIC), Harrell's concordance index (C-index), and area under the receiver operating characteristic curves (AUC). RESULTS: The OS of patients were significantly longer in those with SLNr relative to those with ILNr (for stage IIIA, 68.2 vs. 43.2 months, P = 0.042; for stage IIIB, 43.7 vs. 24.9 months, P < 0.001; for stage IIIC, 23.9 vs. 8.3 months, P < 0.001; and for total stage III, 37.7 vs. 21.7 months, P < 0.001). However, the OS were similar between stage IIIA patients with ILNr and stage IIIB patients with SLNr (P = 0.928), between IIIB patients with ILNr and IIIC patients with SLNr (P = 0.962), and IIIC patients with ILNr and stage IV (P = 0.668), respectively. A substage increase in the AJCC classification system, from IIIA to IIIB, from IIIB to IIIC, and from IIIC to IV in patients with ILNr, enhanced the accuracy of prognostic prediction in patients with stage III gastric cancer compared to the current TNM system (Likelihood ratio χ2, 188.6 vs. 184.8; AIC, 4336.4 vs. 4340.6; C-index, 0.695 vs. 0.679, P = 0.002). The ROC curves revealed that the performance of prognostic prediction was better in the new prediction system (AUC = 0.699) compared with the current TNM system (AUC = 0.676). CONCLUSIONS: ILNr (LNs <16) impairs the long-term outcomes of stage III gastric cancer underwent adjuvant chemotherapy. The status of LNs removal adds values to the current TNM system in prognostic prediction of stage III gastric cancer.

Anti-EGFR therapy in metastatic colorectal cancer: mechanisms and potential regimens of drug resistance.

Cetuximab and panitumumab, as the highly effective antibodies targeting epidermal growth factor receptor (EGFR), have clinical activity in the patients with metastatic colorectal cancer (mCRC). These agents have good curative efficacy, but drug resistance also exists at the same time. The effects of KRAS, NRAS, and BRAF mutations and HER2 amplification on the treatment of refractory mCRC have been elucidated and the corresponding countermeasures have been put forward. However, the changes in EGFR and its ligands, the mutations or amplifications of PIK3CA, PTEN, TP53, MET, HER3, IRS2, FGFR1, and MAP2K1, the overexpression of insulin growth factor-1, the low expression of Bcl-2-interacting mediator of cell death, mismatch repair-deficient, and epigenetic instability may also lead to drug resistance in mCRC. Although the emergence of drug resistance has genetic or epigenetic heterogeneity, most of these molecular changes relating to it are focused on the key signaling pathways, such as the RAS/RAF/mitogen-activated protein kinase or phosphatidylinositol 3-kinase/Akt/mammalian target of the rapamycin pathway. Accordingly, numerous efforts to target these signaling pathways and develop the novel therapeutic regimens have been carried out. Herein, we have reviewed the underlying mechanisms of the resistance to anti-EGFR therapy and the possible implications in clinical practice.

Gastric duplication 20 years after a partial distal gastrectomy: a case report and review of literature.

Gastric duplications are the least common gastrointestinal duplications, especially in adults. Duplication cyst with an accessory pancreatic lobe is extremely rare and is even more uncommon in the setting of polysplenia. No gastric duplication after partial gastrectomy has been reported. We present a 41-year-old male diagnosed with gastric duplications with an accessory pancreatic lobe and polysplenia. Another characteristic of this case is partial gastrectomy 20 years ago without the discovery of duplication cysts. The gastric duplications, accessory pancreatic lobe and accessory spleen were successfully resected.

Multiparametric radiomics improve prediction of lymph node metastasis of rectal cancer compared with conventional radiomics.

AIMS: To establish multiparametric radiomics of rectal tumor for the preoperative prediction of lymph node (LN) metastasis. MATERIALS AND METHODS: This prospective study consisted of 115 consecutive patients with rectal carcinoma between April 2015 and April 2017. The multiparametric radiomics scores were extracted from the endorectal ultrasound (ERUS), computed tomography (CT) and shear-wave elastography (SWE) features of the rectal tumor, LN, and peripheral tissues. The three radiomics scores were generated. Further validation as an independent predictor was performed using multivariate logistic regression together with clinical data, and a nomogram was subsequently developed. The predictive performance of the multiparametric radiomics nomogram was compared with that of conventional radiomics. KEY FINDINGS: All three scores (ERUS, CT, and SWE) were significantly higher in patients with LN metastasis than in patients with negative LN metastasis (all P < 0.05) in both training and validation set. Multivariate analysis indicated that CT and SWE scores were independent risk variables (odds ratio, OR = 6.764 and 5.482, respectively). In validation cohort, the multiparametric radiomics nomogram showed the highest predictive accuracy for LN metastasis, with a concordance index (C-index) of 0.857 compared with the conventional radiomics nomogram (C-index, 0.703, P = 0.100), resulting in a significantly improved net reclassification index (NRI) (P < 0.05) and integrated discriminatory improvement (IDI) (P = 0.002). Decision curve analysis showed that the multiparametric radiomics nomogram had a higher overall net benefit. SIGNIFICANCE: Multiparametric radiomics of rectal cancer, which captures blood supply and stiffness phenotypes, is a useful tool for predicting LN metastasis preoperatively and has marked discrimination accuracy compared to conventional radiomics.

Transabdominal Ultrasound Colonography for Detection of Colorectal Neoplasms: Initial Clinical Experience.

We investigated the feasibility of using ultrasound colonography (USC) to visualize the healthy colon and rectum and detect colorectal polyps. Eight healthy volunteers underwent USC after standard bowel preparation. The feasibility and image quality of USC in different segments were evaluated. Then, USC was conducted on eight patients with known colonic neoplasms using colonoscopy as the reference standard. For volunteers, USC examinations were successfully performed on four (50.0%) ascending, three (37.5%) transverse and eight (100%) descending colons, as well as all sigmoid colons and rectums. One of four (25.0%) ascending, two of eight (25.0%) descending and all sigmoid colons and rectums were well visualized and free of artifacts. For patients, colonoscopy revealed that eight patients had 17 neoplasms in the distal sigmoid colon and rectum, which included 3 lesions ≤5 mm, 3 lesions 6-9 mm and 11 lesions ≥10 mm. USC visualized 12 of 17 (70.6%) neoplasms. Lesion detection by USC was 0% (0/3), 33.3% (1/3) and 100% (11/11) for neoplasms ≤5, 6-9 mm and ≥10 mm in size. USC can visualize the sigmoid colon and rectum well and detect distal sigmoid and rectal neoplasms ≥10 mm in diameter.

[Application of enteral nutrition in preoperative bowel preparation for rectal cancer patients undergoing radical operation].

OBJECTIVE: To explore the feasibility and safety of enteral nutrition in preoperative bowel preparation for rectal cancer patients undergoing radical operation. METHODS: Sixty rectal cancer patients undergoing selective low anterior resection were randomized into the trial group(n=30) and the control group(n=30). Patients in the trial group received clean liquid integral protein diet for 3 days before operation without mechanical bowel preparation. Patients in the control group received traditional diet and mechanical bowel preparation. The intraoperative and postoperative clinical data, the quality of bowel preparation, postoperative complications, and nutritional parameters were compared between the two groups. RESULTS: There were no significant differences in clinicopathological characteristics between the two groups before operation. The operative time, blood loss, quality of bowel preparation as well as postoperative hospital stay were not significantly different(all P>0.05). While the time to first flatus [(2.53±0.91) d vs. (3.03±0.68) d] and semi-liquid diet intake[(3.95±0.83) d vs. (4.52±1.14) d] were significantly shorter in the trial group as compared with the control group(all P<0.05). There were no death and no significant difference in postoperative complications [16.7%(5/30) vs. 20.0%(6/30), P>0.05]. The levels of postoperative total protein, albumin, and prealbumin decreased significantly. Meanwhile, the levels of postoperative albumin[(36.2±2.5) g/L vs. (33.5±2.6) g/L, P<0.01] and prealbumin [(325.4±28.2) mg/L vs. (302.5±34.2) mg/L, P<0.01] in the trial group were significantly higher than those in the control group. CONCLUSIONS: Preoperative enteral nutrition can replace the mechanical bowel preparation with better efficacy, and improve the postoperative nutritional status without increasing surgical risk in rectal cancer patients undergoing radical operation.

Pathological diagnosis is maybe non-essential for special gastric cancer: case reports and review.

Histopathological results are critical for the diagnosis and surgical decision regarding gastric cancer. However, opposite opinions from radiology and pathology can sometimes affect clinical decisions. The two cases reported in this article were both highly suspected as gastric cancer by clinical manifestations and radiologic findings, although both showed negative results in the first biopsy examination. One was confirmed as gastric cancer by the time of the 6(th) biopsy, while the other was still negative even after 8 biopsies. With a definite pathologic result and the agreement of the patient for the latter case, both of them finally received surgery. Postoperative pathological examination revealed findings that were the same as Borrmann type IV gastric cancer. We believed that duplicate biopsies under radiologic guidance were necessary for highly suspected gastric cancer cases in the absence of a definite pathology result, and patients should be under close follow-up. We propose that, if gastric cancer is highly suspected when typical radiology changes of widely diffuse gastric parietal lesions suffice to exclude lymphoma and other similar situations, and even in absence of a positive biopsy result, a diagnostic laparotomy under laparoscopy and even radical gastrectomy may be reasonably performed by an experienced gastric cancer center with the agreement of the patient after being decided by a multidisciplinary discussion team.